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Title: The Antiquity of Man
Author: Lyell, Charles, Sir, 1797-1875
Language: English
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THE GEOLOGICAL EVIDENCE OF THE ANTIQUITY OF MAN
By Sir Charles Lyell, BT., F.R.S., Etc.
London: Published By J.M. Dent & Sons Ltd.
And In New York By E.P. Dutton & Co.
With Introduction And Notes By R.H. Rastall, M.A., F.G.S.
EVERYMAN
I WILL GO WITH THEE
& BE THY GUIDE
IN THY MOST NEED
TO GO BY THY SIDE.
EVERYMAN'S LIBRARY
EDITED BY ERNEST RHYS.
SCIENCE.
HOC SOLUM SCIO QUOD NIHIL SCIO.
INTRODUCTION.
The "Antiquity of Man" was published in 1863, and ran into a third
edition in the course of that year. The cause of this is not far to
seek. Darwin's "Origin of Species" appeared in 1859, only four years
earlier, and rapidly had its effect in drawing attention to the great
problem of the origin of living beings. The theories of Darwin and
Wallace brought to a head and presented in a concrete shape the somewhat
vague speculations as to development and evolution which had long been
floating in the minds of naturalists. In the actual working out of
Darwin's great theory it is impossible to overestimate the influence of
Lyell. This is made abundantly clear in Darwin's letters, and it must
never be forgotten that Darwin himself was a geologist. His training
in this science enabled him to grasp the import of the facts so ably
marshalled by Lyell in the "Principles of Geology," a work which,
as Professor Judd has clearly shown,* contributed greatly to the
advancement of evolutionary theory in general. (* Judd "The Coming of
Evolution" ("Cambridge Manuals of Science and Literature") Cambridge
1910 chapters 6 and 7.)
From a study of the evolution of plants and of the lower animals it was
an easy and obvious transition to man, and this step was soon taken.
Since in his physical structure man shows so close a resemblance to the
higher animals it was a natural conclusion that the laws governing
the development of the one should apply also to the other, in spite of
preconceived opinions derived from authority. Unfortunately the times
were then hardly ripe for a calm and logical treatment of this question:
prejudice in many cases took the place of argument, and the result was
too often an undignified squabble instead of a scientific discussion.
However, the dogmatism was not by any means all on one side. The
disciples as usual went farther than the master, and their teaching
when pushed to extremities resulted in a peculiarly dreary kind of
materialism, a mental attitude which still survives to a certain extent
among scientific and pseudo-scientific men of the old school. In more
Recent times this dogmatic agnosticism of the middle Victorian period
has been gradually replaced by speculations of a more positive type,
such as those of the Mendelian school in biology and the doctrines of
Bergson on the philosophical side. With these later developments we are
not here concerned.
In dealing with the evolution and history of man as with that of any
other animal, the first step is undoubtedly to collect the facts, and
this is precisely what Lyell set out to do in the "Antiquity of
Man." The first nineteen chapters of the book are purely an empirical
statement of the evidence then available as to the existence of man in
pre-historic times: the rest of the book is devoted to a consideration
of the connection between the facts previously stated and Darwin's
theory of the origin of species by variation and natural selection. The
keynote of Lyell's work, throughout his life, was observation. Lyell was
no cabinet geologist; he went to nature and studied phenomena at first
hand. Possessed of abundant leisure and ample means he travelled far and
wide, patiently collecting material and building up the modern science
of physical geology, whose foundations had been laid by Hutton and
Playfair. From the facts thus collected he drew his inferences, and if
later researches showed these inferences to be wrong, unlike some of his
contemporaries, he never hesitated to say so. Thus and thus only is true
progress in science attained.
Lyell is universally recognised as the leader of the Uniformitarian
school of geologists, and it will be well to consider briefly what is
implied in this term. The principles of Uniformitarianism may be
summed up thus: THE PRESENT IS THE KEY TO THE PAST. That is to say,
the processes which have gone on in the past were the same in general
character as those now seen in operation, though probably differing
in degree. This theory is in direct opposition to the ideas of the
CATASTROPHIC school, which were dominant at the beginning of the
nineteenth century. The catastrophists attributed all past changes to
sudden and violent convulsions of nature, by which all living beings
were destroyed, to be replaced by a fresh creation. At least such were
the tenets of the extremists. In opposition to these views the school of
Hutton and Lyell introduced the principle of continuity and development.
There is no discrepancy between Uniformitarianism and evolution. The
idea of Uniformitarianism does not imply that things have always been
the same; only that they were similar, and between these two terms there
is a wide distinction. Evolution of any kind whatever naturally implies
continuity, and this is the fundamental idea of Lyellian geology.
In spite, however, of this clear and definite conception of natural
and organic evolution, in all those parts of his works dealing with
earth-history, with the stratified rocks and with the organisms entombed
in them, Lyell adopted a plan which has now been universally abandoned.
He began with the most Recent formations and worked backwards from the
known to the unknown. To modern readers this is perhaps the greatest
drawback to his work, since it renders difficult the study of events in
their actual sequence. However, it must be admitted that, taking into
account the state of geological knowledge before his time, this course
was almost inevitable. The succession of the later rocks was fairly well
known, thanks to the labours of William Smith and others, but in the
lower part of the sequence of stratified rocks there were many gaps, and
more important still, there was no definite base. Although this want of
a starting point has been largely supplied by the labours of Sedgwick,
Murchison, De la Beche, Ramsay, and a host of followers, still
considerable doubt prevails as to which constitutes the oldest
truly stratified series, and the difficulty has only been partially
circumvented by the adoption of an arbitrary base-line, from which the
succession is worked out both upwards and downwards. So the problem
is only removed a stage further back. In the study of human origins a
similar difficulty is felt with special acuteness; the beginnings must
of necessity be vague and uncertain, and the farther back we go the
fainter will naturally be the traces of human handiwork and the more
primitive and doubtful those traces when discovered.
The reprinting of the "Antiquity of Man" is particularly appropriate at
the present time, owing to the increased attention drawn to the subject
by recent discoveries. Ever since the publication of the "Origin of
Species" and the discussions that resulted from that publication, the
popular imagination has been much exercised by the possible existence
of forms intermediate between the apes and man; the so-called "Missing
Link." Much has been written on this subject, some of it well-founded
and some very much the reverse. The discovery of the Neanderthal skull
is fully described in this volume, and this skull is certainly of a low
type, but it is more human than ape-like. The same remark applies
still more strongly to the Engis skull, the man of Spy, the recently
discovered Sussex skull, and other well-known examples of early human
remains. The Pithecanthropus of Java alone shows perhaps more affinity
to the apes. The whole subject has been most ably discussed by Professor
Sollas in his recent book entitled "Ancient Hunters."
The study of Palaeolithic flint implements has been raised to a fine
art. Both in England and France a regular succession of primitive types
has been established and correlated with the gravel terraces of existing
rivers, and even with the deposits of rivers no longer existing and
with certain glacial deposits. But with all of these the actual bodily
remains of man are comparatively scanty. From this it may be concluded
that primitive methods of burial were such as to be unfavourable to the
actual preservation of human remains. Attempts have also been made to
prove the existence of man in pre-glacial times, but hitherto none of
these have met with general acceptance, since in no case is the evidence
beyond doubt.
One of the most important results of recent research in the subject has
been the establishment of the existence of man in interglacial times.
When Lyell wrote, it was not fully recognised that the glaciation of
Europe was not one continuous process, but that it could be divided into
several episodes, glaciations, or advances of the ice, separated by
a warm interglacial period. The monumental researches of Penck and
Bruckner in the Alps have there established four glaciations with mild
interglacial periods, but all of these cannot be clearly traced in
Britain. One very important point also is the recognition of the
affinities of certain types of Palaeolithic man to the Eskimo, the
Australians, and the Bushmen of South Africa. However, it is impossible
to give here a review of the whole subject. Full details of recent
researches will be found in the works mentioned in the notes at the end
of the book.
Another point of great interest and importance, arising directly from
the study of early man is the nature of the events constituting the
glacial period in Britain and elsewhere. This has been for many years a
fertile subject of controversy, and is likely to continue such. Lyell,
in common with most of the geologists of his day, assumes that during
the glacial period the British Isles were submerged under the sea to a
depth of many hundreds of feet, at any rate as regards the region
north of a line drawn from London to Bristol. Later authors, however,
explained the observed phenomena on the hypothesis of a vast ice-sheet
of the Greenland type, descending from the mountains of Scotland
and Scandinavia, filling up the North Sea and spreading over eastern
England. This explanation is now accepted by the majority, but it must
be recognised that it involves enormous mechanical difficulties. It is
impossible to pursue the subject here; for a full discussion reference
may be made to Professor Bonney's presidential address to the British
Association at Sheffield in 1910.
It will be seen, therefore, that the "Antiquity of Man" opens up a wide
field of speculation into a variety of difficult and obscure though
interesting subjects. In the light of modern research it would be an
easy task to pile up a mountain of criticism on points of detail. But,
though easy, it would be a thankless task. It is scarcely too much to
say that the dominant impression of most readers after perusing this
book will be one of astonishment and admiration at the insight and
breadth of view displayed by the author. When it was written the subject
was a particularly thorny one to handle, and it undoubtedly required
much courage to tackle the origin and development of the human race from
a purely critical and scientific standpoint. It must be admitted on all
hands that the result was eminently successful, taking into account the
paucity of the available material, and the "Antiquity of Man" must ever
remain one of the classics of prehistoric archaeology.
This edition of the "Antiquity of Man" has been undertaken in order to
place before the public in an easily accessible form one of the best
known works of the great geologist Sir Charles Lyell; the book had an
immense influence in its own day, and it still remains one of the best
general accounts of an increasingly important branch of knowledge.
In order to avoid a multiplicity of notes and thus to save space, the
nomenclature has been to a certain extent modernised: a new general
table of strata has been inserted in the first chapter, in place of the
one originally there printed, which was cumbrous and included many minor
subdivisions of unnecessary minuteness.
The notes have been kept as short as possible, and they frequently
contain little more than references to recent literature elucidating the
points under discussion in the text.
R.H. RASTALL.
1914.
BIBLIOGRAPHY.
The passage of the Beresina (in verse), 1815.
Principles of Geology, being an attempt to explain the former
changes of the earth's surface, by reference to causes now in
operation, 1830-33
(third edition, 1834;
fourth, 1835;
fifth, 1837;
sixth, 1840;
seventh, 1847;
ninth, entirely revised edition, 1853;
tenth, entirely revised edition, 1867, 1868;
eleventh, entirely revised edition, 1872;
twelfth, edited by L. Lyell, 1875).
Elements of Geology, 1838
(second edition, 1841).
A Manual of Elementary Geology
(third and entirely revised edition of the former work, 1851;
fourth and entirely revised edition, 1852;
fifth, enlarged edition, 1855;
Supplement to the fifth edition, 1857;
second edition of the Supplement, revised, 1857).
Elements of Geology,
sixth edition, greatly enlarged, 1865.
Travels in North America, with geological observations
on the United States, Canada, and Nova Scotia, 1845.
A Second Visit to the United States of North America, 1849.
The Students' Elements of Geology, 1871
(second edition, revised and corrected, 1874;
third, revised, with a table of British fossils
[by R. Etheridge], 1878;
fourth, revised by P.M. Duncan, with a table of British fossils
[by R. Etheridge], 1884).
The Geological Evidences of the Antiquity of Man,
with remarks on theories of the origin of species
by variation, 1863;
(second edition, revised, 1863;
third edition, revised, 1863;
fourth edition, revised, 1873).
There has also been published The Student's Lyell: a Manual of
Elementary Geology, edited by J.W. Judd, 1896 (second edition
revised and enlarged, 1911).
LECTURES, ADDRESSES, AND ARTICLES:
On a Recent Formation of Freshwater Limestone in Forfarshire
("Transactions of the Geological Society" 2nd series, volume 2,
1826, part 1).
On a Dike of Serpentine in the County of Forfar ("Edinburgh Journal
of Science" 1825).
English Scientific Societies ("Quarterly Review" volume 34; three
papers with Sir Roderick and Mrs. Murchison; "Edinburgh
Philosophical Journal," 1829; abstract in "Proceedings of the
Geological Society" 1; "Annales des Sciences Naturelles" 1829;
abstract in "Proceedings of the Geological Society" 1).
Address delivered at the Geological Society of London, 1836.
Lectures on Geology--Eight Lectures on Geology, delivered at the
Broadway Tabernacle, New York ("New York Tribune" 1842).
A Paper on Madeira ("Quarterly Journal of the Geological Society"
10, 1853).
On the Structure of Lavas which have Consolidated on Steep Slopes
("Philosophical Transactions" 1858).
Address (to the British Association) 1864.
TRANSLATIONS:
Antiquity of Man, translated into French by M. Chaper, 1864; and
into German by L. Buchner, 1874.
Elements of Geology (sixth edition), translated into French by M.
J. Gineston, 1867.
Report, extracted from the "Aberdeen Free Press" and translated
into French, of Sir C. Lyell's address before the British
Association, 1859, under the title of Antiquities antediluviennes:
L'homme fossile.
LIFE:
Life, Letters and Journals of Sir Charles Lyell, edited by his
sister-in-law, Mrs. Lyell, 1881.
See also:
Life and Letters of Charles Darwin, 1887.
Life and Letters of Sedgwick, by Clark and Hughes, 1890.
LIST OF CONTENTS.
CHAP. 1.
INTRODUCTORY.
Preliminary Remarks on the Subjects treated of in this Work.
Definition of the terms Recent and Pleistocene.
Tabular View of the entire Series of Fossiliferous Strata.
CHAP. 2.
RECENT PERIOD--DANISH PEAT AND SHELL MOUNDS--
SWISS LAKE-DWELLINGS.
Works of Art in Danish Peat-Mosses.
Remains of three Periods of Vegetation in the Peat.
Ages of Stone, Bronze, and Iron.
Shell-Mounds or ancient Refuse-Heaps of the Danish Islands.
Change in geographical Distribution of Marine Mollusca
since their Origin.
Embedded Remains of Mammalia of Recent Species.
Human Skulls of the same Period.
Swiss Lake-Dwellings built on Piles.
Stone and Bronze Implements found in them.
Fossil Cereals and other Plants.
Remains of Mammalia, wild and domesticated.
No extinct Species.
Chronological Computations of the Date of the Bronze and Stone
Periods in Switzerland.
Lake-Dwellings, or artificial Islands called "Crannoges,"
in Ireland.
CHAP. 3.
FOSSIL HUMAN REMAINS AND WORKS OF ART OF
THE RECENT PERIOD--continued.
Delta and Alluvial Plain of the Nile.
Burnt Bricks in Egypt before the Roman Era.
Borings in 1851-54.
Ancient Mounds of the Valley of the Ohio.
Their Antiquity.
Sepulchral Mound at Santos in Brazil.
Delta of the Mississippi.
Ancient Human Remains in Coral Reefs of Florida.
Changes in Physical Geography in the Human Period.
Buried Canoes in Marine Strata near Glasgow.
Upheaval since the Roman Occupation of the Shores of the
Firth of Forth.
Fossil Whales near Stirling.
Upraised Marine Strata of Sweden on Shores of the Baltic
and the Ocean.
Attempts to compute their Age.
CHAP. 4.
PLEISTOCENE PERIOD--BONES OF MAN AND EXTINCT MAMMALIA
IN BELGIAN CAVERNS.
Earliest Discoveries in Caves of Languedoc of Human Remains
with Bones of extinct Mammalia.
Researches in 1833 of Dr. Schmerling in the Liege Caverns.
Scattered Portions of Human Skeletons associated with Bones
of Elephant and Rhinoceros.
Distribution and probable Mode of Introduction of the Bones.
Implements of Flint and Bone.
Schmerling's Conclusions as to the Antiquity of Man ignored.
Present State of the Belgian Caves.
Human Bones recently found in Cave of Engihoul.
Engulfed Rivers.
Stalagmitic Crust.
Antiquity of the Human Remains in Belgium how proved.
CHAP. 5.
PLEISTOCENE PERIOD--FOSSIL HUMAN SKULLS OF THE
NEANDERTHAL AND ENGIS CAVES.
Human Skeleton found in Cave near Dusseldorf.
Its geological Position and probable Age.
Its abnormal and ape-like Characters.
Fossil Human Skull of the Engis Cave near Liege.
Professor Huxley's Description of these Skulls.
Comparison of each, with extreme Varieties of the native
Australian Race.
Range of Capacity in the Human and Simian Brains.
Skull from Borreby in Denmark.
Conclusions of Professor Huxley.
Bearing of the peculiar Characters of the Neanderthal Skull
on the Hypothesis of Transmutation.
CHAP. 6.
PLEISTOCENE ALLUVIUM AND CAVE DEPOSITS WITH FLINT IMPLEMENTS.
General Position of Drift with extinct Mammalia in Valleys.
Discoveries of M. Boucher de Perthes at Abbeville.
Flint Implements found also at St. Acheul, near Amiens.
Curiosity awakened by the systematic Exploration of the
Brixham Cave.
Flint Knives in same, with Bones of extinct Mammalia.
Superposition of Deposits in the Cave.
Visits of English and French Geologists to Abbeville and Amiens.
CHAP. 7.
PEAT AND PLEISTOCENE ALLUVIUM OF THE VALLEY OF THE SOMME.
Geological Structure of the Valley of the Somme and of the
surrounding Country.
Position of Alluvium of different Ages.
Peat near Abbeville.
Its animal and vegetable Contents.
Works of Art in Peat.
Probable Antiquity of the Peat, and Changes of Level
since its Growth began.
Flint Implements of antique Type in older Alluvium.
Their various Forms and great Numbers.
CHAP. 8.
PLEISTOCENE ALLUVIUM WITH FLINT IMPLEMENTS OF THE VALLEY
OF THE SOMME--concluded.
Fluvio-marine Strata, with Flint Implements, near Abbeville.
Marine Shells in same.
Cyrena fluminalis.
Mammalia.
Entire Skeleton of Rhinoceros.
Flint Implements, why found low down in Fluviatile Deposits.
Rivers shifting their Channels.
Relative Ages of higher and lower-level Gravels.
Section of Alluvium of St. Acheul.
Two Species of Elephant and Hippopotamus coexisting with Man
in France.
Volume of Drift, proving Antiquity of Flint Implements.
Absence of Human Bones in tool-bearing Alluvium, how explained.
Value of certain Kinds of negative Evidence tested thereby.
Human Bones not found in drained Lake of Haarlem.
CHAP. 9.
WORKS OF ART IN PLEISTOCENE ALLUVIUM OF FRANCE AND ENGLAND.
Flint Implements in ancient Alluvium of the Basin of the Seine.
Bones of Man and of extinct Mammalia in the Cave of Arcy.
Extinct Mammalia in the Valley of the Oise.
Flint Implement in Gravel of same Valley.
Works of Art in Pleistocene Drift in Valley of the Thames.
Musk Ox.
Meeting of northern and southern Fauna.
Migrations of Quadrupeds.
Mammals of Mongolia.
Chronological Relation of the older Alluvium of the Thames
to the Glacial Drift.
Flint Implements of Pleistocene Period in Surrey, Middlesex,
Kent, Bedfordshire, and Suffolk.
CHAP. 10.
CAVERN DEPOSITS, AND PLACES OF SEPULTURE OF THE PLEISTOCENE PERIOD.
Flint Implements in Cave containing Hyaena and other extinct
Mammalia in Somersetshire.
Caves of the Gower Peninsula in South Wales.
Rhinoceros hemitoechus.
Ossiferous Caves near Palermo.
Sicily once part of Africa.
Rise of Bed of the Mediterranean to the Height of three hundred
Feet in the Human Period in Sardinia.
Burial-place of Pleistocene Date of Aurignac in the South of France.
Rhinoceros tichorhinus eaten by Man.
M. Lartet on extinct Mammalia and Works of Art found in the
Aurignac Cave.
Relative Antiquity of the same considered.
CHAP. 11.
AGE OF HUMAN FOSSILS OF LE PUY IN CENTRAL FRANCE
AND OF NATCHEZ ON THE MISSISSIPPI DISCUSSED.
Question as to the Authenticity of the Fossil Man of Denise,
near Le Puy-en-Velay, considered.
Antiquity of the Human Race implied by that Fossil.
Successive Periods of Volcanic Action in Central France.
With what Changes in the Mammalian Fauna they correspond.
The Elephas meridionalis anterior in Time to the Implement-bearing
Gravel of St. Acheul.
Authenticity of the Human Fossil of Natchez on the Mississippi
discussed.
The Natchez Deposit, containing Bones of Mastodon and Megalonyx,
probably not older than the Flint Implements of St. Acheul.
CHAP. 12.
ANTIQUITY OF MAN RELATIVELY TO THE GLACIAL PERIOD
AND TO THE EXISTING FAUNA AND FLORA.
Chronological Relation of the Glacial Period, and the earliest
known Signs of Man's Appearance in Europe.
Series of Tertiary Deposits in Norfolk and Suffolk immediately
antecedent to the Glacial Period.
Gradual Refrigeration of Climate proved by the Marine Shells
of successive Groups.
Marine Newer Pliocene Shells of Northern Character near Woodbridge.
Section of the Norfolk Cliffs.
Norwich Crag.
Forest Bed and Fluvio-marine Strata.
Fossil Plants and Mammalia of the same.
Overlying Boulder Clay and Contorted Drift.
Newer freshwater Formation of Mundesley compared to that of Hoxne.
Great Oscillations of Level implied by the Series of Strata
in the Norfolk Cliffs.
Earliest known Date of Man long subsequent to the existing
Fauna and Flora.
CHAP. 13.
CHRONOLOGICAL RELATIONS OF THE GLACIAL PERIOD
AND THE EARLIEST SIGNS OF MAN'S APPEARANCE IN EUROPE.
Chronological Relations of the Close of the Glacial Period
and the earliest geological Signs of the Appearance of Man.
Effects of Glaciers and Icebergs in polishing and scoring Rocks.
Scandinavia once encrusted with Ice like Greenland.
Outward Movement of Continental Ice in Greenland.
Mild Climate of Greenland in the Miocene Period.
Erratics of Recent Period in Sweden.
Glacial State of Sweden in the Pleistocene Period.
Scotland formerly encrusted with Ice.
Its subsequent Submergence and Re-elevation.
Latest Changes produced by Glaciers in Scotland.
Remains of the Mammoth and Reindeer in Scotch Boulder Clay.
Parallel Roads of Glen Roy formed in Glacier Lakes.
Comparatively modern Date of these Shelves.
CHAP. 14.
CHRONOLOGICAL RELATIONS OF THE GLACIAL PERIOD
AND THE EARLIEST SIGNS OF MAN'S APPEARANCE IN EUROPE--continued.
Signs of extinct Glaciers in Wales.
Great Submergence of Wales during the Glacial Period
proved by Marine Shells.
Still greater Depression inferred from Stratified Drift.
Scarcity of Organic Remains in Glacial Formations.
Signs of extinct Glaciers in England.
Ice Action in Ireland.
Maps illustrating successive Revolutions in Physical Geography
during the Pleistocene Period.
Southernmost Extent of Erratics in England.
Successive Periods of Junction and Separation of England, Ireland,
and the Continent.
Time required for these Changes.
Probable Causes of the Upheaval and Subsidence of the Earth's Crust.
Antiquity of Man considered in relation to the Age of the existing
Fauna and Flora.
CHAP. 15.
EXTINCT GLACIERS OF THE ALPS AND THEIR CHRONOLOGICAL RELATION
TO THE HUMAN PERIOD.
Extinct Glaciers of Switzerland.
Alpine Erratic Blocks on the Jura.
Not transported by floating Ice.
Extinct Glaciers of the Italian Side of the Alps.
Theory of the Origin of Lake-Basins by the erosive Action
of Glaciers considered.
Successive phases in the Development of Glacial Action in the Alps.
Probable Relation of these to the earliest known Date of Man.
Correspondence of the same with successive Changes in the
Glacial Condition of the Scandinavian and British Mountains.
Cold Period in Sicily and Syria.
CHAP. 16.
HUMAN REMAINS IN THE LOESS, AND THEIR PROBABLE AGE.
Nature, Origin, and Age of the Loess of the Rhine and Danube.
Impalpable Mud produced by the Grinding Action of Glaciers.
Dispersion of this Mud at the Period of the Retreat of the
great Alpine Glaciers.
Continuity of the Loess from Switzerland to the Low Countries.
Characteristic Organic Remains not Lacustrine.
Alpine Gravel in the Valley of the Rhine covered by Loess.
Geographical Distribution of the Loess and its Height above the Sea.
Fossil Mammalia.
Loess of the Danube.
Oscillations in the Level of the Alps and lower Country required
to explain the Formation and Denudation of the Loess.
More rapid Movement of the Inland Country.
The same Depression and Upheaval might account for the
Advance and Retreat of the Alpine Glaciers.
Himalayan Mud of the Plains of the Ganges compared to
European Loess.
Human Remains in Loess near Maestricht, and their probable
Antiquity.
CHAP. 17.
POST-GLACIAL DISLOCATIONS AND FOLDINGS OF CRETACEOUS AND
DRIFT STRATA IN THE ISLAND OF MOEN, IN DENMARK.
Geological Structure of the Island of Moen.
Great Disturbances of the Chalk posterior in Date to the
Glacial Drift, with Recent Shells.
M. Puggaard's Sections of the Cliffs of Moen.
Flexures and Faults common to the Chalk and Glacial Drift.
Different Direction of the Lines of successive Movement,
Fracture, and Flexure.
Undisturbed Condition of the Rocks in the adjoining Danish Islands.
Unequal Movements of Upheaval in Finmark.
Earthquake of New Zealand in 1855.
Predominance in all Ages of uniform Continental Movements
over those by which the Rocks are locally convulsed.
CHAP. 18.
THE GLACIAL PERIOD IN NORTH AMERICA.
Post-glacial Strata containing Remains of Mastodon giganteus
in North America.
Scarcity of Marine Shells in Glacial Drift of Canada and the
United States.
Greater southern Extension of Ice-action in North America than
in Europe.
Trains of Erratic Blocks of vast Size in Berkshire, Massachusetts.
Description of their Linear Arrangement and Points of Departure.
Their Transportation referred to Floating and Coast Ice.
General Remarks on the Causes of former Changes of Climate
at successive geological Epochs.
Supposed Effects of the Diversion of the Gulf Stream in a
Northerly instead of North-Easterly Direction.
Development of extreme Cold on the opposite Sides of the Atlantic
in the Glacial period not strictly simultaneous.
Effect of Marine Currents on Climate.
Pleistocene Submergence of the Sahara.
CHAP. 19.
RECAPITULATION OF GEOLOGICAL PROOFS OF MAN'S ANTIQUITY.
Recapitulation of Results arrived at in the earlier Chapters.
Ages of Stone and Bronze.
Danish Peat and Kitchen-Middens.
Swiss Lake-Dwellings.
Local Changes in Vegetation and in the wild and domesticated
Animals and in Physical Geography coeval with the Age of
Bronze and the later Stone Period.
Estimates of the positive Date of some Deposits of the later
Stone Period.
Ancient Division of the Age of Stone of St. Acheul and Aurignac.
Migrations of Man in that Period from the Continent to England
in Post-Glacial Times.
Slow Rate of Progress in barbarous Ages.
Doctrine of the superior Intelligence and Endowments of the
original Stock of Mankind considered.
Opinions of the Greeks and Romans, and their Coincidence with
those of the Modern Progressionist.
CHAP. 20.
THEORIES OF PROGRESSION AND TRANSMUTATION.
Antiquity and Persistence in Character of the existing Races
of Mankind.
Theory of their Unity of Origin considered.
Bearing of the Diversity of Races on the Doctrine of Transmutation.
Difficulty of defining the Terms "Species" and "Race."
Lamarck's Introduction of the Element of Time into the Definition
of a Species.
His Theory of Variation and Progression.
Objections to his Theory, how far answered.
Arguments of modern Writers in favour of Progression in the
Animal and Vegetable World.
The old Landmarks supposed to indicate the first Appearance of Man,
and of different Classes of Animals, found to be erroneous.
Yet the Theory of an advancing Series of Organic Beings not
inconsistent with Facts.
Earliest known Fossil Mammalia of low Grade.
No Vertebrata as yet discovered in the oldest Fossiliferous Rocks.
Objections to the Theory of Progression considered.
Causes of the Popularity of the Doctrine of Progression as
compared to that of Transmutation.
CHAP. 21.
ON THE ORIGIN OF SPECIES BY VARIATION AND NATURAL SELECTION.
Mr. Darwin's Theory of the Origin of Species by Natural Selection.
Memoir by Mr. Wallace.
Manner in which favoured Races prevail in the Struggle for
Existence.
Formation of new Races by breeding.
Hypotheses of definite and indefinite Modifiability equally
arbitrary.
Competition and Extinction of Races.
Progression not a necessary Accompaniment of Variation.
Distinct Classes of Phenomena which Natural Selection explains.
Unity of Type, Rudimentary Organs, Geographical Distribution,
Relation of the extinct to the living Fauna and Flora,
and mutual Relations of successive Groups of Fossil Forms.
Light thrown on Embryological Development by Natural Selection.
Why large Genera have more variable Species than small ones.
Dr. Hooker on the Evidence afforded by the Vegetable Kingdom
in favour of Creation by Variation.
Steenstrup on alternation of Generations.
How far the Doctrine of Independent Creation is opposed to the
Laws now governing the Migration of Species.
CHAP. 22.
OBJECTIONS TO THE HYPOTHESIS OF TRANSMUTATION CONSIDERED.
Statement of Objections to the Hypothesis of Transmutation
founded on the Absence of Intermediate Forms.
Genera of which the Species are closely allied.
Occasional Discovery of the missing Links in a Fossil State.
Davidson's Monograph on the Brachiopoda.
Why the Gradational Forms, when found, are not accepted as
Evidence of Transmutation.
Gaps caused by Extinction of Races and Species.
Vast Tertiary Periods during which this Extinction has been going
on in the Fauna and Flora now existing.
Genealogical Bond between Miocene and Recent Plants and Insects.
Fossils of Oeningen.
Species of Insects in Britain and North America represented by
distinct Varieties.
Falconer's Monograph on living and fossil Elephants.
Fossil Species and Genera of the Horse Tribe in North and
South America.
Relation of the Pliocene Mammalia of North America, Asia,
and Europe.
Species of Mammalia, though less persistent than the Mollusca,
change slowly.
Arguments for and against Transmutation derived from the
Absence of Mammalia in Islands.
Imperfection of the Geological Record.
Intercalation of newly discovered Formation of intermediate Age
in the chronological Series.
Reference of the St. Cassian Beds to the Triassic Periods.
Discovery of new organic Types.
Feathered Archaeopteryx of the Oolite.
CHAP. 23.
ORIGIN AND DEVELOPMENT OF LANGUAGES AND SPECIES COMPARED.
Aryan Hypothesis and Controversy.
The Races of Mankind change more slowly than their Languages.
Theory of the gradual Origin of Languages.
Difficulty of defining what is meant by a Language as distinct
from a Dialect.
Great Number of extinct and living Tongues.
No European Language a Thousand Years old.
Gaps between Languages, how caused.
Imperfection of the Record.
Changes always in Progress.
Struggle for Existence between rival Terms and Dialects.
Causes of Selection.
Each Language formed slowly in a single Geographical Area.
May die out gradually or suddenly.
Once lost can never be revived.
Mode of Origin of Languages and Species a Mystery.
Speculations as to the Number of original Languages or
Species unprofitable.
CHAP. 24.
BEARING OF THE DOCTRINE OF TRANSMUTATION ON THE ORIGIN OF MAN,
AND HIS PLACE IN THE CREATION.
Whether Man can be regarded as an Exception to the Rule if the
Doctrine of Transmutation be embraced for the rest of the
Animal Kingdom.
Zoological Relations of Man to other Mammalia.
Systems of Classification.
Term Quadrumanous, why deceptive.
Whether the Structure of the Human Brain entitles Man to form
a distinct Sub-class of the Mammalia.
Intelligence of the lower Animals compared to the Intellect and
Reason of Man.
Grounds on which Man has been referred to a distinct Kingdom
of Nature.
Immaterial Principle common to Man and Animals.
Non-discovery of intermediate Links among Fossil Anthropomorphous
Species.
Hallam on the compound Nature of Man, and his Place in the Creation.
Great Inequality of mental Endowment in different Human Races and
Individuals developed by Variation and ordinary Generation.
How far a corresponding Divergence in physical Structure may
result from the Working of the same Causes.
Concluding remarks.
NOTES.
PLATES AND FIGURES.
PLATE 1. A VILLAGE BUILT ON PILES IN A SWISS LAKE.
FIGURE 1. SECTION OF THE NEANDERTHAL CAVE.
FIGURE 2. SIDE VIEW OF THE CAST OF PART OF A HUMAN SKULL FOUND BY DR.
SCHMERLING EMBEDDED AMONGST THE REMAINS OF EXTINCT MAMMALIA IN THE CAVE
OF ENGIS.
FIGURE 3. SIDE VIEW OF THE CAST OF A PART OF A HUMAN SKULL FROM A CAVE
IN THE NEANDERTHAL.
FIGURE 4. OUTLINE OF THE SKULL OF AN ADULT CHIMPANZEE, OF THAT FROM THE
NEANDERTHAL, AND OF THAT OF A EUROPEAN.
FIGURE 5. SKULL ASSOCIATED WITH GROUND FLINT IMPLEMENTS.
FIGURE 6. OUTLINES OF THE SKULL FROM THE NEANDERTHAL, OF AN AUSTRALIAN
SKULL FROM PORT ADELAIDE, AND OF THE SKULL FROM THE CAVE OF ENGIS.
FIGURE 7. SECTION ACROSS THE VALLEY OF THE SOMME IN PICARDY.
FIGURE 8. FLINT IMPLEMENT FROM ST. ACHEUL, NEAR AMIENS, OF THE
SPEAR-HEAD SHAPE.
FIGURE 9. OVAL-SHAPED FLINT HATCHET FROM MAUTORT.
FIGURE 10. FLINT TOOL FROM ST. ACHEUL.
FIGURES 11, 12 AND 13. DENDRITES ON SURFACES OF FLINT HATCHETS IN THE
DRIFT OF ST. ACHEUL.
FIGURE 14. FLINT KNIFE OR FLAKE FROM BELOW THE SAND CONTAINING Cyrena
fluminalis.
FIGURE 15. FOSSILS OF THE WHITE CHALK.
FIGURE 16. SECTION OF FLUVIO-MARINE STRATA, CONTAINING FLINT IMPLEMENTS
AND BONES OF EXTINCT MAMMALIA.
FIGURE 17. Cyrena fluminalis, O.F. Muller, sp.
FIGURE 18. Elephas primigenius.
FIGURE 19. Elephas antiquus, Falconer.
FIGURE 20. Elephas meridionalis, Nesti.
FIGURE 21. SECTION OF GRAVEL PIT CONTAINING FLINT IMPLEMENTS AT ST.
ACHEUL.
FIGURE 22. CONTORTED FLUVIATILE STRATA AT ST. ACHEUL.
FIGURE 23. SECTION ACROSS THE VALLEY OF THE OUSE.
FIGURE 24. SECTION SHOWING THE POSITION OF THE FLINT WEAPONS AT HOXNE.
FIGURE 25. SECTION OF PART OF THE HILL OF FAJOLES.
FIGURE 26. SECTION THROUGH THE ALLUVIAL PLAIN OF THE MISSISSIPPI.
FIGURE 27. DIAGRAM TO ILLUSTRATE THE GENERAL SUCCESSION OF THE STRATA IN
THE NORFOLK CLIFFS.
FIGURE 28. Cyclas (Pisidium) amnica var.(?)
FIGURE 29. CLIFF 50 FEET HIGH BETWEEN BACTON GAP AND MUNDESLEY.
FIGURE 30. FOLDING OF THE STRATA BETWEEN EAST AND WEST RUNTON.
FIGURE 31. SECTION OF CONCENTRIC BEDS WEST OF CROMER.
FIGURE 32. INCLUDED PINNACLE OF CHALK AT OLD HYTHE POINT.
FIGURE 33. SECTION OF THE NEWER FRESH-WATER FORMATION IN THE CLIFFS AT
MUNDESLEY.
FIGURE 34. Paludina marginata, Michaud (P. minuta, Strickland). Hydrobia
marginata.
FIGURE 35. OVAL AND FLATTISH PEBBLES.
PLATE 2. VIEW OF THE MOUTHS OF GLEN ROY AND GLEN SPEAN.
FIGURE 36. MAP OF THE PARALLEL ROADS OF GLEN ROY.
FIGURE 37. SECTION THROUGH SIDE OF LOCH.
FIGURE 38. DOME-SHAPED ROCKS, OR "ROCHES MOUTONEES."
FIGURE 39. MAP OF THE BRITISH ISLES AND PART OF THE NORTH-WEST OF
EUROPE, SHOWING THE GREAT AMOUNT OF SUPPOSED SUBMERGENCE
OF LAND BENEATH THE SEA DURING PART OF THE GLACIAL PERIOD.
FIGURE 40. MAP SHOWING WHAT PARTS OF THE BRITISH ISLANDS WOULD REMAIN
ABOVE WATER AFTER A SUBSIDENCE OF THE AREA TO THE EXTENT
OF 600 FEET.
FIGURE 41. MAP OF PART OF THE NORTH-WEST OF EUROPE, INCLUDING THE
BRITISH ISLES, SHOWING THE EXTENT OF SEA WHICH WOULD BECOME
LAND IF THERE WERE A GENERAL RISE OF THE AREA TO THE EXTENT OF
600 FEET.
FIGURE 42. MAP SHOWING THE SUPPOSED COURSE OF THE ANCIENT AND NOW
EXTINCT GLACIER OF THE RHONE.
FIGURE 43. MAP OF THE MORAINES OF EXTINCT GLACIERS EXTENDING FROM THE
ALPS INTO THE PLAINS OF THE PO NEAR TURIN.
FIGURE 44. Succinea oblonga.
FIGURE 45. Pupa muscorum.
FIGURE 46. Helix hispida, Lin.; H. plebeia, Drap.
FIGURE 47. SOUTHERN EXTREMITY OF MOENS KLINT.
FIGURE 48. SECTION OF MOENS KLINT.
FIGURE 49. POST-GLACIAL DISTURBANCES OF VERTICAL, FOLDED, AND SHIFTED
STRATA OF CHALK AND DRIFT, IN THE DRONNINGESTOL.
FIGURE 50. MAP SHOWING THE RELATIVE POSITION AND DIRECTION OF SEVEN
TRAINS OF ERRATIC BLOCKS IN BERKSHIRE, MASSACHUSETTS,
AND IN PART OF THE STATE OF NEW YORK.
FIGURE 51. ERRATIC DOME-SHAPED BLOCK OF COMPACT CHLORITIC ROCK.
FIGURE 52. SECTION SHOWING THE POSITION OF THE BLOCK IN FIGURE 51.
FIGURE 53. SECTION THROUGH CANAAN AND RICHMOND VALLEYS AT A TIME WHEN
THEY WERE MARINE CHANNELS.
FIGURE 54. UPPER SURFACE OF BRAIN OF CHIMPANZEE, DISTORTED.
FIGURE 55. SIDE VIEW OF BRAIN OF CHIMPANZEE, DISTORTED.
FIGURE 56. CORRECT SIDE VIEW OF CHIMPANZEE'S BRAIN.
FIGURE 57. CORRECT VIEW OF UPPER SURFACE OF CHIMPANZEE'S BRAIN.
FIGURE 58. SIDE VIEW OF HUMAN BRAIN.)
GEOLOGICAL EVIDENCE OF THE ANTIQUITY OF MAN.
CHAPTER 1. -- INTRODUCTORY.
Preliminary Remarks on the Subjects treated of in this Work.
Definition of the Terms Recent and Pleistocene.
Tabular View of the entire Series of Fossiliferous Strata.
No subject has lately excited more curiosity and general interest among
geologists and the public than the question of the Antiquity of the
Human Race--whether or no we have sufficient evidence in caves, or in
the superficial deposits commonly called drift or "diluvium," to prove
the former co-existence of man with certain extinct mammalia. For the
last half-century the occasional occurrence in various parts of Europe
of the bones of Man or the works of his hands in cave-breccias and
stalagmites, associated with the remains of the extinct hyaena, bear,
elephant, or rhinoceros, has given rise to a suspicion that the date of
Man must be carried farther back than we had heretofore imagined. On
the other hand extreme reluctance was naturally felt on the part of
scientific reasoners to admit the validity of such evidence, seeing that
so many caves have been inhabited by a succession of tenants and have
been selected by Man as a place not only of domicile, but of sepulture,
while some caves have also served as the channels through which the
waters of occasional land-floods or engulfed rivers have flowed, so that
the remains of living beings which have peopled the district at more
than one era may have subsequently been mingled in such caverns and
confounded together in one and the same deposit. But the facts brought
to light in 1858, during the systematic investigation of the Brixham
cave, near Torquay in Devonshire, which will be described in the sequel,
excited anew the curiosity of the British public and prepared the way
for a general admission that scepticism in regard to the bearing of cave
evidence in favour of the antiquity of Man had previously been pushed to
an extreme.
Since that period many of the facts formerly adduced in favour of the
co-existence in ancient times of Man with certain species of mammalia
long since extinct have been re-examined in England and on the
Continent, and new cases bearing on the same question, whether relating
to caves or to alluvial strata in valleys, have been brought to light.
To qualify myself for the appreciation and discussion of these cases,
I have visited in the course of the last three years many parts of
England, France, and Belgium, and have communicated personally or by
letter with not a few of the geologists, English and foreign, who have
taken part in these researches. Besides explaining in the present volume
the results of this inquiry, I shall give a description of the glacial
formations of Europe and North America, that I may allude to the
theories entertained respecting their origin, and consider their
probable relations in a chronological point of view to the human epoch,
and why throughout a great part of the northern hemisphere they so often
interpose an abrupt barrier to all attempts to trace farther back into
the past the signs of the existence of Man upon the earth.
In the concluding chapters I shall offer a few remarks on the recent
modifications of the Lamarckian theory of progressive development and
transmutation, which are suggested by Mr. Darwin's work on the "Origin
of Species by Variation and Natural Selection," and the bearing of this
hypothesis on the different races of mankind and their connection with
other parts of the animal kingdom.
NOMENCLATURE.
Some preliminary explanation of the nomenclature adopted in the
following pages will be indispensable, that the meaning attached to
the terms Recent, Pleistocene, and Post-Tertiary may be correctly
understood. [1]
Previously to the year 1833, when I published the third volume of the
"Principles of Geology," the strata called Tertiary had been divided
by geologists into Lower, Middle, and Upper; the Lower comprising the
oldest formations of the environs of Paris and London, with others of
like age; the Middle, those of Bordeaux and Touraine; and the Upper, all
that lay above or were newer than the last-mentioned group.
When engaged in 1828 in preparing for the press the treatise on geology
above alluded to, I conceived the idea of classing the whole of this
series of strata according to the different degrees of affinity
which their fossil testacea bore to the living fauna. Having obtained
information on this subject during my travels on the Continent, I learnt
that M. Deshayes of Paris, already celebrated as a conchologist, had
been led independently by the study of a large collection of Recent
and fossil shells to very similar views respecting the possibility of
arranging the Tertiary formations in chronological order, according to
the proportional number of species of shells identical with living ones,
which characterised each of the successive groups above mentioned. After
comparing 3000 fossil species with 5000 living ones, the result arrived
at was, that in the lower Tertiary strata there were about 3 1/2 per
cent identical with Recent; in the middle Tertiary (the faluns of the
Loire and Gironde), about 17 per cent; and in the upper tertiary, from
35 to 50, and sometimes in the most modern beds as much as 90 to 95 per
cent.
For the sake of clearness and brevity, I proposed to give short
technical names to these sets of strata, or the periods to which they
respectively belonged. I called the first or oldest of them Eocene, the
second Miocene, and the third Pliocene. The first of the above terms,
Eocene, is derived from Greek eos, dawn, and Greek kainos, recent;
because an extremely small proportion of the fossil shells of this
period could be referred to living species, so that this era seemed to
indicate the dawn of the present testaceous fauna, no living species of
shells having been detected in the antecedent or Secondary rocks.
Some conchologists are now unwilling to allow that any Eocene species of
shell has really survived to our times so unaltered as to allow of its
specific identification with a living species. I cannot enter in this
place into this wide controversy. It is enough at present to remark
that the character of the Eocene fauna, as contrasted with that of the
antecedent Secondary formations, wears a very modern aspect, and that
some able living conchologists still maintain that there are Eocene
shells not specifically distinguishable from those now extant; though
they may be fewer in number than was supposed in 1833.
The term Miocene (from Greek meion, less; and Greek kainos, recent) is
intended to express a minor proportion of Recent species (of testacea);
the term Pliocene (from Greek pleion, more; and Greek kainos, recent), a
comparative plurality of the same.
It has sometimes been objected to this nomenclature that certain species
of infusoria found in the chalk are still existing, and, on the other
hand, the Miocene and Older Pliocene deposits often contain the remains
of mammalia, reptiles, and fish, exclusively of extinct species. But the
reader must bear in mind that the terms Eocene, Miocene, and Pliocene
were originally invented with reference purely to conchological data,
and in that sense have always been and are still used by me.
Since the first introduction of the terms above defined, the number of
new living species of shells obtained from different parts of the globe
has been exceedingly great, supplying fresh data for comparison, and
enabling the palaeontologist to correct many erroneous identifications
of fossil and Recent forms. New species also have been collected in
abundance from Tertiary formations of every age, while newly discovered
groups of strata have filled up gaps in the previously known
series. Hence modifications and reforms have been called for in the
classifications first proposed. The Eocene, Miocene, and Pliocene
periods have been made to comprehend certain sets of strata of which the
fossils do not always conform strictly in the proportion of Recent to
extinct species with the definitions first given by me, or which are
implied in the etymology of those terms. These innovations have been
treated of in my "Elements or Manual of Elementary Geology," and in the
Supplement to the fifth edition of the same, published in 1859,
where some modifications of my classification, as first proposed, are
introduced; but I need not dwell on these on the present occasion, as
the only formations with which we shall be concerned in the present
volume are those of the most modern date, or the Post-Tertiary. It
will be convenient to divide these into two groups, the Recent and the
Pleistocene. In the Recent we may comprehend those deposits in which not
only all the shells but all the fossil mammalia are of living species;
in the Pleistocene those strata in which, the shells being Recent,
a portion, and often a considerable one, of the accompanying fossil
quadrupeds belongs to extinct species.
Cases will occur where it may be scarcely possible to draw the line of
demarcation between the Newer Pliocene and Pleistocene, or between the
latter and the recent deposits; and we must expect these difficulties to
increase rather than diminish with every advance in our knowledge, and
in proportion as gaps are filled up in the series of geological records.
The annexed tabular view (Table 1/1) of the whole series of
fossiliferous strata will enable the reader to see at a glance the
chronological relation of the Recent and Pleistocene to the antecedent
periods. [2]
TABLE 1/1. STRATIFIED ROCKS.
KAINOZOIC OR TERTIARY: Pleistocene and Recent. Pliocene.
Miocene.
Oligocene.
Eocene.
MESOZOIC OR SECONDARY: Cretaceous. Jurassic.
Triassic.
PALAEOZOIC OR PRIMARY: Permian. Carboniferous.
Devonian or old Red Sandstone.
Silurian.
Ordovician.
Cambrian.
PRECAMBRIAN OR ARCHAEAN.
CHAPTER 2. -- RECENT PERIOD--DANISH PEAT AND SHELL MOUNDS--SWISS
LAKE-DWELLINGS.
[Illustration: PLATE 1. A VILLAGE BUILT ON PILES IN A SWISS LAKE]
(Restored by Dr. F. Keller, partly from Dumont D'Urville's
Sketch of similar habitations in New Guinea.)
Works of Art in Danish Peat-Mosses.
Remains of three Periods of Vegetation in the Peat.
Ages of Stone, Bronze, and Iron.
Shell-Mounds or ancient Refuse-Heaps of the Danish Islands.
Change in geographical Distribution of Marine Mollusca
since their Origin.
Embedded Remains of Mammalia of Recent Species.
Human Skulls of the same Period.
Swiss Lake-Dwellings built on Piles.
Stone and Bronze Implements found in them.
Fossil Cereals and other Plants.
Remains of Mammalia, wild and domesticated.
No extinct Species.
Chronological Computations of the Date of the Bronze and
Stone Periods in Switzerland.
Lake-Dwellings, or artificial Islands called "Crannoges,"
in Ireland.
WORKS OF ART IN DANISH PEAT.
When treating in the "Principles of Geology" of the changes of the earth
which have taken place in comparatively modern times, I have spoken of
the embedding of organic bodies and human remains in peat, and explained
under what conditions the growth of that vegetable substance is going on
in northern and humid climates. Of late years, since I first alluded
to the subject, more extensive investigations have been made into the
history of the Danish peat-mosses. Of the results of these inquiries
I shall give a brief abstract in the present chapter, that we may
afterwards compare them with deposits of older date, which throw light
on the antiquity of the human race.
The deposits of peat in Denmark,* varying in depth from 10 to 30 feet,
have been formed in hollows or depressions in the northern drift or
boulder formation hereafter to be described. (* An excellent account of
these researches of Danish naturalists and antiquaries has been drawn
up by an able Swiss geologist, M.A. Morlot, and will be found in the
"Bulletin de la Societe Vaudoise des Sci. Nat." tome 6 Lausanne 1860.)
The lowest stratum, 2 to 3 feet thick, consists of swamp-peat composed
chiefly of moss or sphagnum, above which lies another growth of peat,
not made up exclusively of aquatic or swamp plants. Around the borders
of the bogs, and at various depths in them, lie trunks of trees,
especially of the Scotch fir (Pinus sylvestris), often 3 feet in
diameter, which must have grown on the margin of the peat-mosses, and
have frequently fallen into them. This tree is not now, nor has ever
been in historical times, a native of the Danish Islands, and when
introduced there has not thriven; yet it was evidently indigenous in the
human period, for Steenstrup has taken out with his own hands a flint
instrument from below a buried trunk of one of these pines. It appears
clear that the same Scotch fir was afterwards supplanted by the sessile
variety of the common oak, of which many prostrate trunks occur in the
peat at higher levels than the pines; and still higher the pedunculated
variety of the same oak (Quercus robur, L.) occurs with the alder, birch
(Betula verrucosa, Ehrh.), and hazel. The oak has now in its turn been
almost superseded in Denmark by the common beech. Other trees, such as
the white birch (Betula alba), characterise the lower part of the
bogs, and disappear from the higher; while others again, like the aspen
(Populus tremula), occur at all levels, and still flourish in Denmark.
All the land and freshwater shells, and all the mammalia as well as the
plants, whose remains occur buried in the Danish peat, are of Recent
species. [3]
It has been stated, that a stone implement was found under a buried
Scotch fir at a great depth in the peat. By collecting and studying a
vast variety of such implements, and other articles of human workmanship
preserved in peat and in sand-dunes on the coast, as also in certain
shell-mounds of the aborigines presently to be described, the Danish
and Swedish antiquaries and naturalists, MM. Nilsson, Steenstrup,
Forchhammer, Thomsen, Worsaae, and others, have succeeded in
establishing a chronological succession of periods, which they have
called the ages of stone, of bronze, and of iron, named from the
materials which have each in their turn served for the fabrication of
implements.
The age of stone in Denmark coincided with the period of the first
vegetation, or that of the Scotch fir, and in part at least with the
second vegetation, or that of the oak. But a considerable portion of the
oak epoch coincided with "the age of bronze," for swords and shields of
that metal, now in the Museum of Copenhagen, have been taken out of peat
in which oaks abound. The age of iron corresponded more nearly with that
of the beech tree.*
(* Morlot "Bulletin de la Societe Vaudoise des Sci. Nat."
tome 6 page 292.) [4]
M. Morlot, to whom we are indebted for a masterly sketch of the recent
progress of this new line of research, followed up with so much success
in Scandinavia and Switzerland, observes that the introduction of the
first tools made of bronze among a people previously ignorant of the use
of metals, implies a great advance in the arts, for bronze is an alloy
of about nine parts of copper and one of tin; and although the former
metal, copper, is by no means rare, and is occasionally found pure or
in a native state, tin is not only scarce but never occurs native. To
detect the existence of this metal in its ore, then to disengage it
from the matrix, and finally, after blending it in due proportion with
copper, to cast the fused mixture in a mould, allowing time for it to
acquire hardness by slow cooling, all this bespeaks no small sagacity
and skilful manipulation. Accordingly, the pottery found associated with
weapons of bronze is of a more ornamental and tasteful style than any
which belongs to the age of stone. Some of the moulds in which the
bronze instruments were cast, and "tags," as they are called, of bronze,
which are formed in the hole through which the fused metal was poured,
have been found. The number and variety of objects belonging to the age
of bronze indicates its long duration, as does the progress in the arts
implied by the rudeness of the earlier tools, often mere repetitions
of those of the stone age, as contrasted with the more skilfully worked
weapons of a later stage of the same period.
It has been suggested that an age of copper must always have intervened
between that of stone and bronze; but if so, the interval seems to have
been short in Europe, owing apparently to the territory occupied by the
aboriginal inhabitants having been invaded and conquered by a people
coming from the East, to whom the use of swords, spears, and other
weapons of bronze was familiar. Hatchets, however, of copper have been
found in the Danish peat.
The next stage of improvement, or that manifested by the substitution of
iron for bronze, indicates another stride in the progress of the arts.
Iron never presents itself, except in meteorites, in a native state,
so that to recognise its ores, and then to separate the metal from its
matrix, demands no inconsiderable exercise of the powers of observation
and invention. To fuse the ore requires an intense heat, not to be
obtained without artificial appliances, such as pipes inflated by the
human breath, or bellows, or some other suitable machinery.
DANISH SHELL-MOUNDS, OR KJOKKENMODDING.*
(* Mr. John Lubbock published, after these sheets were
written, an able paper on the Danish "Shell-mounds" in the
October number of the "Natural History Review" 1861 page
489, in which he has described the results of a recent visit
to Denmark, made by him in company with Mr. Busk.)
In addition to the peat-mosses, another class of memorials found in
Denmark has thrown light on the pre-historical age. At certain points
along the shores of nearly all the Danish islands, mounds may be seen,
consisting chiefly of thousands of cast-away shells of the oyster,
cockle, and other molluscs of the same species as those which are now
eaten by Man. These shells are plentifully mixed up with the bones of
various quadrupeds, birds, and fish, which served as the food of the
rude hunters and fishers by whom the mounds were accumulated. I have
seen similar large heaps of oysters, and other marine shells with
interspersed stone implements, near the seashore, both in Massachusetts
and in Georgia, U.S.A., left by the native North American Indians at
points near to which they were in the habit of pitching their wigwams
for centuries before the white man arrived.
Such accumulations are called by the Danes, Kjokkenmodding, or
"kitchen-middens." Scattered all through them are flint knives,
hatchets, and other instruments of stone, horn, wood, and bone, with
fragments of coarse pottery, mixed with charcoal and cinders, but never
any implements of bronze, still less of iron. The stone hatchets and
knives had been sharpened by rubbing, and in this respect are one degree
less rude than those of an older date, associated in France with the
bones of extinct mammalia, of which more in the sequel. The mounds vary
in height from 3 to 10 feet, and in area are some of them 1000 feet
long, and from 150 to 200 wide. They are rarely placed more than 10
feet above the level of the sea, and are confined to its immediate
neighbourhood, or if not (and there are cases where they are several
miles from the shore), the distance is ascribable to the entrance of a
small stream, which has deposited sediment, or to the growth of a peaty
swamp, by which the land has been made to advance on the Baltic, as it
is still doing in many places, aided, according to Puggaard, by a very
slow upheaval of the whole country at the rate of 2 or 3 inches in a
century.
There is also another geographical fact equally in favour of the
antiquity of the mounds, namely, that they are wanting on those parts of
the coast which border the Western Ocean, or exactly where the waves are
now slowly eating away the land. There is every reason to presume that
originally there were stations along the coast of the North Sea as well
as that of the Baltic, but by the gradual undermining of the cliffs they
have all been swept away.
Another striking proof, perhaps the most conclusive of all, that the
"kitchen-middens" are very old, is derived from the character of their
embedded shells. These consist entirely of living species; but, in the
first place, the common eatable oyster is among them, attaining its
full size, whereas the same Ostrea edulis cannot live at present in the
brackish waters of the Baltic except near its entrance, where, whenever
a north-westerly gale prevails, a current setting in from the ocean
pours in a great body of salt water. Yet it seems that during the whole
time of the accumulation of the "kitchen-middens" the oyster flourished
in places from which it is now excluded. In like manner the eatable
cockle, mussel, and periwinkle (Cardium edule, Mytilus edulis, and
Littorina littorea), which are met with in great numbers in the
"middens," are of the ordinary dimensions which they acquire in the
ocean, whereas the same species now living in the adjoining parts of
the Baltic only attain a third of their natural size, being stunted and
dwarfed in their growth by the quantity of fresh water poured by rivers
into that inland sea.*
(* See "Principles of Geology" chapter 30.)
Hence we may confidently infer that in the days of the aboriginal
hunters and fishers, the ocean had freer access than now to the Baltic,
communicating probably through the peninsula of Jutland, Jutland having
been at no remote period an archipelago. Even in the course of the
nineteenth century, the salt waters have made one irruption into the
Baltic by the Lymfiord, although they have been now again excluded. It
is also affirmed that other channels were open in historical times which
are now silted up.*
(* See Morlot "Bulletin de la Societe Vaudoise des Sci.
Nat." tome 6.)
If we next turn to the remains of vertebrata preserved in the mounds,
we find that here also, as in the Danish peat-mosses, all the quadrupeds
belong to species known to have inhabited Europe within the memory of
Man. No remains of the mammoth, or rhinoceros, or of any extinct
species appear, except those of the wild bull (Bos urus, Linn., or Bos
primigenius, Bojanus), which are in such numbers as to prove that the
species was a favourite food of the ancient people. But as this animal
was seen by Julius Caesar, and survived long after his time, its
presence alone would not go far to prove the mounds to be of high
antiquity. The Lithuanian aurochs or bison (Bos bison, L., Bos priscus,
Boj.), which has escaped extirpation only because protected by the
Russian Czars, surviving in one forest in Lithuania) has not yet been
met with, but will no doubt be detected hereafter, as it has been
already found in the Danish peat. The beaver, long since destroyed in
Denmark, occurs frequently, as does the seal (Phoca Gryppus, Fab.), now
very rare on the Danish coast. With these are mingled bones of the red
deer and roe, but the reindeer has not yet been found. There are also
the bones of many carnivora, such as the lynx, fox, and wolf, but no
signs of any domesticated animals except the dog. The long bones of the
larger mammalia have been all broken as if by some instrument, in such
a manner as to allow of the extraction of the marrow, and the gristly
parts have been gnawed off, as if by dogs, to whose agency is also
attributed the almost entire absence of the bones of young birds and of
the smaller bones and softer parts of the skeletons of birds in general,
even of those of large size. In reference to the latter, it has been
proved experimentally by Professor Steenstrup, that if the same species
of birds are now given to dogs, they will devour those parts of the
skeleton which are missing, and leave just those which are preserved in
the old "kitchen-middens."
The dogs of the mounds, the only domesticated animals, are of a smaller
race than those of the bronze period, as shown by the peat-mosses, and
the dogs of the bronze age are inferior in size and strength to those
of the iron age. The domestic ox, horse, and sheep, which are wanting
in the mounds, are confined to that part of the Danish peat which was
formed in the ages of bronze and iron.
Among the bones of birds, scarcely any are more frequent in the mounds
than those of the auk (Alca impennis), now extinct. The Capercailzie
(Tetrao urogallus) is also met with, and may, it is suggested, have fed
on the buds of the Scotch fir in times when that tree flourished around
the peat-bogs. The different stages of growth of the roedeer's horns,
and the presence of the wild swan, now only a winter visitor, have
been appealed to as proving that the aborigines resided in the same
settlements all the year round. That they also ventured out to sea in
canoes such as are now found in the peat-mosses, hollowed out of the
trunk of a single tree, to catch fish far from land, is testified by the
bony relics of several deep-sea species, such as the herring, cod, and
flounder. The ancient people were not cannibals, for no human bones
are mingled with the spoils of the chase. Skulls, however, have been
obtained not only from peat, but from tumuli of the stone period
believed to be contemporaneous with the mounds. These skulls are small
and round, and have a prominent ridge over the orbits of the eyes,
showing that the ancient race was of small stature, with round heads and
overhanging eyebrows--in short, they bore a considerable resemblance to
the modern Laplanders. The human skulls of the bronze age found in the
Danish peat, and those of the iron period, are of an elongated form and
larger size. There appear to be very few well-authenticated examples
of crania referable to the bronze period--a circumstance no doubt
attributable to the custom prevalent among the people of that era of
burning their dead and collecting their bones in funeral urns.
No traces of grain of any sort have hitherto been discovered, nor
any other indication that the ancient people had any knowledge of
agriculture. The only vegetable remains in the mounds are burnt pieces
of wood and some charred substance referred by Dr. Forchhammer to the
Zostera marina, a sea plant which was perhaps used in the production of
salt.
What may be the antiquity of the earliest human remains preserved in
the Danish peat cannot be estimated in centuries with any approach
to accuracy. In the first place, in going back to the bronze age, we
already find ourselves beyond the reach of history or even of tradition.
In the time of the Romans the Danish Isles were covered, as now, with
magnificent beech forests. Nowhere in the world does this tree flourish
more luxuriantly than in Denmark, and eighteen centuries seem to have
done little or nothing towards modifying the character of the forest
vegetation. Yet in the antecedent bronze period there were no beech
trees, or at most but a few stragglers, the country being then covered
with oak. In the age of stone again, the Scotch fir prevailed, and
already there were human inhabitants in those old pine forests. How many
generations of each species of tree flourished in succession before the
pine was supplanted by the oak, and the oak by the beech, can be but
vaguely conjectured, but the minimum of time required for the formation
of so much peat must, according to the estimate of Steenstrup and other
good authorities, have amounted to at least 4000 years; and there
is nothing in the observed rate of the growth of peat opposed to the
conclusion that the number of centuries may not have been four times as
great, even though the signs of Man's existence have not yet been traced
down to the lowest or amorphous stratum. As to the "kitchen-middens,"
they correspond in date to the older portion of the peaty record, or to
the earliest part of the age of stone as known in Denmark.
ANCIENT SWISS LAKE-DWELLINGS, BUILT ON PILES.
[Illustration: Plate 1. Swiss Lake-Dwellings]
In the shallow parts of many Swiss lakes, where there is a depth of no
more than from 5 to 15 feet of water, ancient wooden piles are observed
at the bottom sometimes worn down to the surface of the mud, sometimes
projecting slightly above it. These have evidently once supported
villages, nearly all of them of unknown date, but the most ancient of
which certainly belonged to the age of stone, for hundreds of implements
resembling those of the Danish shell-mounds and peat-mosses have been
dredged up from the mud into which the piles were driven.
The earliest historical account of such habitations is that given by
Herodotus of a Thracian tribe, who dwelt, in the year 520 B.C., in
Prasias, a small mountain-lake of Paeonia, now part of modern Roumelia.*
(* Herodotus lib. 5 cap. 16. Rediscovered by M. de Ville
"Natural History Review" volume 2 1862 page 486.)
Their habitations were constructed on platforms raised above the lake,
and resting on piles. They were connected with the shore by a narrow
causeway of similar formation. Such platforms must have been of
considerable extent, for the Paeonians lived there with their families
and horses. Their food consisted largely of the fish which the lake
produced in abundance.
In rude and unsettled times, such insular sites afforded safe retreats,
all communication with the mainland being cut off, except by boats, or
by such wooden bridges as could be easily removed.
The Swiss lake-dwellings seem first to have attracted attention during
the dry winter of 1853-54, when the lakes and rivers sank lower than had
ever been previously known, and when the inhabitants of Meilen, on the
Lake of Zurich, resolved to raise the level of some ground and turn it
into land, by throwing mud upon it obtained by dredging in the adjoining
shallow water. During these dredging operations they discovered a number
of wooden piles deeply driven into the bed of the lake, and among them
a great many hammers, axes, celts, and other instruments. All these
belonged to the stone period with two exceptions, namely, an armlet of
thin brass wire, and a small bronze hatchet.
Fragments of rude pottery fashioned by the hand were abundant, also
masses of charred wood, supposed to have formed parts of the platform
on which the wooden cabins were built. Of this burnt timber, on this and
other sites, subsequently explored, there was such an abundance as to
lead to the conclusion that many of the settlements must have perished
by fire. Herodotus has recorded that the Paeonians, above alluded to,
preserved their independence during the Persian invasion, and defied the
attacks of Darius by aid of the peculiar position of their dwellings.
"But their safety," observes Mr. Wylie,* "was probably owing to their
living in the middle of the lake, (Greek) en mese te limne, whereas the
ancient Swiss settlers were compelled by the rapidly increasing depth of
the water near the margins of their lakes to construct their habitations
at a short distance from the shore, within easy bowshot of the land, and
therefore not out of reach of fiery projectiles, against which thatched
roofs and wooden walls could present but a poor defence."
(* W.M. Wylie "Archaeologia" volume 38 1859, a valuable
paper on the Swiss and Irish lake-habitations.)
To these circumstances and to accidental fires we are probably indebted
for the frequent preservation, in the mud around the site of the old
settlements, of the most precious tools and works of art, such as would
never have been thrown into the Danish "kitchen-middens," which have
been aptly compared to a modern dusthole.
Dr. Ferdinand Keller of Zurich has drawn up a series of most instructive
memoirs, illustrated with well-executed plates, of the treasures
in stone, bronze, and bone brought to light in these subaqueous
repositories, and has given an ideal restoration of part of one of the
old villages (see Plate 1 above),* such as he conceives may have existed
on the lakes of Zurich and Bienne.
(*Keller "Pfahlbauten, Antiquarische Gesellschaft in Zurich"
Bd. 12 and 13 1858-1861. In the fifth number of the "Natural
History Review" January 9, 1862, Mr. Lubbock has published
an excellent account of the works of the Swiss writers on
their lake-habitations.)
In this view, however, he has not simply trusted to his imagination,
but has availed himself of a sketch published by M. Dumont d'Urville, of
similar habitations of the Papuans in New Guinea in the Bay of Dorei. It
is also stated by Dr. Keller, that on the River Limmat, near Zurich, so
late as the last century, there were several fishing-huts constructed on
this same plan.*
(* Keller "Pfahlbauten, Antiquarische Gesellschaft in
Zurich" Bd. 9 page 81 note.)
It will be remarked that one of the cabins is represented as circular.
That such was the form of many in Switzerland is inferred from the
shape of pieces of clay which lined the interior, and which owe their
preservation apparently to their having been hardened by fire when the
village was burnt. In the sketch (Plate 1), some fishing-nets are seen
spread out to dry on the wooden platform. The Swiss archaeologist has
found abundant evidence of fishing-gear, consisting of pieces of cord,
hooks, and stones used as weights. A canoe also is introduced, such as
are occasionally met with. One of these, made of the trunk of a single
tree, fifty feet long and three and a half feet wide, was found capsized
at the bottom of the Lake of Bienne. It appears to have been laden
with stones, such as were used to raise the foundation of some of the
artificial islands.
It is believed that as many as 300 wooden huts were sometimes comprised
in one settlement, and that they may have contained about 1000
inhabitants. At Wangen, M. Lohle has calculated that 40,000 piles were
used, probably not all planted at one time nor by one generation. Among
the works of great merit devoted specially to a description of the Swiss
lake-habitations is that of M. Troyon, published in 1860.*
(* "Sur les Habitations lacustres.")
The number of sites which he and other authors have already enumerated
in Switzerland is truly wonderful. They occur on the large lakes of
Constance, Zurich, Geneva, and Neufchatel, and on most of the smaller
ones. Some are exclusively of the stone age, others of the bronze
period. Of these last more than twenty are spoken of on the Lake of
Geneva alone, more than forty on that of Neufchatel, and twenty on the
small Lake of Bienne.
One of the sites first studied by the Swiss antiquaries was the small
lake of Moosseedorf, near Berne, where implements of stone, horn, and
bone, but none of metal, were obtained. Although the flint here employed
must have come from a distance (probably from the south of France), the
chippings of the material are in such profusion as to imply that there
was a manufactory of implements on the spot. Here also, as in several
other settlements, hatchets and wedges of jade have been observed of a
kind said not to occur in Switzerland or the adjoining parts of Europe,
and which some mineralogists would fain derive from the East; amber
also, which, it is supposed, was imported from the shores of the Baltic.
At Wangen near Stein, on the Lake of Constance, another of the most
ancient of the lake-dwellings, hatchets of serpentine and greenstone,
and arrow-heads of quartz have been met with. Here also remains of a
kind of cloth, supposed to be of flax, not woven but plaited, have
been detected. Professor Heer has recognised lumps of carbonised wheat,
Triticum vulgare, and grains of another kind, T. dicoccum, and barley,
Hordeum distichum, and flat round cakes of bread; and at Robbenhausen
and elsewhere Hordeum hexastichum in fine ears, the same kind of barley
which is found associated with Egyptian mummies, showing clearly that in
the stone period the lake-dwellers cultivated all these cereals, besides
having domesticated the dog, the ox, the sheep, and the goat.
Carbonised apples and pears of small size, such as still grow in the
Swiss forests, stones of the wild plum, seeds of the raspberry and
blackberry, and beech-nuts, also occur in the mud, and hazel-nuts in
great plenty.
Near Morges, on the Lake of Geneva, a settlement of the bronze period,
no less than forty hatchets of that metal have been dredged up, and in
many other localities the number and variety of weapons and utensils
discovered, in a fine state of preservation, is truly astonishing.
It is remarkable that as yet all the settlements of the bronze period
are confined to Western and Central Switzerland. In the more eastern
lakes those of the stone period alone have as yet been discovered.
The tools, ornaments, and pottery of the bronze period in Switzerland
bear a close resemblance to those of corresponding age in Denmark,
attesting the wide spread of a uniform civilisation over Central Europe
at that era. In some few of the Swiss aquatic stations a mixture of
bronze and iron implements has been observed, but no coins. At Tiefenau,
near Berne, in ground supposed to have been a battle-field, coins
and medals of bronze and silver, struck at Marseilles, and of Greek
manufacture, and iron swords, have been found, all belonging to the
first and pre-Roman division of the age of iron.
In the settlements of the bronze era the wooden piles are not so much
decayed as those of the stone period; the latter having wasted down
quite to the level of the mud, whereas the piles of the bronze age (as
in the Lake of Bienne, for example) still project above it.
Professor Rutimeyer of Basle, well-known to palaeontologists as the
author of several important memoirs on fossil vertebrata, has recently
published a scientific description of great interest of the animal
remains dredged up at various stations where they had been embedded for
ages in the mud into which the piles were driven.*
(* "Die Fauna der Pfahlbauten in der Schweiz" Basel 1861.)
These bones bear the same relation to the primitive inhabitants of
Switzerland and some of their immediate successors as do the contents of
the Danish "kitchen-middens" to the ancient fishing and hunting tribes
who lived on the shores of the Baltic.
The list of wild mammalia enumerated in this excellent treatise contains
no less than twenty-four species, exclusive of several domesticated
ones: besides which there are eighteen species of birds, the wild swan,
goose, and two species of ducks being among them; also three reptiles,
including the eatable frog and freshwater tortoise; and lastly, nine
species of freshwater fish. All these (amounting to fifty-four species)
are with one exception still living in Europe. The exception is the wild
bull (Bos primigenius), which, as before stated, survived in historical
times. The following are the mammalia alluded to:--The bear (Ursus
arctos), the badger, the common marten, the polecat, the ermine, the
weasel, the otter, wolf, fox, wild cat, hedgehog, squirrel, field-mouse
(Mus sylvaticus), hare, beaver, hog (comprising two races, namely, the
wild boar and swamp-hog), the stag (Cervus elaphus), the roe-deer,
the fallow-deer, the elk, the steinbock (Capra ibex), the chamois, the
Lithuanian bison, and the wild bull. The domesticated species comprise
the dog, horse, ass, pig, goat, sheep, and several bovine races.
The greater number, if not all, of these animals served for food, and
all the bones which contained marrow have been split open in the same
way as the corresponding ones found in the shell-mounds of Denmark
before mentioned. The bones both of the wild bull and the bison are
invariably split in this manner. As a rule, the lower jaws with teeth
occur in greater abundance than any other parts of the skeleton--a
circumstance which, geologists know, holds good in regard to fossil
mammalia of all periods. As yet the reindeer is missing in the Swiss
lake-settlements as in the Danish "kitchen-middens," although this
animal in more ancient times ranged over France, together with the
mammoth, as far south as the Pyrenees.
A careful comparison of the bones from different sites has shown that
in settlements such as Wangen and Moosseedorf, belonging to the earliest
age of stone, when the habits of the hunter state predominated over
those of the pastoral, venison, or the flesh of the stag and roe, was
more eaten than the flesh of the domestic cattle and sheep. This was
afterwards reversed in the later stone period and in the age of bronze.
At that later period also the tame pig, which is wanting in some of the
oldest stations, had replaced the wild boar as a common article of
food. In the beginning of the age of stone, in Switzerland, the goats
outnumbered the sheep, but towards the close of the same period the
sheep were more abundant than the goats.
The fox in the first era was very common, but it nearly disappears in
the bronze age, during which period a large hunting-dog, supposed to
have been imported into Switzerland from some foreign country, becomes
the chief representative of the canine genus.
A single fragment of the bone of a hare (Lepus timidus) has been found
at Moosseedorf. The almost universal absence of this quadruped is
supposed to imply that the Swiss lake-dwellers were prevented from
eating that animal by the same superstition which now prevails among
the Laplanders, and which Julius Caesar found in full force amongst the
ancient Britons.*
(* "Commentaries" lib 5 chapter 12.)
That the lake-dwellers should have fed so largely on the fox, while
they abstained from touching the hare, establishes, says Rutimeyer, a
singular contrast between their tastes and ours.
Even in the earliest settlements, as already hinted, several
domesticated animals occur, namely, the ox, sheep, goat, and dog. Of the
three last, each was represented by one race only; but there were two
races of cattle, the most common being of small size, and called by
Rutimeyer Bos brachyceros (Bos longifrons, Owen), or the marsh cow,
the other derived from the wild bull; though, as no skull has yet been
discovered, this identification is not so certain as could be wished.
It is, however, beyond question that at a later era, namely, towards the
close of the stone and beginning of the bronze period, the lake-dwellers
had succeeded in taming that formidable brute the Bos primigenius, the
Urus of Caesar, which he described as very fierce, swift, and strong,
and scarcely inferior to the elephant in size. In a tame state its
bones were somewhat less massive and heavy, and its horns were somewhat
smaller than in wild individuals. Still in its domesticated form, it
rivalled in dimensions the largest living cattle, those of Friesland,
in North Holland, for example. When most abundant, as at Concise on
the Lake of Neufchatel, it had nearly superseded the smaller race,
Bos brachyceros, and was accompanied there for a short time by a third
bovine variety, called Bos trochoceros, an Italian race, supposed
to have been imported from the southern side of the Alps. (Caesar
"Commentaries" lib 5 chapter 12.) This last-mentioned race, however,
seems only to have lasted for a short time in Switzerland.
The wild bull (Bos primigenius) is supposed to have flourished for a
while in a wild and tame state, just as now in Europe the domestic
pig co-exists with the wild boar; and Rutimeyer agrees with Cuvier and
Bell,* in considering our larger domestic cattle of northern Europe as
the descendants of this wild bull, an opinion which Owen disputes.**
(* "British Quadrupeds" page 415.)
(** "British Fossil Mammal." page 500.)
In the later division of the stone period, there were two tame races of
the pig, according to Rutimeyer; one large, and derived from the
wild boar, the other smaller, called the "marsh-hog," or Sus scrofa
palustris. It may be asked how the osteologist can distinguish the tame
from the wild races of the same species by their skeletons alone.
Among other characters, the diminished thickness of the bones and the
comparative smallness of the ridges, which afford attachment to the
muscles, are relied on; also the smaller dimensions of the tusks in
the boar, and of the whole jaw and skull; and, in like manner, the
diminished size of the horns of the bull and other modifications, which
are the effects of a regular supply of food, and the absence of all
necessity of exerting their activity and strength to obtain subsistence
and defend themselves against their enemies.
A middle-sized race of dogs continued unaltered throughout the whole of
the stone period; but the people of the bronze age possessed a larger
hunting-dog, and with it a small horse, of which genus very few traces
have been detected in the earlier settlements--a single tooth, for
example, at Wangen, and only one or two bones at two or three other
places.
In passing from the oldest to the most modern sites, the extirpation of
the elk and beaver, and the gradual reduction in numbers of the bear,
stag, roe, and freshwater tortoise are distinctly perceptible. The
aurochs, or Lithuanian bison, appears to have died out in Switzerland
about the time when weapons of bronze came into use. It is only in a few
of the most modern lake-dwellings, such as Noville and Chavannes in the
Canton de Vaud (which the antiquaries refer to the sixth century), that
some traces are observable of the domestic cat, as well as of a sheep
with crooked horns and with them bones of the domestic fowl.
After the sixth century, no extinction of any wild quadruped nor
introduction of any tame one appears to have taken place, but the fauna
was still modified by the wild species continuing to diminish in number
and the tame ones to become more diversified by breeding and crossing,
especially in the case of the dog, horse, and sheep. On the whole,
however, the divergence of the domestic races from their aboriginal wild
types, as exemplified at Wangen and Moosseedorf, is confined, according
to Professor Rutimeyer, within narrow limits. As to the goat, it has
remained nearly constant and true to its pristine form, and the small
race of goat-horned sheep still lingers in some alpine valleys in the
Upper Rhine; and in the same region a race of pigs, corresponding to the
domesticated variety of Sus scrofa palustris, may still be seen.
Amidst all this profusion of animal remains extremely few bones of Man
have been discovered; and only one skull, dredged up from Meilen, on
the Lake of Zurich, of the early stone period, seems as yet to have been
carefully examined. Respecting this specimen, Professor His observes
that it exhibits, instead of the small and rounded form proper to
the Danish peat-mosses, a type much more like that now prevailing
in Switzerland, which is intermediate between the long-headed and
short-headed form. (Rutimeyer "Die Fauna der Pfahlbauten in der Schweiz"
page 181.)
So far, therefore, as we can draw safe conclusions from a single
specimen, there has been no marked change of race in the human
population of Switzerland during the periods above considered.
It is still a question whether any of these subaqueous repositories
of ancient relics in Switzerland go back so far in time as the
kitchen-middens of Denmark, for in these last there are no domesticated
animals except the dog, and no signs of the cultivation of wheat or
barley; whereas we have seen that, in one of the oldest of the
Swiss settlements, at Wangen, no less than three cereals make their
appearance, with four kinds of domestic animals. Yet there is no small
risk of error in speculating on the relative claims to antiquity of such
ancient tribes, for some of them may have remained isolated for ages and
stationary in their habits, while others advanced and improved.
We know that nations, both before and after the introduction of metals,
may continue in very different stages of civilisation, even after
commercial intercourse has been established between them, and where they
are separated by a less distance than that which divides the Alps from
the Baltic.
The attempts of the Swiss geologists and archaeologists to estimate
definitely in years the antiquity of the bronze and stone periods,
although as yet confessedly imperfect, deserve notice, and appear to me
to be full of promise. The most elaborate calculation is that made by M.
Morlot, respecting the delta of the Tiniere, a torrent which flows
into the Lake of Geneva near Villeneuve. This small delta, to which the
stream is annually making additions, is composed of gravel and sand.
Its shape is that of a flattened cone, and its internal structure has of
late been laid open to view in a railway cutting 1000 feet long and 32
feet deep. The regularity of its structure throughout implies that it
has been formed very gradually, and by the uniform action of the same
causes. Three layers of vegetable soil, each of which must at one time
have formed the surface of the cone, have been cut through at different
depths. The first of these was traced over a surface of 15,000 square
feet, having an average thickness of 5 inches, and being about 4 feet
below the present surface of the cone. This upper layer belonged to the
Roman period, and contained Roman tiles and a coin. The second layer,
followed over a surface of 25,000 square feet, was 6 inches thick, and
lay at a depth of 10 feet. In it were found fragments of unvarnished
pottery and a pair of tweezers in bronze, indicating the bronze epoch.
The third layer, followed for 35,000 square feet, was 6 or 7 inches
thick and 19 feet deep. In it were fragments of rude pottery, pieces of
charcoal, broken bones, and a human skeleton having a small, round and
very thick skull. M. Morlot, assuming the Roman period to represent an
antiquity of from sixteen to eighteen centuries, assigns to the bronze
age a date of between 3000 and 4000 years, and to the oldest layer, that
of the stone period, an age of from 5000 to 7000 years.
Another calculation has been made by M. Troyon to obtain the approximate
date of the remains of an ancient settlement built on piles and
preserved in a peat-bog at Chamblon, near Yverdun, on the Lake of
Neufchatel. The site of the ancient Roman town of Eburodunum (Yverdun),
once on the borders of the lake, and between which and the shore there
now intervenes a zone of newly-gained dry land, 2500 feet in breadth,
shows the rate at which the bed of the lake has been filled up with
river sediment in fifteen centuries. Assuming the lake to have retreated
at the same rate before the Roman period, the pile-works of Chamblon,
which are of the bronze period, must be at the least 3300 years old.
For the third calculation, communicated to me by M. Morlot, we are
indebted to M. Victor Gillieron, of Neuveville, on the Lake of Bienne.
It relates to the age of a pile-dwelling, the mammalian bones of which
are considered by M. Rutimeyer to indicate the earliest portion of
the stone period of Switzerland, and to correspond in age with the
settlement of Moosseedorf.
The piles in question occur at the Pont de Thiele, between the lakes of
Bienne and Neufchatel. The old convent of St. Jean, founded 750 years
ago, and built originally on the margin of the Lake of Bienne, is now
at a considerable distance from the shore, and affords a measure of the
rate of the gain of land in seven centuries and a half. Assuming that
a similar rate of the conversion of water into marshy land prevailed
antecedently, we should require an addition of sixty centuries for the
growth of the morass intervening between the convent and the aquatic
dwelling of Pont de Thiele, in all 6750 years. M. Morlot, after
examining the ground, thinks it highly probable that the shape of the
bottom on which the morass rests is uniform; but this important point
has not yet been tested by boring. The result, if confirmed, would agree
exceedingly well with the chronological computation before mentioned
of the age of the stone period of Tiniere. As I have not myself visited
Switzerland since these chronological speculations were first hazarded,
I am unable to enter critically into a discussion of the objections
which have been raised to the two first of them, or to decide on the
merits of the explanations offered in reply.
IRISH LAKE-DWELLINGS OR CRANNOGES.
The lake-dwellings of the British isles, although not explored as yet
with scientific zeal, as those of Switzerland have been in the last ten
years, are yet known to be very numerous, and when carefully examined
will not fail to throw great light on the history of the bronze and
stone periods.
In the lakes of Ireland alone, no less than forty-six examples of
artificial islands, called crannoges, have been discovered. They occur
in Leitrim, Roscommon, Cavan, Down, Monaghan, Limerick, Meath, King's
County, and Tyrone.*
(* W.M. Wylie "Archaeologia" volume 38 1859 page 8.)
One class of these "stockaded islands," as they have been sometimes
called, was formed, according to Mr. Digby Wyatt, by placing horizontal
oak beams at the bottom of the lake, into which oak posts, from 6 to
8 feet high, were mortised, and held together by cross beams, till a
circular enclosure was obtained.
A space of 520 feet diameter, thus enclosed at Lagore, was divided into
sundry timbered compartments, which were found filled up with mud or
earth, from which were taken "vast quantities of the bones of oxen,
swine, deer, goats, sheep, dogs, foxes, horses, and asses." All these
were discovered beneath 16 feet of bog, and were used for manure; but
specimens of them are said to be preserved in the museum of the Royal
Irish Academy. From the same spot were obtained a great collection of
antiquities, which, according to Lord Talbot de Malahide and Mr. Wylie,
were referable to the ages of stone, bronze, and iron.*
(* W.M. Wylie "Archaeologia" volume 38 1859 page 8, who
cites "Archaeological Journal" volume 6 page 101.)
In Ardekillin Lake, in Roscommon, an islet of an oval form was observed,
made of a layer of stones resting on logs of timber. Round this
artificial islet or crannoge thus formed was a stone wall raised on oak
piles. A careful description has been put on record by Captain Mudge,
R.N., of a curious log-cabin discovered by him in 1833 in Drumkellin
bog, in Donegal, at a depth of 14 feet from the surface. It was 12 feet
square and 9 feet high, being divided into two stories each 4 feet high.
The planking was of oak split with wedges of stone, one of which was
found in the building. The roof was flat. A staked enclosure had been
raised round the cabin, and remains of other similar huts adjoining were
seen but not explored. A stone celt, found in the interior of the hut,
and a piece of leather sandal, also an arrow-head of flint, and in the
bog close at hand a wooden sword, give evidence of the remote antiquity
of this building, which may be taken as a type of the early dwellings on
the Crannoge islands.
"The whole structure," says Captain Mudge, "was wrought with the
rudest kind of implements, and the labour bestowed on it must have been
immense. The wood of the mortises was more bruised than cut, as if by a
blunt stone chisel."*
(* Mudge "Archaeologia" volume 26.)
Such a chisel lay on the floor of the hut, and by comparing it with
the marks of the tool used in forming the mortises, they were found "to
correspond exactly, even to the slight curved exterior of the chisel;
but the logs had been hewn by a larger instrument, in the shape of an
axe. On the floor of the dwelling lay a slab of freestone, 3 feet
long and 14 inches thick, in the centre of which was a small pit three
quarters of an inch deep, which had been chiselled out. This is presumed
to have been used for holding nuts to be cracked by means of one of the
round shingle stones, also found there, which had served as a hammer.
Some entire hazel-nuts and a great quantity of broken shells were
strewed about the floor."
The foundations of the house were made of fine sand, such as is found
with shingle on the seashore about 2 miles distant. Below the layer of
sand the bog or peat was ascertained, on probing it with an instrument,
to be at least 15 feet thick. Although the interior of the building when
discovered was full of "bog" or peaty matter, it seems when inhabited to
have been surrounded by growing trees, some of the trunks and roots
of which are still preserved in their natural position. The depth of
overlying peat affords no safe criterion for calculating the age of the
cabin or village, for I have shown in the "Principles of Geology" that
both in England and Ireland, within historical times, bogs have burst
and sent forth great volumes of black mud, which has been known to
creep over the country at a slow pace, flowing somewhat at the rate of
ordinary lava-currents, and sometimes overwhelming woods and cottages,
and leaving a deposit upon them of bog-earth 15 feet thick.
None of these Irish lake-dwellings were built, like those of Helvetia,
on platforms supported by piles deeply driven into the mud. "The
Crannoge system of Ireland seems," says Mr. Wylie, "well nigh without a
parallel in Swiss waters."
CHAPTER 3. -- FOSSIL HUMAN REMAINS AND WORKS OF ART OF THE RECENT
PERIOD--CONTINUED.
Delta and Alluvial Plain of the Nile.
Burnt Bricks in Egypt before the Roman Era.
Borings in 1851-54.
Ancient Mounds of the Valley of the Ohio.
Their Antiquity.
Sepulchral Mound at Santos in Brazil.
Delta of the Mississippi.
Ancient Human Remains in Coral Reefs of Florida.
Changes in Physical Geography in the Human Period.
Buried Canoes in Marine Strata near Glasgow.
Upheaval since the Roman Occupation of the Shores of the Firth of Forth.
Fossil Whales near Stirling.
Upraised Marine Strata of Sweden on Shores of the Baltic and the Ocean.
Attempts to compute their Age.
DELTA AND ALLUVIAL PLAIN OF THE NILE.
Some new facts of high interest illustrating the geology of the alluvial
land of Egypt were brought to light between the years 1851 and 1854,
in consequence of investigations suggested to the Royal Society by Mr.
Leonard Horner, and which were partly carried out at the expense of
the Society. The practical part of the undertaking was entrusted by Mr.
Horner to an Armenian officer of engineers, Hekekyan Bey, who had for
many years pursued his scientific studies in England, and was in every
way highly qualified for the task.
It was soon found that to obtain the required information respecting
the nature, depth, and contents of the Nile mud in various parts of
the valley, a larger outlay was called for than had been originally
contemplated. This expense the late viceroy, Abbas Pasha, munificently
undertook to defray out of his treasury, and his successor, after his
death, continued the operations with the same princely liberality.
Several engineers and a body of sixty workmen were employed under the
superintendence of Hekekyan Bey, men inured to the climate and able to
carry on the sinking of shafts and borings during the hot months, after
the waters of the Nile had subsided, and in a season which would have
been fatal to Europeans.
The results of chief importance arising out of this inquiry were
obtained from two sets of shafts and borings sunk at intervals in lines
crossing the great valley from east to west. One of these consisted of
no fewer than fifty-one pits and artesian borings, made where the
valley is 16 miles wide from side to side between the Arabian and Libyan
deserts, in the latitude of Heliopolis, about 8 miles above the apex of
the delta. The other line of borings and pits, twenty-seven in number,
was in the parallel of Memphis, where the valley is only five miles
broad.
Everywhere in these sections the sediment passed through was similar in
composition to the ordinary Nile mud of the present day, except near the
margin of the valley, where thin layers of quartzose sand, such as is
sometimes blown from the adjacent desert by violent winds, were observed
to alternate with the loam.
A remarkable absence of lamination and stratification was observed
almost universally in the sediment brought up from all points except
where the sandy layers above alluded to occurred. Mr. Horner attributes
this want of all indication of successive deposition to the extreme
thinness of the film of matter which is thrown down annually on the
great alluvial plain during the season of inundation. The tenuity of
this layer must indeed be extreme, if the French engineers are tolerably
correct in their estimate of the amount of sediment formed in a century,
which they suppose not to exceed on the average 5 inches. When the
waters subside, this thin layer of new soil, exposed to a hot sun, dries
rapidly, and clouds of dust are raised by the winds. The superficial
deposit, moreover, is disturbed almost everywhere by agricultural
labours, and even were this not the case, the action of worms, insects,
and the roots of plants would suffice to confound together the deposits
of two successive years.
All the remains of organic bodies, such as land-shells, and the bones
of quadrupeds, found during the excavations belonged to living species.
Bones of the ox, hog, dog, dromedary and ass were not uncommon, but no
vestiges of extinct mammalia. No marine shells were anywhere detected;
but this was to be expected, as the borings, though they sometimes
reached as low as the level of the Mediterranean, were never carried
down below it--a circumstance much to be regretted, since where artesian
borings have been made in deltas, as in those of the Po and Ganges, to
the depth of several hundred feet below the sea level it has been
found, contrary to expectation, that the deposits passed through were
fluviatile throughout, implying, probably, that a general subsidence of
those deltas and alluvial formations has taken place. Whether there has
been in like manner a sinking of the land in Egypt, we have as yet no
means of proving; but Sir Gardner Wilkinson infers it from the position
in the delta on the shore near Alexandria of the tombs commonly called
Cleopatra's Baths, which cannot, he says, have been originally built so
as to be exposed to the sea which now fills them, but must have stood on
land above the level of the Mediterranean. The same author adduces, as
additional signs of subsidence, some ruined towns, now half under water,
in the Lake Menzaleh, and channels of ancient arms of the Nile submerged
with their banks beneath the waters of that same lagoon.
In some instances, the excavations made under the superintendence of
Hekekyan Bey were on a large scale for the first 16 or 24 feet, in which
cases jars, vases, pots and a small human figure in burnt clay, a copper
knife, and other entire articles were dug up; but when water soaking
through from the Nile was reached the boring instrument used was too
small to allow of more than fragments of works of art being brought up.
Pieces of burnt brick and pottery were extracted almost everywhere, and
from all depths, even where they sank 60 feet below the surface towards
the central parts of the valley. In none of these cases did they get
to the bottom of the alluvial soil. It has been objected, among other
criticisms, that the Arabs can always find whatever their employers
desire to obtain. Even those who are too well acquainted with the
sagacity and energy of Hekekyan Bey to suspect him of having been
deceived, have suggested that the artificial objects might have fallen
into old wells which had been filled up. This notion is inadmissible
for many reasons. Of the ninety-five shafts and borings, seventy or more
were made far from the sites of towns or villages; and allowing that
every field may once have had its well, there would be but small chance
of the borings striking upon the site even of a small number of them in
seventy experiments.
Others have suggested that the Nile may have wandered over the whole
valley, undermining its banks on one side and filling up old channels
on the other. It has also been asked whether the delta with the numerous
shifting arms of the river may not once have been at every point where
the auger pierced.*
(* For a detailed account of these sections, see Mr.
Horner's paper in the "Philosophical Transactions" for 1855
to 1858.)
To all these objections there are two obvious answers:--First, in
historical times the Nile has on the whole been very stationary, and
has not shifted its position in the valley; secondly, if the mud pierced
through had been thrown down by the river in ancient channels, it would
have been stratified, and would not have corresponded so closely with
inundation mud, we learn from Captain Newbold that he observed in some
excavations in the great plain alternations of sand and clay, such as
are seen in the modern banks of the Nile; but in the borings made by
Hekekyan Bey, such stratification seems scarcely in any case to have
been detected.
The great aim of the criticisms above enumerated has been to get rid of
the supposed anomaly of finding burnt brick and pottery at depths and
places which would give them claim to an antiquity far exceeding that of
the Roman domination in Egypt. For until the time of the Romans, it is
said, no clay was burnt into bricks in the valley of the Nile. But a
distinguished antiquary, Mr. S. Birch, assures me that this notion is
altogether erroneous, and that he has under his charge in the British
Museum, first, a small rectangular baked brick, which came from a Theban
tomb which bears the name of Thothmes, a superintendent of the granaries
of the god Amen Ra, the style of art, inscription, and name, showing
that it is as old as the 18th dynasty (about 1450 B.C.); secondly, a
brick bearing an inscription, partly obliterated, but ending with the
words "of the temple of Amen Ra." This brick, decidedly long anterior to
the Roman dominion, is referred conjecturally, by Mr. Birch, to the 19th
dynasty, or 1300 B.C. Sir Gardner Wilkinson has also in his possession
pieces of mortar, which he took from each of the three great pyramids,
in which bits of broken pottery and of burnt clay or brick are embedded.
M. Girard, of the French expedition to Egypt, supposed the average rate
of the increase of Nile mud on the plain between Assouan and Cairo to
be five English inches in a century. This conclusion, according to Mr.
Horner, is very vague, and founded on insufficient data; the amount of
matter thrown down by the waters in different parts of the plain varying
so much that to strike an average with any approach to accuracy must
be most difficult. Were we to assume six inches in a century, the burnt
brick met with at a depth of 60 feet would be 12,000 years old.
Another fragment of red brick was found by Linant Bey, in a boring 72
feet deep, being 2 or 3 feet below the level of the Mediterranean,
in the parallel of the apex of the delta, 200 metres distant from the
river, on the Libyan side of the Rosetta branch.*
(* Horner "Philosophical Transactions" 1858.)
M. Rosiere, in the great French work on Egypt, has estimated the mean
rate of deposit of sediment in the delta at 2 1/4 inches in a century;*
were we to take 2 1/2 inches, a work of art 72 feet deep must have been
buried more than 30,000 years ago.
(* Description de l'Egypte "Histoire Naturelle" tome 2 page
494.)
But if the boring of Linant Bey was made where an arm of the river had
been silted up at a time when the apex of the delta was somewhat farther
south, or more distant from the sea than now, the brick in question
might be comparatively very modern.
The experiments instituted by Mr. Horner at the pedestal of the fallen
statue of King Rameses at Memphis, in the hope of obtaining an accurate
chronometric scale for testing the age of a given thickness of
Nile sediment, are held by some experienced Egyptologists not to be
satisfactory, on the ground of the uncertainty of the rate of deposit
accumulated at that locality. The point sought to be determined was the
exact amount of Nile mud which had accumulated there since the time when
that statue is supposed by some antiquaries to have been erected. Could
we have obtained possession of such a measure, the rate of deposition
might be judged of, approximately at least, whenever similar mud
was observed in other places, or below the foundations of those same
monuments. But the ancient Egyptians are known to have been in the habit
of enclosing with embankments the areas on which they erected temples,
statues, and obelisks, so as to exclude the waters of the Nile; and the
point of time to be ascertained, in every case where we find a monument
buried to a certain depth in mud, as at Memphis and Heliopolis, is the
era when the city fell into such decay that the ancient embankments were
neglected, and the river allowed to inundate the site of the temple,
obelisk, or statue.
Even if we knew the date of the abandonment of such embankments,
the enclosed areas would not afford a favourable opportunity for
ascertaining the average rate of deposit in the alluvial plain; for
Herodotus tells us that in his time those spots from which the Nile
waters had been shut out for centuries appeared sunk, and could be
looked down into from the surrounding grounds, which had been raised by
the gradual accumulation over them of sediment annually thrown down. If
the waters at length should break into such depressions, they must at
first carry with them into the enclosure much mud washed from the steep
surrounding banks, so that a greater quantity would be deposited in a
few years than perhaps in as many centuries on the great plain outside
the depressed area, where no such disturbing causes intervened.
ANCIENT MOUNDS OF THE VALLEY OF THE OHIO.
As I have already given several European examples of monuments of
prehistoric date belonging to the Recent period, I will now turn to
the American continent. Before the scientific investigation by Messrs.
Squier and Davis of the "Ancient Monuments of the Mississippi Valley",*
no one suspected that the plains of that river had been occupied, for
ages before the French and British colonists settled there, by a nation
of older date and more advanced in the arts than the Red Indians whom
the Europeans found there.
(* "Smithsonian Contributions" volume 1 1847.)
There are hundreds of large mounds in the basin of the Mississippi, and
especially in the valleys of the Ohio and its tributaries, which have
served, some of them for temples, others for outlook or defence, and
others for sepulture. The unknown people by whom they were constructed,
judging by the form of several skulls dug out of the burial-places, were
of the Mexican or Toltec race. Some of the earthworks are on so grand a
scale as to embrace areas of 50 or 100 acres within a simple enclosure,
and the solid contents of one mould are estimated at 20 million of cubic
feet, so that four of them would be more than equal in bulk to the Great
Pyramid of Egypt, which comprises 75 million. From several of these
repositories pottery and ornamental sculpture have been taken, and
various articles in silver and copper, also stone weapons, some composed
of hornstone unpolished, and much resembling in shape some ancient flint
implements found near Amiens and other places in Europe, to be alluded
to in the sequel.
It is clear that the Ohio mound-builders had commercial intercourse with
the natives of distant regions, for among the buried articles some are
made of native copper from Lake Superior, and there are also found mica
from the Alleghenies, sea-shells from the Gulf of Mexico, and obsidian
from the Mexican mountains.
The extraordinary number of the mounds implies a long period, during
which a settled agricultural population had made considerable progress
in civilisation, so as to require large temples for their religious
rites, and extensive fortifications to protect them from their enemies.
The mounds were almost all confined to fertile valleys or alluvial
plains, and some at least are so ancient that rivers have had time since
their construction to encroach on the lower terraces which support them,
and again to recede for the distance of nearly a mile, after having
undermined and destroyed a part of the works. When the first European
settlers entered the valley of the Ohio, they found the whole region
covered with an uninterrupted forest, and tenanted by the Red Indian
hunter, who roamed over it without any fixed abode, or any traditionary
connection with his more civilised predecessors. The only positive data
as yet obtained for calculating the minimum of time which must have
elapsed since the mounds were abandoned, have been derived from the age
and nature of the trees found growing on some of these earthworks. When
I visited Marietta in 1842, Dr. Hildreth took me to one of the mounds,
and showed me where he had seen a tree growing on it, the trunk of which
when cut down displayed eight hundred rings of annual growth.*
(* Lyell's "Travels in North America" volume 2 page 29.)
But the late General Harrison, President in 1841 of the United States,
who was well skilled in woodcraft, has remarked, in a memoir on this
subject, that several generations of trees must have lived and died
before the mounds could have been overspread with that variety of
species which they supported when the white man first beheld them, for
the number and kinds of trees were precisely the same as those which
distinguished the surrounding forest. "We may be sure," observed
Harrison, "that no trees were allowed to grow so long as the earthworks
were in use; and when they were forsaken, the ground, like all newly
cleared land in Ohio, would for a time be monopolised by one or two
species of tree, such as the yellow locust and the black or white
walnut. When the individuals which were the first to get possession of
the ground had died out one after the other, they would in many cases,
instead of being replaced by the same species, be succeeded (by virtue
of the law which makes a rotation of crops profitable in agriculture)
by other kinds, till at last, after a great number of centuries
(several thousand years, perhaps), that remarkable diversity of species
characteristic of North America, and far exceeding what is seen in
European forests, would be established."
MOUNDS OF SANTOS IN BRAZIL.
I will next say a few words respecting certain human bones embedded in
a solid rock at Santos in Brazil, to which I called attention in my
"Travels in North America" in 1842.*
(* Volume 1 page 200.)
I then imagined the deposit containing them to be of submarine
origin--an opinion which I have long ceased to entertain. We learn
from a memoir of Dr. Meigs that the River Santos has undermined a large
mound, 14 feet in height, and about 3 acres in area, covered with trees,
near the town of St. Paul, and has exposed to view many skeletons,
all inclined at angles between 20 and 25 degrees, and all placed in a
similar east and west position.*
(* Meigs "Transactions of the American Philosophical
Society" 1828 page 285.)
Seeing, in the Museum of Philadelphia, fragments of the calcareous stone
or tufa from this spot, containing a human skull with teeth, and in the
same matrix, oysters with serpulae attached, I at first concluded that
the whole deposit had been formed beneath the waters of the sea, or at
least, that it had been submerged after its origin, and again upheaved;
also, that there had been time since its emergence for the growth on it
of a forest of large trees. But after reading again, with more care, the
original memoir of Dr. Meigs, I cannot doubt that the shells, like
those of eatable kinds, so often accumulated in the mounds of the North
American Indians not far from the sea, may have been brought to the
place and heaped up with other materials at the time when the bodies
were buried. Subsequently, the whole artificial earthwork, with its
shells and skeletons, may have been bound together into a solid stone by
the infiltration of carbonate of lime, and the mound may therefore be
of no higher antiquity than some of those above alluded to on the Ohio,
which, as we have seen, have in like manner been exposed in the course
of ages to the encroachments and undermining action of rivers.
DELTA OF THE MISSISSIPPI.
I have shown in my "Travels in North America" that the deposits forming
the delta and alluvial plain of the Mississippi consist of sedimentary
matter, extending over an area of 30,000 square miles, and known in
some parts to be several hundred feet deep. Although we cannot estimate
correctly how many years it may have required for the river to bring
down from the upper country so large a quantity of earthy matter--the
data for such a computation being as yet incomplete--we may still
approximate to a minimum of the time which such an operation must have
taken, by ascertaining experimentally the annual discharge of water by
the Mississippi, and the mean annual amount of solid matter contained
in its waters. The lowest estimate of the time required would lead us
to assign a high antiquity, amounting to many tens of thousands of years
(probably more than 100,000) to the existing delta.
Whether all or how much of this formation may belong to the recent
period, as above defined, I cannot pretend to decide, but in one part of
the modern delta near New Orleans, a large excavation has been made
for gas-works, where a succession of beds, almost wholly made up of
vegetable matter, has been passed through, such as we now see forming
in the cypress swamps of the neighbourhood, where the deciduous cypress
(Taxodium distichum), with its strong and spreading roots, plays a
conspicuous part. In this excavation, at the depth of sixteen feet
from the surface, beneath four buried forests superimposed one upon
the other, the workmen are stated by Dr. B. Dowler to have found some
charcoal and a human skeleton, the cranium of which is said to belong to
the aboriginal type of the Red Indian race. As the discovery in question
had not been made when I saw the excavation in progress at the gas-works
in 1846, I cannot form an opinion as to the value of the chronological
calculations which have led Dr. Dowler to ascribe to this skeleton an
antiquity of 50,000 years. In several sections, both natural in the
banks of the Mississippi and its numerous arms, and where artificial
canals had been cut, I observed erect stumps of trees, with their roots
attached, buried in strata at different heights, one over the other. I
also remarked, that many cypresses which had been cut through, exhibited
many hundreds of rings of annual growth, and it then struck me that
nowhere in the world could the geologist enjoy a more favourable
opportunity for estimating in years the duration of certain portions of
the Recent epoch.*
(* Dowler cited by Dr. W. Usher in Nott and Gliddon's "Types
of Mankind" page 352.)
CORAL REEFS OF FLORIDA.
Professor Agassiz has described a low portion of the peninsula of
Florida as consisting of numerous reefs of coral, which have grown in
succession so as to give rise to a continual annexation of land, gained
gradually from the sea in a southerly direction. This growth is still
in full activity, and assuming the rate of advance of the land to be one
foot in a century, the reefs being built up from a depth of 75 feet, and
that each reef has in its turn added ten miles to the coast, Professor
Agassiz calculates that it has taken 135,000 years to form the southern
half of this peninsula. Yet the whole is of Post-Tertiary origin, the
fossil zoophytes and shells being all of the same species as those now
inhabiting the neighbouring sea.*
(* Agassiz in Nott and Gliddon ibid. page 352.)
In a calcareous conglomerate forming part of the above-mentioned series
of reefs, and supposed by Agassiz, in accordance with his mode of
estimating the rate of growth of those reefs, to be about 10,000 years
old, some fossil human remains were found by Count Pourtales. They
consisted of jaws and teeth, with some bones of the foot.
RECENT DEPOSITS OF SEAS AND LAKES.
I have shown, in the "Principles of Geology," where the recent changes
of the earth illustrative of geology are described at length, that the
deposits accumulated at the bottom of lakes and seas within the last
4000 or 5000 years can neither be insignificant in volume or extent.
They lie hidden, for the most part, from our sight; but we have
opportunities of examining them at certain points where newly-gained
land in the deltas of rivers has been cut through during floods, or
where coral reefs are growing rapidly, or where the bed of a sea or lake
has been heaved up by subterranean movements and laid dry.
As examples of such changes of level by which marine deposits of the
Recent period have become accessible to human observation, I have
adduced the strata near Naples in which the Temple of Serapis at
Pozzuoli was entombed.*
(* "Principles of Geology" Index "Serapis.")
These upraised strata, the highest of which are about 25 feet above the
level of the sea, form a terrace skirting the eastern shore of the Bay
of Baiae. They consist partly of clay, partly of volcanic matter, and
contain fragments of sculpture, pottery, and the remains of buildings,
together with great numbers of shells, retaining in part their colour,
and of the same species as those now inhabiting the neighbouring sea.
Their emergence can be proved to have taken place since the beginning of
the sixteenth century. [5]
In the same work, as an example of a freshwater deposit of the Recent
period, I have described certain strata in Cashmere, a country where
violent earthquakes, attended by alterations in the level of the ground,
are frequent, in which freshwater shells of species now inhabiting the
lakes and rivers of that region are embedded, together with the remains
of pottery, often at the depth of fifty feet, and in which a splendid
Hindoo temple has lately been discovered, and laid open to view by the
removal of the lacustrine silt which had enveloped it for four or five
centuries.
In the same treatise it is stated that the west coast of South America,
between the Andes and the Pacific, is a great theatre of earthquake
movements, and that permanent upheavals of the land of several feet at
a time have been experienced since the discovery of America. In various
parts of the littoral region of Chile and Peru, strata have been
observed enclosing shells in abundance, all agreeing specifically with
those now swarming in the Pacific. In one bed of this kind, in the
island of San Lorenzo, near Lima, Mr. Darwin found, at the altitude of
85 feet above the sea, pieces of cotton-thread, plaited rush, and the
head of a stalk of Indian corn, the whole of which had evidently been
embedded with the shells. At the same height, on the neighbouring
mainland, he found other signs corroborating the opinion that the
ancient bed of the sea had there also been uplifted 85 feet since the
region was first peopled by the Peruvian race. But similar shelly masses
are also met with at much higher elevations, at innumerable points
between the Chilean and Peruvian Andes and the sea-coast, in which
no human remains have as yet been observed. The preservation for an
indefinite period of such perishable substances as thread is explained
by the entire absence of rain in Peru. The same articles, had they been
enclosed in the permeable sands of an European raised beach, or in
any country where rain falls even for a small part of the year, would
probably have disappeared entirely [6]
In the literature of the eighteenth century, we find frequent allusion
to the "era of existing continents," a period supposed to have coincided
in date with the first appearance of Man upon the earth, since which
event it was imagined that the relative level of the sea and land had
remained stationary, no important geographical changes having occurred,
except some slight additions to the deltas of rivers, or the loss of
narrow strips of land where the sea had encroached upon its shores. But
modern observations have tended continually to dispel this delusion, and
the geologist is now convinced that at no given era of the past have the
boundaries of land and sea, or the height of the one and depth of the
other, or the geographical range of the species inhabiting them, whether
of animals or plants, become fixed and unchangeable. Of the extent to
which fluctuations have been going on since the globe had already become
the dwelling-place of Man, some idea may be formed from the examples
which I shall give in this and the next nine chapters.
UPHEAVAL SINCE THE HUMAN PERIOD OF THE CENTRAL DISTRICT OF SCOTLAND.
[7] It has long been a fact familiar to geologists, that, both
on the east and west coasts of the central part of Scotland, there are
lines of raised beaches, containing marine shells of the same species as
those now inhabiting the neighbouring sea.*
(* R. Chambers "Sea Margins" 1848 and papers by Mr. Smith of
Jordan Hill "Memoirs of the Wernerian Society" volume 8 and
by Mr. C. Maclaren. )
The two most marked of these littoral deposits occur at heights of about
50 and 25 feet above high-water mark, that of 50 feet being considered
as the more ancient, and owing its superior elevation to a continuance
of the upheaving movement. They are seen in some places to rest on the
boulder clay of the glacial period, which will be described in future
chapters.
In those districts where large rivers, such as the Clyde, Forth, and
Tay, enter the sea, the lower of the two deposits, or that of 25 feet,
expands into a terrace fringing the estuaries, and varying in breadth
from a few yards to several miles. Of this nature are the flat lands
which occur along the margin of the Clyde at Glasgow, which consist
of finely laminated sand, silt, and clay. Mr. John Buchanan, a zealous
antiquary, writing in 1855, informs us that in the course of the eighty
years preceding that date, no less than seventeen canoes had been dug
out of this estuarine silt, and that he had personally inspected a large
number of them before they were exhumed. Five of them lay buried in silt
under the streets of Glasgow, one in a vertical position with the prow
uppermost as if it had sunk in a storm. In the inside of it were a
number of marine shells. Twelve other canoes were found about 100 yards
back from the river, at the average depth of about 19 feet from the
surface of the soil, or 7 feet above high-water mark; but a few of them
were only 4 or 5 feet deep, and consequently more than 20 feet above
the sea-level. One was sticking in the sand at an angle of 45 degrees,
another had been capsized and lay bottom uppermost; all the rest were in
a horizontal position, as if they had sunk in smooth water.*
(* J. Buchanan "Report of the British Association" 1855 page
80; also "Glasgow, Past and Present" 1856.)
Almost every one of these ancient boats was formed out of a single
oak-stem, hollowed out by blunt tools, probably stone axes, aided by
the action of fire; a few were cut beautifully smooth, evidently with
metallic tools. Hence a gradation could be traced from a pattern of
extreme rudeness to one showing great mechanical ingenuity. Two of them
were built of planks, one of the two, dug up on the property of Bankton
in 1853, being 18 feet in length, and very elaborately constructed. Its
prow was not unlike the beak of an antique galley; its stern, formed of
a triangular-shaped piece of oak, fitted in exactly like those of our
day. The planks were fastened to the ribs, partly by singularly shaped
oaken pins, and partly by what must have been square nails of some kind
of metal; these had entirely disappeared, but some of the oaken pins
remained. This boat had been upset, and was lying keel uppermost,
with the prow pointing straight up the river. In one of the canoes, a
beautifully polished celt or axe of greenstone was found, in the bottom
of another a plug of cork, which, as Mr. Geikie remarks, "could only
have come from the latitudes of Spain, Southern France, or Italy."*
(* Geikie, "Quarterly Journal of the Geological Society"
volume 18 1862 page 224.)
There can be no doubt that some of these buried vessels are of far more
ancient date than others. Those most roughly hewn, may be relics of
the stone period; those more smoothly cut, of the bronze age; and the
regularly built boat of Bankton may perhaps come within the age of
iron. The occurrence of all of them in one and the same upraised marine
formation by no means implies that they belong to the same era, for
in the beds of all great rivers and estuaries, there are changes
continually in progress brought about by the deposition, removal, and
redeposition of gravel, sand, and fine sediment, and by the shifting of
the channel of the main currents from year to year, and from century
to century. All these it behoves the geologist and antiquary to bear in
mind, so as to be always on their guard, when they are endeavouring
to settle the relative date, whether of objects of art or of organic
remains embedded in any set of alluvial strata. Some judicious
observations on this head occur in Mr. Geikie's memoir above cited,
which are so much in point that I shall give them in full, and in his
own words.
"The relative position in the silt, from which the canoes were exhumed,
could help us little in any attempt to ascertain their relative ages,
unless they had been found vertically above each other. The varying
depths of an estuary, its banks of silt and sand, the set of its
currents, and the influence of its tides in scouring out alluvium
from some parts of its bottom and redepositing it in others, are
circumstances which require to be taken into account in all such
calculations. Mere coincidence of depth from the present surface of the
ground, which is tolerably uniform in level, by no means necessarily
proves contemporaneous deposition. Nor would such an inference follow
even from the occurrence of the remains in distant parts of the very
same stratum. A canoe might be capsized and sent to the bottom just
beneath low-water mark; another might experience a similar fate on
the following day, but in the middle of the channel. Both would become
silted up on the floor of the estuary; but as that floor would be
perhaps 20 feet deeper in the centre than towards the margin of the
river, the one canoe might actually be twenty feet deeper in the
alluvium than the other; and on the upheaval of the alluvial deposits,
if we were to argue merely from the depth at which the remains were
embedded, we should pronounce the canoe found at the one locality to be
immensely older than the other, seeing that the fine mud of the estuary
is deposited very slowly and that it must therefore have taken a long
period to form so great a thickness as 20 feet. Again, the tides and
currents of the estuary, by changing their direction, might sweep away a
considerable mass of alluvium from the bottom, laying bare a canoe that
may have foundered many centuries before. After the lapse of so long an
interval, another vessel might go to the bottom in the same locality and
be there covered up with the older one on the same general plane.
These two vessels, found in such a position, would naturally be classed
together as of the same age, and yet it is demonstrable that a very
long period may have elapsed between the date of the one and that of
the other. Such an association of these canoes, therefore, cannot be
regarded as proving synchronous deposition; nor, on the other hand, can
we affirm any difference of age from mere relative position, unless we
see one canoe actually buried beneath another."*
(* Geikie, "Quarterly Journal of the Geological Society"
volume 18 1862, page 222.)
At the time when the ancient vessels, above described, were navigating
the waters where the city of Glasgow now stands, the whole of the low
lands which bordered the present estuary of the Clyde formed the bed of
a shallow sea. The emergence appears to have taken place gradually and
by intermittent movements, for Mr. Buchanan describes several narrow
terraces one above the other on the site of the city itself, with steep
intervening slopes composed of the laminated estuary formation. Each
terrace and steep slope probably mark pauses in the process of upheaval,
during which low cliffs were formed, with beaches at their base. Five
of the canoes were found within the precincts of the city at different
heights on or near such terraces.
As to the date of the upheaval, the greater part of it cannot be
assigned to the stone period, but must have taken place after tools of
metal had come into use.
Until lately, when attempts were made to estimate the probable antiquity
of such changes of level, it was confidently assumed, as a safe
starting-point, that no alteration had occurred in the relative level
of land and sea, in the central district of Scotland, since the
construction of the Roman or Pictish wall (the "Wall of Antonine"),
which reached from the Firth of Forth to that of the Clyde. The two
extremities, it was said, of this ancient structure, bear such a
relation to the present level of the two estuaries, that neither
subsidence nor elevation of the land could have occurred for seventeen
centuries at least.
But Mr. Geikie has lately shown that a depression of 25 feet on the
Forth would not lay the eastern extremity of the Roman wall at Carriden
under water, and he was therefore desirous of knowing whether the
western end of the same would be submerged by a similar amount of
subsidence. It has always been acknowledged that the wall terminated
upon an eminence called the Chapel Hill, near the village of West
Kilpatrick, on the Clyde. The foot of this hill, Mr. Geikie estimates to
be about 25 or 27 feet above high-water mark, so that a subsidence of 25
feet could not lay it under water. Antiquaries have sometimes wondered
that the Romans did not carry the wall farther west than this Chapel
Hill; but Mr. Geikie now suggests, in explanation, that all the low land
at present intervening between that point and the mouth of the Clyde,
was sixteen or seventeen centuries ago, washed by the tides at high
water.
The wall of Antonine, therefore, yields no evidence in favour of the
land having remained stationary since the time of the Romans, but on
the contrary, appears to indicate that since its erection the land has
actually risen. Recent explorations by Mr. Geikie and Dr. Young, of the
sites of the old Roman harbours along the southern margin of the Firth
of Forth, lead to similar inferences. In the first place, it has long
been known that there is a raised beach containing marine shells of
living littoral species, at a height of about 25 feet, at Leith, as well
as at other places along the coast above and below Edinburgh. Inveresk,
a few miles below that city, is the site of an ancient Roman port,
and if we suppose the sea at high water to have washed the foot of the
heights on which the town stood, the tide would have ascended far up the
valley of the Esk, and would have made the mouth of that river a safe
and commodious harbour; whereas, had it been a shoaling estuary, as at
present, it is difficult to see how the Romans should have made choice
of it as a port.
At Cramond, at the mouth of the river Almond, above Edinburgh, was
Alaterva, the chief Roman harbour on the southern coast of the Forth,
where numerous coins, urns, sculptured stones and the remnant of a
harbour have been detected. The old Roman quays built along what must
then have been the sea margin, have been found on what is now dry land,
and although some silt carried down in suspension by the waters of the
Forth may account for a part of the gain of low land, we yet require
an upward movement of about 20 feet to explain the growth of the dreary
expanse of mud now stretching along the shore and extending outwards,
where it attains its greatest breadth, well-nigh two miles, across which
vessels, even of light burden, can now only venture at full tide. Had
these shoals existed eighteen centuries ago, they would have prevented
the Romans from selecting this as their chief port; whereas, if the
land were now to sink 20 feet, Cramond would unquestionably be the best
natural harbour along the whole of the south side of the Forth.*
(* Geikie, "Edinburgh New Philosophical Journal" for July
1861.)
Corresponding in level with the raised beach at Leith, above mentioned
(or about 25 feet above high-water mark), is the Carse of Stirling, a
low tract of land consisting of loamy and peaty beds, in which several
skeletons of whales of large size have been found. One of these was dug
up at Airthrie,* near Stirling, about a mile from the river, and 7 miles
from the sea.
(* Bald, "Edinburgh Philosophical Journal" 1 page 393 and
"Memoirs of the Wernerian Society" 3 page 327.)
Mr. Bald mentions that near it were found two pieces of stag's horn,
artificially cut, through one of which a hole, about an inch in
diameter, had been perforated. Another whale, 85 feet long, was found at
Dunmore, a few miles below Stirling,* which, like that of Airthrie, lay
about 20 feet above high-water mark.
(* "Edinburgh Philosophical Journal" 11 pages 220, 415.)
Three other skeletons of whales were found at Blair Drummond, between
the years 1819 and 1824, 7 miles up the estuary above Stirling,* also at
an elevation of between 20 and 30 feet above the sea. Near two of these
whales, pointed instruments of deer's horn were found, one of which
retained part of a wooden handle, probably preserved by having been
enclosed in peat. This weapon is now in the museum at Edinburgh.
(* "Memoirs of the Wernerian Society" volume 5 page 440.)
The position of these fossil whales and bone implements, and still more
of an iron anchor found in the Carse of Falkirk, below Stirling, shows
that the upheaval by which the raised beach of Leith was laid dry
extended far westward probably as far as the Clyde, where, as we have
seen, marine strata containing buried canoes rise to a similar height
above the sea.
The same upward movement which reached simultaneously east and west from
sea to sea was also felt as far north as the estuary of the Tay. This
may be inferred from the Celtic name of Inch being attached to many
hillocks, which rise above the general level of the alluvial plains,
implying that these eminences were once surrounded by water or marshy
ground. At various localities also in the silt of the Carse of Gowrie
iron implements have been found.
The raised beach, also containing a great number of marine shells of
recent species, traced up to a height of 14 feet above the sea by Mr.
W.J. Hamilton at Elie, on the southern coast of Fife, is doubtless
another effect of the same extensive upheaval.*
(* "Proceedings of the Geological Society" volume 2 1833
page 280.)
A similar movement would also account for some changes which antiquaries
have recorded much farther south, on the borders of the Solway Firth;
though in this case, as in that of the estuary of the Forth, the
conversion of sea into land has always been referred to the silting
up of estuaries, and not to upheaval. Thus Horsley insists on the
difficulty of explaining the position of certain Roman stations, on the
Solway, the Forth, and the Clyde, without assuming that the sea has been
excluded from certain areas which it formerly occupied.*
(* "Britannia" page 157 1860.)
On a review of the whole evidence, geological and archaeological,
afforded by the Scottish coast-line, we may conclude that the last
upheaval of 25 feet took place not only since the first human population
settled in the island; but long after metallic implements had come into
use, and there seems even a strong presumption in favour of the opinion
that the date of the elevation may have been subsequent to the Roman
occupation.
But the 25 feet rise is only the last stage of a long antecedent process
of elevation, for examples of Recent marine shells have been observed 40
feet and upwards above the sea in Ayrshire. At one of these localities,
Mr. Smith of Jordanhill informs me that a rude ornament made of cannel
coal has been found on the coast in the parish of Dundonald, lying 50
feet above the sea-level, on the surface of the boulder-clay or till,
and covered with gravel containing marine shells. If we suppose the
upward movement to have been uniform in central Scotland before and
after the Roman era, and assume that as 25 feet indicate seventeen
centuries, so 50 feet imply a lapse of twice that number, or 3400
years, we should then carry back the date of the ornament in question
to fifteen centuries before our era, or to the days of Pharaoh, and the
period usually assigned to the exodus of the Israelites from Egypt. [8]
But all such estimates must be considered, in the present state of
science, as tentative and conjectural, since the rate of movement of the
land may not have been uniform, and its direction not always upwards,
and there may have been long stationary periods, one of which of more
than usual duration seems indicated by the 50-foot raised beach, which
has been traced for vast distances along the western coast of Scotland.
COAST OF CORNWALL.
Sir H. De la Beche has adduced several proofs of changes of level,
in the course of the human period, in his "Report on the Geology of
Cornwall and Devon," 1839. He mentions (page 406) that several human
skulls and works of art, buried in an estuary deposit, were found in
mining gravel for tin at Pentuan, near St. Austell, the skulls lying at
the depth of 40 feet from the surface, and others at Carnon at the depth
of 53 feet. The overlying strata were marine, containing sea-shells
of living species, and bones of whales, besides the remains of several
living species of mammalia.
Other examples of works of art, such as stone hatchets, canoes,
and ships, buried in ancient river-beds in England, and in peat and
shell-marl, I have mentioned in my work before cited.
SWEDEN AND NORWAY.
In the same work I have shown that near Stockholm, in Sweden, there
occur, at slight elevations above the sea-level, horizontal beds
of sand, loam, and marl, containing the same peculiar assemblage of
testacea which now live in the brackish waters of the Baltic. Mingled
with these, at different depths, have been detected various works of art
implying a rude state of civilization, and some vessels built before the
introduction of iron, and even the remains of an ancient hut, the
marine strata containing it, which had been formed during a previous
depression, having been upraised, so that the upper beds are now 60 feet
higher than the surface of the Baltic. In the neighbourhood of these
recent strata, both to the north-west and south of Stockholm, other
deposits similar in mineral composition occur, which ascend to greater
heights, in which precisely the same assemblage of fossil shells is met
with, but without any intermixture, so far as is yet known, of human
bones or fabricated articles.
On the opposite or western coast of Sweden, at Uddevalla, Post-Tertiary
strata, containing recent shells, not of that brackish water character
peculiar to the Baltic, but such as now live in the Northern Ocean,
ascend to the height of 200 feet; and beds of clay and sand of the same
age attain elevations of 300 and even 600 feet in Norway, where they
have been usually described as "raised beaches." They are, however,
thick deposits of submarine origin, spreading far and wide, and filling
valleys in the granite and gneiss, just as the Tertiary formations, in
different parts of Europe, cover or fill depressions in the older rocks.
Although the fossil fauna characterising these upraised sands and clays
consists exclusively of existing northern species of testacea, it is
more than probable that they may not all belong to that division of the
Pleistocene strata which we are now considering. If the contemporary
mammalia were known, they would, in all likelihood, be found to be
referable, at least in part, to extinct species; for, according to Loven
(an able living naturalist of Norway), the species do not constitute
such an assemblage as now inhabits corresponding latitudes in the North
Sea. On the contrary, they decidedly represent a more arctic fauna. In
order to find the same species flourishing in equal abundance, or
in many cases to find them at all, we must go northwards to higher
latitudes than Uddevalla in Sweden, or even nearer the pole than Central
Norway.
Judging by the uniformity of climate now prevailing from century to
century, and the insensible rate of variation in the geographical
distribution of organic beings in our own times, we may presume that
an extremely lengthened period was required even for so slight a
modification in the range of the molluscous fauna, as that of which
the evidence is here brought to light. There are also other independent
reasons for suspecting that the antiquity of these deposits may be
indefinitely great as compared to the historical period. I allude to
their present elevation above the sea, some of them rising, in Norway,
to the height of 600 feet or more. The upward movement now in progress
in parts of Norway and Sweden extends, as I have elsewhere shown,*
throughout an area about 1000 miles north and south, and for an unknown
distance east and west, the amount of elevation always increasing as we
proceed towards the North Cape, where it is said to equal 5 feet in a
century.
(* "Principles" 9th edition chapter 30.)
If we could assume that there had been an average of 2 1/2 feet in each
hundred years for the last fifty centuries, this would give an elevation
of 125 feet in that period. In other words, it would follow that the
shores, and a considerable area of the former bed of the North Sea, had
been uplifted vertically to that amount, and converted into land in
the course of the last 5000 years. A mean rate of continuous vertical
elevation of 2 1/2 feet in a century would, I conceive, be a high
average; yet, even if this be assumed, it would require 24,000 years for
parts of the sea-coast of Norway, where the Pleistocene marine strata
occur, to attain the height of 600 feet. [9]
CHAPTER 4. -- PLEISTOCENE PERIOD--BONES OF MAN AND EXTINCT MAMMALIA IN
BELGIAN CAVERNS.
Earliest Discoveries in Caves of Languedoc of Human Remains with
Bones of extinct Mammalia.
Researches in 1833 of Dr. Schmerling in the Liege Caverns.
Scattered Portions of Human Skeletons associated with Bones
of Elephant and Rhinoceros.
Distribution and probable Mode of Introduction of the Bones.
Implements of Flint and Bone.
Schmerling's Conclusions as to the Antiquity of Man ignored.
Present State of the Belgian Caves.
Human Bones recently found in Cave of Engihoul.
Engulfed Rivers.
Stalagmitic Crust.
Antiquity of the Human Remains in Belgium how proved.
Having hitherto considered those formations in which both the fossil
shells and the mammalia are of living species, we may now turn our
attention to those of older date, in which the shells being all recent,
some of the accompanying mammalia are extinct, or belong to species not
known to have lived within the times of history or tradition.
DISCOVERIES OF MM. TOURNAL AND CHRISTOL IN 1828 IN THE SOUTH OF FRANCE.
In the "Principles of Geology," when treating of the fossil remains
found in alluvium and the mud of caverns, I gave an account in 1832
of the investigations made by MM. Tournal and Christol in the South of
France.*
(* 1st edition volume 2 chapter 14 1832, and 9th edition
page 738, 1853.)
M. Tournal stated in his memoir that in the cavern of Bize, in the
department of the Aude, he had found human bones and teeth, together
with fragments of rude pottery, in the same mud and breccia cemented by
stalagmite in which land-shells of living species were embedded, and the
bones of mammalia, some of extinct, others of recent species. The human
bones were declared by his fellow-labourer, M. Marcel de Serres, to be
in the same chemical condition as those of the accompanying quadrupeds.*
(* "Annales des Sciences Naturelles" tome 15 1828 page 348.)
Speaking of these fossils of the Bize cavern five years later, M.
Tournal observed that they could not be referred, as some suggested,
to a "diluvial catastrophe," for they evidently had not been washed in
suddenly by a transient flood, but must have been introduced gradually,
together with the enveloping mud and pebbles, at successive periods.*
(* "Annales de Chimie et de Physique" 1833 page 161.)
M. Christol, who was engaged at the same time in similar researches in
another part of Languedoc, published an account of them a year later,
in which he described some human bones, as occurring in the cavern of
Pondres, near Nimes, in the same mud with the bones of an extinct hyaena
and rhinoceros.*
(* Christol, "Notice sur les Ossements humains des Cavernes
du Gard" Montpellier 1829.)
The cavern was in this instance filled up to the roof with mud and
gravel, in which fragments of two kinds of pottery were detected, the
lowest and rudest near the bottom of the cave, below the level of the
extinct mammalia.
It has never been questioned that the hyaena and rhinoceros found by M.
Christol were of extinct species; but whether the animals enumerated
by M. Tournal might not all of them be referred to quadrupeds which
are known to have been living in Europe in the historical period seems
doubtful. They were said to consist of a stag, an antelope, and a
goat, all named by M. Marcel de Serres as new; but the majority of
palaeontologists do not agree with this opinion. Still it is true, as
M. Lartet remarks, that the fauna of the cavern of Bize must be of very
high antiquity, as shown by the presence, not only of the Lithuanian
aurochs (Bison europaeus), but also of the reindeer, which has not been
an inhabitant of the South of France in historical times, and which,
in that country, is almost everywhere associated, whether in ancient
alluvium or in the mud of caverns, with the mammoth.
In my work before cited,* I stated that M. Desnoyers, an observer
equally well versed in geology and archaeology, had disputed the
conclusion arrived at by MM. Tournal and Christol, that the fossil
rhinoceros, hyaena, bear, and other lost species had once been
inhabitants of France contemporaneously with Man.
(* "Principles" 9th edition page 739.)
"The flint hatchets and arrow-heads," he said, "and the pointed bones
and coarse pottery of many French and English caves, agree precisely in
character with those found in the tumuli, and under the dolmens (rude
altars of unhewn stone) of the primitive inhabitants of Gaul, Britain,
and Germany. The human bones, therefore, in the caves which are
associated with such fabricated objects, must belong not to antediluvian
periods, but to a people in the same stage of civilization as those who
constructed the tumuli and altars."
"In the Gaulish monuments," he added, "we find, together with the
objects of industry above mentioned, the bones of wild and domestic
animals of species now inhabiting Europe, particularly of deer, sheep,
wild boars, dogs, horses, and oxen. This fact has been ascertained in
Quercy and other provinces; and it is supposed by antiquaries that the
animals in question were placed beneath the Celtic altars in memory of
sacrifices offered to the Gaulish divinity Hesus, and in the tombs to
commemorate funeral repasts, and also from a superstition prevalent
among savage nations, which induces them to lay up provisions for
the manes of the dead in a future life. But in none of these ancient
monuments have any bones been found of the elephant, rhinoceros, hyaena,
tiger, and other quadrupeds, such as are found in caves, which might
certainly have been expected had these species continued to flourish at
the time that this part of Gaul was inhabited by Man."*
(* Desnoyers, "Bulletin de la Societe Geologique de France"
tome 2 page 252; and article on Caverns, "Dictionnaire
Universelle d'Histoire Naturelle" Paris 1845.)
After giving no small weight to the arguments of M. Desnoyers, and
the writings of Dr. Buckland on the same subject, and myself visiting
several caves in Germany, I came to the opinion that the human bones
mixed with those of extinct animals, in osseous breccias and cavern
mud, in different parts of Europe, were probably not coeval. The caverns
having been at one period the dens of wild beasts, and having served
at other times as places of human habitation, worship, sepulture,
concealment, or defence, one might easily conceive that the bones of Man
and those of animals, which were strewed over the floors of subterranean
cavities, or which had fallen into tortuous rents connecting them
with the surface, might, when swept away by floods, be mingled in one
promiscuous heap in the same ossiferous mud or breccia.*
(* "Principles" 9th edition page 740.)
That such intermixtures have really taken place in some caverns, and
that geologists have occasionally been deceived, and have assigned to
one and the same period fossils which had really been introduced at
successive times, will readily be conceded. But of late years we have
obtained convincing proofs, as we shall see in the sequel, that the
mammoth, and many other extinct mammalian species very common in caves,
occur also in undisturbed alluvium, embedded in such a manner with
works of art, as to leave no room for doubt that Man and the mammoth
coexisted; Such discoveries have led me, and other geologists, to
reconsider the evidence previously derived from caves brought forward
in proof of the high antiquity of Man. With a view of re-examining this
evidence, I have lately explored several caverns in Belgium and other
countries, and re-read the principal memoirs and treatises treating of
the fossil remains preserved in them, the results of which inquiries I
shall now proceed to lay before the reader.
RESEARCHES, IN 1833-1834, OF DR. SCHMERLING IN THE CAVERNS NEAR LIEGE.
The late Dr. Schmerling of Liege, a skilful anatomist and
palaeontologist, after devoting several years to the exploring of the
numerous ossiferous caverns which border the valleys of the Meuse and
its tributaries, published two volumes descriptive of the contents of
more than forty caverns. One of these volumes consisted of an atlas of
plates, illustrative of the fossil bones.*
(* "Recherches sur les Ossements fossiles decouverts dans
les Cavernes de la Province de Liege", Liege 1833-1834.)
Many of the caverns had never before been entered by scientific
observers, and their floors were encrusted with unbroken stalagmite. At
a very early stage of his investigations, Dr. Schmerling found the bones
of Man so rolled and scattered as to preclude all idea of their having
been intentionally buried on the spot. He also remarked that they were
of the same colour, and in the same condition as to the amount of animal
matter contained in them, as those of the accompanying animals, some
of which, like the cave-bear, hyaena, elephant, and rhinoceros, were
extinct; others, like the wild cat, beaver, wild boar, roe-deer, wolf,
and hedgehog, still extant. The fossils were lighter than fresh bones,
except such as had their pores filled with carbonate of lime, in which
case they were often much heavier. The human remains of most frequent
occurrence were teeth detached from the jaw, and the carpal, metacarpal,
tarsal, metatarsal, and phalangeal bones separated from the rest of the
skeleton. The corresponding bones of the cave-bear, the most abundant
of the accompanying mammalia, were also found in the Liege caverns
more commonly than any others, and in the same scattered condition.
Occasionally, some of the long bones of mammalia were observed to
have been first broken across, and then reunited or cemented again by
stalagmite, as they lay on the floor of the cave.
No gnawed bones nor any coprolites were found by Schmerling. He
therefore inferred that the caverns of the province of Liege had not
been the dens of wild beasts, but that their organic and inorganic
contents had been swept into them by streams communicating with the
surface of the country. The bones, he suggested, may often have been
rolled in the beds of such streams before they reached their underground
destination. To the same agency the introduction of many land-shells
dispersed through the cave-mud was ascribed, such as Helix nemoralis,
H. lapicida, H. pomatia, and others of living species. Mingled with such
shells, in some rare instances, the bones of freshwater fish, and of a
snake (Coluber), as well as of several birds, were detected.
The occurrence here and there of bones in a very perfect state, or of
several bones belonging to the same skeleton in natural juxtaposition,
and having all their most delicate apophyses uninjured, while many
accompanying bones in the same breccia were rolled, broken, or decayed,
was accounted for by supposing that portions of carcasses were sometimes
floated in during floods while still clothed with their flesh. No
example was discovered of an entire skeleton, not even of one of the
smaller mammalia, the bones of which are usually the least injured.
The incompleteness of each skeleton was especially ascertained in regard
to the human subjects, Dr. Schmerling being careful, whenever a fragment
of such presented itself, to explore the cavern himself, and see whether
any other bones of the same skeleton could be found. In the Engis
cavern, distant about eight miles to the south-west of Liege, on the
left bank of the Meuse, the remains of at least three human individuals
were disinterred. The skull of one of these, that of a young person, was
embedded by the side of a mammoth's tooth. It was entire but so fragile,
that nearly all of it fell to pieces during its extraction. Another
skull, that of an adult individual, and the only one preserved by Dr.
Schmerling in a sufficient state of integrity to enable the anatomist to
speculate on the race to which it belonged, was buried 5 feet deep in a
breccia, in which the tooth of a rhinoceros, several bones of a horse,
and some of the reindeer, together with some ruminants, occurred. This
skull, now in the museum of the University of Liege, is figured in
Chapter 5 (Figure 2), where further observations will be offered on
its anatomical character, after a fuller account of the contents of the
Liege caverns has been laid before the reader.
On the right bank of the Meuse, on the opposite side of the river to
Engis, is the cavern of Engihoul. Bones of extinct animals mingled with
those of Man were observed to abound in both caverns; but with this
difference, that whereas in the Engis cave there were several human
crania and very few other bones, in Engihoul there occurred numerous
bones of the extremities belonging to at least three human individuals,
and only two small fragments of a cranium. The like capricious
distribution held good in other caverns, especially with reference to
the cave-bear, the most frequent of the extinct mammalia. Thus, for
example in the cave of Chokier, skulls of the bear were few, and other
parts of the skeleton abundant, whereas in several other caverns these
proportions were exactly reversed, while at Goffontaine skulls of
the bear and other parts of the skeleton were found in their natural
numerical proportions. Speaking generally, it may be said that human
bones, where any were met with, occurred at all depths in the cave-mud
and gravel, sometimes above and sometimes below those of the bear,
elephant, rhinoceros, hyaena, etc.
Some rude flint implements of the kind commonly called flint knives or
flakes, of a triangular form in the cross section (as in Figure 14),
were found by Schmerling dispersed generally through the cave-mud, but
he was too much engrossed with his osteological inquiries to collect
them diligently. He preserved some few of them, however, which I have
seen in the museum at Liege. He also discovered in the cave of Chokier,
2 1/2 miles south-west from Liege, a polished and jointed needle-shaped
bone, with a hole pierced obliquely through it at the base; such a
cavity, he observed, as had never given passage to an artery. This
instrument was embedded in the same matrix with the remains of a
rhinoceros.*
(* Schmerling part 2 page 177.)
Another cut bone and several artificially-shaped flints were found in
the Engis cave, near the human skulls before alluded to. Schmerling
observed, and we shall have to refer to the fact in the sequel (Chapter
8), that although in some forty fossiliferous caves explored by
him human bones were the exception, yet these flint implements were
universal, and he added that "none of them could have been subsequently
introduced, being precisely in the same position as the remains of
the accompanying animals." "I therefore," he continues, "attach great
importance to their presence; for even if I had not found the human
bones under conditions entirely favourable to their being considered
as belonging to the antediluvian epoch, proofs of Man's existence would
still have been supplied by the cut bones and worked flints."*
(* Schmerling, part 2 page 179.)
Dr. Schmerling, therefore, had no hesitation in concluding from the
various facts ascertained by him, that Man once lived in the Liege
district contemporaneously with the cave-bear and several other extinct
species of quadrupeds. But he was much at a loss when he attempted to
invent a theory to explain the former state of the fauna of the region
now drained by the Meuse; for he shared the notion, then very prevalent
among naturalists, that the mammoth and the hyaena* were beasts of a
warmer climate than that now proper to Western Europe.
(* Ibid. part 2 pages 70 and 96.)
In order to account for the presence of such "tropical species," he was
half-inclined to imagine that they had been transported by a flood from
some distant region; then again he raised the question whether they
might not have been washed out of an older alluvium, which may have
pre-existed in the neighbourhood. This last hypothesis was directly at
variance with his own statements, that the remains of the mammoth and
hyaena were identical in appearance, colour, and chemical condition with
those of the bear and other associated fossil animals, none of which
exhibited signs of having been previously enveloped in any dissimilar
matrix. Another enigma which led Schmerling astray in some of his
geological speculations was the supposed presence of the agouti, a
South American rodent, "proper to the torrid zone." My friend M. Lartet,
guided by Schmerling's figures of the teeth of this species, suggests,
and I have little doubt with good reason, that they appertain to the
porcupine, a genus found fossil in Pleistocene deposits of certain
caverns in the south of France.
In the year 1833, I passed through Liege, on my way to the Rhine, and
conversed with Dr. Schmerling, who showed me his splendid collection,
and when I expressed some incredulity respecting the alleged antiquity
of the fossil human bones, he pointedly remarked that if I doubted their
having been contemporaneous with the bear or rhinoceros, on the ground
of Man being a species of more modern date, I ought equally to doubt the
co-existence of all the other living species, such as the red deer, roe,
wild cat, wild boar, wolf, fox, weasel, beaver, hare, rabbit, hedgehog,
mole, dormouse, field-mouse, water-rat, shrew, and others, the bones
of which he had found scattered everywhere indiscriminately through the
same mud with the extinct quadrupeds. The year after this conversation
I cited Schmerling's opinions, and the facts bearing on the antiquity of
Man, in the 3rd edition of my "Principles of Geology" (page 161, 1834),
and in succeeding editions, without pretending to call in question their
trustworthiness, but at the same time without giving them the weight
which I now consider they were entitled to. He had accumulated ample
evidence to prove that Man had been introduced into the earth at an
earlier period than geologists were then willing to believe.
One positive fact, it will be said, attested by so competent a witness,
ought to have outweighed any amount of negative testimony, previously
accumulated, respecting the non-occurrence elsewhere of human remains
in formations of the like antiquity. In reply, I can only plead that
a discovery which seems to contradict the general tenor of previous
investigations is naturally received with much hesitation. To have
undertaken in 1832, with a view of testing its truth, to follow the
Belgian philosopher through every stage of his observations and proofs,
would have been no easy task even for one well-skilled in geology and
osteology. To be let down, as Schmerling was, day after day, by a rope
tied to a tree, so as to slide to the foot of the first opening of the
Engis cave,* where the best-preserved human skulls were found; and,
after thus gaining access to the first subterranean gallery, to creep on
all fours through a contracted passage leading to larger chambers, there
to superintend by torchlight, week after week and year after year,
the workmen who were breaking through the stalagmitic crust as hard as
marble, in order to remove piece by piece the underlying bone-breccia
nearly as hard; to stand for hours with one's feet in the mud, and
with water dripping from the roof on one's head, in order to mark the
position and guard against the loss of each single bone of a skeleton;
and at length, after finding leisure, strength, and courage for all
these operations, to look forward, as the fruits of one's labour, to the
publication of unwelcome intelligence, opposed to the prepossessions
of the scientific as well as of the unscientific public--when these
circumstances are taken into account, we need scarcely wonder, not only
that a passing traveller failed to stop and scrutinise the evidence,
but that a quarter of a century should have elapsed before even the
neighbouring professors of the University of Liege came forth to
vindicate the truthfulness of their indefatigable and clear-sighted
countryman.
(* Schmerling part 1 page 30.)
In 1860, when I revisited Liege, twenty-six years after my interview
with Schmerling, I found that several of the caverns described by him
had in the interval been annihilated. Not a vestige, for example, of the
caves of Engis, Chokier, and Goffontaine remained. The calcareous stone,
in the heart of which the cavities once existed, had been quarried away,
and removed bodily for building and lime-making. Fortunately, a great
part of the Engihoul cavern, situated on the right bank of the Meuse,
was still in the same state as when Schmerling delved into it in 1831,
and drew from it the bones of three human skeletons. I determined,
therefore, to examine it, and was so fortunate as to obtain the
assistance of a zealous naturalist of Liege, Professor Malaise, who
accompanied me to the cavern, where we engaged some workmen to break
through the crust of stalagmite, so that we could search for bones in
the undisturbed earth beneath. Bones and teeth of the cave-bear were
soon found, and several other extinct quadrupeds which Schmerling has
enumerated. My companion, continuing the work perseveringly for weeks
after my departure, succeeded at length in extracting from the same
deposit, at the depth of 2 feet below the crust of stalagmite, three
fragments of a human skull, and two perfect lower jaws with teeth, all
associated in such a manner with the bones of bears, large pachyderms,
and ruminants, and so precisely resembling these in colour and state of
preservation, as to leave no doubt in his mind that Man was contemporary
with the extinct animals. Professor Malaise has given figures of the
human remains in the "Bulletin" of the Royal Academy of Belgium for
1860.*
(* Volume 10 page 546.)
The rock in which the Liege caverns occur belongs generally to the
Carboniferous or Mountain Limestone, in some few cases only to the older
Devonian formation. Whenever the work of destruction has not gone too
far, magnificent sections, sometimes 200 and 300 feet in height, are
exposed to view. They confirm Schmerling's doctrine, that most of the
materials, organic and inorganic, now filling the caverns, have been
washed into them through narrow vertical or oblique fissures, the upper
extremities of which are choked up with soil and gravel, and would
scarcely ever be discoverable at the surface, especially in so wooded
a country. Among the sections obtained by quarrying, one of the
finest which I saw was in the beautiful valley of Fond du Foret, above
Chaudefontaine, not far from the village of Magnee, where one of the
rents communicating with the surface has been filled up to the brim with
rounded and half-rounded stones, angular pieces of limestone and shale,
besides sand and mud, together with bones, chiefly of the cave-bear.
Connected with this main duct, which is from 1 to 2 feet in width, are
several minor ones, each from 1 to 3 inches wide, also extending to the
upper country or table-land, and choked up with similar materials. They
are inclined at angles of 30 and 40 degrees, their walls being generally
coated with stalactite, pieces of which have here and there been broken
off and mingled with the contents of the rents, thus helping to explain
why we so often meet with detached pieces of that substance in the mud
and breccia of the Belgian caves. It is not easy to conceive that a
solid horizontal floor of hard stalagmite should, after its formation,
be broken up by running water; but when the walls of steep and tortuous
rents, serving as feeders to the principal fissures and to inferior
vaults and galleries are encrusted with stalagmite, some of the
incrustation may readily be torn up when heavy fragments of rock are
hurried by a flood through passages inclined at angles of 30 or 40
degrees.
The decay and decomposition of the fossil bones seem to have been
arrested in most of the caves by a constant supply of water charged with
carbonate of lime, which dripped from the roofs while the caves were
becoming gradually filled up. By similar agency the mud, sand, and
pebbles were usually consolidated.
The following explanation of this phenomenon has been suggested by the
eminent chemist Liebig. On the surface of Franconia, where the limestone
abounds in caverns, is a fertile soil in which vegetable matter is
continually decaying. This mould or humus, being acted on by moisture
and air, evolves carbonic acid, which is dissolved by rain. The rain
water, thus impregnated, permeates the porous limestone, dissolves
a portion of it, and afterwards, when the excess of carbonic acid
evaporates in the caverns, parts with the calcareous matter and forms
stalactite. So long as water flows, even occasionally, through a suite
of caverns, no layer of pure stalagmite can be produced; hence the
formation of such a layer is generally an event posterior in date to the
cessation of the old system of drainage, an event which might be brought
about by an earthquake causing new fissures, or by the river wearing its
way down to a lower level, and thenceforth running in a new channel.
In all the subterranean cavities, more than forty in number, explored
by Schmerling, he only observed one cave, namely that of Chokier, where
there were two regular layers of stalagmite, divided by fossiliferous
cave-mud. In this instance, we may suppose that the stream, after
flowing for a long period at one level, cut its way down to an inferior
suite of caverns, and, flowing through them for centuries, choked them
up with debris; after which it rose once more to its original higher
level: just as in the Mountain Limestone district of Yorkshire some
rivers, habitually absorbed by a "swallow hole," are occasionally unable
to discharge all their water through it; in which case they rise and
rush through a higher subterranean passage, which was at some former
period in the regular line of drainage, as is often attested by the
fluviatile gravel still contained in it.
There are now in the basin of the Meuse, not far from Liege, several
examples of engulfed brooks and rivers: some of them, like that of St.
Hadelin, east of Chaudefontaine, which reappears after an underground
course of a mile or two; others, like the Vesdre, which is lost near
Goffontaine, and after a time re-emerges; some, again, like the torrent
near Magnee, which, after entering a cave, never again comes to the day.
In the season of floods such streams are turbid at their entrance, but
clear as a mountain-spring where they issue again; so that they must
be slowly filling up cavities in the interior with mud, sand, pebbles,
snail-shells, and the bones of animals which may be carried away during
floods.
The manner in which some of the large thigh and shank bones of the
rhinoceros and other pachyderms are rounded, while some of the smaller
bones of the same creatures, and of the hyaena, bear, and horse, are
reduced to pebbles, shows that they were often transported for some
distance in the channels of torrents, before they found a resting-place.
When we desire to reason or speculate on the probable antiquity of human
bones found fossil in such situations as the caverns near Liege, there
are two classes of evidence to which we may appeal for our guidance.
First, considerations of the time required to allow of many species
of carnivorous and herbivorous animals, which flourished in the cave
period, becoming first scarce, and then so entirely extinct as we have
seen that they had become before the era of the Danish peat and Swiss
lake dwellings; secondly, the great number of centuries necessary for
the conversion of the physical geography of the Liege district from its
ancient to its present configuration; so many old underground channels,
through which brooks and rivers flowed in the cave period, being now
laid dry and choked up.
The great alterations which have taken place in the shape of the valley
of the Meuse and some of its tributaries are often demonstrated by the
abrupt manner in which the mouths of fossiliferous caverns open in the
face of perpendicular precipices 200 feet or more in height above
the present streams. There appears also, in many cases, to be such a
correspondence in the openings of caverns on opposite sides of some of
the valleys, both large and small, as to incline one to suspect that
they originally belonged to a series of tunnels and galleries which
were continuous before the present system of drainage came into play, or
before the existing valleys were scooped out. Other signs of subsequent
fluctuations are afforded by gravel containing elephant's bones at
slight elevations above the Meuse and several of its tributaries. It may
be objected that, according to the present rate of change, no lapse of
ages would suffice to bring about such revolutions in physical geography
as we are here contemplating. This may be true. It is more than probable
that the rate of change was once far more active than it is now in the
basin of the Meuse. Some of the nearest volcanoes, namely, those of
the Lower Eifel about 60 miles to the eastward, seem to have been in
eruption in Pleistocene times, and may perhaps have been connected
and coeval with repeated risings or sinkings of the land in the Liege
district. It might be said, with equal truth, that according to the
present course of events, no series of ages would suffice to reproduce
such an assemblage of cones and craters as those of the Eifel (near
Andernach, for example); and yet some of them may be of sufficiently
modern date to belong to the era when Man was contemporary with the
mammoth and rhinoceros in the basin of the Meuse.
But, although we may be unable to estimate the minimum of time required
for the changes in physical geography above alluded to, we cannot
fail to perceive that the duration of the period must have been very
protracted, and that other ages of comparative inaction may have
followed, separating the Pleistocene from the historical periods, and
constituting an interval no less indefinite in its duration.
CHAPTER 5. -- PLEISTOCENE PERIOD--FOSSIL HUMAN SKULLS OF THE NEANDERTHAL
AND ENGIS CAVES.
Human Skeleton found in Cave near Dusseldorf.
Its geological Position and probable Age.
Its abnormal and ape-like Characters.
Fossil Human Skull of the Engis Cave near Liege.
Professor Huxley's Description of these Skulls.
Comparison of each, with extreme Varieties of the native
Australian Race.
Range of Capacity in the Human and Simian Brains.
Skull from Borreby in Denmark.
Conclusions of Professor Huxley.
Bearing of the peculiar Characters of the Neanderthal Skull
on the Hypothesis of Transmutation.
FOSSIL HUMAN SKELETON OF THE NEANDERTHAL CAVE NEAR DUSSELDORF.
Before I speak more particularly of the opinions which anatomists have
expressed respecting the osteological characters of the human skull from
Engis, near Liege, mentioned in the last chapter and described by Dr.
Schmerling, it will be desirable to say something of the geological
position of another skull, or rather skeleton, which, on account of its
peculiar conformation, has excited no small sensation in the last few
years. I allude to the skull found in 1857 in a cave situated in that
part of the valley of the Dussel, near Dusseldorf, which is called the
Neanderthal. The spot is a deep and narrow ravine about 70 English miles
north-east of the region of the Liege caverns treated of in the last
chapter, and close to the village and railway station of Hochdal between
Dusseldorf and Elberfeld. The cave occurs in the precipitous southern or
left side of the winding ravine, about sixty feet above the stream,
and a hundred feet below the top of the cliff. The accompanying section
(Figure 1.) will give the reader an idea of its position.
[Illustration: Figure 1]
When Dr. Fuhlrott of Elberfeld first examined the cave, he found it to
be high enough to allow a man to enter. The width was 7 or 8 feet, and
the length or depth 15. I visited the spot in 1860, in company with Dr.
Fuhlrott, who had the kindness to come expressly from Elberfeld to be my
guide, and who brought with him the original fossil skull, and a cast
of the same, which he presented to me. In the interval of three years,
between 1857 and 1860, the ledge of rock, f, on which the cave opened,
and which was originally 20 feet wide, had been almost entirely quarried
away, and, at the rate at which the work of dilapidation was proceeding,
its complete destruction seemed near at hand.
(FIGURE 1. SECTION OF THE NEANDERTHAL CAVE NEAR DUSSELDORF.
a. Cavern 60 feet above the Dussel, and 100 feet below the
surface of the country at c.
b. Loam covering the floor of the cave near the bottom of which
the human skeleton was found.
b, c. Rent connecting the cave with the upper surface of the
country.
d. Superficial sandy loam.
e. Devonian limestone.
f. Terrace, or ledge of rock.)
In the limestone are many fissures, one of which, still partially filled
with mud and stones, is represented in the section at a c as continuous
from the cave to the upper surface of the country. Through this passage
the loam, and possibly the human body to which the bones belonged, may
have been washed into the cave below. The loam, which covered the uneven
bottom of the cave, was sparingly mixed with rounded fragments of chert,
and was very similar in composition to that covering the general surface
of that region.
There was no crust of stalagmite overlying the mud in which the human
skeleton was found, and no bones of other animals in the mud with the
skeleton; but just before our visit in 1860 the tusk of a bear had
been met with in some mud in a lateral embranchment of the cave, in a
situation precisely similar to b, Figure 1, and on a level corresponding
with that of the human skeleton. This tusk, shown us by the proprietor
of the cave, was 2 1/2 inches long and quite perfect; but whether it was
referable to a recent or extinct species of bear, I could not determine.
From a printed letter of Dr. Fuhlrott we learn that on removing the
loam, which was five feet thick, from the cave, the human skull was
first noticed near the entrance, and, further in, the other bones lying
in the same horizontal plane. It is supposed that the skeleton was
complete, but the workmen, ignorant of its value, scattered and lost
most of the bones, preserving only the larger ones.*
(* Fuhlrott, Letter to Professor Schaaffhausen, cited
"Natural History Review" Number 2 page 156. See also
"Naturhistorischer Verein" Bonn 1859.)
The cranium, which Dr. Fuhlrott showed me, was covered both on its outer
and inner surface, and especially on the latter, with a profusion of
dendritical crystallisations, and some other bones of the skeleton were
ornamented in the same way. These markings, as Dr. Hermann von Meyer
observes, afford no sure criterion of antiquity, for they have been
observed on Roman bones. Nevertheless, they are more common in bones
that have been long embedded in the earth. The skull and bones,
moreover, of the Neanderthal skeleton had lost so much of their animal
matter as to adhere strongly to the tongue, agreeing in this respect
with the ordinary condition of fossil remains of the Pleistocene period.
On the whole, I think it probable that this fossil may be of about the
same age as those found by Schmerling in the Liege caverns; but, as no
other animal remains were found with it, there is no proof that it
may not be newer. Its position lends no countenance whatever to the
supposition of its being more ancient.
When the skull and other parts of the skeleton were first exhibited at
a German scientific meeting at Bonn, in 1857, some doubts were
expressed by several naturalists, whether it was truly human. Professor
Schaaffhausen, who, with the other experienced zoologists, did not share
these doubts, observed that the cranium, which included the frontal
bone, both parietals, part of the squamous, and the upper third of the
occipital, was of unusual size and thickness, the forehead narrow and
very low, and the projection of the supra-orbital ridges enormously
great. He also stated that the absolute and relative length of the thigh
bone, humerus, radius, and ulna, agreed well with the dimensions of a
European individual of like stature at the present day; but that the
thickness of the bones was very extraordinary, and the elevations and
depressions for the attachment of muscles were developed in an unusual
degree. Some of the ribs, also, were of a singularly rounded shape and
abrupt curvature, which was supposed to indicate great power in the
thoracic muscles.*
(* Professor Schaaffhausen's "Memoir" translated "Natural
History Review" April 1861.)
In the same memoir, the Prussian anatomist remarks that the depression
of the forehead (See Figure 3.), is not due to any artificial
flattening, such as is practised in various modes by barbarous nations
in the Old and New World, the skull being quite symmetrical, and showing
no indication of counter-pressure at the occiput; whereas, according
to Morton, in the Flat-heads of the Columbia, the frontal and parietal
bones are always unsymmetrical.*
(* "Natural History Review" Number 2 page 160.)
On the whole, Professor Schaaffhausen concluded that the individual
to whom the Neanderthal skull belonged must have been distinguished by
small cerebral development, and uncommon strength of corporeal frame.
When on my return to England I showed the cast of the cranium to
Professor Huxley, he remarked at once that it was the most ape-like
skull he had ever beheld. Mr. Busk, after giving a translation of
Professor Schaaffhausen's memoir in the "Natural History Review," added
some valuable comments of his own on the characters in which this skull
approached that of the gorilla and chimpanzee.
Professor Huxley afterwards studied the cast with the object of
assisting me to give illustrations of it in this work, and in doing so
discovered what had not previously been observed, that it was quite
as abnormal in the shape of its occipital as in that of its frontal
or superciliary region. Before citing his words on the subject, I will
offer a few remarks on the Engis skull which the same anatomist has
compared with that of the Neanderthal. [10]
FOSSIL SKULL OF THE ENGIS CAVE NEAR LIEGE.
Among six or seven human skeletons, portions of which were collected by
Dr. Schmerling from three or four caverns near Liege, embedded in the
same matrix with the remains of the elephant, rhinoceros, bear, hyaena,
and other extinct quadrupeds, the most perfect skull, as I have before
stated, was that of an adult individual found in the cavern of Engis.
This skull, Dr. Schmerling figured in his work, observing that it was
too imperfect to enable the anatomist to determine the facial angle, but
that one might infer, from the narrowness of the frontal portion, that
it belonged to an individual of small intellectual development. He
speculated on its Ethiopian affinities, but not confidently, observing
truly that it would require many more specimens to enable an anatomist
to arrive at sound conclusions on such a point. M. Geoffroy St. Hilaire
and other osteologists, who examined the specimen, denied that it
resembled a negro's skull. When I saw the original in the museum at
Liege, I invited Dr. Spring, one of the professors of the university, to
whom we are indebted for a valuable memoir on the human bones found in
the cavern of Chauvaux, near Namur, to have a cast made of this Engis
skull. He not only had the kindness to comply with my request, but
rendered a service to the scientific world by adding to the original
cranium several detached fragments which Dr. Schmerling had obtained
from Engis, and which were found to fit in exactly, so that the cast
represented at Figure 2 is more complete than that given in the first
plate of Schmerling's work. It exhibits on the right side the position
of the auditory foramen (see Figure 6), which was not included in
Schmerling's figure. Mr. Busk, when he saw this cast, remarked to
me that, although the forehead was, as Schmerling had truly stated,
somewhat narrow, it might nevertheless be matched by the skulls of
individuals of European race, an observation since fully borne out by
measurements, as will be seen in the sequel.
OBSERVATIONS BY PROFESSOR HUXLEY ON THE HUMAN SKULLS OF ENGIS AND THE
NEANDERTHAL.
[Illustration: Figure 2]
"The Engis skull, as originally figured by Professor Schmerling, was in
a very imperfect state; but other fragments have since been added to it
by the care of Dr. Spring, and the cast upon which my observations are
based (Figure 2) exhibits the frontal, parietal, and occipital regions,
as far as the middle of the occipital foramen, with the squamous and
mastoid portions of the right temporal bone entire, or nearly so, while
the left temporal bone is wanting. From the middle of the occipital
foramen to the middle of the roof of each orbit, the base of the skull
is destroyed, and the facial bones are entirely absent.
"The extreme length of the skull is 7.7 inches, and as its extreme
breadth is not more than 5.25, its form is decidedly dolichocephalic.
At the same time its height (4 3/4 inches from the plane of the
glabello-occipital line (a d) to the vertex) is good, and the forehead
is well arched; so that while the horizontal circumference of the skull
is about 20 1/2 inches, the longitudinal arc from the nasal spine of
the frontal bone to the occipital protuberance (d) measures about 13 3/4
inches. The transverse arc from one auditory foramen to the other across
the middle of the sagittal suture measures about 13 inches. The sagittal
suture (b c) is 5 1/2 inches in length. The superciliary prominences
are well, but not excessively, developed, and are separated by a median
depression in the region of the glabella. They indicate large frontal
sinuses. If a line joining the glabella and the occipital protuberance
(a d) be made horizontal, no part of the occiput projects more than
1/10th of an inch behind the posterior extremity of that line; and the
upper edge of the auditory foramen is almost in contact with the same
line, or rather with one drawn parallel to it on the outer surface of
the skull.
(FIGURE 2. SIDE VIEW OF THE CAST OF PART OF A HUMAN SKULL
FOUND BY DR. SCHMERLING EMBEDDED AMONGST THE REMAINS OF
EXTINCT MAMMALIA IN THE CAVE OF ENGIS, NEAR LIEGE.
a. Superciliary ridge and glabella.
b. Coronal suture.
c. The apex of the lamboidal suture.
d. The occipital protuberance.)
"The Neanderthal skull, with which also I am acquainted only by means
of Professor Schaaffhausen's drawings of an excellent cast and of
photographs, is so extremely different in appearance from the Engis
cranium, that it might well be supposed to belong to a distinct race
of mankind. It is 8 inches in extreme length and 5.75 inches in extreme
breadth, but only measures 3.4 inches from the glabello-occipital line
to the vertex. The longitudinal arc, measured as above, is 12 inches;
the transverse arc cannot be exactly ascertained, in consequence of
the absence of the temporal bones, but was probably about the same, and
certainly exceeded 10 1/4 inches. The horizontal circumference is
23 inches. This great circumference arises largely from the vast
development of the superciliary ridges, which are occupied by great
frontal sinuses whose inferior apertures are displayed exceedingly well
in one of Dr. Fuhlrott's photographs, and form a continuous transverse
prominence, somewhat excavated in the middle line, across the lower part
of the brows. In consequence of this structure, the forehead appears
still lower and more retreating than it really is. To an anatomical eye
the posterior part of the skull is even more striking than the anterior.
The occipital protuberance occupies the extreme posterior end of the
skull when the glabello-occipital line is made horizontal, and so far
from any part of the occipital region extending beyond it, this region
of the skull slopes obliquely upward and forward, so that the lambdoidal
suture is situated well upon the upper surface of the cranium. At the
same time, notwithstanding the great length of the skull, the sagittal
suture is remarkably short (4 1/2 inches), and the squamosal suture is
very straight.
[Illustration: Figure 3. Cast of Human Skull]
(FIGURE 3. SIDE VIEW OF THE CAST OF A PART OF A HUMAN SKULL
FROM A CAVE IN THE NEANDERTHAL, NEAR DUSSELDORF.
a. Superciliary ridge and glabella.
b. The coronal suture.
c. The apex of the lamboidal suture.
d. The occipital protuberance.)
"In human skulls, the superior curved ridge of the occipital bone and
the occipital protuberance correspond, approximatively, with the level
of the tentorium and with the lateral sinuses, and consequently with the
inferior limit of the posterior lobes of the brain. At first, I found
some difficulty in believing that a human brain could have its posterior
lobes so flattened and diminished as must have been the case in the
Neanderthal man, supposing the ordinary relation to obtain between the
superior occipital ridges and the tentorium; but on my application,
through Sir Charles Lyell, Dr. Fuhlrott, the possessor of the skull, was
good enough not only to ascertain the existence of the lateral sinuses
in their ordinary position, but to send convincing proofs of the fact,
in excellent photographic views of the interior of the skull, exhibiting
clear indications of these sinuses.
"There can be no doubt that, as Professor Schaaffhausen and Mr. Busk
have stated, this skull is the most brutal of all known human skulls,
resembling those of the apes not only in the prodigious development of
the superciliary prominences and the forward extension of the orbits,
but still more in the depressed form of the brain-case, in the
straightness of the squamosal suture, and in the complete retreat of the
occiput forwards and upward, from the superior occipital ridges.
[Illustration: Figure 4. Skull of Chimpanzee]
(FIGURE 4. OUTLINE OF THE SKULL OF AN ADULT CHIMPANZEE, OF THAT
FROM THE NEANDERTHAL, AND OF THAT OF A EUROPEAN, DRAWN TO THE SAME
ABSOLUTE SIZE, IN ORDER BETTER TO EXHIBIT THEIR RELATIVE
DIFFERENCES.
The superciliary region of the Neanderthal skull
appears less prominent than in Figure 3, as the contours are all
taken along the middle line where the superciliary projection of
the Neanderthal skull is least marked. a. The glabella. b. The
occipital protuberance, or the point on the exterior of each skull
which corresponds roughly with the attachment of the tentorium, or
with the inferior boundary of the posterior cerebral lobes.)
"But the cranium, in its present condition, is stated by Professor
Schaaffhausen to contain 1033.24 cubic centimetres of water, or, in
other words, about 63 English cubic inches. As the entire skull could
hardly have held less than 12 cubic inches more, its minimum capacity
may be estimated at 75 cubic inches. The most capacious healthy European
skull yet measured had a capacity of 114 cubic inches, the smallest (as
estimated by weight of brain) about 55 cubic inches, while, according to
Professor Schaaffhausen, some Hindoo skulls have as small a capacity as
about 46 cubic inches (27 ounces of water). The largest cranium of
any Gorilla yet measured contained 34.5 cubic inches. The Neanderthal
cranium stands, therefore, in capacity, very nearly on a level with
the mean of the two human extremes, and very far above the pithecoid
maximum.
[Illustration: Figure 5. Skull]
(FIGURE 5. SKULL ASSOCIATED WITH GROUND FLINT IMPLEMENTS,
FROM A TUMULUS AT BORREBY IN DENMARK, AFTER A CAMERA LUCIDA
DRAWING BY MR. G. BUSK, F.R.S.
The thick dark line indicates so much of the skull as
corresponds with the fragment from the Neanderthal.
a. Superciliary ridge.
b. Coronal suture.
c. The apex of the lamboidal suture.
d. The occipital protuberance.
e. The auditory foramen.)
"Hence, even in the absence of the bones of the arm and thigh, which,
according to Professor Schaaffhausen, had the precise proportions found
in Man, although they were stouter than ordinary human bones, there
could be no reason for ascribing this cranium to anything but a man;
while the strength and development of the muscular ridges of the
limb-bones are characters in perfect accordance with those exhibited,
in a minor degree, by the bones of such hardy savages, exposed to a
rigorous climate, as the Patagonians.
"The Neanderthal cranium has certainly not undergone compression, and,
in reply to the suggestion that the skull is that of an idiot, it may be
urged that the onus probandi lies with those who adopt the hypothesis.
Idiotcy is compatible with very various forms and capacities of the
cranium, but I know of none which present the least resemblance to the
Neanderthal skull; and, furthermore, I shall proceed to show that
the latter manifests but an extreme degree of a stage of degradation
exhibited, as a natural condition, by the crania of certain races of
mankind.
"Mr. Busk drew my attention, some time ago, to the resemblance between
some of the skulls taken from tumuli of the stone period at Borreby in
Denmark, of which Mr. Busk possesses numerous accurate figures, and the
Neanderthal cranium. One of the Borreby skulls in particular (Figure 5)
has remarkably projecting superciliary ridges, a retreating forehead, a
low flattened vertex, and an occiput which shelves upward and forward.
But the skull is relatively higher and broader, or more brachycephalic,
the sagittal suture longer, and the superciliary ridges less projecting,
than in the Neanderthal skull. Nevertheless, there is, without doubt,
much resemblance in character between the two skulls--a circumstance
which is the more interesting, since the other Borreby skulls have
better foreheads and less prominent superciliary ridges, and exhibit
altogether a higher conformation.
"The Borreby skulls belong to the stone period of Denmark, and the
people to whom they appertained were probably either contemporaneous
with, or later than, the makers of the 'refuse-heaps' of that country.
In other words, they were subsequent to the last great physical changes
of Europe, and were contemporaries of the urus and bison, not of the
Elephas primigenius, Rhinoceros tichorhinus, and Hyaena spelaea.
"Supposing for a moment, what is not proven, that the Neanderthal skull
belonged to a race allied to the Borreby people and was as modern
as they, it would be separated by as great a distance of time as of
anatomical character from the Engis skull, and the possibility of its
belonging to a distinct race from the latter might reasonably appear to
be greatly heightened.
"To prevent the possibility of reasoning in a vicious circle, however,
I thought it would be well to endeavour to ascertain what amount of
cranial variation is to be found in a pure race at the present day; and
as the natives of Southern and Western Australia are probably as pure
and homogeneous in blood, customs, and language, as any race of savages
in existence, I turned to them, the more readily as the Hunterian museum
contains a very fine collection of such skulls.
"I soon found it possible to select from among these crania two
(connected by all sorts of intermediate gradations), the one of which
should very nearly resemble the Engis skull, while the other should
somewhat less closely approximate the Neanderthal cranium in form, size,
and proportions. And at the same time others of these skulls presented
no less remarkable affinities with the low type of Borreby skull.
"That the resemblances to which I allude are by no means of a merely
superficial character, is shown by the accompanying diagram (Figure 6),
which gives the contours of the two ancient and of one of the Australian
skulls, and by the following table of measurements.
TABLE 5/1.
COLUMN 1: TYPE OF SKULL.
COLUMN 2 (A): The horizontal circumference in the plane of a line
joining the glabella with the occipital protuberance.
COLUMN 3 (B): The longitudinal arc from the nasal depression along the
middle line of the skull to the occipital tuberosity.
COLUMN 4 (C): From the level of the glabello-occipital line on each
side, across the middle of the sagittal suture to the same point on the
opposite side.
COLUMN 5 (D): The vertical height from the glabello-occipital line.
COLUMN 6 (E): The extreme longitudinal measurement.
COLUMN 7 (F): The extreme transverse measurement.*
(* I have taken the glabello-occipital line as a base in
these measurements, simply because it enables me to compare
all the skulls, whether fragments or entire, together. The
greatest circumference of the English skull lies in a plane
considerably above that of the glabello-occipital line, and
amounts to 22 inches.)
Engis : 20 1/2: 13 3/4: 12 1/2: 4 3/4: 7 3/4: 5 1/4.
Australian,
Number 1: 20 1/2: 13 : 12 : 4 3/4: 7 1/2: 5 4/10.
Australian,
Number 2: 22 : 12 1/2: 10 3/4: 3 8/10: 7.9: 5 3/4.
Neanderthal: 23 : 12 : 10 : 3 3/4: 8 : 5 3/4.
"The question whether the Engis skull has rather the character of one
of the high races or of one of the lower has been much disputed, but the
following measurements of an English skull, noted in the catalogue of
the Hunterian museum as typically Caucasian (see Figure 4) will serve to
show that both sides may be right, and that cranial measurements alone
afford no safe indication of race.
English : 21 : 13 3/4: 12 1/2: 4 4/10: 7 7/8: 5 1/3.
"In making the preceding statement, it must be clearly understood that I
neither desire to affirm that the Engis and Neanderthal skulls belong to
the Australian race, nor to assert even that the ancient skulls belong
to one and the same race, so far as race is measured by language, colour
of skin, or character of hair. Against the conclusion that they are of
the same race as the Australians various minor anatomical differences
of the ancient skulls, such as the great development of the frontal
sinuses, might be urged; while against the supposition of either
the identity, or the diversity, of race of the two arises the known
independence of the variation of cranium on the one hand, and of hair,
colour, and language on the other.
"But the amount of variation of the Borreby skulls, and the fact that
the skulls of one of the purest and most homogeneous of existing races
of men can be proved to differ from one another in the same characters,
though perhaps not quite to the same extent, as the Engis and
Neanderthal skulls, seem to me to prohibit any cautious reasoner from
affirming the latter to have been necessarily of distinct races.
[Illustration: Figure 6. Outlines of Skulls]
(FIGURE 6. OUTLINES OF THE SKULL FROM THE NEANDERTHAL,
OF AN AUSTRALIAN SKULL FROM PORT ADELAIDE, AND OF THE
SKULL FROM THE CAVE OF ENGIS, DRAWN TO THE SAME ABSOLUTE
LENGTH, IN ORDER THE BETTER TO CONTRAST THEIR PROPORTIONS.
a. The glabella.
b. The occipital protuberance, or the point on the exterior
of each skull which corresponds roughly with the attachment
of the tentorium, or with the inferior boundary of the
posterior cerebral lobes.
e. The position of the auditory foramen of the Engis skull.)
"The marked resemblances between the ancient skulls and their modern
Australian analogues, however, have a profound interest, when it is
recollected that the stone axe is as much the weapon and the implement
of the modern as of the ancient savage; that the former turns the bones
of the kangaroo and of the emu to the same account as the latter did the
bones of the deer and the urus; that the Australian heaps up the shells
of devoured shellfish in mounds which represent the "refuse-heaps" or
"Kjokkenmodding," of Denmark; and, finally, that, on the other side of
Torres Straits, a race akin to the Australians are among the few people
who now build their houses on pile-works, like those of the ancient
Swiss lakes.
"That this amount of resemblance in habit and in the conditions
of existence is accompanied by as close a resemblance in cranial
configuration, illustrates on a great scale that what Cuvier
demonstrated of the animals of the Nile valley is no less true of men;
circumstances remaining similar, the savage varies little more, it would
seem, than the ibis or the crocodile, especially if we take into account
the enormous extent of the time over which our knowledge of man
now extends, as compared with that measured by the duration of the
sepulchres of Egypt.
"Finally, the comparatively large cranial capacity of the Neanderthal
skull, overlaid though it may be by pithecoid bony walls, and the
completely human proportions of the accompanying limb-bones, together
with the very fair development of the Engis skull, clearly indicate that
the first traces of the primordial stock whence Man has proceeded need
no longer be sought, by those who entertain any form of the doctrine of
progressive development, in the newest Tertiaries; but that they may
be looked for in an epoch more distant from the age of the Elephas
primigenius than that is from us."
The two skulls which form the subject of the preceding comments and
illustrations have given rise to nearly an equal amount of surprise for
opposite reasons; that of Engis because being so unequivocally ancient,
it approached so near to the highest or Caucasian type; that of the
Neanderthal, because, having no such decided claims to antiquity,
it departs so widely from the normal standard of humanity. Professor
Huxley's observation regarding the wide range of variation, both as
to shape and capacity, in the skulls of so pure a race as the native
Australian, removes to no small extent this supposed anomaly, assuming
what though not proved is very probable, that both varieties co-existed
in the Pleistocene period in Western Europe.
As to the Engis skull, we must remember that although associated with
the elephant, rhinoceros, bear, tiger, and hyaena, all of extinct
species, it nevertheless is also accompanied by a bear, stag, wolf, fox,
beaver, and many other quadrupeds of species still living. Indeed many
eminent palaeontologists, and among them Professor Pictet, think that,
numerically considered, the larger portion of the mammalian fauna
agrees specifically with that of our own period, so that we are scarcely
entitled to feel surprised if we find human races of the Pleistocene
epoch undistinguishable from some living ones. It would merely tend to
show that Man has been as constant in his osteological characters as
many other mammalia now his contemporaries. The expectation of always
meeting with a lower type of human skull, the older the formation in
which it occurs, is based on the theory of progressive development, and
it may prove to be sound; nevertheless we must remember that as yet we
have no distinct geological evidence that the appearance of what
are called the inferior races of mankind has always preceded in
chronological order that of the higher races.
It is now admitted that the differences between the brain of the highest
races of Man and that of the lowest,* though less in degree, are of the
same order as those which separate the human from the simian brain; and
the same rule holds good in regard to the shape of the skull.
(* "Natural History Review" 1861 page 8.)
The average Negro skull differs from that of the European in having a
more receding forehead, more prominent superciliary ridges, and more
largely developed prominences and furrows for the attachment of muscles;
the face also, and its lines, are larger proportionally. The brain is
somewhat less voluminous on the average in the lower races of mankind,
its convolutions rather less complicated, and those of the two
hemispheres more symmetrical, in all which points an approach is made
to the simian type. It will also be seen, by reference to the late Dr.
Morton's works, and by the foregoing statements of Professor Huxley,
that the range of size or capacity between the highest and lowest human
brain is greater than that between the highest simian and lowest human
brain; but the Neanderthal skull, although in several respects it is
more ape-like than any human skull previously discovered, is, in regard
to volume, by no means contemptible.
Eminent anatomists have shown that in the average proportions of some of
the bones the Negro differs from the European, and that in most of
these characters, he makes a slightly nearer approach to the anthropoid
quadrumana;* but Professor Schaaffhausen has pointed out that in these
proportions the Neanderthal skeleton does not differ from the ordinary
standard, so that the skeleton by no means indicates a transition
between Homo and Pithecus. (* "The inferior races of mankind exhibit
proportions which are in many respects intermediate between the higher,
or European, orders, and the monkeys. In the Negro, for instance, the
stature is less than in the European. The cranium, as is well known,
bears a small proportion to the face. Of the extremities the upper are
proportionately longer, and there is, in both upper and lower, a less
marked preponderance of the proximal over the distal segments. For
instance, in the Negro, the thigh and arm are rather shorter than in
the European; the leg is actually of equal length in both races, and is
therefore, relatively, a little longer in the Negro; the fore-arm in the
latter is actually, as well as relatively, a little longer; the foot
is an eighth, and the hand a twelfth longer than in the European. It is
well known that the foot is less well formed in the Negro than in the
European. The arch of the instep, the perfect conformation of which is
essential to steadiness and ease of gait, is less elevated in the former
than in the latter. The foot is thereby rendered flatter as well as
longer, more nearly resembling the monkey's, between which and the
European there is a marked difference in this particular."--From "A
Treatise on the Human Skeleton" by Dr. Humphry, Lecturer on Surgery and
Anatomy in the Cambridge University Medical School, page 91.)
There is doubtless, as shown in the diagram Figure 4, a nearer
resemblance in the outline of the Neanderthal skull to that of a
chimpanzee than had ever been observed before in any human cranium; and
Professor Huxley's description of the occipital region shows that the
resemblance is not confined to the mere excessive prominence of the
superciliary ridges.
The direct bearing of the ape-like character of the Neanderthal skull on
Lamarck's doctrine of progressive development and transmutation, or on
that modification of it which has of late been so ably advocated by
Mr. Darwin, consists in this, that the newly observed deviation from
a normal standard of human structure is not in a casual or random
direction, but just what might have been anticipated if the laws of
variation were such as the transmutationists require. For if we conceive
the cranium to be very ancient, it exemplifies a less advanced stage of
progressive development and improvement. If it be a comparatively modern
race, owing its peculiarities of conformation to degeneracy, it is
an illustration of what botanists call "atavism," or the tendency of
varieties to revert to an ancestral type, which type, in proportion
to its antiquity, would be of lower grade. To this hypothesis, of a
genealogical connection between Man and the lower animals, I shall again
allude in the concluding chapters. [11]
CHAPTER 6. -- PLEISTOCENE ALLUVIUM AND CAVE DEPOSITS WITH FLINT
IMPLEMENTS.
General Position of Drift with extinct Mammalia in Valleys.
Discoveries of M. Boucher de Perthes at Abbeville.
Flint Implements found also at St. Acheul, near Amiens.
Curiosity awakened by the systematic Exploration of the Brixham Cave.
Flint Knives in same, with Bones of extinct Mammalia.
Superposition of Deposits in the Cave.
Visits of English and French Geologists to Abbeville and Amiens.
PLEISTOCENE ALLUVIUM CONTAINING FLINT IMPLEMENTS IN THE VALLEY OF THE
SOMME.
Throughout a large part of Europe we find at moderate elevations above
the present river-channels, usually at a height of less than 40 feet,
but sometimes much higher, beds of gravel, sand, and loam containing
bones of the elephant, rhinoceros, horse, ox, and other quadrupeds, some
of extinct, others of living, species, belonging for the most part to
the fauna already alluded to in the fourth chapter as characteristic
of the interior of caverns. The greater part of these deposits contain
fluviatile shells, and have undoubtedly been accumulated in ancient
river-beds. These old channels have long since been dry, the streams
which once flowed in them having shifted their position, deepening the
valleys, and often widening them on one side.
It has naturally been asked, if Man co-existed with the extinct species
of the caves, why were his remains and the works of his hands never
embedded outside the caves in ancient river-gravel containing the same
fossil fauna? Why should it be necessary for the geologist to resort
for evidence of the antiquity of our race to the dark recesses of
underground vaults and tunnels which may have served as places of refuge
or sepulture to a succession of human beings and wild animals, and where
floods may have confounded together in one breccia the memorials of
the fauna of more than one epoch? Why do we not meet with a similar
assemblage of the relics of Man, and of living and extinct quadrupeds,
in places where the strata can be thoroughly scrutinised in the light of
day?
Recent researches have at length demonstrated that such memorials, so
long sought for in vain, do in fact exist, and their recognition is
the chief cause of the more favourable reception now given to the
conclusions which MM. Tournal, Christol, Schmerling, and others, arrived
at thirty years ago respecting the fossil contents of caverns. [12]
A very important step in this new direction was made thirteen years
after the publication of Schmerling's researches, by M. Boucher de
Perthes, who found in ancient alluvium at Abbeville, in Picardy, some
flint implements, the relative antiquity of which was attested by their
geological position. The antiquarian knowledge of their discoverer
enabled him to recognise in their rude and peculiar type a character
distinct from that of the polished stone weapons of a later period,
usually called "celts." In the first volume of his "Antiquites
Celtiques," published in 1847, M. Boucher de Perthes styled these older
tools "antediluvian," because they came from the lowest beds of a series
of ancient alluvial strata bordering the valley of the Somme, which
geologists had termed "diluvium." He had begun to collect these
implements in 1841. From that time they had been annually dug out of the
drift or deposits of gravel and sand, of which fine sections were laid
open from 20 to 35 feet in depth, whenever excavations were made in
repairing the fortifications of Abbeville; or as often as flints were
wanted for the roads, or loam for making bricks. For years previously
bones of quadrupeds of the genera elephant, rhinoceros, bear, hyaena,
stag, ox, horse, and others, had been collected there, and sent from
time to time to Paris to be examined and named by Cuvier, who had
described them in his Ossements Fossiles. A correct account of the
associated flint tools and of their position was given in 1847 by M.
Boucher de Perthes in his work above cited, and they were stated to
occur at various depths, often 20 or 30 feet from the surface, in sand
and gravel, especially in those strata which were nearly in contact with
the subjacent white Chalk. But the scientific world had no faith in
the statement that works of art, however rude, had been met with in
undisturbed beds of such antiquity. Few geologists visited Abbeville
in winter, when the sand-pits were open, and when they might have
opportunities of verifying the sections, and judging whether the
instruments had really been embedded by natural causes in the same
strata with the bones of the mammoth, rhinoceros, and other extinct
mammalia. Some of the tools figured in the "Antiquites Celtiques" were
so rudely shaped, that many imagined them to have owed their peculiar
forms to accidental fracture in a river's bed; others suspected frauds
on the part of the workmen, who might have fabricated them for sale, or
that the gravel had been disturbed, and that the worked flints had got
mingled with the bones of the mammoth long after that animal and its
associates had disappeared from the earth.
No one was more sceptical than the late eminent physician of Amiens, Dr.
Rigollot, who had long before (in the year 1819) written a memoir on the
fossil mammalia of the valley of the Somme. He was at length induced to
visit Abbeville, and, having inspected the collection of M. Boucher de
Perthes, returned home resolved to look for himself for flint tools in
the gravel-pits near Amiens. There, accordingly, at a distance of about
30 miles from Abbeville, he immediately found abundance of similar flint
implements, precisely the same in the rudeness of their make, and the
same in their geological position; some of them in gravel nearly on a
level with the Somme, others in similar deposits resting on Chalk at a
height of about 90 feet above the river.
Dr. Rigollot having in the course of four years obtained several hundred
specimens of these tools, most of them from St. Acheul in the south-east
suburbs of Amiens, lost no time in communicating an account of them to
the scientific world, in a memoir illustrated by good figures of the
worked flints and careful sections of the beds. These sections were
executed by M. Buteux, an engineer well qualified for the task, who had
written a good description of the geology of Picardy. Dr. Rigollot, in
this memoir, pointed out most clearly that it was not in the vegetable
soil, nor in the brick-earth with land and freshwater shells next below,
but in the lower beds of coarse flint-gravel, usually 12, 20, or 25 feet
below the surface, that the implements were met with, just as they had
been previously stated by M. Boucher de Perthes to occur at Abbeville.
The conclusion, therefore, which was legitimately deduced from all the
facts, was that the flint tools and their fabricators were coeval with
the extinct mammalia embedded in the same strata.
BRIXHAM CAVE, NEAR TORQUAY, DEVONSHIRE.
Four years after the appearance of Dr. Rigollot's paper, a sudden
change of opinion was brought about in England respecting the probable
co-existence, at a former period, of Man and many extinct mammalia, in
consequence of the results obtained from a careful exploration of a cave
at Brixham, near Torquay, in Devonshire. As the new views very generally
adopted by English geologists had no small influence on the subsequent
progress of opinion in France, I shall interrupt my account of the
researches made in the valley of the Somme, by a brief notice of those
which were carried on in 1858 in Devonshire with more than usual care
and scientific method. Dr. Buckland, in his celebrated work, entitled
"Reliquiae Diluvianae," published in 1823, in which he treated of the
organic remains contained in caves, fissures, and "diluvial gravel" in
England, had given a clear statement of the results of his own original
observations, and had declared that none of the human bones or stone
implements met with by him in any of the caverns could be considered
to be as old as the mammoth and other extinct quadrupeds. Opinions in
harmony with this conclusion continued until very lately to be generally
in vogue in England; although about the time that Schmerling was
exploring the Liege caves, the Reverend Mr. McEnery, a Catholic priest,
residing near Torquay, had found in a cave one mile east of that town,
called "Kent's Hole," in red loam covered with stalagmite, not only
bones of the mammoth, tichorhine rhinoceros, hippopotamus, cave-bear,
and other mammalia, but several remarkable flint tools, some of which he
supposed to be of great antiquity, while there were also remains of Man
in the same cave of a later date.*
(* The manuscript and plates prepared for a joint memoir on
Kent's Hole, by Mr. McEnery and Dr. Buckland, have recently
been published by Mr. Vivian of Torquay, from which, as well
as from some of the unprinted manuscript, I infer that Mr.
McEnery only refrained out of deference to Dr. Buckland from
declaring his belief in the contemporaneousness of certain
flint implements of an antique type and the bones of extinct
animals. Two of these implements from Kent's Hole, figured
in Plate 12 of the posthumous work above alluded to,
approach very closely in form and size to the common
Abbeville implements.)
About ten years afterwards, in a "Memoir on the Geology of South
Devon," published in 1842 by the Geological Society of London,* an able
geologist, Mr. Godwin-Austen, declared that he had obtained in the same
cave (Kent's Hole) works of Man from undisturbed loam or clay, under
stalagmite, mingled with the remains of extinct animals, and that all
these must have been introduced "before the stalagmite flooring had been
formed." He maintained that such facts could not be explained away by
the hypothesis of sepulture, as in Dr. Buckland's well-known case of
the human skeleton of Paviland, because in the Devon cave the flint
implements were widely distributed through the loam, and lay beneath the
stalagmite.
(* "Transactions of the Geological Society" 2nd series
volume 6 page 444.)
As the osseous and other contents of Kent's Hole had, by repeated
diggings, been thrown into much confusion, it was thought desirable in
1858, when a new and intact bone-cave was discovered at Brixham,
about four miles south of Torquay, to have a thorough and systematic
examination made of it. The Royal Society, chiefly at the instance of
Dr. Falconer, made two grants towards defraying the expenses, and
Miss Burdett-Coutts contributed liberally towards the same object. A
committee of geologists was charged with the investigations, among whom
Dr. Falconer and Mr. Prestwich took a prominent part, visiting Torquay
while the excavations were in progress. Mr. Pengelly, another member
of the committee, well qualified for the task by nearly twenty years'
previous experience in cave explorations, zealously directed and
superintended the work. By him, in 1859, I was conducted through
the subterranean galleries after they had been cleared out; and Dr.
Falconer, who was also at Torquay, showed me the numerous fossils which
had been discovered, and which he was then studying, all numbered and
labelled, with reference to a journal in which the geological position
of each specimen was recorded with scrupulous care.
The discovery of the existence of this suite of caverns near the sea at
Brixham was made accidentally by the roof of one of them being broken
through in quarrying. None of the four external openings now exposed
to view in steep cliffs or in the sloping side of a valley were visible
before the breccia and earthy matter which blocked them up were removed
during the late exploration. According to a ground-plan drawn up by
Professor Ramsay, it appears that some of the passages which run nearly
north and south are fissures connected with the vertical dislocation of
the rocks, while another set, running nearly east and west, are tunnels,
which have the appearance of having been to a great extent hollowed out
by the action of running water. The central or main entrance, leading to
what is called the "reindeer gallery," because a perfect antler of that
animal was found sticking in the stalagmitic floor, is 95 feet above
the level of the sea, being also 78 above the bottom of the adjoining
valley. The united length of the galleries which were cleared out
amounted to several hundred feet. Their width never exceeded 8 feet.
They were sometimes filled up to the roof with mud, but occasionally
there was a considerable space between the roof and floor. The latter,
in the case of the fissure-caves, was covered with stalagmite, but
in the tunnels it was usually free from any such incrustation. The
following was the general succession of the deposits forming the
contents of the underground passages and channels:--
First. At the top, a layer of stalagmite varying in thickness from 1 to
15 inches, which sometimes contained bones, such as the reindeer's horn,
already mentioned, and an entire humerus of the cave-bear.
Secondly. Next below, loam or bone-earth, of an ochreous red colour,
with angular stones and some pebbles, from 2 to 13 feet in thickness.
Thirdly. At the bottom of all, gravel with many rounded pebbles in
it. This was everywhere removed so long as the tunnels which narrowed
downwards were wide enough to be worked. It proved to be almost entirely
barren of fossils.
The mammalia obtained from the bone-earth consisted of Elephas
primigenius, or mammoth; Rhinoceros tichorhinus; Ursus spelaeus; Hyaena
spelaea; Felis spelaea, or the cave-lion; Cervus tarandus, or the
reindeer; a species of horse, ox, and several rodents, and others not
yet determined.
No human bones were obtained anywhere during these excavations, but many
flint knives, chiefly from the lowest part of the bone-earth; and one of
the most perfect lay at the depth of 13 feet from the surface, and was
covered with bone-earth of that thickness. Neglecting the less perfect
specimens, some of which were met with even in the lowest gravel,
about fifteen knives, recognised as artificially formed by the most
experienced antiquaries, were taken from the bone-earth, and usually
from near the bottom. Such knives, considered apart from the associated
mammalia, afford in themselves no safe criterion of antiquity, as
they might belong to any part of the age of stone, similar tools
being sometimes met with in tumuli posterior in date to the era of the
introduction of bronze. But the contemporaneity of those at Brixham with
the extinct animals is demonstrated not only by the occurrence at one
point in overlying stalagmite of the bone of a cave-bear, but also
by the discovery at the same level in the bone-earth, and in close
proximity to a very perfect flint tool, of the entire left hind-leg of
a cave-bear. This specimen, which was shown me by Dr. Falconer and Mr.
Pengelly, was exhumed from the earthy deposit in the reindeer gallery,
near its junction with the flint-knife gallery, at the distance of about
sixty-five feet from the main entrance. The mass of earth containing
it was removed entire, and the matrix cleared away carefully by Dr.
Falconer in the presence of Mr. Pengelly. Every bone was in its natural
place, the femur, tibia, fibula, ankle-bone, or astragalus, all in
juxtaposition. Even the patella or detached bone of the knee-pan was
searched for, and not in vain. Here, therefore, we have evidence of an
entire limb not having been washed in a fossil state out of an older
alluvium, and then swept afterwards into a cave, so as to be mingled
with flint implements, but having been introduced when clothed with
its flesh, or at least when it had the separate bones bound together by
their natural ligaments, and in that state buried in mud.
If they were not all of contemporary date, it is clear from this case,
and from the humerus of the Ursus spelaeus, before cited, as found in
a floor of stalagmite, that the bear lived after the flint tools were
manufactured, or in other words, that Man in this district preceded the
cave-bear.
A glance at the position of Windmill Hill, in which the caverns are
situated, and a brief survey of the valleys which bound it on three
sides, are enough to satisfy a geologist that the drainage and
geographical features of this region have undergone great changes since
the gravel and bone-earth were carried by streams into the subterranean
cavities above described. Some worn pebbles of haematite, in particular,
can only have come from their nearest parent rock, at a period when the
valleys immediately adjoining the caves were much shallower than they
now are. The reddish loam in which the bones are embedded is such as
may be seen on the surface of limestone in the neighbourhood, but the
currents which were formerly charged with such mud must have run at a
level 78 feet above that of the stream now flowing in the same valley.
It was remarked by Mr. Pengelly that the stones and bones in the loam
had their longest axes parallel to the direction of the tunnels and
fissures, showing that they were deposited by the action of a stream.*
(* Pengelly, "Geologist" volume 4 1861 page 153.)
It appears that so long as the flowing water had force enough to propel
stony fragments, no layer of fine mud could accumulate, and so long as
there was a regular current capable of carrying in fine mud and bones,
no superficial crust of stalagmite. In some passages, as before stated,
stalagmite was wanting, while in one place seven or eight alternations
of stalagmite and loam were observed, seeming to indicate a prevalence
of more rainy seasons, succeeded by others, when the water was for
a time too low to flood the area where the calcareous incrustation
accumulated.
If the regular sequence of the three deposits of pebbles, mud, and
stalagmite was the result of the causes above explained, the order
of superposition would be constant, yet we could not be sure that the
gravel in one passage might not sometimes be coeval with the bone-earth
or stalagmite in another.
If therefore the flint knives had not been very widely dispersed, and if
one of them had not been at the bottom of the bone-earth, close to
the leg of the bear above described, their antiquity relatively to the
extinct mammalia might have been questioned. No coprolites were found in
the Brixham excavations, and very few gnawed bones. These few may have
been brought from some distance before they reached their place of
rest. Upon the whole, the same conclusion which Dr. Schmerling came to,
respecting the filling up of the caverns near Liege, seems applicable to
the caves of Brixham.
Dr. Falconer, after aiding in the investigations above alluded to near
Torquay, stopped at Abbeville on his way to Sicily, in the autumn of
1858, and saw there the collection of M. Boucher de Perthes. Being at
once satisfied that the flints called hatchets had really been fashioned
by the hand of Man, he urged Mr. Prestwich, by letter, thoroughly to
explore the geology of the valley of the Somme. This he accordingly
accomplished, in company with Mr. John Evans [13], of the Society
of Antiquaries, and, before his return that same year, succeeded in
dissipating all doubts from the minds of his geological friends by
extracting, with his own hands, from a bed of undisturbed gravel, at St.
Acheul, a well-shaped flint hatchet. This implement was buried in the
gravel at a depth of 17 feet from the surface, and was lying on its flat
side. There were no signs of vertical rents in the enveloping matrix,
nor in the overlying beds of sand and loam, in which were many land and
freshwater shells; so that it was impossible to imagine that the tool
had gradually worked its way downwards, as some had suggested, through
the incumbent soil, into an older formation.*
(* Prestwich, "Proceedings of the Royal Society" 1859 and
"Philosophical Transactions" 1860.)
There was no one in England whose authority deserved to have so much
weight in overcoming incredulity in regard to the antiquity of the
implements in question. For Mr. Prestwich, besides having published a
series of important memoirs on the Tertiary formations of Europe, had
devoted many years specially to the study of the drift and its organic
remains. His report, therefore, to the Royal Society, accompanied by a
photograph showing the position of the flint tool in situ before it was
removed from its matrix, not only satisfied many inquirers, but induced
others to visit Abbeville and Amiens; and one of these, Mr. Flower, who
accompanied Mr. Prestwich on his second excursion to St. Acheul, in June
1859, succeeded, by digging into the bank of gravel, in disinterring,
at the depth of 22 feet from the surface, a fine, symmetrically-shaped
weapon of an oval form, lying in and beneath strata which were observed
by many witnesses to be perfectly undisturbed.*
(* "Quarterly Journal of the Geological Society" volume 16
1860 page 190.)
Shortly afterwards, in the year 1859, I visited the same pits, and
obtained seventy flint tools, one of which was taken out while I was
present, though I did not see it before it had fallen from the matrix.
I expressed my opinion in favour of the antiquity of the flint tools to
the meeting of the British Association at Aberdeen, in the same year.*
(* See "Report of British Association" for 1859. )
On my way through Rouen, I stated my convictions on this subject to
M. George Pouchet, who immediately betook himself to St. Acheul,
commissioned by the municipality of Rouen, and did not quit the pits
till he had seen one of the hatchets extracted from gravel in its
natural position.*
(* "Actes du Musee d'Histoire Naturelle de Rouen" 1860 page
33.)
M. Gaudry also gave the following account of his researches in the same
year to the Royal Academy of Sciences at Paris. "The great point was
not to leave the workmen for a single instant, and to satisfy oneself
by actual inspection whether the hatchets were found in situ. I caused a
deep excavation to be made, and found nine hatchets, most distinctly
in situ in the diluvium, associated with teeth of Equus fossilis and a
species of Bos, different from any now living, and similar to that of
the diluvium and of caverns."*
(* "Comptes rendus" September 26 and October 3, 1859.)
In 1859, M. Hebert, an original observer of the highest authority,
declared to the Geological Society of France that he had, in 1854, or
four years before Mr. Prestwich's visit to St. Acheul, seen the sections
at Abbeville and Amiens, and had come to the opinion that the hatchets
were imbedded in the "lower diluvium," and that their origin was as
ancient as that of the mammoth and the rhinoceros. M. Desnoyers also
made excavations after M. Gaudry, at St. Acheul, in 1859, with the same
results.*
(* "Bulletin" volume 17 page 18.)
After a lively discussion on the subject in England and France, it was
remembered, not only that there were numerous recorded cases leading to
similar conclusions in regard to cavern deposits, but, also, that Mr.
Frere had, so long ago as 1797, found flint weapons, of the same type
as those of Amiens, in a freshwater formation in Suffolk, in conjunction
with elephant remains; and nearly a hundred years earlier (1715),
another tool of the same kind had been exhumed from the gravel of
London, together with bones of an elephant; to all which examples I
shall allude more fully in the sequel.
I may conclude this chapter by quoting a saying of Professor Agassiz,
"that whenever a new and startling fact is brought to light in science,
people first say, 'it is not true,' then that 'it is contrary to
religion,' and lastly, 'that everybody knew it before.'"
If I were considering merely the cultivators of geology, I should say
that the doctrine of the former co-existence of Man with many extinct
mammalia had already gone through these three phases in the progress
of every scientific truth towards acceptance. But the grounds of this
belief have not yet been fully laid before the general public, so as
to enable them fairly to weigh and appreciate the evidence. I shall
therefore do my best in the next three chapters to accomplish this task.
CHAPTER 7. -- PEAT AND PLEISTOCENE ALLUVIUM OF THE VALLEY OF THE SOMME.
Geological Structure of the Valley of the Somme and of the
surrounding Country.
Position of Alluvium of different Ages.
Peat near Abbeville.
Its animal and vegetable Contents.
Works of Art in Peat.
Probable Antiquity of the Peat, and Changes of Level
since its Growth began.
Flint Implements of antique Type in older Alluvium.
Their various Forms and great Numbers.
GEOLOGICAL STRUCTURE OF THE SOMME VALLEY.
The valley of the Somme in Picardy, alluded to in the last chapter, is
situated geologically in a region of white Chalk with flints, the strata
of which are nearly horizontal. The Chalk hills which bound the valley
are almost everywhere between 200 and 300 feet in height. On ascending
to that elevation, we find ourselves on an extensive table-land, in
which there are slight elevations and depressions. The white Chalk
itself is scarcely ever exposed at the surface on this plateau, although
seen on the slopes of the hills, as at b and c (Figure 7). The general
surface of the upland region is covered continuously for miles in every
direction by loam or brick-earth (Number 4), about 5 feet thick, devoid
of fossils. To the wide extent of this loam the soil of Picardy chiefly
owes its great fertility. Here and there we also observe, on the Chalk,
outlying patches of Tertiary sand and clay (Number 5, Figure 7), with
Eocene fossils, the remnants of a formation once more extensive, and
which probably once spread in one continuous mass over the Chalk,
before the present system of valleys had begun to be shaped out. It is
necessary to allude to these relics of Tertiary strata, of which the
larger part is missing, because their denudation has contributed largely
to furnish the materials of gravels in which the flint implements and
bones of extinct mammalia are entombed. From this source have been
derived not only the regular-formed egg-shaped pebbles, so common in
the old fluviatile alluvium at all levels, but those huge masses of
hard sandstone, several feet in diameter, to which I shall allude in the
sequel. The upland loam also (Number 4) has often, in no slight degree,
been formed at the expense of the same Tertiary sands and clays, as is
attested by its becoming more or less sandy or argillaceous, according
to the nature of the nearest Eocene outlier in the neighbourhood.
The average width of the valley of the Somme between Amiens and
Abbeville is one mile. The height, therefore, of the hills, in relation
to the river-plain, could not be correctly represented in the annexed
diagram (Figure 7), as they would have to be reduced in altitude; or if
not, it would be necessary to make the space between c and b four times
as great. The dimensions also of the masses, of drift or alluvium, 2
and 3, have been exaggerated, in order to render them sufficiently
conspicuous; for, all important as we shall find them to be as
geological monuments of the Pleistocene period, they form a truly
insignificant feature in the general structure of the country, so much
so, that they might easily be overlooked in a cursory survey of the
district, and are usually unnoticed in geological maps not specially
devoted to the superficial formations.
[Illustration: Figure 7. Valley of the Somme]
(FIGURE 7. SECTION ACROSS THE VALLEY OF THE SOMME IN PICARDY.
1. Peat, 20 to 30 feet thick, resting on gravel, a.
2. Lower level gravel with elephants' bones and flint tools,
covered with fluviatile loam, 20 to 40 feet thick.
3. Higher level gravel with similar fossils, and with overlying
loam, in all 30 feet thick.
4. Upland loam without shells (Limon des plateaux), 5 or 6
feet thick.
5. Eocene strata, resting on the Chalk in patches.)
It will be seen by the description given of the section (Figure 7) that
Number 2 indicates the lower level gravels, and Number 3 the higher
ones, or those rising to elevations of 80 or 100 feet above the river.
Newer than these is the peat Number 1, which is from 10 to 30 feet in
thickness, and which is not only of later date than the alluvium, 2 and
3, but is also posterior to the denudation of those gravels, or to the
time when the valley was excavated through them. Underneath the peat is
a bed of gravel, a, from 3 to 14 feet thick, which rests on undisturbed
Chalk. This gravel was probably formed, in part at least, when the
valley was scooped out to its present depth, since which time no
geological change has taken place, except the growth of the peat, and
certain oscillations in the general level of the country, to which we
shall allude by and by. A thin layer of impervious clay separates the
gravel a from the peat Number 1, and seems to have been a necessary
preliminary to the growth of the peat.
PEAT OF THE VALLEY OF THE SOMME.
As hitherto, in our retrospective survey, we have been obliged, for
the sake of proceeding from the known to the less known, to reverse the
natural order of history, and to treat of the newer before the older
formations, I shall begin my account of the geological monuments of the
valley of the Somme by saying something of the most modern of all of
them, the peat. This substance occupies the lower parts of the valley
far above Amiens, and below Abbeville as far as the sea. It has already
been stated to be in some places 30 feet thick, and is even occasionally
more than 30 feet, corresponding in that respect to the Danish mosses
before described (Chapter 2). Like them, it belongs to the Recent
period; all the embedded mammalia, as well as the shells, being of the
same species as those now inhabiting Europe. The bones of quadrupeds are
very numerous, as I can bear witness, having seen them brought up from
a considerable depth near Abbeville, almost as often as the dredging
instrument was used. Besides remains of the beaver, I was shown, in the
collection of M. Boucher de Perthes, two perfect lower jaws with teeth
of the bear, Ursus arctos; and in the Paris Museum there is another
specimen, also from the Abbeville peat.
The list of mammalia already comprises a large proportion of those
proper to the Swiss lake-dwellings, and to the shell-mounds and peat of
Denmark; but unfortunately as yet no special study has been made of the
French fauna, like that by which the Danish and Swiss zoologists and
botanists have enabled us to compare the wild and tame animals and the
vegetation of the age of stone with that of the age of iron.
Notwithstanding the abundance of mammalian bones in the peat, and the
frequency of stone implements of the Celtic and Gallo-Roman periods, M.
Boucher de Perthes has only met with three or four fragments of human
skeletons.
At some depth in certain places in the valley near Abbeville, the trunks
of alders have been found standing erect as they grew, with their roots
fixed in an ancient soil, afterwards covered with peat. Stems of the
hazel, and nuts of the same, abound; trunks, also, of the oak and
walnut. The peat extends to the coast, and is there seen passing under
the sand-dunes and below the sea-level. At the mouth of the river
Canche, which joins the sea near the embouchure of the Somme, yew trees,
firs, oaks, and hazels have been dug out of peat, which is there worked
for fuel, and is about three feet thick.*
(* D'Archiac, "Histoire des Progres" volume 2 page 154.)
During great storms, large masses of compact peat, enclosing trunks of
flattened trees, have been thrown up on the coast at the mouth of the
Somme; seeming to indicate that there has been a subsidence of the land
and a consequent submergence of what was once a westward continuation of
the valley of the Somme into what is now a part of the English Channel.
Whether the vegetation of the lowest layers of peat differed as to the
geographical distribution of some of the trees from the middle, and this
from the uppermost peat, as in Denmark, has not yet been ascertained;
nor have careful observations been made with a view of calculating the
minimum of time which the accumulation of so dense a mass of vegetable
matter must have taken. A foot in thickness of highly compressed peat,
such as is sometimes reached in the bottom of the bogs, is obviously
the equivalent in time of a much greater thickness of peat of spongy
and loose texture, found near the surface. The workmen who cut peat, or
dredge it up from the bottom of swamps and ponds, declare that in the
course of their lives none of the hollows which they have found, or
caused by extracting peat, have ever been refilled, even to a small
extent. They deny, therefore, that the peat grows. This, as M. Boucher
de Perthes observes, is a mistake; but it implies that the increase in
one generation is not very appreciable by the unscientific.
The antiquary finds near the surface Gallo-Roman remains, and still
deeper Celtic weapons of the stone period. [14] But the depth at which
Roman works of art occur varies in different places, and is no sure test
of age; because in some parts of the swamps, especially near the river,
the peat is often so fluid that heavy substances may sink through it,
carried down by their own gravity. In one case, however, M. Boucher de
Perthes observed several large flat dishes of Roman pottery, lying in a
horizontal position in the peat, the shape of which must have prevented
them from sinking or penetrating through the underlying peat. Allowing
about fourteen centuries for the growth of the superincumbent vegetable
matter, he calculated that the thickness gained in a hundred years would
be no more than three centimetres.*
(* "Antiquites Celtiques" volume 2 page 134.)
This rate of increase would demand so many thousands of years for the
formation of the entire thickness of 30 feet that we must hesitate
before adopting it as a chronometric scale. Yet, by multiplying
observations of this kind, and bringing one to bear upon and check
another, we may eventually succeed in obtaining data for estimating the
age of the peaty deposit. [15]
The rate of increase in Denmark may not be applicable to France; because
differences in the humidity of the climate, or in the intensity and
duration of summer's heat and winter's cold, as well as diversity in the
species of plants which most abound, would cause the peat to grow more
or less rapidly, not only when we compare two distinct countries in
Europe, but the same country at two successive periods.
I have already alluded to some facts which favour the idea that there
has been a change of level on the coast since the peat began to grow.
This conclusion seems confirmed by the mere thickness of peat at
Abbeville, and the occurrence of alder and hazel-wood near the bottom of
it. If 30 feet of peat were now removed, the sea would flow up and fill
the valley for miles above Abbeville. Yet this vegetable matter is all
of supra-marine origin, for where shells occur in it they are all of
terrestrial or fluviatile kinds, so that it must have grown above the
sea-level when the land was more elevated than now. We have already
seen what changes in the relative level of sea and land have occurred
in Scotland subsequently to the time of the Romans, and are therefore
prepared to meet with proofs of similar movements in Picardy. In that
country they have probably not been confined simply to subsidence, but
have comprised oscillations in the level of the land, by which marine
shells of the Pleistocene period have been raised some 10 feet or more
above the level of the sea.
Small as is the progress hitherto made in interpreting the pages of the
peaty record, their importance in the valley of the Somme is enhanced by
the reflection that, whatever be the number of centuries to which they
relate, they belong to times posterior to the ancient implement-bearing
beds, which we are next to consider, and are even separated from them,
as we shall see, by an interval far greater than that which divides the
earliest strata of the peat from the latest.
FLINT IMPLEMENTS OF THE PLEISTOCENE PERIOD IN THE VALLEY OF THE SOMME.
The alluvium of the valley of the Somme exhibits nothing extraordinary
or exceptional in its position or external appearance, nor in the
arrangement or composition of its materials, nor in its organic remains;
in all these characters it might be matched by the drift of a hundred
other valleys in France or England. Its claim to our peculiar attention
is derived from the wonderful number of flint tools, of a very antique
type, which, as stated in the last chapter, occur in undisturbed strata,
associated with the bones of extinct quadrupeds.
As much doubt has been cast on the question, whether the so-called
flint hatchets have really been shaped by the hands of Man, it will be
desirable to begin by satisfying the reader's mind on that point, before
inviting him to study the details of sections of successive beds of mud,
sand, and gravel, which vary considerably even in contiguous localities.
Since the spring of 1859, I have paid three visits to the Valley of the
Somme, and examined all the principal localities of these flint tools.
In my excursions around Abbeville, I was accompanied by M. Boucher de
Perthes, and during one of my explorations in the Amiens district,
by Mr. Prestwitch. The first time I entered the pits at St. Acheul, I
obtained seventy flint instruments, all of them collected from the drift
in the course of the preceding five or six weeks. The two prevailing
forms of these tools are represented in the annexed Figures 8 and 9,
each of which are half the size of the originals; the first being the
spear-headed form, varying in length from six to eight inches; the
second, the oval form, which is not unlike some stone implements, used
to this day as hatchets and tomahawks by natives of Australia, but with
this difference, that the edge in the Australian weapons (as in the case
of those called celts in Europe) has been produced by friction, whereas
the cutting edge in the old tools of the valley of the Somme was always
gained by the simple fracture of the flint, and by the repetition of
many dexterous blows.
The oval-shaped Australian weapons, however, differ in being sharpened
at one end only. The other, though reduced by fracture to the same
general form, is left rough, in which state it is fixed into a cleft
stick, which serves as a handle. To this it is firmly bound by thin
straps of opossum's hide. One of these tools, now in my possession, was
given me by Mr. Farquharson of Haughton, who saw a native using it in
1854 on the Auburn river, in Burnet district, North Australia.
Out of more than a hundred flint implements which I obtained at St.
Acheul, not a few had their edges more or less fractured or worn, either
by use as instruments before they were buried in gravel, or by being
rolled in the river's bed.
Some of these tools were probably used as weapons, both of war and
of the chase, others to grub up roots, cut down trees, and scoop out
canoes. Some of them may have served, as Mr. Prestwich has suggested,
for cutting holes in the ice both for fishing and for obtaining
water, as will be explained in the eighth chapter when we consider
the arguments in favour of the higher level drift having belonged to a
period when the rivers were frozen over for several months every winter.
[Illustration: Figure 8. Flint Implement]
(FIGURE 8. FLINT IMPLEMENT FROM ST. ACHEUL, NEAR AMIENS,
OF THE SPEAR-HEAD SHAPE
(half the size of the original, which is 7 1/2 inches long).
a. Side view.
b. Same seen edgewise.
These spear-headed implements have been found in greater number,
proportionally to the oval ones, in the upper level gravel at St.
Acheul, than in any of the lower gravels in the valley of the Somme. In
these last the oval form predominates, especially at Abbeville.)
When the natural form of a Chalk-flint presented a suitable handle at
one end, as in the specimen, Figure 10, that part was left as found. The
portion, for example, between b and c has probably not been altered; the
protuberances which are fractured having been broken off by river action
before the flint was chipped artificially. The other extremity, a, has
been worked till it acquired a proper shape and cutting edge.
[Illustration: Figures 9 and 10. Flint Implements]
(FIGURES 9 AND 10. FLINT IMPLEMENTS FROM THE PLEISTOCENE DRIFT OF
ABBEVILLE AND AMIENS.
FIGURE 9. a. OVAL-SHAPED FLINT HATCHET FROM MAUTORT,
NEAR ABBEVILLE,
half size of original, which is 5 1/2 inches long, from
a bed of gravel underlying the fluvio-marine stratum. b. Same seen
edgewise. c. Shows a recent fracture of the edge of the same at the
point a, or near the top. This portion of the tool, c, is drawn of
the natural size, the black central part being the unaltered flint,
the white outer coating, the layer which has been formed by
discoloration or bleaching since the tool was first made. The
entire surface of Number 9 must have been black when first shaped,
and the bleaching to such a depth must have been the work of time,
whether produced by exposure to the sun and air before it was
embedded, or afterwards when it lay deep in the soil.
FIGURE 10. FLINT TOOL FROM ST. ACHEUL, seen edgewise;
original 6 1/2 inches long, and 3 inches wide.
b, c. Portion not artificially shaped.
a, b. Part chipped into shape, and having a cutting edge at a.)
Many of the hatchets are stained of an ochreous-yellow colour, when they
have been buried in yellow gravel, others have acquired white or brown
tints, according to the matrix in which they have been enclosed.
This accordance in the colouring of the flint tools with the character
of the bed from which they have come, indicates, says Mr. Prestwich, not
only a real derivation from such strata, but also a sojourn therein of
equal duration to that of the naturally broken flints forming part of
the same beds.*
(* "Philosophical Transactions" 1861 page 297.)
[Illustration: Figures 11, 12 and 13. Dendrites on Fling Hatchets]
(FIGURES 11, 12 AND 13. DENDRITES ON SURFACES OF FLINT HATCHETS IN
THE DRIFT OF ST. ACHEUL, NEAR AMIENS.
FIGURE 11. a. Natural size.
FIGURE 12. b. Natural size. c. Magnified.
FIGURE 13. d. Natural size.
e. Magnified.)
The surface of many of the tools is encrusted with a film of carbonate
of lime, while others are adorned by those ramifying crystallisations
called dendrites (see Figures 11, 12 and 13), usually consisting of the
mixed oxides of iron and manganese, forming extremely delicate blackish
brown sprigs, resembling the smaller kinds of sea weed. They are a
useful test of antiquity when suspicions are entertained of the workmen
having forged the hatchets which they offer for sale. The most general
test, however, of the genuineness of the implements obtained by purchase
is their superficial varnish-like or vitreous gloss, as contrasted with
the dull aspect of freshly fractured flints. I also remarked, during
each of my three visits to Amiens, that there were some extensive
gravel-pits, such as those of Montiers and St. Roch, agreeing in their
geological character with those of St. Acheul, and only a mile or
two distant, where the workmen, although familiar with the forms, and
knowing the marketable value of the articles above described, assured me
that they had never been able to find a single implement.
Respecting the authenticity of the tools as works of art, Professor
Ramsay, than whom no one could be a more competent judge, observes: "For
more than twenty years, like others of my craft, I have daily handled
stones, whether fashioned by nature or art; and the flint hatchets of
Amiens and Abbeville seem to me as clearly works of art as any Sheffield
whittle."*
(* "Athenaeum" July 16, 1859.)
Mr. Evans classifies the implements under three heads, two of which,
the spear heads and the oval or almond-shaped kinds, have already been
described. The third form (Figure 14) consists of flakes, apparently
intended for knives or some of the smaller ones for arrow heads.
[Illustration: Figure 14. Flint Knife or Flake]
(FIGURE 14. FLINT KNIFE OR FLAKE FROM BELOW THE SAND CONTAINING
CYRENA FLUMINALIS. MENCHECOURT, ABBEVILLE.
d. Transverse section along the line of fracture, b, c.
Size, two-thirds of the original.)
In regard to their origin, Mr. Evans observes that there is a uniformity
of shape, a correctness of outline, and a sharpness about the cutting
edges and points, which cannot be due to anything but design.*
(* "Archaeologia" volume 38.)
Of these knives and flakes, I obtained several specimens from a pit
which I caused to be dug at Abbeville, in sand in contact with the
Chalk, and below certain fluvio-marine beds, which will be alluded to in
the next chapter.
Between the spear-head and oval shapes, there are various intermediate
gradations, and there are also a vast variety of very rude implements,
many of which may have been rejected as failures, and others struck off
as chips in the course of manufacturing the more perfect ones. Some
of these chips can only be recognised by an experienced eye as bearing
marks of human workmanship.
It has often been asked, how, without the use of metallic hammers, so
many of these oval and spear-headed tools could have been wrought into
so uniform a shape. Mr. Evans, in order experimentally to illustrate the
process, constructed a stone hammer, by mounting a pebble in a wooden
handle, and with this tool struck off flakes from the edge on both sides
of a Chalk flint, till it acquired precisely the same shape as the oval
tool, Figure 9.
If I were invited to estimate the probable number of the more perfect
tools found in the valley of the Somme since 1842, rejecting all the
knives, and all that might be suspected of being spurious or forged, I
should conjecture that they far exceeded a thousand. Yet it would be
a great mistake to imagine that an antiquary or geologist, who should
devote a few weeks to the exploration of such a valley as that of the
Somme, would himself be able to detect a single specimen. But few tools
were lying on the surface. The rest have been exposed to view by the
removal of such a volume of sand, clay, and gravel, that the price of
the discovery of one of them could only be estimated by knowing how many
hundred labourers have toiled at the fortifications of Abbeville, or
in the sand and gravel pits near that city, and around Amiens, for road
materials and other economic purposes, during the last twenty years.
[Illustration: Figure 15. Fossils of the White Chalk]
(FIGURE 15. FOSSILS OF THE WHITE CHALK.
a, b. Coscinopora globularis, D'Orbigny. Orbitolina concava,
Parker and Jones. c. Part of same magnified.)
In the gravel pits of St. Acheul, and in some others near Amiens, small
round bodies, having a tubular cavity in the centre, occur. They are
well known as fossils of the White Chalk. Dr. Rigollot suggested that
they might have been strung together as beads, and he supposed the hole
in the middle to have been artificial. Some of these round bodies are
found entire in the Chalk and in the gravel, others have naturally a
hole passing through them, and sometimes one or two holes penetrating
some way in from the surface, but not extending to the other side.
Others, like b, Figure 15, have a large cavity, which has a very
artificial aspect. It is impossible to decide whether they have or have
not served as personal ornaments, recommended by their globular form,
lightness, and by being less destructible than ordinary Chalk. Granting
that there were natural cavities in the axis of some of them, it does
not follow that these may not have been taken advantage of for stringing
them as beads, while others may have been artificially bored through.
Dr. Rigollot's argument in favour of their having been used as necklaces
or bracelets, appears to me a sound one. He says he often found small
heaps or groups of them in one place, all perforated, just as if, when
swept into the river's bed by a flood, the bond which had united them
together remained unbroken.*
(* Rigollot, "Memoire sur des Instruments en Silex" etc.,
Amiens 1854 page 16.)
CHAPTER 8. -- PLEISTOCENE ALLUVIUM WITH FLINT IMPLEMENTS OF THE VALLEY
OF THE SOMME--CONCLUDED.
Fluvio-marine Strata, with Flint Implements, near Abbeville.
Marine Shells in same.
Cyrena fluminalis.
Mammalia.
Entire Skeleton of Rhinoceros.
Flint Implements, why found low down in Fluviatile Deposits.
Rivers shifting their Channels.
Relative Ages of higher and lower-level Gravels.
Section of Alluvium of St. Acheul.
Two Species of Elephant and Hippopotamus coexisting with Man
in France.
Volume of Drift, proving Antiquity of Flint Implements.
Absence of Human Bones in tool-bearing Alluvium, how explained.
Value of certain Kinds of negative Evidence tested thereby.
Human Bones not found in drained Lake of Haarlem.
In the section of the valley of the Somme given in Figure 7, the
successive formations newer than the Chalk are numbered in chronological
order, beginning with the most modern, or the peat, which is marked
Number 1, and which has been treated of in the last chapter. Next in the
order of antiquity are the lower-level gravels, Number 2, which we have
now to describe; after which the alluvium, Number 3, found at higher
levels, or about 80 and 100 feet above the river-plain, will remain to
be considered.
I have selected, as illustrating the old alluvium of the Somme occurring
at levels slightly elevated above the present river, the sand and
gravel-pits of Menchecourt, in the northwest suburbs of Abbeville, to
which, as before stated, attention was first drawn by M. Boucher de
Perthes, in his work on Celtic antiquities. Here, although in every
adjoining pit some minor variations in the nature and thickness of the
superimposed deposits may be seen, there is yet a general approach to
uniformity in the series. The only stratum of which the relative age
is somewhat doubtful, is the gravel marked a, underlying the peat, and
resting on the Chalk. It is only known by borings, and some of it may be
of the same age as Number 3; but I believe it to be for the most part
of more modern origin, consisting of the wreck of all the older gravel,
including Number 3, and formed during the last hollowing out and
deepening of the valley immediately before the commencement of the
growth of peat.
The greater number of flint implements have been dug out of Number 3,
often near the bottom, and twenty-five, thirty, or even more than thirty
feet below the surface of Number 1.
A geologist will perceive by a glance at the section that the valley of
the Somme must have been excavated nearly to its present depth and
width when the strata of Number 3 were thrown down, and that after the
deposits Numbers 3, 2, and 1 had been formed in succession, the present
valley was scooped out, patches only of Numbers 3 and 2 being left. For
these deposits cannot originally have ended abruptly as they now do, but
must have once been continuous farther towards the centre of the valley.
[Illustration: Figure 16. Fluvio-Marine Strata]
(FIGURE 16. SECTION OF FLUVIO-MARINE STRATA, CONTAINING FLINT
IMPLEMENTS AND BONES OF EXTINCT MAMMALIA, AT MENCHECOURT,
ABBEVILLE.*
(* For detailed sections and maps of this district, see
Prestwich, "Philosophical Transactions" 1860 page 277.)
1. Brown clay with angular flints, and occasionally Chalk rubble,
unstratified, following the slope of the hill, probably of
subaerial origin, of very varying thickness, from 2 to 5 feet
and upwards.
2. Calcareous loam, buff-coloured, resembling loess, for the most
part unstratified, in some places with slight traces of
stratification, containing freshwater and land shells, with
bones of elephants, etc.; thickness about 15 feet.
3. Alternations of beds of gravel, marl, and sand, with
freshwater and land shells, and, in some of the lower sands,
a mixture of marine shells; also bones of elephant, rhinoceros,
etc., and flint implements; thickness about 12 feet.
a. Gravel underlying peat, age undetermined.
b. Layer of impervious clay, separating the gravel from the peat.)
To begin with the oldest, Number 3, it is made up of a succession of
beds, chiefly of freshwater origin, but occasionally a mixture of marine
and fluviatile shells is observed in it, proving that the sea sometimes
gained upon the river, whether at high tides or when the fresh water was
less in quantity during the dry season, and sometimes perhaps when the
land was slightly depressed in level. All these accidents might occur
again and again at the mouth of any river, and give rise to alternations
of fluviatile and marine strata, such as are seen at Menchecourt.
In the lowest beds of gravel and sand in contact with the Chalk, flint
hatchets, some perfect, others much rolled, have been found; and in a
sandy bed in this position some workmen, whom I employed to sink a pit,
found four flint knives. Above this sand and gravel occur beds of white
and siliceous sand, containing shells of the genera Planorbis, Limnea,
Paludina, Valvata, Cyclas, Cyrena, Helix, and others, all now natives of
the same part of France, except Cyrena fluminalis (Figure 17), which no
longer lives in Europe, but inhabits the Nile, and many parts of Asia,
including Cashmere, where it abounds. No species of Cyrena is now met
with in a living state in Europe. Mr. Prestwich first observed it fossil
at Menchecourt, and it has since been found in two or three contiguous
sand-pits, always in the fluvio-marine bed. [16]
[Illustration: Figure 17. Cyrena fluminalis]
(FIGURE 17. Cyrena fluminalis, O.F. Muller, sp.*
(* For synonyms, see S. Woodward "Tibet Shells" "Proceedings
of the Zoological Society" July 8, 1856.)
a. Interior of left valve, from Gray's Thurrock, Essex.
b. Hinge of the same magnified.
c. Interior of right valve of a small specimen, from Shacklewell,
London.
d. Outer surface of right valve, from Erith, Kent.)
TABLE 8/1. DATES OF SPECIFIC NAMES.
COLUMN 1: SPECIES.
COLUMN 2: DATE.
LIVING:
Tellina fluminalis, O.F. Muller: 1774.
Venus fluminalis Euphratis, Chemnitz: 1782.
Cyclas Euphratica, Lam.: 1806.
Cyrena cor, Lam. (Nile): 1818.
Cyrena consobrina, Caillaud (Nile): 1823.
Cyrena Cashmiriensis, Desh.:
Corbicuia fluminalis, Muhlfeldt.: 1811.
FOSSIL:
Cyrena trigonula, S. Woodward: 1834.
Cyrena Gemmellarii, Philippi: 1836.
Cyrena Duchastelii, Nyst: 1838.
The following marine shells occur mixed with the freshwater species
above enumerated:--Buccinum undatum, Littorina littorea, Nassa
reticulata, Purpura lapillus, Tellina solidula, Cardium edule, and
fragments of some others. Several of these I have myself collected
entire, though in a state of great decomposition, lying in the white
sand called "sable aigre" by the workmen. They are all littoral species
now proper to the contiguous coast of France. Their occurrence in a
fossil state associated with freshwater shells at Menchecourt had been
noticed as long ago as 1836 by MM. Ravin and Baillon, before M. Boucher
de Perthes commenced the researches which have since made the locality
so celebrated.*
(* D'Archiac, "Histoire des Progres" etc. volume 2 page
154.)
The numbers since collected preclude all idea of their having been
brought inland as eatable shells by the fabricators of the flint
hatchets found at the bottom of the fluvio-marine sands. From the same
beds, and in marls alternating with the sands, remains of the elephant,
rhinoceros, and other mammalia have been exhumed.
Above the fluvio-marine strata are those designated Number 2 in the
section (Figure 16), which are almost devoid of stratification, and
probably formed of mud or sediment thrown down by the waters of the
river when they overflowed the ancient alluvial plain of that day. Some
land shells, a few river shells, and bones of mammalia, some of them
extinct, occur in Number 2. Its upper surface has been deeply furrowed
and cut into by the action of water, at the time when the earthy matter
of Number 1 was superimposed. The materials of this uppermost deposit
are arranged as if they had been the result of land floods, taking place
after the formations 2 and 3 had been raised, or had become exposed to
denudation.
The fluvio-marine strata and overlying loam of Menchecourt recur on the
opposite or left bank of the alluvial plain of the Somme, at a distance
of 2 or 3 miles. They are found at Mautort, among other places, and I
obtained there the flint hatchet shown in Figure 9, of an oval form. It
was extracted from gravel, above which were strata containing a mixture
of marine and freshwater shells, precisely like those of Menchecourt.
In the alluvium of all parts of the valley, both at high and low levels,
rolled bones are sometimes met with in the gravel. Some of the flint
tools in the gravel of Abbeville have their angles very perfect, others
have been much triturated, as if in the bed of the main river or some of
its tributaries.
The mammalia most frequently cited as having been found in the deposits
Numbers 2 and 3 at Menchecourt, are the following:--
Elephas primigenius.
Rhinoceros tichorhinus.
Equus fossilis, Owen.
Bos primigenius.
Cervus somonensis, Cuvier.
C. tarandus priscus, Cuvier.
Felis spelaea.
Hyaena spelaea.
The Ursus spelaeus has also been mentioned by some writers; but
M. Lartet says he has sought in vain for it among the osteological
treasures sent from Abbeville to Cuvier at Paris, and in other
collections. The same palaeontologist, after a close scrutiny of the
bones sent formerly to the Paris Museum from the valley of the Somme,
observed that some of them bore the evident marks of an instrument,
agreeing well with incisions such as a rude flint-saw would produce.
Among other bones mentioned as having been thus artificially cut,
are those of a Rhinoceros tichorhinus, and the antlers of Cervus
somonensis.*
(* "Quarterly Journal of the Geological Society" volume 16
1860 page 471.)
The evidence obtained by naturalists that some of the extinct mammalia
of Menchecourt really lived and died in this part of France, at the
time of the embedding of the flint tools in fluviatile strata, is most
satisfactory; and not the less so for having been put on record long
before any suspicion was entertained that works of art would ever be
detected in the same beds. Thus M. Baillon, writing in 1834 to M. Ravin,
says: "They begin to meet with fossil bones at the depth of 10 or 12
feet in the Menchecourt sand-pits, but they find a much greater quantity
at the depth of 18 and 20 feet. Some of them were evidently broken
before they were embedded, others are rounded, having, without doubt,
been rolled by running water. It is at the bottom of the sand-pits that
the most entire bones occur. Here they lie without having undergone
fracture or friction, and seem to have been articulated together at the
time when they were covered up. I found in one place a whole hind limb
of a rhinoceros, the bones of which were still in their true relative
position. They must have been joined together by ligaments, and even
surrounded by muscles at the time of their interment. The entire
skeleton of the same species was lying at a short distance from the
spot."*
(* "Societe Roy. d'Emulation d'Abbeville" 1834 page 197.)
If we suppose that the greater number of the flint implements occurring
in the neighbourhood of Abbeville and Amiens were brought by river
action into their present position, we can at once explain why so large
a proportion of them are found at considerable depths from the surface,
for they would naturally be buried in gravel and not in fine sediment,
or what may be termed "inundation mud," such as Number 2 (Figure 16),
a deposit from tranquil water, or where the stream had not sufficient
force or velocity to sweep along Chalk flints, whether wrought or
unwrought. Hence we have almost always to pass down through a mass of
incumbent loam with land shells, or through fine sand with freshwater
molluscs, before we get into the beds of gravel containing hatchets.
Occasionally a weapon used as a projectile may have fallen into quiet
water, or may have dropped from a canoe to the bottom of the river, or
may have been floated by ice, as are some stones occasionally by the
Thames in severe winters, and carried over the meadows bordering its
banks; but such cases are exceptional, though helping to explain how
isolated flint tools or pebbles and angular stones are now and then to
be seen in the midst of the finest loams.
The endless variety in the sections of the alluvium of the valley of the
Somme, may be ascribed to the frequent silting up of the main stream and
its tributaries during different stages of the excavation of the valley,
probably also during changes in the level of the land. As a rule, when a
river attacks and undermines one bank, it throws down gravel and sand on
the opposite side of its channel, which is growing somewhere shallower,
and is soon destined to be raised so high as to form an addition to
the alluvial plain, and to be only occasionally inundated. In this way,
after much encroachment on cliff or meadow at certain points, we find
at the end of centuries that the width of the channel has not been
enlarged, for the new made ground is raised after a time to the average
height of the older alluvial tract. Sometimes an island is formed in
midstream, the current flowing for a while on both sides of it, and
at length scooping out a deeper channel on one side so as to leave the
other to be gradually filled up during freshets and afterwards elevated
by inundation mud, or "brick-earth." During the levelling up of these
old channels, a flood sometimes cuts into and partially removes portions
of the previously stratified matter, causing those repeated signs of
furrowing and filling up of cavities, those memorials of doing and
undoing, of which the tool-bearing sands and gravels of Abbeville and
Amiens afford such reiterated illustrations, and of which a parallel is
furnished by the ancient alluvium of the Thames valley, where similar
bones of extinct mammalia and shells, including Cyrena fluminalis, are
found.
Professor Noeggerath, of Bonn, informs me that, about the year 1845,
when the bed of the Rhine was deepened artificially by the blasting
and removal of rock in the narrows at Bingerloch, not far from Bingen,
several flint hatchets and an extraordinary number of iron weapons of
the Roman period were brought up by the dredge from the bed of the great
river. The decomposition of the iron had caused much of the gravel to
be cemented together into a conglomerate. In such a case we have only
to suppose the Rhine to deviate slightly from its course, changing
its position, as it has often done in various parts of its plain in
historical times, and then tools of the stone and iron periods would
be found in gravel at the bottom with a great thickness of sand and
overlying loam deposited above them.
Changes in a river plain, such as those above alluded to, give rise
frequently to ponds, swamps, and marshes, marking the course of old beds
or branches of the river not yet filled up, and in these depressions
shells proper both to running and stagnant water may be preserved, and
quadrupeds may be mired. The latest and uppermost deposit of the series
will be loam or brick-earth, with land and amphibious shells (Helix and
Succinea), while below will follow strata containing freshwater shells,
implying continuous submergence; and lowest of all in most sections will
be the coarse gravel accumulated by a current of considerable strength
and velocity.
When the St. Katharine docks were excavated at London, and similar works
executed on the banks of the Mersey, old ships were dug out, as I have
elsewhere noticed,* showing how the Thames and Mersey have in modern
times been shifting their channels.
(* "Principles of Geology" 10th edition volume 2 page 547.)
Recently, an old silted-up bed of the Thames has been discovered by
boring at Shoeburyness at the mouth of the river opposite Sheerness, as
I learn from Mr. Mylne. The old deserted branch is separated from the
new or present channel of the Thames, by a mass of London Clay which
has escaped denudation. The depth of the old branch, or the thickness
of fluviatile strata with which it has been filled up, is 75 feet. The
actual channel in the neighbourhood is now 60 feet deep, but there is
probably 10 or 15 feet of stratified sand and gravel at the bottom; so
that, should the river deviate again from its course, its present bed
might be the receptacle of a fluvio-marine formation 75 feet thick,
equal to the former one of Shoeburyness, and more considerable than that
of Abbeville. It would consist both of freshwater and marine strata,
as the salt water is carried by the tide far up above Sheerness; but in
order that such deposits should resemble, in geological position, the
Menchecourt beds, they must be raised 10 or 15 feet above their present
level, and be partially eroded. Such erosion they would not fail to
suffer during the process of upheaval, because the Thames would scour
out its bed, and not alter its position relatively to the sea, while the
land was gradually rising.
Before the canal was made at Abbeville, the tide was perceptible in
the Somme for some distance above that city. It would only require,
therefore, a slight subsidence to allow the salt water to reach
Menchecourt, as it did in the Pleistocene period. As a stratum
containing exclusively land and freshwater shells usually underlies
the fluvio-marine sands at Menchecourt, it seems that the river first
prevailed there, after which the land subsided; and then there was an
upheaval which raised the country to a greater height than that at which
it now stands, after which there was a second sinking, indicated by the
position of the peat, as already explained. All these changes happened
since Man first inhabited this region.
At several places in the environs of Abbeville there are fluviatile
deposits at a higher level by 50 feet than the uppermost beds at
Menchecourt, resting in like manner on the Chalk. One of these occurs in
the suburbs of the city at Moulin Quignon, 100 feet above the Somme
and on the same side of the valley as Menchecourt, and containing flint
implements of the same antique type and the bones of elephants; but no
marine shells have been found there, nor in any gravel or sand at higher
elevations than the Menchecourt marine shells.
It has been a matter of discussion among geologists whether the higher
or the lower sands and gravels of the Somme valley are the more ancient.
As a general rule, when there are alluvial formations of different ages
in the same valley, those which occupy a more elevated position above
the river plain are the oldest. In Auvergne and Velay, in Central
France, where the bones of fossil quadrupeds occur at all heights above
the present rivers from 10 to 1000 feet, we observe the terrestrial
fauna to depart in character from that now living in proportion as
we ascend to higher terraces and platforms. We pass from the lower
alluvium, containing the mammoth, tichorhine rhinoceros, and reindeer,
to various older groups of fossils, till, on a tableland 1000 feet high
(near Le Puy, for example), the abrupt termination of which overlooks
the present valley, we discover an old extinct river-bed covered by
a current of ancient lava, showing where the lowest level was once
situated. In that elevated alluvium the remains of a Tertiary mastodon
and other quadrupeds of like antiquity are embedded.
If the Menchecourt beds had been first formed, and the valley, after
being nearly as deep and wide as it is now, had subsided, the sea
must have advanced inland, causing small delta-like accumulations at
successive heights, wherever the main river and its tributaries met
the sea. Such a movement, especially if it were intermittent, and
interrupted occasionally by long pauses, would very well account for the
accumulation of stratified debris which we encounter at certain points
in the valley, especially around Abbeville and Amiens. But we are
precluded from adopting this theory by the entire absence of marine
shells, and the presence of freshwater and land species, and mammalian
bones, in considerable abundance, in the drift both of higher and lower
levels above Abbeville. Had there been a total absence of all organic
remains, we might have imagined the former presence of the sea, and the
destruction of such remains might have been ascribed to carbonic acid
or other decomposing causes; but the Pleistocene and implement-bearing
strata can be shown by their fossils to be of fluviatile origin.
FLINT IMPLEMENTS IN GRAVEL NEAR AMIENS. GRAVEL OF ST. ACHEUL.
When we ascend the valley of the Somme, from Abbeville to Amiens, a
distance of about 25 miles, we observe a repetition of all the same
alluvial phenomena which we have seen exhibited at Menchecourt and its
neighbourhood, with the single exception of the absence of marine shells
and of Cyrena fluminalis. We find lower-level gravel, such as Number 2,
Figure 7, and higher-level alluvium, such as Number 3, the latter rising
to 100 feet above the plain, which at Amiens is about 50 feet above the
level of the river at Abbeville. In both the upper and lower gravels,
as Dr. Rigollot stated in 1854, flint tools and the bones of extinct
animals, together with river shells and land shells of living species,
abound.
[Illustration: Figures 18, 19 and 20. Elephas]
(FIGURE 18.* Elephas primigenius.
Penultimate molar, lower jaw, right side, one-third of
natural size, Pleistocene. Co-existed with Man.)
(FIGURE 19.* Elephas antiquus, Falconer.
Penultimate molar, lower jaw, right side, one-third of natural
size, Pleistocene and Newer Pliocene. Co-existed with Man.)
(FIGURE 20.* Elephas meridionalis, Nesti.
Penultimate molar, lower jaw, right side, one-third of natural
size, Newer Pliocene, Saint Prest, near Chartres, and
Norwich Crag. Not yet proved to have coexisted with Man.)
(* For Figure 20 I am indebted to M. Lartet, and Figure 18
will be found in his paper in "Bulletin de la Societe
Geologique de France" March 1859. Figure 19 is from Falconer
and Cautley "Fauna Sivalensis.")
Immediately below Amiens, a great mass of stratified gravel, slightly
elevated above the alluvial plain of the Somme, is seen at St. Roch,
and half a mile farther down the valley at Montiers. Between these two
places a small tributary stream, called the Celle, joins the Somme. In
the gravel at Montiers, Mr. Prestwich and I found some flint knives, one
of them flat on one side, but the other carefully worked, and exhibiting
many fractures, clearly produced by blows skilfully applied. Some of
these knives were taken from so low a level as to satisfy us that this
great bed of gravel at Montiers, as well as that of the contiguous
quarries of St. Roch, which seems to be a continuation of the same
deposit, may be referred to the human period. Dr. Rigollot had already
mentioned flint hatchets as obtained by him from St. Roch, but as
none have been found there of late years, his statement was thought to
require confirmation. The discovery, therefore, of these flint knives
in gravel of the same age was interesting, especially as many tusks of
a hippopotamus have been obtained from the gravel of St. Roch--some of
these recently by Mr. Prestwich; while M. Garnier of Amiens has procured
a fine elephant's molar from the same pits, which Dr. Falconer refers to
Elephas antiquus, see Figure 19. Hence I infer that both these animals
co-existed with Man.
The alluvial formations of Montiers are very instructive in another
point of view. If, leaving the lower gravel of that place, which is
topped with loam or brick-earth (of which the upper portion is about
30 feet above the level of the Somme), we ascend the Chalk slope to
the height of about 80 feet, another deposit of gravel and sand, with
fluviatile shells in a perfect condition, occurs, indicating most
clearly an ancient river-bed, the waters of which ran habitually at
that higher level before the valley had been scooped out to its present
depth. This superior deposit is on the same side of the Somme, and about
as high, as the lowest part of the celebrated formation of St. Acheul, 2
or 3 miles distant, to which I shall now allude.
The terrace of St. Acheul may be described as a gently sloping ledge of
Chalk, covered with gravel, topped as usual with loam or fine sediment,
the surface of the loam being 100 feet above the Somme, and about 150
above the sea.
Many stone coffins of the Gallo-Roman period have been dug out of the
upper portion of this alluvial mass. The trenches made for burying
them sometimes penetrate to the depth of 8 or 9 feet from the surface,
entering the upper part of Number 3 of the sections Figures 21 and 22.
They prove that when the Romans were in Gaul they found this terrace in
the same condition as it is now, or rather as it was before the removal
of so much gravel, sand, clay, and loam, for repairing roads, and for
making bricks and pottery.
[Illustration: Figure 21. Section of Gravel Pit]
(FIGURE 21. SECTION OF GRAVEL PIT CONTAINING FLINT IMPLEMENTS
AT ST. ACHEUL, NEAR AMIENS, OBSERVED IN JULY 1860.
1. Vegetable soil and made ground, 2 to 3 feet thick.
2. Brown loam with some angular flints, in parts passing into
ochreous gravel, filling up indentations on the surface
of Number 3, 3 feet thick.
3. White siliceous sand with layers of chalky marl, and included
fragments of Chalk, for the most part unstratified, 9 feet.
4. Flint-gravel, and whitish chalky sand, flints subangular,
average size of fragments, 3 inches diameter, but with some
large unbroken Chalk flints intermixed, cross stratification
in parts. Bones of mammalia, grinder of elephant at b, and
flint implement at c, 10 to 14 feet.
5. Chalk with flints.
a. Part of elephant's molar, 11 feet from the surface.
b. Entire molar of Elephas primigenius, 17 feet from the surface.
c. Position of flint hatchet, 18 feet from the surface.)
In the annexed section (Figure 21), which I observed during my last
visit in 1860, it will be seen that a fragment of an elephant's tooth is
noticed as having been dug out of unstratified sandy loam at the point
a, 11 feet from the surface. This was found at the time of my visit; and
at a lower point, at b, 18 feet from the surface, a large nearly entire
and unrolled molar of the same species was obtained, which is now in my
possession. It has been pronounced by Dr. Falconer to belong to Elephas
primigenius.
A stone hatchet of an oval form, like that represented at Figure 9, was
discovered at the same time, about one foot lower down, at c, in densely
compressed gravel. The surface of the fundamental Chalk is uneven
in this pit, and slopes towards the valley-plain of the Somme. In a
horizontal distance of 20 feet, I found a difference in vertical height
of 7 feet. In the chalky sand, sometimes occurring in interstices
between the separate fragments of flint, constituting the coarse gravel
Number 4, entire as well as broken freshwater shells are often met with.
To some it may appear enigmatical how such fragile objects could have
escaped annihilation in a river-bed, when flint tools and much gravel
were shoved along the bottom; but I have seen the dredging instrument
employed in the Thames, above and below London Bridge, to deepen the
river, and worked by steam power, scoop up gravel and sand from the
bottom, and then pour the contents pell-mell into the boat, and still
many specimens of Limnaea, Planorbis, Paludina, Cyclas, and other shells
might be taken out uninjured from the gravel.
It will be observed that the gravel Number 4 is obliquely stratified,
and that its surface had undergone denudation before the white sandy
loam Number 3 was superimposed. The materials of the gravel at d must
have been cemented or frozen together into a somewhat coherent mass
to allow the projecting ridge, d, to stand up 5 feet above the general
surface, the sides being in some places perpendicular. In Number 3 we
probably behold an example of a passage from river-silt to inundation
mud. In some parts of it, land shells occur.
It has been ascertained by MM. Buteux, Ravin, and other observers
conversant with the geology of this part of France, that in none of the
alluvial deposits, ancient or modern, are there any fragments of rocks
foreign to the basin of the Somme--no erratics which could only be
explained by supposing them to have been brought by ice, during a
general submergence of the country, from some other hydrographical
basin.
But in some of the pits at St. Acheul there are seen in the beds Number
4, Figure 21, not only well-rounded Tertiary pebbles, but great
blocks of hard sandstone, of the kind called in the south of England
"greywethers," some of which are 3 or 4 feet and upwards in diameter.
They are usually angular, and when spherical owe their shape generally
to an original concretionary structure, and not to trituration in a
river's bed. These large fragments of stone abound both in the higher
and lower level gravels round Amiens and at the higher level at
Abbeville. They have also been traced far up the valley above Amiens,
wherever patches of the old alluvium occur. They have all been derived
from the Tertiary strata which once covered the Chalk. Their dimensions
are such that it is impossible to imagine a river like the present
Somme, flowing through a flat country, with a gentle fall towards
the sea, to have carried them for miles down its channel unless ice
co-operated as a transporting power. Their angularity also favours the
supposition of their having been floated by ice, or rendered so
buoyant by it as to have escaped much of the wear and tear which blocks
propelled along the bottom of a river channel would otherwise suffer.
We must remember that the present mildness of the winters in Picardy
and the northwest of Europe generally is exceptional in the northern
hemisphere, and that large fragments of granite, sandstone, and
limestone are now carried annually by ice down the Canadian rivers in
latitudes farther south than Paris.*
(* "Principles of Geology" 9th edition page 220.)
[Illustration: Figure 22. Contorted Strata]
(FIGURE 22. CONTORTED FLUVIATILE STRATA AT ST. ACHEUL
(Prestwich, "Philosophical Transactions" 1861, page 299).
1. Surface soil.
2. Brown loam as in Figure 21, thickness, 6 feet.
3. White sand with bent and folded layers of marl, thickness,
6 feet.
4. Gravel, as in Figure 21, with bones of mammalia and flint
implements.
A. Graves filled with made ground and human bones.
b and c. Seams of laminated marl often bent round upon themselves.
d. Beds of gravel with sharp curves.)
Another sign of ice agency, of which Mr. Prestwich has given a good
illustration in one of his published sections, and which I myself
observed in several pits at St. Acheul, deserves notice. It consists
in flexures and contortions of the strata of sand, marl, and gravel (as
seen at b, c, and d, Figure 22), which they have evidently undergone
since their original deposition, and from which both the underlying
Chalk and part of the overlying beds of sand Number 3 are usually
exempt.
In my former writings I have attributed this kind of derangement to two
causes; first, the pressure of ice running aground on yielding banks of
mud and sand; and, secondly, the melting of masses of ice and snow of
unequal thickness, on which horizontal layers of mud, sand, and other
fine and coarse materials had accumulated. The late Mr. Trimmer first
pointed out in what manner the unequal failure of support caused by the
liquefaction of underlying or intercalated snow and ice might give rise
to such complicated foldings.*
(* See chapter 12.)
When "ice-jams" occur on the St. Lawrence and other Canadian rivers
(latitude 46 degrees north), the sheets of ice, which become packed or
forced under or over one another, assume in most cases a highly inclined
and sometimes even a vertical position. They are often observed to be
coated on one side with mud, sand, or gravel frozen on to them, derived
from shallows in the river on which they rested when congelation first
reached the bottom.
As often as portions of these packs melt near the margin of the
river, the layers of mud, sand, and gravel, which result from their
liquefaction, cannot fail to assume a very abnormal arrangement--very
perplexing to a geologist who should undertake to interpret them without
having the ice-clue in his mind.
Mr. Prestwich has suggested that ground-ice may have had its influence
in modifying the ancient alluvium of the Somme.*
(* Prestwich, Memoir read to Royal Society, April 1862.)
It is certain that ice in this form plays an active part every winter
in giving motion to stones and gravel in the beds of rivers in European
Russia and Siberia. It appears that when in those countries the streams
are reduced nearly to the freezing point, congelation begins frequently
at the bottom; the reason being, according to Arago, that the current is
slowest there, and the gravel and large stones, having parted with much
of their heat by radiation, acquire a temperature below the average of
the main body of the river. It is, therefore, when the water is clear,
and the sky free from clouds, that ground ice forms most readily, and
oftener on pebbly than on muddy bottoms. Fragments of such ice, rising
occasionally to the surface, bring up with them gravel, and even large
stones.
Without dwelling longer on the various ways in which ice may affect the
forms of stratification in drift, so as to cause bendings and foldings
in which the underlying or over-lying strata do not participate, a
subject to which I shall have occasion again to allude in the sequel,
I will state in this place that such contortions, whether explicable or
not, are very characteristic of glacial formations. They have also no
necessary connection with the transportation of large blocks of stone,
and they therefore afford, as Mr. Prestwich remarks, independent proof
of ice-action in the Pleistocene gravel of the Somme.
Let us, then, suppose that, at the time when flint hatchets were
embedded in great numbers in the ancient gravel which now forms the
terrace of St. Acheul, the main river and its tributaries were annually
frozen over for several months in winter. In that case, the primitive
people may, as Mr. Prestwich hints, have resembled in their mode of life
those American Indians who now inhabit the country between Hudson's Bay
and the Polar Sea. The habits of those Indians have been well described
by Hearne, who spent some years among them. As often as deer and other
game become scarce on the land, they betake themselves to fishing in
the rivers; and for this purpose, and also to obtain water for drinking,
they are in the constant practice of cutting round holes in the ice, a
foot or more in diameter, through which they throw baited hooks or nets.
Often they pitch their tent on the ice, and then cut such holes through
it, using ice-chisels of metal when they can get copper or iron, but
when not, employing tools of flint or hornstone.
The great accumulation of gravel at St. Acheul has taken place in part
of the valley where the tributary streams, the Noye and the Arve, now
join the Somme. These tributaries, as well as the main river, must have
been running at the height first of 100 feet, and afterwards at various
lower levels above the present valley-plain, in those earlier times
when the flint tools of the antique type were buried in successive river
beds. I have said at various levels, because there are, here and there,
patches of drift at heights intermediate between the higher and lower
gravel, and also some deposits, showing that the river once flowed
at elevations above as well as below the level of the platform of St.
Acheul. As yet, however, no patch of gravel skirting the valley at
heights exceeding 100 feet above the Somme has yielded flint tools or
other signs of the former sojourn of Man in this region.
Possibly, in the earlier geographical condition of this country, the
confluence of tributaries with the Somme afforded inducements to a
hunting and fishing tribe to settle there, and some of the same natural
advantages may have caused the first inhabitants of Amiens and Abbeville
to fix on the same sites for their dwellings. If the early hunting and
fishing tribes frequented the same spots for hundreds or thousands of
years in succession, the number of the stone implements lost in the
bed of the river need not surprise us. Ice-chisels, flint hatchets, and
spear-heads may have slipped accidentally through holes kept constantly
open, and the recovery of a lost treasure once sunk in the bed of the
ice-bound stream, inevitably swept away with gravel on the breaking up
of the ice in the spring, would be hopeless. During a long winter, in a
country affording abundance of flint, the manufacture of tools would be
continually in progress; and, if so, thousands of chips and flakes
would be purposely thrown into the ice-hole, besides a great number of
implements having flaws, or rejected as too unskilfully made to be worth
preserving.
As to the fossil fauna of the drift, considered in relation to the
climate, when, in 1859, I took a collection which I had made of all the
more common species of land and freshwater shells from the Amiens and
Abbeville drift, to my friend M. Deshayes at Paris, he declared them to
be, without exception, the same as those now living in the basin of the
Seine. This fact may seem at first sight to imply that the climate had
not altered since the flint tools were fabricated; but it appears that
all these species of molluscs now range as far north as Norway and
Finland, and may therefore have flourished in the valley of the Somme
when the river was frozen over annually in winter.*
(* See Prestwich, Paper read to the Royal Society in 1862.)
In regard to the accompanying mammalia, some of them, like the mammoth
and tichorhine rhinoceros, may have been able to endure the rigours of
a northern winter as well as the reindeer, which we find fossil in
the same gravel. It is a more difficult point to determine whether the
climate of the lower gravels (those of Menchecourt, for example) was
more genial than that of the higher ones. Mr. Prestwich inclines to this
opinion. None of those contortions of the strata above described have
as yet been observed in the lower drift. It contains large blocks of
Tertiary sandstone and grit, which may have required the aid of ice to
convey them to their present sites; but as such blocks already abounded
in the older and higher alluvium, they may simply be monuments of its
destruction, having been let down successively to lower and lower levels
without making much seaward progress.
The Cyrena fluminalis of Menchecourt and the hippopotamus of St. Roch
seem to be in favour of a less severe temperature in winter; but so
many of the species of mammalia, as well as of the land and freshwater
shells, are common to both formations, and our information respecting
the entire fauna is still so imperfect, that it would be premature to
pretend to settle this question in the present state of our knowledge.
We must be content with the conclusion (and it is one of no small
interest), that when Man first inhabited this part of Europe, at the
time that the St. Acheul drift was formed, the climate as well as the
physical geography of the country differed considerably from the state
of things now established there.
Among the elephant remains from St. Acheul, in M. Garnier's collection,
Dr. Falconer recognised a molar of the Elephas antiquus, Figure 19, the
same species which has been already mentioned as having been found in
the lower-level gravels of St. Roch. This species, therefore, endured
while important changes took place in the geographical condition of the
valley of the Somme. Assuming the lower-level gravel to be the newer,
it follows that the Elephas antiquus and the hippopotamus of St. Roch
continued to flourish long after the introduction of the mammoth, a
well characterised tooth of which, as I before stated, was found at St.
Acheul at the time of my visit in 1860.
As flint hatchets and knives have been discovered in the alluvial
deposits both at high and low levels, we may safely affirm that Man was
as old an inhabitant of this region as were any of the fossil quadrupeds
above enumerated, a conclusion which is independent of any difference of
opinion as to the relative age of the higher and lower gravels.
The disappearance of many large pachyderms and beasts of prey from
Europe has often been attributed to the intervention of Man, and no
doubt he played his part in hastening the era of their extinction; but
there is good reason for suspecting that other causes co-operated to
the same end. No naturalist would for a moment suppose that the
extermination of the Cyrena fluminalis throughout the whole of Europe--a
species which co-existed with our race in the valley of the Somme, and
which was very abundant in the waters of the Thames at the time when
the elephant, rhinoceros, and hippopotamus flourished on its banks--was
accelerated by human agency. The great modification in climate and in
other conditions of existence which affected this aquatic mollusc, may
have mainly contributed to the gradual dying out of many of the large
mammalia.
We have already seen that the peat of the valley of the Somme is a
formation which, in all likelihood, took thousands of years for
its growth. But no change of a marked character has occurred in the
mammalian fauna since it began to accumulate. The contrast of the fauna
of the ancient alluvium, whether at high or low levels, with the fauna
of the oldest peat is almost as great as its contrast with the existing
fauna, the memorials of Man being common to the whole series; hence we
may infer that the interval of time which separated the era of the
large extinct mammalia from that of the earliest peat, was of far longer
duration than that of the entire growth of the peat. Yet we by no means
need the evidence of the ancient fossil fauna to establish the antiquity
of Man in this part of France. The mere volume of the drift at various
heights would alone suffice to demonstrate a vast lapse of time during
which such heaps of shingle, derived both from the Eocene and the
Cretaceous rocks, were thrown down in a succession of river-channels. We
observe thousands of rounded and half-rounded flints, and a vast number
of angular ones, with rounded pieces of white Chalk of various sizes,
testifying to a prodigious amount of mechanical action, accompanying
the repeated widening and deepening of the valley, before it became the
receptacle of peat; and the position of many of the flint tools leaves
no doubt in the mind of the geologist that their fabrication preceded
all this reiterated denudation.
ON THE ABSENCE OF HUMAN BONES IN THE ALLUVIUM OF THE SOMME.
It is naturally a matter of no small surprise that, after we have
collected many hundred flint implements (including knives, many
thousands), not a single human bone has yet been met with in the old
alluvial sand and gravel of the Somme. This dearth of the mortal remains
of our species holds true equally, as yet, in all other parts of
Europe where the tool-bearing drift of the Pleistocene period has been
investigated in valley deposits. Yet in these same formations there is
no want of bones of mammalia belonging to extinct and living species. In
the course of the last quarter of a century, thousands of them have been
submitted to the examination of skilful osteologists, and they have been
unable to detect among them one fragment of a human skeleton, not even
a tooth. Yet Cuvier pointed out long ago, that the bones of Man found
buried in ancient battle-fields were not more decayed than those of
horses interred in the same graves. We have seen that in the Liege
caverns, the skulls, jaws, and teeth, with other bones of the human
race, were preserved in the same condition as those of the cave-bear,
tiger, and mammoth.
That ere long, now that curiosity has been so much excited on this
subject, some human remains will be detected in the older alluvium of
European valleys, I confidently expect. In the meantime, the absence of
all vestige of the bones which belonged to that population by which so
many weapons were designed and executed, affords a most striking and
instructive lesson in regard to the value of negative evidence, when
adduced in proof of the non-existence of certain classes of terrestrial
animals at given periods of the past. It is a new and emphatic
illustration of the extreme imperfection of the geological record, of
which even they who are constantly working in the field cannot easily
form a just conception.
We must not forget that Dr. Schmerling, after finding extinct mammalia
and FLINT TOOLS in forty-two Belgian caverns, was only rewarded by the
discovery of human bones in three or four of those rich repositories of
osseous remains. In like manner, it was not till the year 1855 that
the first skull of the musk ox (Bubalus moschatus) was detected in the
fossiliferous gravel of the Thames, and not till 1860, as will be
seen in the next chapter, that the same quadruped was proved to have
co-existed in France with the mammoth. The same theory which will
explain the comparative rarity of such species would no doubt account
for the still greater scarcity of human bones, as well as for our
general ignorance of the Pleistocene terrestrial fauna, with the
exception of that part of it which is revealed to us by cavern
researches.
In valley drift we meet commonly with the bones of quadrupeds which
graze on plains bordering rivers. Carnivorous beasts, attracted to the
same ground in search of their prey, sometimes leave their remains
in the same deposits, but more rarely. The whole assemblage of fossil
quadrupeds at present obtained from the alluvium of Picardy is obviously
a mere fraction of the entire fauna which flourished contemporaneously
with the primitive people by whom the flint hatchets were made.
Instead of its being part of the plan of nature to store up enduring
records of a large number of the individual plants and animals which
have lived on the surface, it seems to be her chief care to provide the
means of disencumbering the habitable areas lying above and below the
waters of those myriads of solid skeletons of animals, and those massive
trunks of trees, which would otherwise soon choke up every river, and
fill every valley. To prevent this inconvenience she employs the heat
and moisture of the sun and atmosphere, the dissolving power of carbonic
and other acids, the grinding teeth and gastric juices of quadrupeds,
birds, reptiles, and fish, and the agency of many of the invertebrata.
We are all familiar with the efficacy of these and other causes on the
land; and as to the bottoms of seas, we have only to read the published
reports of Mr. MacAndrew, the late Edward Forbes, and other experienced
dredgers, who, while they failed utterly in drawing up from the deep a
single human bone, declared that they scarcely ever met with a work
of art even after counting tens of thousands of shells and zoophytes,
collected on a coast line of several hundred miles in extent, where
they often approached within less than half a mile of a land peopled by
millions of human beings.
LAKE OF HAARLEM.
It is not many years since the Government of Holland resolved to lay dry
that great sheet of water formerly called the Lake of Haarlem, extending
over 45,000 acres. They succeeded, in 1853, in turning it into dry land,
by means of powerful pumps constantly worked by steam, which raised the
water and discharged it into a canal running for 20 or 30 miles round
the newly-gained land. This land was depressed 13 feet beneath the mean
level of the ocean. I travelled, in 1859, over part of the bed of this
old lake, and found it already converted into arable land, and peopled
by an agricultural population of 5000 souls. Mr. Staring, who had
been for some years employed by the Dutch Government in constructing a
geological map of Holland, was my companion and guide. He informed me
that he and his associates had searched in vain for human bones in the
deposits which had constituted for three centuries the bed of the great
lake.
There had been many a shipwreck, and many a naval fight in those waters,
and hundreds of Dutch and Spanish soldiers and sailors had met there
with a watery grave. The population which lived on the borders of this
ancient sheet of water numbered between thirty and forty thousand souls.
In digging the great canal, a fine section had been laid open, about 30
miles long, of the deposits which formed the ancient bottom of the lake.
Trenches, also, innumerable, several feet deep, had been freshly dug on
all the farms, and their united length must have amounted to thousands
of miles. In some of the sandy soil recently thrown out of the trenches,
I observed specimens of freshwater and brackish-water shells, such as
Unio and Dreissena, of living species; and in clay brought up from below
the sand, shells of Tellina, Lutraria, and Cardium, all of species now
inhabiting the adjoining sea.
As the Dreissena is believed by conchologists to have been introduced
into Western Europe in very modern times, brought with foreign timber
in the holds of vessels from the rivers flowing into the Black Sea, the
layer of sand containing it in the Haarlem lake is probably not more
than a hundred years old.
One or two wrecked Spanish vessels, and arms of the same period, have
rewarded the antiquaries who had been watching the draining operations
in the hope of a richer harvest, and who were not a little disappointed
at the result. In a peaty tract on the margin of one part of the lake a
few coins were dug up; but if history had been silent, and if there had
been a controversy whether Man was already a denizen of this planet
at the time when the area of the Haarlem lake was under water, the
archaeologist, in order to answer this question, must have appealed,
as in the case of the valley of the Somme, not to fossil bones, but to
works of art embedded in the superficial strata.
Mr. Staring, in his valuable memoir on the "Geological Map of Holland,"
has attributed the general scarcity of human bones in Dutch peat,
notwithstanding the many works of art preserved in it, to the power of
the humic and sulphuric acids to dissolve bones, the peat in question
being plentifully impregnated with such acids. His theory may be
correct, but it is not applicable to the gravel of the valley of the
Somme, in which the bones of fossil mammalia are frequent, nor to the
uppermost freshwater strata forming the bottom of a large part of the
Haarlem Lake, in which it is not pretended that such acids occur.
The primitive inhabitants of the valley of the Somme may have been too
wary and sagacious to be often surprised and drowned by floods, which
swept away many an incautious elephant or rhinoceros, horse and ox. But
even if those rude hunters had cherished a superstitious veneration for
the Somme, and had regarded it as a sacred river (as the modern Hindoos
revere the Ganges), and had been in the habit of committing the bodies
of their dead or dying to its waters--even had such funeral rites
prevailed, it by no means follows that the bones of many individuals
would have been preserved to our time.
A corpse cast into the stream first sinks, and must then be almost
immediately overspread with sediment of a certain weight, or it will
rise again when distended with gases, and float perhaps to the sea
before it sinks again. It may then be attacked by fish of marine
species, some of which are capable of digesting bones. If, before being
carried into the sea and devoured, it is enveloped with fluviatile mud
and sand, the next flood, if it lie in mid-channel, may tear it out
again, scatter all the bones, roll some of them into pebbles, and
leave others exposed to destroying agencies; and this may be repeated
annually, till all vestiges of the skeleton may disappear. On the other
hand, a bone washed through a rent into a subterranean cavity, even
though a rarer contingency, may have a greater chance of escaping
destruction, especially if there be stalactite dropping from the roof of
the cave or walls of a rent, and if the cave be not constantly traversed
by too strong a current of engulfed water.
CHAPTER 9. -- WORKS OF ART IN PLEISTOCENE ALLUVIUM OF FRANCE AND
ENGLAND.
Flint Implements in ancient Alluvium of the Basin of the Seine.
Bones of Man and of extinct Mammalia in the Cave of Arcy.
Extinct Mammalia in the Valley of the Oise.
Flint Implement in Gravel of same Valley.
Works of Art in Pleistocene Drift in Valley of the Thames.
Musk Ox.
Meeting of northern and southern Fauna.
Migrations of Quadrupeds.
Mammals of Mongolia.
Chronological Relation of the older Alluvium of the Thames to the
Glacial Drift.
Flint Implements of Pleistocene Period in Surrey, Middlesex, Kent,
Bedfordshire, and Suffolk.
FLINT IMPLEMENTS IN PLEISTOCENE ALLUVIUM IN THE BASIN OF THE SEINE.
In the ancient alluvium of the valleys of the Seine and its principal
tributaries, the same assemblage of fossil animals, which has been
alluded to in the last chapter as characterising the gravel of Picardy,
has long been known; but it was not till the year 1860, and when
diligent search had been expressly made for them, that flint implements
of the Amiens type were discovered in this part of France.
In the neighbourhood of Paris deposits of drift occur answering both to
those of the higher and lower levels of the basin of the Somme before
described.*
(* Prestwich, "Proceedings of the Royal Society" 1862.)
In both are found, mingled with the wreck of the Tertiary and Cretaceous
rocks of the vicinity, a large quantity of granitic sand and pebbles,
and occasionally large blocks of granite, from a few inches to a foot
or more in diameter. These blocks are peculiarly abundant in the lower
drift commonly called the "diluvium gris." The granitic materials are
traceable to a chain of hills called the Morvan, where the head waters
of the Yonne take their rise, 150 miles to the south-south-east of
Paris.
It was in this lowest gravel that M. H.T. Gosse, of Geneva, found, in
April 1860, in the suburbs of Paris, at La Motte Piquet, on the left
bank of the Seine, one or two well-formed flint implements of the Amiens
type, accompanied by a great number of ruder tools or attempts at tools.
I visited the spot in 1861 with M. Hebert, and saw the stratum from
which the worked flints had been extracted, 20 feet below the surface,
and near the bottom of the "grey diluvium," a bed of gravel from which
I have myself, in and near Paris, frequently collected the bones of the
elephant, horse, and other mammalia.
More recently, M. Lartet has discovered at Clichy, in the environs of
Paris, in the same lower gravel, a well-shaped flint implement of the
Amiens type, together with remains both of Elephas primigenius and
E. antiquus. No tools have yet been met with in any of the gravels
occurring at the higher levels of the valley of the Seine; but no
importance can be attached to this negative fact, as so little search
has yet been made for them.
Mr. Prestwich has observed contortions indicative of ice-action, of the
same kind as those near Amiens, in the higher-level drift of Charonne,
near Paris; but as yet no similar derangement has been seen in the
lower gravels--a fact, so far as it goes, in unison with the phenomena
observed in Picardy.
In the cavern of Arcy-sur-Yonne a series of deposits have lately been
investigated by the Marquis de Vibraye, who discovered human bones in
the lowest of them, mixed with remains of quadrupeds of extinct and
recent species. This cavern occurs in Jurassic limestone, at a slight
elevation above the Cure, a small tributary of the Yonne, which last
joins the Seine near Fontainebleau about 40 miles south of Paris. The
lowest formation in the cavern resembles the "diluvium gris" of Paris,
being composed of granitic materials, and like it derived chiefly from
the waste of the crystalline rocks of the Morvan. In it have been found
the two branches of a human lower jaw with teeth well-preserved, and
the bones of the Elephas primigenius, Rhinoceros tichorhinus, Ursus
spelaeus, Hyaena spelaea, and Cervus tarandus, all specifically
determined by M. Lartet. I have been shown this collection of fossils by
M. de Vibraye, and remarked that the human and other remains were in the
same condition and of the same colour.
Above the grey gravel is a bed of red alluvium, made up of fragments of
Jurassic limestone, in a red argillaceous matrix, in which were embedded
several flint knives, with bones of the reindeer and horse, but no
extinct mammalia. Over this, in a higher bed of alluvium, were several
polished hatchets of the more modern type called "celts," and above all
loam or cave-mud, in which were Gallo-Roman antiquities.*
(* "Bulletin de la Societe Geologique de France" 1860.)
The French geologists have made as yet too little progress in
identifying the age of the successive deposits of ancient alluvium of
various parts of the basin of the Seine, to enable us to speculate with
confidence as to the coincidence in date of the granitic gravel with
human bones of the Grotte d'Arcy and the stone-hatchets buried in "grey
diluvium" of La Motte Piquet, before mentioned; but as the associated
extinct mammalia are of the same species in both localities, I feel
strongly inclined to believe that the stone hatchets found by M. Gosse
at Paris, and the human bones discovered by M. de Vibraye, may be
referable to the same period.
VALLEY OF THE OISE.
A flint hatchet, of the old Abbeville and Amiens type, was found lately
by M. Peigne Delacourt at Precy, near Creil, on the Oise, in gravel,
resembling, in its geological position, the lower-level gravels of
Montiers, near Amiens, already described. I visited these extensive
gravel-pits in 1861, in company with Mr. Prestwich; but we remained
there too short a time to entitle us to expect to find a flint
implement, even if they had been as abundant as at St. Acheul.
In 1859, I examined, in a higher part of the same valley of the
Oise, near Chauny and Noyon, some fine railway cuttings, which passed
continuously through alluvium of the Pleistocene period for half a
mile. All this alluvium was evidently of fluviatile origin, for, in
the interstices between the pebbles, the Ancylus fluviatilis and other
freshwater shells were abundant. My companion, the Abbe E. Lambert,
had collected from the gravel a great many fossil bones, among which M.
Lartet has recognised both Elephas primigenius and E. antiquus, besides
a species of hippopotamus (H. major?), also the reindeer, horse, and the
musk ox (Bubalus moschatus). The latter seems never to have been seen
before in the old alluvium of France.*
(* Lartet, "Annales des Sciences Naturelles Zoologiques"
tome 15 page 224.)
Over the gravel above mentioned, near Chauny, are seen dense masses of
loam like the loess of the Rhine, containing shells of the genera
Helix and Succinea. We may suppose that the gravel containing the flint
hatchet at Precy is of the same age as that of Chauny, with which it is
continuous, and that both of them are coeval with the tool-bearing beds
of Amiens, for the basins of the Oise and the Somme are only separated
by a narrow water-shed, and the same fossil quadrupeds occur in both.
The alluvium of the Seine and its tributaries, like that of the Somme,
contains no fragments of rocks brought from any other hydrographical
basin; yet the shape of the land, or fall of the river, or the climate,
or all these conditions, must have been very different when the grey
alluvium in which the flint tools occur at Paris was formed. The great
size of some of the blocks of granite, and the distance which they have
travelled, imply a power in the river which it no longer possesses. We
can hardly doubt that river-ice once played a much more active part than
now in the transportation of such blocks, one of which may be seen in
the Museum of the Ecole des Mines at Paris, 3 or 4 feet in diameter.
PLEISTOCENE ALLUVIUM OF ENGLAND, CONTAINING WORKS OF ART.
In the ancient alluvium of the basin of the Thames, at moderate heights
above the main river and its tributaries, we find fossil bones of the
same species of extinct and living mammalia, accompanied by recent
species of land and freshwater shells, as we have shown to be
characteristic of the basins of the Somme and the Seine. We can
scarcely therefore doubt that these quadrupeds, during some part of
the Pleistocene period, ranged freely from the continent of Europe to
England, at a time when there was an uninterrupted communication by land
between the two countries. The reader will not therefore be surprised
to learn that flint implements of the same antique type as those of the
valley of the Somme have been detected in British alluvium.
The most marked feature of this alluvium in the Thames valley is that
great bed of ochreous gravel, composed chiefly of broken and slightly
worn Chalk flints, on which a great part of London is built. It extends
from above Maidenhead through the metropolis to the sea, a distance from
west to east of 50 miles, having a width varying from 2 to 9 miles. Its
thickness ranges commonly from 5 to 15 feet.*
(* Prestwich, "Quarterly Journal of the Geological Society"
volume 12 1856 page 131.)
Interstratified with this gravel, in many places, are beds of sand,
loam, and clay, the whole containing occasionally remains of the mammoth
and other extinct quadrupeds. Fine sections have been exposed to view,
at different periods, at Brentford and Kew Bridge, others in London
itself, and below it at Erith in Kent, on the right bank of the Thames,
and at Ilford and Gray's Thurrock in Essex, on the left bank. The united
thickness of the beds of sand, gravel, and loam amounts sometimes to 40
or even 60 feet. They are for the most part elevated above, but in some
cases they descend below, the present level of the overflowed plain of
the Thames.
If the reader will refer to the section of the Pleistocene sands and
gravels of Menchecourt, near Abbeville, given at page 96, he will
perfectly understand the relations of the ancient Thames alluvium to the
modern channel and plain of the river, and their relation, on the other
hand, to the boundary formations of older date, whether Tertiary or
Cretaceous.
So far as they are known, the fossil mollusca and mammalia of the two
districts also agree very closely, the Cyrena fluminalis being common to
both, and being the only extra-European shell, this and all the species
of testacea being Recent. Of this agreement with the living fauna there
is a fine illustration in Essex; for the determination of which we are
indebted to the late Mr. John Brown, F.G.S., who collected at Copford,
in Essex, from a deposit containing bones of the mammoth, a large bear
(probably Ursus spelaeus), a beaver, stag, and aurochs, no less than
sixty-nine species of land and freshwater shells. Forty-eight of these
were terrestrial, and two of them, Helix incarnata and H. ruderata, no
longer inhabit the British Isles, but are still living on the continent,
ruderata in high northern latitudes.*
(* "Quarterly Journal of the Geological Society" volume 8
1852 page 190. Mr. Brown calls them extinct species, which
may mislead some readers, but he merely meant extinct in
England. See also Jeffreys, "Brit. Conch." page 174.)
The Cyrena fluminalis and the Unio littoralis, to which last I shall
presently allude, were not among the number.
I long ago suggested the hypothesis, that in the basin of the Thames
there are indications of a meeting in the Pleistocene period of a
northern and southern fauna. To the northern group may have belonged the
mammoth (Elephas primigenius) and the Rhinoceros tichorhinus, both of
which Pallas found in Siberia, preserved with their flesh in the ice.
With these are occasionally associated the reindeer. In 1855 the skull
of the musk ox (Bubalus moschatus) was also found in the ochreous
gravel of Maidenhead, by the Reverend C. Kingsley and Mr. Lubbock; the
identification of this fossil with the living species being made by
Professor Owen. A second fossil skull of the same arctic animal was
afterwards found by Mr. Lubbock near Bromley, in the valley of a small
tributary of the Thames; and two other skulls, those of a bull and a cow
were dug up near Bath Easton from the gravel of the valley of the Avon
by Mr. Charles Moore. Professor Owen has truly said, that "as this
quadruped has a constitution fitting it at present to inhabit the
high northern regions of America, we can hardly doubt that its former
companions, the warmly-clad mammoth and the two-horned woolly rhinoceros
(R. tichorhinus), were in like manner capable of supporting life in a
cold climate."*
(* "Quarterly Journal of the Geological Society" volume 12
1856 page 124.)
I have already alluded to the recent discovery of this same ox near
Chauny, in the valley of the Oise, in France; and in 1856 I found
a skull of it preserved in the museum at Berlin, which Professor
Quenstedt, the curator, had correctly named so long ago as 1836, when
the fossil was dug out of drift, in the hill called the Kreuzberg, in
the southern suburbs of that city. By an account published at the time,
we find that the mammalia which accompanied the musk ox were the mammoth
and tichorhine rhinoceros, with the horse and ox;* but I can find no
record of the occurrence of a hippopotamus, nor of Elephas antiquus or
Rhinoceros leptorhinus, in the drift of the north of Germany, bordering
the Baltic.
(* "Leonhard and Bronn's Jahrbuch" 1836 page 215.)
On the other hand, in another locality in the same drift of North
Germany, Dr. Hensel, of Berlin, detected, near Quedlinburg, the
Norwegian Lemming (Myodes lemmus), and another species of the same
family called by Pallas Myodes torquatus (by Hensel, Misothermus
torquatus)--a still more arctic quadruped, found by Parry in latitude 82
degrees, and which never strays farther south than the northern borders
of the woody region. Professor Beyrich also informs me that the remains
of the Rhinoceros tichorhinus were obtained at the same place.*
(* "Zeitschrift der Deutschen Geologischen Gesellschaft"
volume 7 1855 page 497 etc.)
As an example of what may possibly have constituted a more southern
fauna in the valley of the Thames, I may allude to the fossil remains
found in the fluviatile alluvium of Gray's Thurrock, in Essex, situated
on the left bank of the river, 21 miles below London. The strata of
brick-earth, loam, and gravel exposed to view in artificial excavations
in that spot, are precisely such as would be formed by the silting up
of an old river channel. Among the mammalia are Elephas antiquus,
Rhinoceros leptorhinus (R. megarhinus, Christol), Hippopotamus major,
species of horse, bear, ox, stag, etc., and, among the accompanying
shells, Cyrena fluminalis, which is extremely abundant, instead of being
scarce, as at Abbeville. It is associated with Unio littoralis also in
great numbers and with both valves united. This conspicuous freshwater
mussel is no longer an inhabitant of the British Isles, but still
lives in the Seine, and is still more abundant in the Loire. Another
freshwater univalve (Paludina marginata, Michaud), not British, but
common in the south of France, likewise occurs, and a peculiar variety
of Cyclas amnica, which by some naturalists has been regarded as a
distinct species. With these, moreover, is found a peculiar variety of
Valvata piscinalis.
If we consult Dr. Von Schrenck's account of the living mammalia of
Mongolia, lying between latitude 45 and 55 degrees north, we learn
that, in that part of North-Eastern Asia recently annexed to the Russian
empire, no less than thirty-four out of fifty-eight living quadrupeds
are identical with European species, while some of those which do not
extend their range to Europe are arctic, others tropical forms. The
Bengal tiger ranges northwards occasionally to latitude 52 degrees
north, where he chiefly subsists on the flesh of the reindeer, and the
same tiger abounds in latitude 48 degrees, to which the small tailless
hare or pika, a polar resident, sometimes wanders southwards.*
(* Mammalia of Amoorland, "Natural History Review" volume 1
1861 page 12.)
We may readily conceive that the countries now drained by the Thames,
the Somme, and the Seine, were, in the Pleistocene period, on the
borders of two distinct zoological provinces, one lying to the north,
the other to the south, in which case many species belonging to each
fauna endowed with migratory habits, like the living musk-ox or the
Bengal tiger, may have been ready to take advantage of any, even the
slightest, change in their favour to invade the neighbouring province,
whether in the summer or winter months, or permanently for a series of
years, or centuries. The Elephas antiquus and its associated Rhinoceros
leptorhinus may have preceded the mammoth and tichorhine rhinoceros in
the valley of the Thames, or both may have alternately prevailed in the
same area in the Pleistocene period.
In attempting to settle the chronology of fluviatile deposits, it is
almost equally difficult to avail ourselves of the evidence of organic
remains and of the superposition of the strata, for we may find two old
river-beds on the same level in juxtaposition, one of them perhaps
many thousands of years posterior in date to the other. I have seen an
example of this at Ilford, where the Thames, or a tributary stream, has
at some former period cut through sands containing Cyrena fluminalis,
and again filled up the channel with argillaceous matter, evidently
derived from the waste of the Tertiary London Clay. Such shiftings
of the site of the main channel of the river, the frequent removal
of gravel and sand previously deposited, and the throwing down of new
alluvium, the flooding of tributaries, the rising and sinking of the
land, fluctuations in the cold and heat of the climate--all these
changes seem to have given rise to that complexity in the fluviatile
deposits of the Thames, which accounts for the small progress we have
hitherto made in determining their order of succession, and that of
the imbedded groups of quadrupeds. It may happen, as at Brentford and
Ilford, that sand-pits in two adjoining fields may each contain distinct
species of elephant and rhinoceros; and the fossil remains in both
cases may occur at the same depth from the surface, yet may be severally
referable to different parts of the Pleistocene epoch, separated by
thousands of years.
The relation of the glacial period to alluvial deposits, such as that of
Gray's Thurrock, where the Cyrena fluminalis, Unio littoralis, and the
hippopotamus seem rather to imply a warmer climate, has been a matter
of long and animated discussion. Patches of the northern drift,
at elevations of about 200 feet above the Thames, occur in the
neighbourhood of London, as at Muswell Hill, near Highgate. In this
drift, blocks of granite, syenite, greenstone, Coal-measure sandstone
with its fossils, and other Palaeozoic rocks, and the wreck of Chalk and
Oolite, occur confusedly mixed together. The same glacial formation
is also found capping some of the Essex hills farther to the east, and
extending some way down their southern slopes towards the valley of
the Thames. Although no fragments washed out of these older and upland
drifts have been found in the gravel of the Thames containing elephants'
bones, it is fair to presume, as Mr. Prestwich has contended,* that the
glacial formation is the older of the two.
(* Prestwich, "Quarterly Journal of the Geological Society"
volume 11 1855 page 110; ibid. volume 12 1856 page 133;
ibid. volume 17 1861 page 446.)
In short, we must suppose that the basin of the Thames and all its
fluviatile deposits are post-glacial, in the modified sense of that
term; i.e. that they were subsequent to the drift of the central and
northern counties.
Having offered these general remarks on the alluvium of the Thames, I
may now say something of the implements hitherto discovered in it. In
the British Museum there is a flint weapon of the spear-headed form,
such as is represented in Figure 8, which we are told was found with
an elephant's tooth at Black Mary's, near Gray's Inn Lane, London. In a
letter dated 1715, printed in Herne's edition of "Leland's Collectanea,"
volume 1 page 73, it is stated to have been found in the presence of Mr.
Conyers, with the skeleton of an elephant.*
(* Evans, "Archaeologia" 1860.)
So many bones of the elephant, rhinoceros, and hippopotamus have been
found in the gravel on which London stands, that there is no reason to
doubt the statement as handed down to us. Fossil remains of all these
three genera have been dug up on the site of Waterloo Place, St. James's
Square, Charing Cross, the London Docks, Limehouse, Bethnal Green, and
other places within the memory of persons now living. In the gravel and
sand of Shacklewell, in the north-east district of London, I have myself
collected specimens of the Cyrena fluminalis in great numbers (see
Figure 17 c), with the bones of deer and other mammalia.
In the alluvium also of the Wey, near Guildford, in a place called Pease
Marsh, a wedge-shaped flint implement, resembling one brought from
St. Acheul by Mr. Prestwich, and compared by some antiquaries to a
sling-stone, was obtained in 1836 by Mr. Whitburn, 4 feet deep in sand
and gravel, in which the teeth and tusks of elephants had been found.
The Wey flows through the gorge of the North Downs at Guildford to join
the Thames. Mr. Austen has shown that this drift is so ancient that one
part of it had been disturbed and tilted before another part was thrown
down.*
(* "Quarterly Journal of the Geological Society" volume 7
1851 page 278.)
Among other places where flint tools of the antique type have been met
with in the course of the last three years, I may mention one of an oval
form found by Mr. Whitaker in the valley of the Darent, in Kent, and
another which Mr. Evans found lying on the shore at Swalecliff, near
Whitstable, in the same county, where Mr. Prestwich had previously
described a freshwater deposit, resting on the London Clay, and
consisting chiefly of gravel, in which an elephant's tooth and the bones
of a bear were embedded. The flint implement was deeply discoloured
and of a peculiar bright light-brown colour, similar to that of the old
fluviatile gravel in the cliff.
Another flint implement was found in 1860 by Mr. T. Leech, at the foot
of the cliff between Herne Bay and the Reculvers, and on further search
five other specimens of the spear-head pattern so common at Amiens.
Messrs. Prestwich and Evans have since found three other similar tools
on the beach, at the base of the same wasting cliff, which consists of
sandy Eocene strata, covered by a gravelly deposit of freshwater origin,
about 50 feet above the sea-level, from which the flint weapons must
have been derived. Such old alluvial deposits now capping the cliffs
of Kent seem to have been the river-beds of tributaries of the Thames
before the sea encroached to its present position and widened its
estuary. On following up one of these freshwater deposits westward of
the Reculvers, Mr. Prestwich found in it, at Chislet, near Grove Ferry,
the Cyrena fluminalis among other shells.
The changes which have taken place in the physical geography of this
part of England during, or since, the Pleistocene period, have consisted
partly of such encroachments of the sea on the coast as are now going
on, and partly of a general subsidence of the land. Among the signs
of the latter movement may be mentioned a freshwater formation at
Faversham, below the level of the sea. The gravel there contains
exclusively land and fluviatile shells of the same species as those of
other localities of the Pleistocene alluvium before mentioned, and
must have been formed when the river was at a higher level and when it
extended farther east. At that era it was probably a tributary of the
Rhine, as represented by Mr. Trimmer in his ideal restoration of the
geography of the olden time.*
(* "Quarterly Journal of the Geological Society" volume 9
1853 Plate 8 Number 4.)
For England was then united to the continent, and what is now the North
Sea was land. It is well known that in many places, especially near the
coast of Holland, elephants' tusks and other bones are often dredged
up from the bed of that shallow sea, and the reader will see in the map
given in Chapter 13 how vast would be the conversion of sea into land by
an upheaval of 600 feet. Vertical movements of much less than half that
amount would account for the annexation of England to the continent, and
the extension of the Thames and its valley far to the north-east, and
the flowing of rivers from the easternmost parts of Kent and Essex into
the Thames, instead of emptying themselves into its estuary.
More than a dozen flint weapons of the Amiens type have already been
found in the basin of the Thames; but the geological position of no one
of them has as yet been ascertained with the same accuracy as that of
many of the tools dug up in the valley of the Somme.
FLINT IMPLEMENTS OF THE VALLEY OF THE OUSE, NEAR BEDFORD.
The ancient fluviatile gravel of the valley of the Ouse, around Bedford,
has been noted for the last thirty years for yielding to collectors a
rich harvest of the bones of extinct mammalia. By observations made in
1854 and 1858, Mr. Prestwich had ascertained that the valley was bounded
on both sides by Oolitic strata, capped by boulder clay, and that the
gravel Number 3, Figure 23, contained bones of the elephant, rhinoceros,
hippopotamus, ox, horse, and deer, which animals he therefore inferred
must have been posterior in date to the boulder clay, through which, as
well as the subjacent Oolite, the valley had been excavated. Mr. Evans
had found in the same gravel many land and freshwater shells, and these
discoveries induced Mr. James Wyatt, of Bedford, to pay two visits to
St. Acheul in order to compare the implement-bearing gravels of the
Somme with the drift of the valley of the Ouse. After his return
he resolved to watch carefully the excavation of the gravel-pits at
Biddenham, 2 miles west-north-west of Bedford, in the hope of finding
there similar works of art. With this view he paid almost daily visits
for months in succession to those pits, and was at last rewarded by the
discovery of two well-formed implements, one of the spear-head and the
other of the oval shape, perfect counterparts of the two prevailing
French types. Both specimens were thrown out by the workmen on the same
day from the lowest bed of stratified gravel and sand, 13 feet thick,
containing bones of the elephant, deer, and ox, and many freshwater
shells. The two implements occurred at the depth of 13 feet from the
surface of the soil, and rested immediately on solid beds of Oolitic
limestone, as represented in the accompanying section (Figure 23).
Having been invited by Mr. Wyatt to verify these facts, I went to
Biddenham within a fortnight of the date of his discovery (April
1861), and, for the first time, saw evidence which satisfied me of the
chronological relations of those three phenomena, the antique tools, the
extinct mammalia, and the glacial formation. On that occasion I examined
the pits in company with Messrs. Prestwich, Evans, and Wyatt, and we
collected ten species of shells from the stratified drift Number 3, or
the beds overlying the lowest gravel from which the flint implements had
been exhumed. They were all of common fluviatile and land species now
living in the same part of England. Since our visit, Mr. Wyatt has
added to them Paludina marginata, Michaud (Hydrobia of some authors), a
species of the South of France no longer inhabiting the British Isles.
The same geologist has also found, since we were at Biddenham, several
other flint tools of corresponding type, both there and at other
localities in the valley of the Ouse, near Bedford.
[Figure 23. Valley of the Ouse]
(FIGURE 23. SECTION ACROSS THE VALLEY OF THE OUSE, TWO MILES
WEST-NORTH-WEST OF BEDFORD.*
(* Prestwich, "Quarterly Journal of the Geological Society"
volume 17 1861 page 364; and Wyatt, "Geologist" 1861 page 242.)
1. Oolitic strata.
2. Boulder clay, or marine northern drift, rising to about
ninety feet above the Ouse.
3. Ancient gravel, with elephant bones, freshwater shells,
and flint implements.
4. Modern alluvium of the Ouse.
a. Biddenham gravel pits, at the bottom of which flint tools
were found.)
The boulder clay Number 2 extends for miles in all directions, and was
evidently once continuous from b to c before the valley was scooped
out. It is a portion of the great marine glacial drift of the midland
counties of England, and contains blocks, some of large size, not
only of the Oolite of the neighbourhood, but of Chalk and other rocks
transported from still greater distances, such as syenite, basalt,
quartz, and New Red Sandstone. These erratic blocks of foreign origin
are often polished and striated, having undergone what is called
glaciation, of which more will be said by and by. Blocks of the same
mineral character, embedded at Biddenham in the gravel Number 3, have
lost all signs of this striation by the friction to which they were
subjected in the old river bed.
The great width of the valley of the Ouse, which is sometimes 2 miles,
has not been expressed in the diagram. It may have been shaped out by
the joint action of the river and the tides when this part of England
was emerging from the waters of the glacial sea, the boulder clay being
first cut through, and then an equal thickness of underlying Oolite.
After this denudation, which may have accompanied the emergence of the
land, the country was inhabited by the primitive people who fashioned
the flint tools. The old river, aided perhaps by the continued upheaval
of the whole country, or by oscillations in its level, went on widening
and deepening the valley, often shifting its channel, until at length
a broad area was covered by a succession of the earliest and latest
deposits, which may have corresponded in age to the higher and lower
gravels of the valley of the Somme, already described.
At Biddenham, and elsewhere in the same gravel, remains of Elephas
antiquus have been discovered, and Mr. Wyatt obtained, January 1863,
a flint implement associated with bones and teeth of hippopotamus from
gravel at Summerhouse hill, which lies east of Bedford, lower down the
valley of the Ouse, and 4 miles from Biddenham.
One step at least we gain by the Bedford sections, which those of
Amiens and Abbeville had not enabled us to make. They teach us that the
fabricators of the antique tools, and the extinct mammalia coeval with
them, were all post-glacial.
FLINT IMPLEMENTS IN A FRESHWATER DEPOSIT AT HOXNE IN SUFFOLK [17].
So early as the first year of the nineteenth century, a remarkable paper
was communicated to the Society of Antiquaries by Mr. John Frere, in
which he gave a clear description of the discovery at Hoxne, near Diss,
in Suffolk, of flint tools of the type since found at Amiens, adding at
the same time good geological reasons for presuming that their antiquity
was very great, or, as he expressed it, beyond that of the present
world, meaning the actual state of the physical geography of that
region. "The flints," he said, "were evidently weapons of war,
fabricated and used by a people who had not the use of metals. They
lay in great numbers at the depth of about 12 feet in a stratified soil
which was dug into for the purpose of raising clay for bricks. Under
a foot and a half of vegetable earth was clay 7 1/2 feet thick, and
beneath this one foot of sand with shells, and under this 2 feet of
gravel, in which the shaped flints were found generally at the rate of
5 or 6 in a square yard. In the sandy beds with shells were found the
jawbone and teeth of an enormous unknown animal. The manner in which the
flint weapons lay would lead to the persuasion that it was a place of
their manufacture, and not of their accidental deposit. Their numbers
were so great that the man who carried on the brick-work told me that
before he was aware of their being objects of curiosity, he had emptied
baskets full of them into the ruts of the adjoining road."
Mr. Frere then goes on to explain that the strata in which the flints
occur are disposed horizontally, and do not lie at the foot of any
higher ground, so that portions of them must have been removed when the
adjoining valley was hollowed out. If the author had not mistaken the
freshwater shells associated with the tools for marine species, there
would have been nothing to correct in his account of the geology of
the district, for he distinctly perceived that the strata in which the
implements were embedded had, since that time, undergone very extensive
denudation.*
(* Frere, "Archaeologia" volume 13 1800 page 206.)
Specimens of the flint spear-heads, sent to London by Mr. Frere, are
still preserved in the British Museum, and others are in the collection
of the Society of Antiquaries.
[Illustration: Figure 24. Position of Flint Weapons]
(FIGURE 24. SECTION SHOWING THE POSITION OF THE FLINT WEAPONS
AT HOXNE, NEAR DISS, SUFFOLK.
See Prestwich "Philosophical Transactions" Plate 11 1860.)
1. Gravel of Gold Brook, a tributary of the Waveney.
2. Higher-level gravel overlying the freshwater deposit.
3 and 4. Sand and gravel, with freshwater shells, and
flint implements, and bones of mammalia.
5. Peaty and clayey beds, with same fossils.
6. Boulder clay or glacial drift.
7. Sand and gravel below boulder clay.
8. Chalk with flints.)
Mr. Prestwich's attention was called by Mr. Evans to these weapons, as
well as to Mr. Frere's memoir after his return from Amiens in 1859,
and he lost no time in visiting Hoxne, a village five miles eastward of
Diss. It is not a little remarkable that he should have found, after a
lapse of sixty years, that the extraction of clay was still going on
in the same brick-pit. Only a few months before his arrival, two flint
instruments had been dug out of the clay, one from a depth of 7 and the
other of 10 feet from the surface. Others have since been disinterred
from undisturbed beds of gravel in the same pit. Mr. Amyot of Diss has
also obtained from the underlying freshwater strata the astragalus of an
elephant, and bones of the deer and horse; but although many of the old
implements have recently been discovered in situ in regular strata and
preserved by Sir Edward Kerrison, no bones of extinct mammalia seem
as yet to have been actually seen in the same stratum with one of the
tools.
By reference to the annexed section, the geologist will see that the
basin-shaped hollow a, b, c has been filled up gradually with the
freshwater strata 3, 4, 5, after the same cavity a, b, c had been
previously excavated out of the more ancient boulder clay Number 6. The
relative position of these formations will be better understood when
I have described in the twelfth chapter the structure of Norfolk and
Suffolk as laid open in the sea-cliffs at Mundesley, about 30 miles
distant from Hoxne, in a north-north-east direction.
I examined the deposits at Hoxne in 1860, when I had the advantage of
being accompanied by the Reverend J. Gunn and the Reverend S.W. King.
In the loamy beds 3 and 4, Figure 24, we observed the common river shell
Valvata piscinalis in great numbers. With it, but much more rare, were
Limnaea palustris, Planorbis albus, P. Spirorbis, Succinea putris,
Bithynia tentaculata, Cyclas cornea; and Mr. Prestwich mentions Cyclas
amnica and fragments of a Unio, besides several land shells. In the
black peaty mass Number 5, fragments of wood of the oak, yew, and fir
have been recognised. The flint weapons which I have seen from Hoxne are
so much more perfect, and have their cutting edge so much sharper than
those from the valley of the Somme, that they seem neither to have been
used by Man, nor to have been rolled in the bed of a river. The opinion
of Mr. Frere, therefore, that there may have been a manufactory of
weapons on the spot, appears probable.
FLINT IMPLEMENTS AT ICKLINGHAM IN SUFFOLK.
In another part of Suffolk, at Icklingham, in the valley of the Lark,
below Bury St. Edmund's, there is a bed of gravel, in which teeth of
Elephas primigenius and several flint tools, chiefly of a lance-head
form, have been found. I have twice visited the spot, which has been
correctly described by Mr. Prestwich.*
(* "Quarterly Journal of the Geological Society" volume 17
1861, page 364.)
The section of the Bedford tool-bearing alluvium, given in Figure 23,
may serve to illustrate that of Icklingham, if we substitute Chalk for
Oolite, and the river Lark for the Ouse. In both cases, the present bed
of the river is about 30 feet below the level of the old gravel, and the
Chalk hill, which bounds the valley of the Lark on the right side, is
capped like the Oolite of Biddenham by boulder clay, which rises to
the height of 100 feet above the Lark. About twelve years ago, a large
erratic block, above 4 feet in diameter, was dug out of the boulder
clay at Icklingham, which I found to consist of a hard siliceous schist,
which must have come from a remote region. The tool-bearing gravel here,
as in the case to which it has been compared near Bedford, is proved
to be newer than the glacial drift, by containing pebbles of basalt and
other rocks derived from that formation.
CHAPTER 10. -- CAVERN DEPOSITS, AND PLACES OF SEPULTURE OF THE
PLEISTOCENE PERIOD.
Flint Implements in Cave containing Hyaena and other extinct
Mammalia in Somersetshire.
Caves of the Gower Peninsula in South Wales.
Rhinoceros hemitoechus.
Ossiferous Caves near Palermo.
Sicily once part of Africa.
Rise of Bed of the Mediterranean to the Height of three hundred
Feet in the Human Period in Sardinia.
Burial-place of Pleistocene Date of Aurignac in the South of France.
Rhinoceros tichorhinus eaten by Man.
M. Lartet on extinct Mammalia and Works of Art found in the
Aurignac Cave.
Relative Antiquity of the same considered.
WORKS OF ART ASSOCIATED WITH EXTINCT MAMMALIA IN A CAVERN IN
SOMERSETSHIRE.
The only British cave from which implements resembling those of Amiens
have been obtained, since the attention of geologists has been awakened
to the importance of minutely observing the position of such relics
relatively to the associated fossil mammalia, is that recently opened
near Wells in Somersetshire. It occurs near the cave of Wookey Hole,
from the mouth of which the river Axe issues on the southern flanks of
the Mendips. No one had suspected that on the left side of the ravine,
through which the river flows after escaping from its subterranean
channel, there were other caves and fissures concealed beneath the green
sward of the steep sloping bank. About ten years ago, a canal was made,
several hundred yards in length, for the purpose of leading the waters
of the Axe to a paper-mill, now occupying the middle of the ravine. In
carrying out this work, about 12 feet of the left bank was cut away,
and a cavernous fissure, choked up to the roof with ossiferous loam, was
then, for the first time, exposed to view. This great cavity, originally
9 feet high and 36 wide, traversed the Dolomitic Conglomerate; and
fragments of that rock, some angular and others water-worn, were
scattered through the red mud of the cave, in which fossil remains were
abundant. For an account of them and the position they occupied we are
indebted to Mr. Dawkins, F.G.S., who, in company with Mr. Williamson,
explored the cavern in 1859, and obtained from it the bones of the
Hyaena spelaea in such numbers as to lead him to conclude that the
cavern had for a long time been a hyaena's den. Among the accompanying
animals found fossil in the same bone-earth, were observed Elephas
primigenius, Rhinoceros tichorhinus, Ursus spelaeus, Bos primigenius,
Megaceros hibernicus, Cervus tarandus (and other species of Cervus),
Felis spelaea, Canis lupus, Canis vulpes, and teeth and bones of the
genus Equus in great numbers.
Intermixed with the above fossil bones were some arrowheads, made of
bone, and many chipped flints, and chipped pieces of chert, a white or
bleached flint weapon of the spearhead Amiens type, which was taken out
of the undisturbed matrix by Mr. Williamson himself, together with a
hyaena's tooth, showing that Man had either been contemporaneous with
or had preceded the extinct fauna. After penetrating 34 feet from the
entrance, Mr. Dawkins found the cave bifurcating into two branches, one
of which was vertical. By this rent, perhaps, some part of the contents
of the cave may have been introduced.*
(* Boyd Dawkins, "Proceedings of the Geological Society"
January 1862.)
When I examined the spot in 1860, after I had been shown some remains of
the hyaena collected there, I felt convinced that a complete revolution
must have taken place in the topography of the district since the time
of the extinct quadrupeds. I was not aware at the time that flint tools
had been met with in the same bone-deposit.
CAVES OF GOWER IN GLAMORGANSHIRE, SOUTH WALES.
The ossiferous caves of the peninsula of Gower in Glamorganshire
have been diligently explored of late years by Dr. Falconer and
Lieutenant-Colonel E.R. Wood, who have thoroughly investigated the
contents of many which were previously unknown. Among these Dr.
Falconer's skilled eye has recognised the remains of almost every
quadruped which he had elsewhere found fossil in British caves: in some
places the Elephas primigenius, accompanied by its usual companion,
the Rhinoceros tichorhinus, in others Elephas antiquus, associated
with Rhinoceros hemitoechus, Falconer; the extinct animals being often
embedded, as in the Belgian caves, in the same matrix with species now
living in Europe, such as the common badger (Meles taxus), the common
wolf, and the fox.
In a cavernous fissure called the Raven's Cliff, teeth of several
individuals of Hippopotamus major, both young and old, were found; and
this in a district where there is now scarce a rill of running water,
much less a river in which such quadrupeds could swim. In one of the
caves, called Spritsail Tor, bones of the elephants above named were
observed, with a great many other quadrupeds of Recent and extinct
species.
From one fissure, called Bosco's Den, no less than one thousand antlers
of the reindeer, chiefly of the variety called Cervus Guettardi, were
extracted by the persevering exertions of Colonel Wood, who estimated
that several hundred more still remained in the bone-earth of the same
rent.
They were mostly shed horns, and of young animals; and had been washed
into the rent with other bones, and with angular fragments of limestone,
and all enveloped in the same ochreous mud. Among the other bones, which
were not numerous, were those of the cave-bear, wolf, fox, ox, stag, and
field-mouse.
But the discovery of most importance, as bearing on the subject of the
present work, is the occurrence in a newly-discovered cave, called
Long Hole, by Colonel Wood, in 1861, of the remains of two species
of rhinoceros, R. tichorhinus and R. hemitoechus, Falconer, in an
undisturbed deposit, in the lower part of which were some well-shaped
flint knives, evidently of human workmanship. It is clear from their
position that Man was coeval with these two species. We have elsewhere
independent proofs of his co-existence with every other species of the
cave-fauna of Glamorganshire; but this is the first well-authenticated
example of the occurrence of R. hemitoechus in connection with human
implements.
In the fossil fauna of the valley of the Thames, Rhinoceros leptorhinus
was mentioned as occurring at Gray's Thurrock with Elephas antiquus.
Dr. Falconer, in a memoir which he is now preparing for the press on the
European Pliocene and Pleistocene species of the genus Rhinoceros,
has shown that, under the above name of R. leptorhinus, three
distinct species have been confounded by Cuvier, Owen, and other
palaeontologists:--
1. R. megarhinus, Christol, being the original and typical R.
leptorhinus of Cuvier, founded on Cortesi's Monte Zago cranium, and the
ONLY Pliocene, or Pleistocene European species, that had not a nasal
septum.--Gray's Thurrock, etc.
2. R. hemitoechus, Falconer, in which the ossification of the septum
dividing the nostrils is incomplete in the middle, besides other cranial
and dental characters distinguishing it from R. tichorhinus, accompanies
Elephas antiquus in most of the oldest British bone-caves, such
as Kirkdale, Cefn, Durdham Down, Minchin Hole, and other Gower
caverns--also found at Clacton, in Essex, and in Northamptonshire.
3. R. etruscus, Falconer, a comparatively slight and slender form, also
with an incomplete bony septum,* occurs deep in the Val d'Arno deposits,
and in the "Forest bed," and superimposed blue clays, with lignite, of
the Norfolk coast, but nowhere as yet found in the ossiferous caves in
Britain.
(* Falconer, "Quarterly Journal of the Geological Society"
volume 15 1859 page 602.)
Dr. Falconer announced in 1860 his opinion that the filling up of the
Gower caves in South Wales took place after the deposition of the marine
boulder clay,* an opinion in harmony with what we have since learnt from
the section of the gravels near Bedford, given above (Figure 23), where
a fauna corresponding to that of the Welsh caves characterises the
ancient alluvium, and is shown to be clearly post-glacial, in the sense
of being posterior in date to the boulder-clay of the midland counties.
(* Ibid. volume 16 1860 page 491.)
In the same sense the late Edward Forbes declared, in 1846, his
conviction that not only the Cervus megaceros, but also the mammoth
and other extinct pachyderms and carnivora, had lived in Britain in
post-glacial times.*
(* "Memoir of the Geological Survey" pages 394 to 397.)
The Gower caves in general have their floors strewed over with sand,
containing marine shells, all of living species; and there are raised
beaches on the adjoining coast, and other geological signs of great
alteration in the relative level of land and sea, since that country was
inhabited by the extinct mammalia, some of which, as we have seen, were
certainly coeval with Man.
OSSIFEROUS CAVES IN THE NORTH OF SICILY.
Geologists have long been familiar with the fact that on the northern
coast of Sicily, between Termini on the east, and Trapani on the west,
there are several caves containing the bones of extinct animals. These
caves are situated in rocks of Hippurite limestone, a member of the
Cretaceous series, and some of them may be seen on both sides of the Bay
of Palermo. If in the neighbourhood of that city we proceed from the
sea inland, ascending a sloping terrace, composed of the marine Newer
Pliocene strata, we reach about a mile from the shore, and at the height
of about 180 feet above it a precipice of limestone, at the base of
which appear the entrances of several caves. In that of San Ciro, on
the east side of the bay, we find at the bottom sand with marine shells,
forty species of which have been examined, and found almost all to agree
specifically with mollusca now inhabiting the Mediterranean. Higher in
position, and resting on the sand, is a breccia, composed of pieces of
limestone, quartz, and schist in a matrix of brown marl, through
which land shells are dispersed, together with bones of two species
of hippopotamus, as determined by Dr. Falconer. Certain bones of the
skeleton were counted in such numbers as to prove that they must have
belonged to several hundred individuals. With these were associated the
remains of Elephas antiquus, and bones of the genera Bos, Cervus, Sus,
Ursus, Canis, and a large Felis. Some of these bones have been rolled
as if partially subjected to the action of water, and may have been
introduced by streams through rents in the Hippurite limestone; but
there is now no running water in the neighbourhood, no river such as
the hippopotamus might frequent, not even a small brook, so that the
physical geography of the district must have been altogether changed
since the time when such remains were swept into fissures, or into the
channels of engulfed rivers.
No proofs seem yet to have been found of the existence of Man at the
period when the hippopotamus and Elephas antiquus flourished at San
Ciro. But there is another cave called the Grotto di Maccagnone, which
much resembles it in geological position, on the opposite or west side
of the Bay of Palermo, near Carini. In the bottom of this cave a bone
deposit like that of San Ciro occurs, and above it other materials
reaching to the roof, and evidently washed in from above, through
crevices in the limestone. In this upper and newer breccia Dr. Falconer
discovered flint knives, bone splinters, bits of charcoal, burnt clay,
and other objects indicating human intervention, mingled with entire
land shells, teeth of horses, coprolites of hyaenas, and other
bones, the whole agglutinated to one another and to the roof by the
infiltration of water holding lime in solution. The perfect condition
of the large fragile helices (Helix vermiculata) afforded satisfactory
evidence, says Dr. Falconer, that the various articles were carried
into the cave by the tranquil agency of water, and not by any tumultuous
action. At a subsequent period other geographical changes took place,
so that the cave, after it had been filled, was washed out again, or
emptied of its contents with the exception of those patches of breccia
which, being cemented together by stalactite, still adhere to the roof.*
(* "Quarterly Journal of the Geological Society" volume 16
1860 page 105.)
Baron Anca, following up these investigations, explored, in 1859,
another cave at Mondello, west of Palermo, and north of Mount Gallo,
where he discovered molars of the living African elephant, and
afterwards additional specimens of the same species in the neighbouring
grotto of Olivella. In reference to this elephant, Dr. Falconer has
reminded us that the distance between the nearest part of Sicily and
the coast of Africa, between Marsala and Cape Bon, is not more than 80
miles, and Admiral Smyth, in his Memoir on the Mediterranean, states
(page 499) that there is a subaqueous plateau, named by him Adventure
Bank, uniting Sicily to Africa by a succession of ridges which are not
more than from 40 to 50 fathoms under water.*
(* Cited by Horner, "Presidential Address to the Geological
Society" 1861 page 42.)
Sicily therefore might be re-united to Africa by movements of upheaval
not greater than those which are already known to have taken place
within the human period on the borders of the Mediterranean, of which
I shall now proceed to cite a well-authenticated example, observed in
Sardinia.
RISE OF THE BED OF THE SEA TO THE HEIGHT OF 300 FEET, IN THE HUMAN
PERIOD, IN SARDINIA.
Count Albert de la Marmora, in his description of the geology of
Sardinia,* has shown that on the southern coast of that island, at
Cagliari and in the neighbourhood, an ancient bed of the sea, containing
marine shells of living species, and numerous fragments of antique
pottery, has been elevated to the height of from 230 to 324 feet above
the present level of the Mediterranean.
(* "Partie Geologique" volume 1 pages 382 and 387.)
Oysters and other shells, of which a careful list has been published,
including the common mussel (Mytilus edulis), many of them having
both valves united, occur, embedded in a breccia in which fragments of
limestone abound. The mussels are often in such numbers as to impart,
when they have decomposed, a violet colour to the marine stratum.
Besides pieces of coarse pottery, a flattened ball of baked earthenware,
with a hole through its axis, was found in the midst of the marine
shells. It is supposed to have been used for weighting a fishing net. Of
this and of one of the fragments of ancient pottery Count de la Marmora
has given figures.
The upraised bed of the sea probably belongs in this instance to the
Pleistocene period, for in a bone breccia, filling fissures in the rocks
around Cagliari, the remains of extinct mammalia have been detected;
among which is a new genus of carnivorous quadruped, named Cynotherium
by M. Studiati, and figured by Count de la Marmora in his Atlas (Plate
7), also an extinct species of Lagomys, determined by Cuvier in 1825.
Embedded in the same bone-breccia, and enveloped with red earth like
the mammalian remains, were detected shells of the Mytilus edulis before
mentioned, implying that the marine formation containing shells and
pottery had been already upheaved and exposed to denudation before the
remains of quadrupeds were washed into these rents and included in the
red earth. In the vegetable soil covering the upraised marine stratum,
fragments of Roman pottery occur.
If we assume the average rate of upheaval to have been, as before
hinted, 2 1/2 feet in a century, 300 feet would give an antiquity of
12,000 years to the Cagliari pottery, even if we simply confine our
estimate to the upheaval above the sea-level, without allowing for
the original depth of water in which the mollusca lived. Even then our
calculation would merely embrace the period during which the upward
movement was going on; and we can form at present no conjecture as to
the probable era of its commencement or termination.
I learn from Captain Spratt, R.N., that the island of Crete or Candia,
about 135 miles in length, has been raised at its western extremity
about 25 feet; so that ancient ports are now high and dry above the sea,
while at its eastern end it has sunk so much that the ruins of old towns
are seen under water. Revolutions like these in the physical geography
of the countries bordering the Mediterranean, may well help us to
understand the phenomena of the Palermo caves, and the presence in
Sicily of African species of mammalia.
CLIMATE AND HABITS OF THE HIPPOPOTAMUS.
As I have alluded more than once in this chapter to the occurrence of
the remains of the hippopotamus in places where there are now no rivers,
not even a rill of water, and as other bones of the same genus have been
met with in the lower-level gravels of the Somme where large blocks
of sandstone seem to imply that ice once played a part in their
transportation, it may be well to consider, before proceeding farther,
what geographical and climatal conditions are indicated by the presence
of these fossil pachyderms.
It is now very generally conceded that the mammoth and tichorhine
rhinoceros were fitted to inhabit northern regions, and it is therefore
natural to begin by asking whether the extinct hippopotamus may not
in like manner have flourished in a cold climate. In answer to this
inquiry, it has been remarked that the living hippopotami, anatomically
speaking so closely allied to the extinct species, are so aquatic and
fluviatile in their habits as to make it difficult to conceive that
their congeners could have thriven all the year round in regions where,
during winter, the rivers were frozen over for months. Moreover, I have
been unable to learn that, in any instance, bones of the hippopotamus
have been found in the drift of northern Germany associated with the
remains of the mammoth, tichorhine rhinoceros, musk-ox, reindeer,
lemming, and other arctic quadrupeds before alluded to; yet, though not
proved to have ever made a part of such a fauna, the presence of the
fossil hippopotamus north of the fiftieth parallel of latitude naturally
tempts us to speculate on the migratory powers and instincts of some
of the extinct species of the genus. They may have resembled, in this
respect, the living musk-ox, herds of which pass for hundreds of miles
over the ice to the rich pastures of Melville Island, and then return
again to southern latitudes before the ice breaks up.
We are indebted to Sir Andrew Smith,* an experienced zoologist, for
having given us an account of the migratory habits of the living
hippopotamus of Southern Africa (H. amphibius, Linn.).
(* "Illustrations of the Zoology of South Africa": article
"Hippopotamus.")
He states that, when the Dutch first colonised the Cape of Good Hope,
this animal abounded in all the great rivers, as far south as the
land extends; whereas, in 1849, they had all disappeared, scarcely one
remaining even within a moderate distance of the colony. He also tells
us that this species evinces great sagacity in changing its quarters
whenever danger threatens, quitting every district invaded by settlers
bearing fire-arms. Bulky as they are, they can travel speedily for miles
over land from one pool of a dried-up river to another; but it is by
water that their powers of locomotion are surpassingly great, not only
in rivers, but in the sea, for they are far from confining themselves to
fresh water. Indeed, Sir A. Smith finds it "difficult to decide whether,
during the daytime and when not feeding, they prefer the pools of rivers
or the waters of the ocean for their abode." In districts where they
have been disturbed by Man, they feed almost entirely in the night,
chiefly on certain kinds of grass, but also on brushwood. Sir A. Smith
relates that, in an expedition which he made north of Port Natal, he
found them swarming in all the rivers about the tropic of Capricorn.
Here they were often seen to have left their footprints on the sands,
entering or coming out of the salt water; and on one occasion Smith's
party tried in vain to intercept a female with her young as she was
making her way to the sea. Another female, which they had wounded on her
precipitate retreat to the sea, was afterwards shot in that element.
The geologist, therefore, may freely speculate on the time when herds of
hippopotami issued from North African rivers, such as the Nile, and
swam northwards in summer along the coasts of the Mediterranean, or even
occasionally visited islands near the shore. Here and there they
may have landed to graze or browse, tarrying awhile and afterwards
continuing their course northwards. Others may have swum in a few summer
days from rivers in the south of Spain or France to the Somme, Thames,
or Severn, making timely retreat to the south before the snow and ice
set in.
BURIAL-PLACE AT AURIGNAC, IN THE SOUTH OF FRANCE, OF PLEISTOCENE DATE.
I have alluded in the beginning of the fourth chapter to a custom
prevalent among rude nations of consigning to the tomb works of art,
once the property of the dead, or objects of their affection, and even
of storing up, in many cases, animal food destined for the manes of the
defunct in a future life. I also cited M. Desnoyers' comments on the
absence among the bones of wild and domestic animals found in old
Gaulish tombs of all intermixture of extinct species of quadrupeds, as
proving that the oldest sepulchral monuments then known in France (1845)
had no claims to high antiquity founded on palaeontological data.
M. Lartet, however, has recently published a circumstantial account of
what seems clearly to have been a sepulchral vault of the Pleistocene
period, near Aurignac, not far from the foot of the Pyrenees. I have had
the advantage of inspecting the fossil bones and works of art obtained
by him from that grotto, and of conversing and corresponding with him
on the subject, and can see no grounds for doubting the soundness of his
conclusions.*
(* See Lartet, "Annales des Sci. Nat." 4mo. Ser. Zoologie
volume 15 page 177 translated in "Natural History Review"
London January 1862.)
[Illustration: Figure 25. Hill of Fajoles]
(FIGURE 25. SECTION OF PART OF THE HILL OF FAJOLES PASSING THROUGH
THE SEPULCHRAL GROTTO OF AURIGNAC (E. Lartet).
a. Part of the vault in which the remains of seventeen human
skeletons were found.
b. Layer of made ground, two feet thick, inside the grotto in
which a few human bones, with entire bones of extinct and
living species of animals, and many works of art were embedded.
c. Layers of ashes and charcoal, six inches thick, with broken,
burnt, and gnawed bones of extinct and Recent mammalia; also
hearth-stones and works of art; no human bones.
d. Deposit with similar contents and a few scattered cinders.
e. Talus of rubbish washed down from the hill above.
f, g. Slab of rock which closed the vault, not ascertained
whether it extended to h.
f i. Rabbit burrow which led to the discovery of the grotto.
h, k. Original terrace on which the grotto opened.
N. Nummulitic limestone of hill of Fajoles.)
The town of Aurignac is situated in the department of the Haute-Garonne,
near a spur of the Pyrenees; adjoining it is the small flat-topped hill
of Fajoles, about 60 feet above the brook called Rodes, which flows at
its foot on one side. It consists of Nummulitic limestone, presenting
a steep escarpment towards the north-west, on which side in the face of
the rock, about 45 feet above the brook, is now visible the entrance of
a grotto a, Figure 25, which opened originally on the terrace h, c, k,
which slopes gently towards the valley.
Until the year 1852, the opening into this grotto was masked by a talus
of small fragments of limestone and earthy matter e, such as the rain
may have washed down the slope of the hill. In that year a labourer
named Bonnemaison, employed in repairing the roads, observed that
rabbits, when hotly pursued by the sportsman, ran into a hole which they
had burrowed in the talus, at i f, Figure 25. On reaching as far into
the opening as the length of his arm, he drew out, to his surprise,
one of the long bones of the human skeleton; and his curiosity being
excited, and having a suspicion that the hole communicated with a
subterranean cavity, he commenced digging a trench through the middle of
the talus, and in a few hours found himself opposite a large heavy slab
of rock f h, placed vertically against the entrance. Having removed
this, he discovered on the other side of it an arched cavity a, 7 or 8
feet in its greatest height, 10 in width, and 7 in horizontal depth. It
was almost filled with bones, among which were two entire skulls, which
he recognised at once as human. The people of Aurignac, astonished to
hear of the occurrence of so many human relics in so lonely a spot,
flocked to the cave, and Dr. Amiel, the Mayor, ordered all the bones to
be taken out and reinterred in the parish cemetery. But before this was
done, having as a medical man a knowledge of anatomy, he ascertained
by counting the homologous bones that they must have formed parts of no
less than seventeen skeletons of both sexes, and all ages; some so young
that the ossification of some of the bones was incomplete. Unfortunately
the skulls were injured in the transfer; and what is worse, after the
lapse of eight years, when M. Lartet visited Aurignac, the village
sexton was unable to tell him in what exact place the trench was dug,
into which the skeletons had been thrown, so that this rich harvest
of ethnological knowledge seems for ever lost to the antiquary and
geologist.
M. Lartet having been shown, in 1860, the remains of some extinct
animals and works of art, found in digging the original trench made by
Bonnemaison through the bed d under the talus, and some others
brought out from the interior of the grotto, determined to investigate
systematically what remained intact of the deposits outside and inside
the vault, those inside, underlying the human skeletons, being supposed
to consist entirely of made ground. Having obtained the assistance of
some intelligent workmen, he personally superintended their labours, and
found outside the grotto, resting on the sloping terrace h k, the layer
of ashes and charcoal c, about 6 inches thick, extending over an area of
6 or 7 square yards, and going as far as the entrance of the grotto and
no farther, there being no cinders or charcoal in the interior. Among
the cinders outside the vault were fragments of fissile sandstone,
reddened by heat, which were observed to rest on a levelled surface of
Nummulitic limestone and to have formed a hearth. The nearest place from
whence such slabs of sandstone could have been brought was the opposite
side of the valley.
Among the ashes, and in some overlying earthy layers, d, separating the
ashes from the talus e, were a great variety of bones and implements;
amongst the latter not fewer than a hundred flint articles--knives,
projectiles, sling stones, and chips, and among them one of those
siliceous cores or nuclei with numerous facets, from which flint flakes
or knives had been struck off, seeming to prove that some instruments
were occasionally manufactured on the very spot.
Among other articles outside the entrance was found a stone of a
circular form, and flattened on two sides, with a central depression,
composed of a tough rock which does not belong to that region of the
Pyrenees. This instrument is supposed by the Danish antiquaries to have
been used for removing by skilful blows the edges of flint knives, the
fingers and thumb being placed in the two opposite depressions during
the operation. Among the bone instruments were arrows without barbs, and
other tools made of reindeer horn, and a bodkin formed out of the
more compact horn of the roedeer. This instrument was well shaped, and
sharply pointed, and in so good a state of preservation that it might
still be used for piercing the tough skins of animals.
Scattered through the same ashes and earth were the bones of the various
species of animals enumerated in the subjoined lists, with the exception
of two, marked with an asterisk, which only occurred in the interior of
the grotto:--
TABLE 10/1. NUMBERS OF INDIVIDUALS, BONES OF WHICH WERE FOUND IN THE
AURIGNAC CAVE.
COLUMN 1: NAME OF SPECIES.
COLUMN 2: NUMBER OF INDIVIDUALS.
1. CARNIVORA
1. Ursus spelaeus (cave-bear): 5 to 6.
2. Ursus arctos? (brown bear): 1.
3. Meles taxus (badger): 1 to 2.
4. Putorius vulgaris (polecat): 1.
5. *Felis spelaea (cave-lion): 1.
6. Felis catus ferus (wild cat): 1.
7. Hyaena spelaea (cave-hyaena): 5 to 6.
8. Canis lupus (wolf): 3.
9. Canis vulpes (fox): 18 to 20.
2. HERBIVORA.
1. Elephas primigenius (mammoth, two molars).
2. Rhinoceros tichorhinus (Siberian rhinoceros): 1.
3. Equus caballus (horse): 12 to 15.
4. Equus asinus (?) (ass): 1.
5. *Sus scrofa (pig, two incisors).
6. Cervus elaphus (stag): 1.
7. Megaceros hibernicus (gigantic Irish deer): 1.
8. C. capreolus (roebuck): 3 to 4.
9. C. tarandus (reindeer): 10 to 12.
10. Bison europaeus (aurochs): 12 to 15.
The bones of the herbivora were the most numerous, and all those on the
outside of the grotto which had contained marrow were invariably split
open, as if for its extraction, many of them being also burnt. The
spongy parts, moreover, were wanting, having been eaten off and gnawed
after they were broken, the work, according to M. Lartet, of hyaenas,
the bones and coprolites of which were mixed with the cinders, and
dispersed through the overlying soil d. These beasts of prey are
supposed to have prowled about the spot and fed on such relics of the
funeral feasts as remained after the retreat of the human visitors,
or during the intervals between successive funeral ceremonies which
accompanied the interment of the corpses within the sepulchre. Many of
the bones were also streaked, as if the flesh had been scraped off by a
flint instrument.
Among the various proofs that the bones were fresh when brought to the
spot, it is remarked that those of the herbivora not only bore the marks
of having had the marrow extracted and having afterwards been gnawed
and in part devoured as if by carnivorous beasts, but that they had also
been acted upon by fire (and this was especially noticed in one case of
a cave-bear's bone), in such a manner as to show that they retained in
them at the time all their animal matter.
Among other quadrupeds which appear to have been eaten at the funeral
feasts, and of which the bones occurred among the ashes, were those of a
young Rhinoceros tichorhinus, the bones of which had been, like those of
the accompanying herbivora, broken and gnawed by a beast of prey at both
extremities.
Outside of the great slab of stone forming the door, not one human bone
occurred; inside of it there were found, mixed with loose soil, the
remains of as many as seventeen human individuals, besides some works
of art and bones of animals. We know nothing of the arrangement of these
bones when they were first broken into. M. Lartet inferred at first that
the bodies were bent down upon themselves in a squatting attitude,
a posture known to have been adopted in most of the sepulchres of
primitive times; and he has so represented them in his restoration of
the cave: but this opinion he has since retracted. His artist also has
inadvertently, in the same drawing, delineated the arched grotto as if
it were shaped very regularly and smoothly, like a finished piece of
masonry, whereas the surface was in truth as uneven and irregular as are
the roofs of all natural grottos.
There was no stalagmite in the grotto, and M. Lartet, an experienced
investigator of ossiferous caverns in the south of France, came to
the conclusion that all the bones and soil found in the inside were
artificially introduced. The substratum b, Figure 25, which remained
after the skeletons had been removed, was about 2 feet thick. In it were
found about ten detached human bones, including a molar tooth; and M.
Delesse ascertained by careful analysis of one of these, as well as of
the bones of a rhinoceros, bear, and some other extinct animals, that
they all contained precisely the same proportion of nitrogen, or had
lost an equal amount of their animal matter. My friend Mr. Evans, before
cited, has suggested to me that such a fact, taken alone, may not be
conclusive in favour of the equal antiquity of the human and other
remains. No doubt, had the human skeletons been found to contain more
gelatine than those of the extinct mammalia, it would have shown that
they were the more modern of the two; but it is possible that after a
bone has gone on losing its animal matter up to a certain point, it may
then part with no more so long as it continues enveloped in the same
matrix. If this be so, it follows that bones of very different degrees
of antiquity, after they have lain for many thousands of years in
a particular soil, may all have reached long ago the maximum of
decomposition attainable in such a matrix. In the present case, however,
the proof of the contemporaneousness of Man and the extinct animals
does not depend simply on the identity of their mineral condition. The
chemical analysis of M. Delesse is only a fact in corroboration of a
great mass of other evidence.
Mixed with the human bones inside the grotto first removed by
Bonnemaison, were eighteen small, round, and flat plates of a white
shelly substance, made of some species of cockle (Cardium), pierced
through the middle as if for being strung into a bracelet. In the
substratum also in the interior examined by M. Lartet was found the tusk
of a young Ursus spelaeus, the crown of which had been stripped of its
enamel, and which had been carved perhaps in imitation of the head of a
bird. It was perforated lengthwise as if for suspension as an ornament
or amulet. A flint knife also was found in the interior which had
evidently never been used; in this respect, unlike the numerous worn
specimens found outside, so that it is conjectured that it may, like
other associated works of art, have been placed there as part of the
funeral ceremonies.
A few teeth of the cave-lion, Felis spelaea, and two tusks of the wild
boar, also found in the interior, were memorials perhaps of the chase.
No remains of the same animals were met with among the external relics.
On the whole, the bones of animals inside the vault offer a remarkable
contrast to those of the exterior, being all entire and uninjured, none
of them broken, gnawed, half-eaten, scraped, or burnt like those lying
among the ashes on the other side of the great slab which formed the
portal. The bones of the interior seem to have been clothed with their
flesh when buried in the layer of loose soil strewed over the floor.
In confirmation of this idea, many bones of the skeleton were often
observed to be in juxtaposition, and in one spot all the bones of the
leg of an Ursus spelaeus were lying together uninjured. Add to this,
the entire absence in the interior of cinders and charcoal, and we
can scarcely doubt that we have here an example of an ancient place of
sepulture, closed at the opening so effectually against the hyaenas or
other carnivora that no marks of their teeth appear on any of the bones,
whether human or brute.
John Carver, in his travels in the interior of North America in a
1766-68 (chapter 15.), gave a minute account of the funeral rites of
an Indian tribe which inhabited the country now called Iowa, at the
junction of the St. Peter's River with the Mississippi; and Schiller,
in his famous "Nadowessische Todtenklage," has faithfully embodied in
a poetic dirge all the characteristic features of the ceremonies so
graphically described by the English traveller, not omitting the many
funeral gifts which, we are told, were placed "in a cave" with the
bodies of the dead. The lines beginning, "Bringet her die letzten
Gaben," have been thus translated, truthfully, and with all the spirit
of the original, by Sir E. L. Bulwer*:--
"Here bring the last gifts!--and with these
The last lament be said;
Let all that pleased, and yet may please,
Be buried with the dead.
"Beneath his head the hatchet hide,
That he so stoutly swung;
And place the bear's fat haunch beside--
The journey hence is long!
"And let the knife new sharpened be
That on the battle-day
Shore with quick strokes--he took but three--
The foeman's scalp away!
"The paints that warriors love to use,
Place here within his hand,
That he may shine with ruddy hues
Amidst the spirit-land."
(* "Poems and Ballads of Schiller.")
If we accept M. Lartet's interpretation of the ossiferous deposits of
Aurignac, both inside and outside the grotto, they add nothing to the
palaeontological evidence in favour of Man's antiquity, for we have seen
all the same mammalia associated elsewhere with flint implements, and
some species, such as the Elephas antiquus, Rhinoceros hemitoechus, and
Hippopotamus major, missing here, have been met with in other places. An
argument, however, having an opposite leaning may perhaps be founded on
the phenomena of Aurignac. It may--indeed it has been said, that they
imply that some of the extinct mammalia survived nearly to our times:
First--Because of the modern style of the works of art at Aurignac.
Secondly--Because of the absence of any signs of change in the physical
geography of the country since the cave was used for a place of
sepulture.
In reference to the first of these propositions, the utensils, it is
said, of bone and stone indicate a more advanced state of the arts than
the flint implements of Abbeville and Amiens. M. Lartet, however, is
of opinion that they do not, and thinks that we have no right to assume
that the fabricators of the various spear-headed and other tools of
the Valley of the Somme possessed no bone instruments or ornaments
resembling those discovered at Aurignac. These last, moreover, he
regards as extremely rude in comparison with others of the stone period
in France, which can be proved palaeontologically, at least by strong
negative evidence, to be of subsequent date. Thus, for example, at
Savigne, near Civray, in the department of Vienne, there is a cave in
which there are no extinct mammalia, but where remains of the reindeer
abound. The works of art of the stone period found there indicate
considerable progress in skill beyond that attested by the objects found
in the Aurignac grotto. Among the Savigne articles, there is the bone of
a stag, on which figures of two animals, apparently meant for deer, are
engraved in outline, as if by a sharp-pointed flint. In another cave,
that of Massat, in the department of Ariege, which M. Lartet ascribes
to the period of the aurochs, a quadruped which survived the reindeer in
the south of France, there are bone instruments of a still more advanced
state of the arts, as, for example, barbed arrows with a small canal in
each, believed to have served for the insertion of poison; also a needle
of bird's bone, finely shaped, with an eye or perforation at one end,
and a stag's horn, on which is carved a representation of a bear's head,
and a hole at one end as if for suspending it. In this figure we see,
says M. Lartet, what may perhaps be the earliest known example of lines
used to express shading.
The fauna of the aurochs (Bison europaeus) agrees with that of the
earlier lake dwellings in Switzerland, in which hitherto the reindeer
is wanting; whereas the reindeer has been found in a Swiss cave, in Mont
Saleve, supposed by Lartet to be more ancient than the lake dwellings.
According to this view, the mammalian fauna has undergone at least two
fluctuations since the remains of some extinct quadrupeds were eaten,
and others buried as funeral gifts in the sepulchral vault of Aurignac.
As to the absence of any marked changes in the physical configuration
of the district since the same grotto was a place of sepulture, we
must remember that it is the normal state of the earth's surface to be
undergoing great alterations in one place, while other areas, often
in close proximity, remain for ages without any modification. In one
region, rivers are deepening and widening their channels, or the waves
of the sea are undermining cliffs, or the land is sinking beneath
or rising above the waters, century after century, or the volcano is
pouring forth torrents of lava or showers of ashes; while, in tracts
hard by, the ancient forest, or extensive heath, or the splendid city
continue scatheless and motionless. Had the talus which concealed from
view the ancient hearth with its cinders and the massive stone portal
of the Aurignac grotto escaped all human interference for thousands of
years to come, there is no reason to suppose that the small stream at
the foot of the hill of Fajoles would have undermined it. At the end of
a long period the only alteration might have been the thickening of the
talus which protected the loose cinders and bones from waste. We behold
in many a valley of Auvergne, within 50 feet of the present river
channel, a volcanic cone of loose ashes, with a crater at its summit,
from which powerful currents of basaltic lava have poured, usurping the
ancient bed of the torrent. By the action of the stream, in the course
of ages, vast masses of the hard columnar basalt have been removed,
pillar after pillar, and much vesicular lava, as in the case, for
example, of the Puy Rouge, near Chalucet, and of the Puy de Tartaret,
near Nechers.*
(* Scrope's "Volcanoes of Central France" 1858 page 97.)
The rivers have even in some cases, as the Sioule, near Chalucet, cut
through not only the basalt which dispossessed them of their ancient
channels, but have actually eaten 50 feet into the subjacent gneiss; yet
the cone, an incoherent heap of scoriae and spongy ejectamenta, stands
unmolested. Had the waters once risen, even for a day, so high as to
reach the level of the base of one of these cones--had there been a
single flood 50 or 60 feet in height since the last eruption occurred,
a great part of these volcanoes must inevitably have been swept away
as readily as all traces of the layer of cinders; and the accompanying
bones would have been obliterated by the Rodes near Aurignac, had it
risen, since the days of the mammoth, rhinoceros, and cave-bear, 50 feet
above its present level.
The Aurignac cave adds no new species to the list of extinct quadrupeds,
which we have elsewhere, and by independent evidence, ascertained to
have once flourished contemporaneously with Man. But if the fossil
memorials have been correctly interpreted--if we have here before us at
the northern base of the Pyrenees a sepulchral vault with skeletons
of human beings, consigned by friends and relatives to their last
resting-place--if we have also at the portal of the tomb the relics of
funeral feasts, and within it indications of viands destined for the
use of the departed on their way to a land of spirits; while among
the funeral gifts are weapons wherewith in other fields to chase the
gigantic deer, the cave-lion, the cave-bear, and woolly rhinoceros--we
have at last succeeded in tracing back the sacred rites of burial,
and, more interesting still, a belief in a future state, to times long
anterior to those of history and tradition. Rude and superstitious
as may have been the savage of that remote era, he still deserved, by
cherishing hopes of a hereafter, the epithet of "noble," which Dryden
gave to what he seems to have pictured to himself as the primitive
condition of our race,
"as Nature first made Man
When wild in woods the noble savage ran."*
(* "Siege of Granada" Part 1 Act 1 Scene 1.)
CHAPTER 11. -- AGE OF HUMAN FOSSILS OF LE PUY IN CENTRAL FRANCE AND OF
NATCHEZ ON THE MISSISSIPPI DISCUSSED.
Question as to the Authenticity of the Fossil Man of Denise,
near Le Puy-en-Velay, considered.
Antiquity of the Human Race implied by that Fossil.
Successive Periods of Volcanic Action in Central France.
With what Changes in the Mammalian Fauna they correspond.
The Elephas meridionalis anterior in Time to the Implement-bearing
Gravel of St. Acheul.
Authenticity of the Human Fossil of Natchez on the Mississippi
discussed.
The Natchez Deposit, containing Bones of Mastodon and Megalonyx,
probably not older than the Flint Implements of St. Acheul.
Among the fossil remains of the human species supposed to have claims to
high antiquity, and which have for many years attracted attention, two
of the most prominent examples are:--
First--"The fossil man of Denise," comprising the remains of more
than one skeleton, found in a volcanic breccia near the town of Le
Puy-en-Velay, in Central France.
Secondly--The fossil human bone of Natchez, on the Mississippi, supposed
to have been derived from a deposit containing remains of Mastodon
and Megalonyx. Having carefully examined the sites of both of these
celebrated fossils, I shall consider in this chapter the nature of the
evidence on which the remote date of their entombment is inferred.
FOSSIL MAN OF DENISE.
An account of the fossil remains, so called, was first published in 1844
by M. Aymard of Le Puy, a writer of deservedly high authority both as a
palaeontologist and archaeologist.*
(* "Bulletin de la Societe Geologique de France" 1844, 1845,
1847.)
M. Pictet, after visiting Le Puy and investigating the site of the
alleged discovery, was satisfied that the fossil bones belonged to the
period of the last volcanic eruptions of Velay; but expressly stated in
his important treatise on palaeontology that this conclusion, though it
might imply that Man had co-existed with the extinct elephant, did not
draw with it the admission that the human race was anterior in date
to the filling of the caverns of France and Belgium with the bones of
extinct mammalia.*
(* "Traite de Paleontologie" volume 1 1853 page 152.)
At a meeting of the "Scientific Congress" of France, held at Le Puy in
1856, the question of the age of the Denise fossil bones was fully gone
into, and in the report of their proceedings published in that year, the
opinions of some of the most skilful osteologists respecting the point
in controversy are recorded. The late Abbe Croizet, a most experienced
collector of fossil bones in the volcanic regions of Central France, and
an able naturalist, and the late M. Laurillard, of Paris, who assisted
Cuvier in modelling many fossil bones, and in the arrangement of the
museum of the Jardin, declared their opinion that the specimen preserved
in the museum of Le Puy is no counterfeit. They believed the human bones
to have been enveloped by natural causes in the tufaceous matrix in
which we now see them.
In the year 1859, Professor Hebert and M. Lartet visited Le Puy,
expressly to investigate the same specimen, and to inquire into the
authenticity of the bones and their geological age. Later in the same
year, I went myself to Le Puy, having the same object in view, and had
the good fortune to meet there my friend Mr. Poulett Scrope, with whom
I examined the Montagne de Denise, where a peasant related to us how he
had dug out the specimen with his own hands and in his own vineyard, not
far from the summit of the volcano. I employed a labourer to make under
his directions some fresh excavations, following up those which had been
made a month earlier by MM. Hebert and Lartet, in the hope of verifying
the true position of the fossils, but all of us without success. We
failed even to find in situ any exact counterpart of the stone of the Le
Puy Museum.
The osseous remains of that specimen consist of a frontal and some other
parts of the skull, including the upper jaw with teeth, both of an adult
and young individual; also a radius, some lumbar vertebrae, and
some metatarsal bones. They are all embedded in a light porous tuff,
resembling in colour and mineral composition the ejectamenta of several
of the latest eruptions of Denise. But none of the bones penetrate into
another part of the same specimen, which consists of a more compact rock
thickly laminated. Nevertheless, I agree with the Abbe Croizet and M.
Aymard, that it is not conceivable even that the less coherent part of
the museum Specimen which envelopes the human bones should have been
artificially put together, whatever may have been the origin of certain
other slabs of tuff which were afterwards sold as coming from the same
place, and which also contained human remains. Whether some of these
were spurious or not is a question more difficult to decide. One of
them, now in the possession of M. Pichot-Dumazel, an advocate of Le Puy,
is suspected of having had some plaster of Paris introduced into it to
bind the bones more firmly together in the loose volcanic tuff. I was
assured that a dealer in objects of natural history at Le Puy had been
in the habit of occasionally securing the cohesion in that manner of
fragments of broken bones, and the juxtaposition of uninjured ones
found free and detachable in loose volcanic tuffs. From this to the
fabrication of a factitious human fossil was, it is suggested, but
a short step. But in reference to M. Pichot's specimen, an expert
anatomist remarked to me that it would far exceed the skill, whether of
the peasant who owned the vineyard or of the dealer above mentioned, to
put together in their true position all the thirty-eight bones of
the hand and fingers, or the sixteen of the wrist, without making any
mistake, and especially without mixing those of the right with the
homologous bones of the left hand, assuming that they had brought bones,
from some other spot, and then artificially introduced them into a
mixture of volcanic tuff and plaster of Paris.
Granting, however, that the high prices given for "human fossils" at
Le Puy may have led to the perpetration of some frauds, it is still
an interesting question to consider whether the admission of the
genuineness of a single fossil, such as that now in the museum at Le
Puy, would lead us to assign a higher antiquity to the existence of Man
in France than is deducible from many other facts explained in the last
seven chapters. In reference to this point, I may observe that although
I was not able to fix with precision the exact bed in the volcanic
mountain from which the rock containing the human bones was taken, M.
Felix Robert has, nevertheless, after studying "the volcanic alluviums"
of Denise, ascertained that, on the side of Cheyrac and the village of
Malouteyre, blocks of tuff frequently occur exactly like the one in the
museum. That tuff he considers a product of the latest eruption of
the volcano. In it have been found the remains of Hyaena spelaea and
Hippopotamus major. The eruptions of steam and gaseous matter which
burst forth from the crater of Denise broke through laminated Tertiary
clays, small pieces of which, some of them scarcely altered, others half
converted into scoriae, were cast out in abundance, while other portions
must have been in a state of argillaceous mud. Showers of such materials
would be styled by the Neapolitans "aqueous lava" or "lava d'aqua," and
we may well suppose that some human individuals, if any existed, would,
together with wild animals, be occasionally overwhelmed in these tuffs.
From near the place on the mountain whence the block with human bones
now in the museum is said to have come, a stream of lava, well marked by
its tabular structure, flowed down the flanks of the hill, within a few
feet of the alluvial plain of the Borne, a small tributary of the Loire,
on the opposite bank of which stands the town of Le Puy. Its continuous
extension to so low a level clearly shows that the valley had already
been deepened to within a few feet of its present depth at the time of
the flowing of the lava.
We know that the alluvium of the same district, having a similar
relation to the present geographical outline of the valleys, is of
Pleistocene date, for it contains around Le Puy the bones of Elephas
primigenius and Rhinoceros tichorhinus; and this affords us a
palaeontological test of the age of the human skeleton of Denise, if the
latter be assumed to be coeval with the lava stream above referred to.
It is important to dwell on this point, because some geologists have
felt disinclined to believe in the genuineness of the "fossil man of
Denise," on the ground that, if conceded, it would imply that the
human race was contemporary with an older fauna, or that of the Elephas
meridionalis. Such a fauna is found fossil in another layer of tuff
covering the slope of Denise, opposite to that where the museum specimen
was exhumed. The quadrupeds obtained from that more ancient tuff
comprise Elephas meridionalis, Hippopotamus major, Rhinoceros
megarhinus, Antilope torticornis, Hyaena brevirostris, and twelve others
of the genera horse, ox, stag, goat, tiger, etc., all supposed to be of
extinct species. This tuff, found between Malouteyre and Polignac, M.
Robert regards as the product of a much older eruption, and referable to
the neighbouring Montagne de St. Anne, a volcano in a much more wasted
and denuded state than Denise, and classed by M. Bertrand de Doue as of
intermediate age between the ancient and modern cones of Velay.
The fauna to which Elephas meridionalis and its associates belong, can
be shown to be of anterior date, in the north of France, to the flint
implements of St. Acheul, by the following train of reasoning. The
valley of the Seine is not only geographically contiguous to the valley
of the Somme, but its ancient alluvium contains the same mammoth and
other fossil species. The Eure, one of the tributaries of the Seine, in
its way to join that river, flows in a valley which follows a line of
fault in the Chalk; and this valley is seen to be comparatively modern,
because it intersects at St. Prest, 4 miles below Chartres, an older
valley belonging to an anterior system of drainage, which has been
filled by a more ancient fluviatile alluvium, consisting of sand and
gravel, 90 feet thick. I have examined the site of this older drift, and
the fossils have been determined by Dr. Falconer. They comprise Elephas
meridionalis, a species of rhinoceros (not R. tichorhinus), and other
mammalia differing from those of the implement-bearing gravels of the
Seine and Somme. The latter, belonging to the period of the mammoth,
might very well have been contemporary with the modern volcanic
eruptions of Central France; and we may presume, even without the aid of
the Denise fossil, that Man may have witnessed these. But the tuffs and
gravels in which the Elephas meridionalis are embedded were synchronous
with an older epoch of volcanic action, to which the cone of St. Anne,
near Le Puy, and many other mountains of M. Bertrand de Doue's middle
period belong, having cones and craters, which have undergone much
waste by aqueous erosion. We have as yet no proof that Man witnessed
the origin of these hills of lava and scoriae of the middle phase of
volcanic action.
Some surprise was expressed in 1856, by several of the assembled
naturalists at Le Puy, that the skull of the "fossil man of Denise,"
although contemporary with the mammoth, and coeval with the last
eruptions of the Le Puy volcanoes [18], should be of the ordinary
Caucasian or European type; but the observations of Professor Huxley on
the Engis skull, cited in the fifth chapter, showing the near approach
of that ancient cranium to the European standard, will help to remove
this source of perplexity.
HUMAN FOSSIL OF NATCHEZ ON THE MISSISSIPPI.
I have already alluded to Dr. Dowler's attempt to calculate, in years,
the antiquity of the human skeleton said to have been buried under four
cypress forests in the delta of the Mississippi, near New Orleans (see
above, Chapter 3). In that case no remains of extinct animals were found
associated with those of Man: but in another part of the basin of
the Mississippi, a human bone, accompanied by bones of Mastodon and
Megalonyx, is supposed to have been washed out of a more ancient
alluvial deposit.
After visiting the spot in 1846, I described the geological position
of the bones, and discussed their probable age, with a stronger bias, I
must confess, as to the antecedent improbability of the contemporaneous
entombment of Man and the mastodon than any geologist would now be
justified in entertaining.
[Illustration: Figure 26. Alluvial Plain of the Mississippi]
(FIGURE 26. SECTION THROUGH THE ALLUVIAL PLAIN OF THE MISSISSIPPI.
1. Modern alluvium of the Mississippi.
2. Loam or loess.
3. f. Eocene.
4. Cretaceous.)
In the latitude of Vicksburg, 32 degrees 50 minutes north, the broad,
flat, alluvial plain of the Mississippi, a b, Figure 26, is bounded on
its eastern side by a table-land d e, about 200 feet higher than the
river, and extending 12 miles eastward with a gentle upward slope. This
elevated platform ends abruptly at d, in a line of perpendicular cliffs
or bluffs, the base of which is continually undermined by the great
river.
The table-land d-e consists at Vicksburg, through which the annexed
section, Figure 26, passes, of loam, overlying the Tertiary strata f-f.
Between the loam and the Tertiary formation there is usually a deposit
of stratified sand and gravel, containing large fragments of silicified
corals and the wreck of older Palaeozoic rocks. The age of this
underlying drift, which is 140 feet thick at Natchez, has not yet been
determined; but it may possibly belong to the glacial period. Natchez is
about 80 miles in a straight line south of Vicksburg, on the same left
bank of the Mississippi. Here there is a bluff, the upper 60 feet of
which consists of a continuous portion of the same calcareous loam as at
Vicksburg, equally resembling the Rhenish loess in mineral character
and in being sometimes barren of fossils, sometimes so full of them that
bleached land-shells stand out conspicuously in relief in the vertical
and weathered face of cliffs which form the banks of streams, everywhere
intersecting the loam.
So numerous are the shells that I was able to collect at Natchez, in
a few hours, in 1846, no less than twenty species of the genera Helix,
Helicina, Pupa, Cyclostoma, Achatina, and Succinea, all identical with
shells now living in the same country; and in one place I observed (as
happens also occasionally in the valley of the Rhine) a passage of the
loam with land-shells into an underlying marly deposit of subaqueous
origin, in which shells of the genera Limnaea, Planorbis, Paludina,
Physa, and Cyclas were embedded, also consisting of recent American
species. Such deposits, more distinctly stratified than the loam
containing land-shells, are produced, as before stated, in all great
alluvial plains, where the river shifts its position, and where marshes,
ponds, and lakes are formed in its old deserted channels. In this part
of America, however, it may have happened that some of these lakes
were caused by partial subsidences, such as were witnessed, during
the earthquakes of 1811-12, around New Madrid, in the valley of the
Mississippi.
Owing to the destructible nature of the yellow loam, d e, Figure 26,
every streamlet flowing over the platform has cut for itself, in its way
to the Mississippi, a deep gully or ravine; and this erosion has of
late years, especially since 1812, proceeded with accelerated speed,
ascribable in some degree to the partial clearing of the native forest,
but partly also to the effects of the earthquake of 1811-12. By
that convulsion the region around Natchez was rudely shaken and much
fissured. One of the narrow valleys near Natchez, due to this fissuring,
is now called the Mammoth Ravine. Though no less than 7 miles long,
and in some parts 60 feet deep, I was assured by a resident proprietor,
Colonel Wiley, that it had no existence before 1812. With its numerous
ramifications, it is said to have been entirely formed since the
earthquake at New Madrid. Before that event, Colonel Wiley had ploughed
some of the land exactly over a spot now traversed by part of this
water-course.
I satisfied myself that the ravine had been considerably enlarged
and lengthened a short time before my visit, and it was then freshly
undermined and undergoing constant waste. From a clayey deposit
immediately below the yellow loam, bones of the Mastodon ohioticus, a
species of Megalonyx, bones of the genera Equus, Bos, and others,
some of extinct and others presumed to be of living species, had been
detached, and had fallen to the base of the cliffs. Mingled with the
rest, the pelvic bone of a man, os innominatum, was obtained by Dr.
Dickeson of Natchez, in whose collection I saw it. It appeared to be
quite in the same state of preservation, and was of the same black
colour as the other fossils, and was believed to have come like them
from a depth of about 30 feet from the surface. In my "Second Visit
to America," in 1846, I suggested, as a possible explanation of this
association of a human bone with remains of Mastodon and Megalonyx, that
the former may possibly have been derived from the vegetable soil at the
top of the cliff, whereas the remains of extinct mammalia were dislodged
from a lower position, and both may have fallen into the same heap or
talus at the bottom of the ravine. The pelvic bone might, I conceived,
have acquired its black colour by having lain for years or centuries
in a dark superficial peaty soil, common in that region. I was informed
that there were many human bones, in old Indian graves in the same
district, stained of as black a dye. On suggesting this hypothesis
to Colonel Wiley of Natchez, I found that the same idea had already
occurred to his mind. No doubt, had the pelvic bone belonged to any
recent mammifer other than Man, such a theory would never have been
resorted to; but so long as we have only one isolated case, and are
without the testimony of a geologist who was present to behold the bone
when still engaged in the matrix, and to extract it with his own hands,
it is allowable to suspend our judgment as to the high antiquity of the
fossil.
If, however, I am asked whether I consider the Natchez loam, with
land-shells and the bones of Mastodon and Megalonyx, to be more ancient
than the alluvium of the Somme containing flint implements and the
remains of the mammoth and hyaena, I must declare that I do not. Both
in Europe and America the land and freshwater shells accompanying the
extinct pachyderms are of living species, and I could detect no shell
in the Natchez loam so foreign to the basin of the Mississippi as is
the Cyrena fluminalis to the rivers of modern Europe. If, therefore, the
relative ages of the Picardy and Natchez alluvium were to be decided on
conchological data alone, the fluvio-marine beds of Abbeville might rank
as a shade older than the loess of Natchez. My reluctance in 1846 to
regard the fossil human bone as of Pleistocene date arose in part from
the reflection that the ancient loess of Natchez is anterior in time to
the whole modern delta of the Mississippi. The table-land, d e, Figure
26, was, I believe, once a part of the original alluvial plain or delta
of the great river before it was upraised. It has now risen more than
200 feet above its pristine level. After the upheaval, or during it, the
Mississippi cut through the old fluviatile formation of which its
bluffs are now formed, just as the Rhine has in many parts of its
valley excavated a passage through the ancient loess. If I was right in
calculating that the present delta of the Mississippi must have required
many tens of thousands of years for its growth, and if the claims of the
Natchez man to have co-existed with the mastodon are admitted, it would
follow that North America was peopled by the human race many tens of
thousands of years before our time. But even were that true, we could
not presume, reasoning from ascertained geological data, that the
Natchez bone was anterior in date to the antique flint hatchets of St.
Acheul. When we ascend the Mississippi from Natchez to Vicksburg, and
then enter the Ohio, we are accompanied everywhere by a continuous
fringe of terraces of sand and gravel at a certain height above the
alluvial plain, first of the great river, and then of its tributary.
We also find that the older alluvium contains the remains of Mastodon
everywhere, and in some places, as at Evansville, those of the
Megalonyx. As in the valley of the Somme in Europe, those old
Pleistocene gravels often occur at more than one level, and the ancient
mounds of the Ohio, with their works of art, are newer than the old
terraces of the mastodon period, just as the Gallo-Roman tombs of St.
Acheul or the Celtic weapons of the Abbeville peat are more modern than
the tools of the mammoth-bearing alluvium.
In the first place, I may remind the reader that the vertical movement
of 250 feet, required to elevate the loess of Natchez to its present
height, is exceeded by the upheaval which the marine stratum of
Cagliari, containing pottery, has been ascertained by Count de la
Marmora to have experienced. Such changes of level, therefore, have
actually occurred in Europe in the human epoch, and may therefore have
happened in America. In the second place, I may observe that if, since
the Natchez mastodon was embedded in clay, the delta of the Mississippi
has been formed, so, since the mammoth and rhinoceros of Abbeville and
Amiens were enveloped in fluviatile mud and gravel, together with flint
tools, a great thickness of peat has accumulated in the valley of the
Somme; and antecedently to the first growth of peat, there had been time
for the extinction of a great many mammalia, requiring, perhaps, a lapse
of ages many times greater than that demanded for the formation of 30
feet of peat, for since the earliest growth of the latter there has been
no change in the species of mammalia in Europe.
Should future researches, therefore, confirm the opinion that the
Natchez man co-existed with the mastodon, it would not enhance the value
of the geological evidence in favour of Man's antiquity, but merely
render the delta of the Mississippi available as a chronometer, by which
the lapse of Pleistocene time could be measured somewhat less vaguely
than by any means of measuring which have as yet been discovered or
rendered available in Europe.
CHAPTER 12. -- ANTIQUITY OF MAN RELATIVELY TO THE GLACIAL PERIOD AND TO
THE EXISTING FAUNA AND FLORA.
Chronological Relation of the Glacial Period, and the earliest
known Signs of Man's Appearance in Europe.
Series of Tertiary Deposits in Norfolk and Suffolk immediately
antecedent to the Glacial Period.
Gradual Refrigeration of Climate proved by the Marine Shells
of successive Groups.
Marine Newer Pliocene Shells of Northern Character near Woodbridge.
Section of the Norfolk Cliffs.
Norwich Crag.
Forest Bed and Fluvio-marine Strata.
Fossil Plants and Mammalia of the same.
Overlying Boulder Clay and Contorted Drift.
Newer freshwater Formation of Mundesley compared to that of Hoxne.
Great Oscillations of Level implied by the Series of Strata in the
Norfolk Cliffs.
Earliest known Date of Man long subsequent to the existing Fauna
and Flora.
Frequent allusions have been made in the preceding pages to a period
called the glacial, to which no reference is made in the Chronological
Table of Formations given above (Chapter 1). It comprises a long series
of ages, during which the power of cold, whether exerted by glaciers
on the land, or by floating ice on the sea, was greater in the northern
hemisphere, and extended to more southern latitudes than now. [19]
It often happens that when in any given region we have pushed back our
geological investigations as far as we can in search of evidence of the
first appearance of Man in Europe, we are stopped by arriving at what is
called the "boulder clay" or "northern drift." This formation is usually
quite destitute of organic remains, so that the thread of our inquiry
into the history of the animate creation, as well as of man, is abruptly
cut short. The interruption, however, is by no means encountered at the
same point of time in every district. In the case of the Danish peat,
for example, we get no farther back than the Recent period of our
Chronologic Table, and then meet with the boulder clay; and it is the
same in the valley of the Clyde, where the marine strata contain
the ancient canoes before described (Chapter 3), and where nothing
intervenes between that Recent formation and the glacial drift. But we
have seen that, in the neighbourhood of Bedford the memorials of Man can
be traced much farther back into the past, namely, into the Pleistocene
epoch, when the human race was contemporary with the mammoth and many
other species of mammalia now extinct. Nevertheless, in Bedfordshire as
in Denmark, the formation next antecedent in date to that containing
the human implements is still a member of the glacial drift, with its
erratic blocks.
If the reader remembers what was stated in the eighth chapter as to
the absence or extreme scarcity of human bones and works of art in
all strata, whether marine or freshwater, even in those formed in the
immediate proximity of land inhabited by millions of human beings, he
will be prepared for the general dearth of human memorials in glacial
formations, whether Recent, Pleistocene, or of more ancient date. If
there were a few wanderers over lands covered with glaciers, or over
seas infested with ice-bergs, and if a few of them left their bones or
weapons in moraines or in marine drift, the chances, after the lapse
of thousands of years, of a geologist meeting with one of them must be
infinitesimally small.
It is natural, therefore, to encounter a gap in the regular sequence
of geological monuments bearing on the past history of Man, wherever we
have proofs of glacial action having prevailed with intensity, as it has
done over large parts of Europe and North America, in the Pleistocene
period. As we advance into more southern latitudes approaching the 50th
parallel of latitude in Europe, and the 40th in North America, this
disturbing cause ceases to oppose a bar to our inquiries; but even then,
in consequence of the fragmentary nature of all geological annals, our
progress is inevitably slow in constructing anything like a connected
chain of history, which can only be effected by bringing the links of
the chain found in one area to supply the information which is wanting
in another.
The least interrupted series of consecutive documents to which we can
refer in the British Islands, when we desire to connect the Pliocene
with the Pleistocene periods, are found in the counties of Norfolk,
Suffolk, and Essex; and I shall speak of them in this chapter, as they
have a direct bearing on the relations of the human and glacial periods,
which will be the subject of several of the following chapters. The
fossil shells of the deposits in question clearly point to a gradual
refrigeration of climate, from a temperature somewhat warmer than
that now prevailing in our latitudes to one of intense cold; and the
successive steps which have marked the coming on of the increasing cold
are matters of no small geological interest. [20]
It will be seen in the Chronological Table, that next before the
Pleistocene period stands the Pliocene. The shelly and sandy
beds representing these periods in Norfolk and Suffolk are termed
provincially Crag, having under the name been long used in agriculture
to fertilise soils deficient in calcareous matter, or to render them
less stiff and impervious. In Suffolk, the older Pliocene strata called
Crag are divisible into the Coralline and the Red Crags, the former
being the older of the two. In Norfolk, a more modern formation,
commonly termed the "Norwich," or sometimes the "mammaliferous" Crag,
which is referable to the newer Pliocene period, occupies large areas.
We are indebted to Mr. Searles Wood, F.G.S., for an admirable monograph
on the fossil shells of these British Pliocene formations. He has not
himself given us an analysis of the results of his treatise, but the
following tables have been drawn up for me by Mr. S.P. Woodward, the
well-known author of the "Manual of Mollusca, Recent and Fossil" (London
1851-56), in order to illustrate some of the general conclusions to
which Mr. Wood's careful examination of 442 species of mollusca has led.
TABLE 12/1. NUMBER OF KNOWN SPECIES OF MARINE TESTACEA IN THE THREE
ENGLISH PLIOCENE DEPOSITS, CALLED THE NORWICH, THE RED, AND THE
CORALLINE CRAGS.
COLUMN 1: NAME.
COLUMN 2: NUMBER.
Brachiopoda: 6.
Lamellibranchia: 206.
Gasteropoda: 230.
TOTAL: 442.
TABLE 12/2. DISTRIBUTION OF THE ABOVE MARINE TESTACEA.
COLUMN 1: NAME.
COLUMN 2: NUMBER.
Norwich Crag: 81.
Red Crag: 225.
Coralline Crag: 327.
Species common to the Norwich and Red Crag (not in Coralline): 33.
Species common to the Norwich and Coralline (not in Red): 4.
Species common to the Red and Coralline (not in Norwich): 116.
Species common to the Norwich, Red, and Coralline: 19.*
(* These 19 species must be added to the numbers 33, 4, and
116 respectively, in order to obtain the full amount of common
species in each of those cases.)
TABLE 12/3. PROPORTION OF RECENT TO EXTINCT SPECIES.
COLUMN 1: NAME.
COLUMN 2: NUMBER OF RECENT.
COLUMN 3: NUMBER OF EXTINCT.
COLUMN 4: PERCENTAGE OF RECENT.
Norwich Crag: 69: 12: 85%.
Red Crag: 130: 95: 57%.
Coralline Crag: 168: 159: 51%.
TABLE 12/4. RECENT SPECIES NOT LIVING NOW IN BRITISH SEAS.
COLUMN 1: NAME.
COLUMN 2: NUMBER OF NORTHERN.
COLUMN 3: NUMBER OF SOUTHERN.
Norwich Crag: 12: 0.
Red Crag: 8: 16.
Coralline Crag: 2: 27.
In the above list I have not included the shells of the glacial beds of
the Clyde and of several other British deposits of newer origin than the
Norwich Crag, in which nearly all--perhaps all--the species are Recent.
The land and freshwater shells, thirty-two in number, have also been
purposely omitted, as well as three species of London Clay shells,
suspected by Mr. Wood himself to be spurious.
By far the greater number of the living marine species included in these
tables are still inhabitants of the British seas; but even these differ
considerably in their relative abundance, some of the commonest of the
Crag shells being now extremely scarce; as, for example, Buccinopsis
Dalei; and others, rarely met with in a fossil state, being now very
common, as Murex erinaceus and Cardium echinatum.
The last table throws light on a marked alteration in the climate of
the three successive periods. It will be seen that in the Coralline
Crag there are twenty-seven southern shells, including twenty-six
Mediterranean, and one West Indian species (Erato Maugeriae). Of these
only thirteen occur in the Red Crag, associated with three new southern
species, while the whole of them disappear from the Norwich beds. On the
other hand, the Coralline Crag contains only two shells closely
related to arctic forms of the genera Admete and Limopsis. The Red Crag
contains, as stated in the table, eight northern species, all of which
recur in the Norwich Crag, with the addition of four others, also
inhabitants of the arctic regions; so that there is good evidence of
a continual refrigeration of climate during the Pliocene period in
Britain. The presence of these northern shells cannot be explained away
by supposing that they were inhabitants of the deep parts of the sea;
for some of them, such as Tellina calcarea and Astarte borealis, occur
plentifully, and sometimes, with the valves united by their ligament, in
company with other littoral shells, such as Mya arenaria and Littorina
rudis, and evidently not thrown up from deep water. Yet the northern
character of the Norwich Crag is not fully shown by simply saying that
it contains twelve northern species. It is the predominance of certain
genera and species, such as Tellina calcarea, Astarte borealis, Scalaria
groenlandica, and Fusus carinatus, which satisfies the mind of a
conchologist as to the arctic character of the Norwich Crag. In like
manner, it is the presence of such genera as Pyrula, Columbella,
Terebra, Cassidaria, Pholadomya, Lingula, Discina, and others which give
a southern aspect to the Coralline Crag shells.
The cold, which had gone on increasing from the time of the Coralline
to that of the Norwich Crag, continued, though not perhaps without some
oscillations of temperature, to become more and more severe after the
accumulation of the Norwich Crag, until it reached its maximum in what
has been called the glacial epoch. The marine fauna of this last period
contains, both in Ireland and Scotland, Recent species of mollusca now
living in Greenland and other seas far north of the areas where we find
their remains in a fossil state.
The refrigeration of climate from the time of the older to that of the
newer Pliocene strata is not now announced for the first time, as it
was inferred from a study of the Crag shells in 1846 by the late Edward
Forbes.*
(* "Memoirs of the Geological Survey" London 1846 page 391.)
The most southern point to which the marine beds of the Norwich Crag
have yet been traced is at Chillesford, near Woodbridge, in Suffolk,
about 80 miles north-east of London, where, as Messrs. Prestwich and
Searles Wood have pointed out,* they exhibit decided marks of having
been deposited in a sea of a much lower temperature than that now
prevailing in the same latitude. (* "Quarterly Journal of the Geological
Society" volume 5 1849 page 345.) Out of twenty-three shells obtained in
that locality from argillaceous strata 20 feet thick, two only, namely,
Nucula Cobboldiae and Tellina obliqua, are extinct, and not a few of the
other species, such as Leda lanceolata, Cardium groenlandicum, Lucina
borealis, Cyprina islandica, Panopaea norvegica, and Mya truncata,
betray a northern, and some of them an arctic character.
These Chillesford beds are supposed to be somewhat more modern than
any of the purely marine strata of the Norwich Crag exhibited by the
sections of the Norfolk cliffs north-west of Cromer, which I am about
to describe. Yet they probably preceded in date the "Forest Bed" and
fluvio-marine deposits of those same cliffs. They are, therefore, of no
small importance in reference to the chronology of the glacial period,
since they afford evidence of an assemblage of fossil shells with a
proportion of between eight and nine in a hundred of extinct species
occurring so far south as latitude 53 degrees north, and indicating so
cold a climate as to imply that the glacial period commenced before the
close of the Pliocene era.
[Illustration: Figure 27. Succession of Strata]
(FIGURE 27. DIAGRAM TO ILLUSTRATE THE GENERAL SUCCESSION
OF THE STRATA IN THE NORFOLK CLIFFS, EXTENDING SEVERAL MILES
NORTH-WEST AND SOUTH-EAST OF CROMER.
A. Site of Cromer Jetty.
1. Upper Chalk with flints in regular stratification.
2. Norwich Crag, rising from low water at Cromer to the top
of the cliffs at Weybourn, seven miles distant.
3. "Forest Bed," with stumps of trees in situ and remains of
Elephas meridionalis, E. primigenius, E. antiquus, Rhinoceros
etruscus, etc. This bed increases in depth and thickness
eastward. No Crag (Number 2) known east of Cromer Jetty.
3 prime. Fluvio-marine series. At Cromer and eastward, with
abundant lignite beds and mammalian remains, and with cones
of the Scotch and spruce firs and wood. At Runton, north-west
of Cromer, expanding into a thick freshwater deposit, with
overlying marine strata, elsewhere consisting of alternating
sands and clays, tranquilly deposited, some with marine,
others with freshwater shells.
4. Boulder clay of glacial period, with far transported erratics,
some of them polished and scratched, 20 to 80 feet in thickness.
5. Contorted drift.
6. Superficial gravel and sand with covering of vegetable soil.)
The annexed section (Figure 27) will give a general idea of the ordinary
succession of the Pliocene and Pleistocene strata which rest upon the
Chalk in the Norfolk and Suffolk cliffs. These cliffs vary in height
from fifty to above three hundred feet. At the north-western extremity
of the section at Weybourn (beyond the limits of the annexed diagram),
and from thence to Cromer, a distance of 7 miles, the Norwich Crag, a
marine deposit, reposes immediately upon the Chalk. A vast majority
of its shells are of living species such as Cardium edule, Cyprina
islandica, Scalaria groenlandica, and Fusus antiquus, and some few
extinct, as Tellina obliqua, and Nucula Cobboldiae. At Cromer jetty this
formation thins out, as expressed in the diagram at A; and to the south
we find Number 3, or what is commonly called the "Forest Bed," reposing
immediately upon the Chalk, and occupying, as it were, the place
previously held by the marine Crag Number 2. This buried forest has
been traced for more than 40 miles, being exposed at certain seasons
and states of the beach between high and low water mark. It extends from
Cromer to near Kessingland, and consists of the stumps of numerous trees
standing erect, with their roots attached to them, and penetrating in
all directions into the loam or ancient vegetable soil on which they
grew. They mark the site of a forest which existed there for a long
time, since, besides the erect trunks of trees, some of them 2 and 3
feet in diameter, there is a vast accumulation of vegetable matter in
the immediately overlying clays. Thirty years ago, when I first examined
this bed, I saw many trees, with their roots in the old soil, laid open
at the base of the cliff near Happisburgh; and long before my visit,
other observers, and among them the late Mr. J.C. Taylor, had noticed
the buried forest. Of late years it has been repeatedly seen at many
points by Mr. Gunn, and, after the great storms of the autumn of 1861,
by Mr. King. In order to expose the stumps to view, a vast body of sand
and shingle must be cleared away by the force of the waves. [21]
As the sea is always gaining on the land, new sets of trees are brought
to light from time to time, so that the breadth as well as length of the
area of ancient forest land seems to have been considerable. Next above
Number 3, we find a series of sands and clays with lignite (Number
3 prime), sometimes 10 feet thick, and containing alternations of
fluviatile and marine strata, implying that the old forest land, which
may at first have been considerably elevated above the level of the sea,
had sunk down so as to be occasionally overflowed by a river, and
at other times by the salt waters of an estuary. There were probably
several oscillations of level which assisted in bringing about these
changes, during which trees were often uprooted and laid prostrate,
giving rise to layers of lignite. Occasionally marshes were formed and
peaty matter accumulated, after which salt water again predominated, so
that species of Mytilus, Mya, Leda, and other marine genera, lived in
the same area where the Unio, Cyclas, and Paludina had flourished for
a time. That the marine shells lived and died on the spot, and were
not thrown up by the waves during a storm, is proved, as Mr. King has
remarked, by the fact that at West Runton, north-west of Cromer, the Mya
truncata and Leda myalis are found with both valves united and erect in
the loam, all with their posterior or siphuncular extremities uppermost.
This attitude affords as good evidence to the conchologist that those
mollusca lived and died on the spot as the upright position of the trees
proves to the botanist that there was a forest over the Chalk east of
Cromer.
Between the stumps of the buried forest, and in the lignite above them,
are many well-preserved cones of the Scotch and spruce firs, Pinus
sylvestris, and Pinus abies. The specific names of these fossils were
determined for me in 1840, by a botanist of no less authority than
the late Robert Brown; and Professor Heer has lately examined a large
collection from the same stratum, and recognised among the cones of the
spruce some which had only the central part or axis remaining, the rest
having been bitten off, precisely in the same manner as when in our
woods the squirrel has been feeding on the seeds. There is also in the
forest-bed a great quantity of resin in lumps, resembling that gathered
for use, according to Professor Heer, in Switzerland, from beneath
spruce firs.
The following is a list of some of the plants and seeds which were
collected by the Reverend S.W. King, in 1861, from the forest bed at
Happisburgh, and named by Professor Heer:--
PLANTS AND SEEDS OF THE FOREST AND LIGNITE BEDS BELOW THE GLACIAL DRIFT
OF THE NORFOLK CLIFFS.
Pinus sylvestris, Scotch fir.
Pinus abies, spruce fir.
Taxus baccata, yew.
Nuphar luteum, yellow water-lily.
Ceratophyllum demersum, hornwort.
Potamogeton, pondweed.
Prunus spinosus, common sloe.
Menyanthes trifoliata, buckbean.
Nymphaea alba, white water-lily.
Alnus, alder.
Quercus, oak.
Betula, birch.
The insects, so far as they are known, including several species of
Donacia, are, like the plants and freshwater shells, of living species.
It may be remarked, however, that the Scotch fir has been confined in
historical times to the northern parts of the British Isles, and the
spruce fir is nowhere indigenous in Great Britain. The other plants are
such as might now be found in Norfolk, and many of them indicate fenny
or marshy ground.*
(* Mr. King discovered in 1863, in the forest bed, several
rhizomes of the large British fern Osmunda regalis, of such
dimensions as they are known to attain in marshy places.
They are distinguishable from those of other British ferns
by the peculiar arrangement of the vessels, as seen under
the microscope in a cross section.)
When we consider the familiar aspect of the flora, the accompanying
mammalia are certainly most extraordinary. There are no less than three
elephants, a rhinoceros and hippopotamus, a large extinct beaver, and
several large estuarine and marine mammalia, such as the walrus, the
narwhal, and the whale.
The following is a list of some of the species of which the bones have
been collected by Messrs. Gunn and King.
Those marked (asterisk) have been recorded by Professor Owen in his
British Fossil Mammalia. Those marked (dagger) have been recognised by
the same authority in the cabinets of Messrs. Gunn and King, or in
the Norwich Museum; the other three are given on the authority of Dr.
Falconer.
MAMMALIA OF THE FOREST AND LIGNITE BEDS BELOW THE GLACIAL DRIFT OF THE
NORFOLK CLIFFS.
Elephas meridionalis.
(asterisk) Elephas primigenius.
Elephas antiquus.
Rhinoceros etruscus.
(asterisk) Hippopotamus (major?).
(asterisk) Sus scrofa.
(asterisk) Equus (fossilis?).
(asterisk) Ursus (sp.?).
(dagger) Canis lupus.
(dagger) Bison priscus.
(dagger) Megaceros hibernicus.
(asterisk) Cervus capreolus.
(dagger) Cervus tarandus.
(dagger) Cervus Sedgwickii.
(asterisk) Arvicola amphibia.
(asterisk) Castor (Trogontherium) Cuvieri.
(asterisk) Castor europaeus.
(asterisk) Palaeospalax magnus.
(dagger) Trichecus rosmarus, Walrus.
(dagger) Monodon monoceros, Narwhal.
(dagger) Balaenoptera.
Mr. Gunn informs me that the vertebrae of two distinct whales were found
in the fluvio-marine beds at Bacton, and that one of them, shown to
Professor Owen, is said by him to imply that the animal was 60 feet
long. A narwhal's tusk was discovered by Mr. King near Cromer, and
the remains of a walrus. No less than three species of elephant, as
determined by Dr. Falconer, have been obtained from the strata 3 and
3 prime, of which, according to Mr. King, E. meridionalis is the most
common, the mammoth next in abundance, and the third, E. antiquus,
comparatively rare.
The freshwater shells accompanying the fossil quadrupeds, above
enumerated, are such as now inhabit rivers and ponds in England; but
among them, as at Runton, between the "forest bed" and the glacial
deposits, a remarkable variety of the Cyclas amnica occurs (Figure 28),
identical with that which accompanies the Elephas antiquus at Ilford and
Grays in the valley of the Thames.
All the freshwater shells of the beds intervening between the Forest-bed
Number 3, and the glacial formation 4, Figure 27, are of Recent
species. As to the small number of marine shells occurring in the
same fluvio-marine series, I have seen none which belonged to extinct
species, although one or two have been cited by authors. I am in doubt,
therefore, whether to class the forest bed and overlying strata as
Pleistocene, or to consider them as beds of passage between the Pliocene
and Pleistocene periods. The fluvio-marine series usually terminates
upwards in finely laminated sands and clays without fossils, on which
reposes the boulder clay.
[Illustration: Figure 28. Cyclas]
(FIGURE 28. Cyclas (Pisidium) amnica var.?
The two middle figures are of the natural size.)
This formation, Number 4, is of very varying thickness. Its glacial
character is shown, not only by the absence of stratification, and the
great size and angularity of some of the included blocks of distant
origin, but also by the polished and scratched surfaces of such of them
as are hard enough to retain any markings.
Near Cromer, blocks of granite from 6 to 8 feet in diameter have been
met with, and smaller ones of syenite, porphyry, and trap, besides
the wreck of the London Clay, Chalk, Oolite, and Lias, mixed with more
ancient fossiliferous rocks. Erratics of Scandinavian origin occur
chiefly in the lower portions of the till. I came to the conclusion in
1834, that they had really come from Norway and Sweden, after having in
that year traced the course of a continuous stream of such blocks from
those countries to Denmark, and across the Elbe, through Westphalia,
to the borders of Holland. It is not surprising that they should then
reappear on our eastern coast between the Tweed and the Thames, regions
not half so remote from parts of Norway as are many Russian erratics
from the sources whence they came. [22]
[Illustration: Figure 29. Cliff]
(FIGURE 29. CLIFF 50 FEET HIGH BETWEEN BACTON GAP AND MUNDESLEY.
Section through Gravel (top), Sand, Loam and Till (bottom).)
According to the observations of the Reverend J. Gunn and the late Mr.
Trimmer, the glacial drift in the cliffs at Lowestoft consists of
two divisions, the lower of which abounds in the Scandinavian blocks,
supposed to have come from the north-east; while the upper, probably
brought by a current from the north-west, contains chiefly fragments of
Oolitic rocks, more rolled than those of the lower deposit. The united
thickness of the two divisions, without reckoning some interposed
laminated beds, is 80 feet, but it probably exceeds 100 feet near
Happisburgh.*
(* "Quarterly Journal of the Geological Society" volume 7
1851 page 21.)
Although these subdivisions of the drift may be only of local
importance, they help to show the changes of currents and other
conditions, and the great lapse of time which the accumulation of so
varied a series of deposits must have required.
The lowest part of the glacial till, resting on the laminated clays
before mentioned, is very even and regular, while its upper surface
is remarkable for the unevenness of its outline, owing partly, in all
likelihood, to denudation, but still more to other causes presently to
be discussed.
The overlying strata of sand and gravel, Number 5, Figure 27, often
display a most singular derangement in their stratification, which in
many places seems to have a very intimate relation to the irregularities
of outline in the subjacent till. There are some cases, however, where
the upper strata are much bent, while the lower beds of the same
series have continued horizontal. Thus the annexed section (Figure 29)
represents a cliff about 50 feet high, at the bottom of which is till,
or unstratified clay, containing boulders, having an even horizontal
surface, on which repose conformably beds of laminated clay and sand
about 5 feet thick, which, in their turn, are succeeded by vertical,
bent, and contorted layers of sand and loam 20 feet thick, the whole
being covered by flint gravel. The curves of the variously coloured beds
of loose sand, loam, and pebbles, are so complicated that not only may
we sometimes find portions of them which maintain their verticality to a
height of 10 or 15 feet, but they have also been folded upon themselves
in such a manner that continuous layers might be thrice pierced in one
perpendicular boring.
[Illustration: Figures 30 and 31. Strata]
(FIGURE 30. FOLDING OF THE STRATA BETWEEN EAST AND WEST RUNTON.)
(FIGURE 31. SECTION OF CONCENTRIC BEDS WEST OF CROMER.
1. Blue clay.
2. White sand.
3. Yellow Sand.
4. Striped loam and clay.
5. Laminated blue clay.)
At some points there is an apparent folding of the beds round a central
nucleus, as at a, Figure 30, where the strata seem bent round a small
mass of Chalk, or, as in Figure 31, where the blue clay Number 1 is in
the centre; and where the other strata 2, 3, 4, 5 are coiled round it;
the entire mass being 20 feet in perpendicular height. This appearance
of concentric arrangement around a nucleus is, nevertheless, delusive,
being produced by the intersection of beds bent into a convex shape; and
that which seems the nucleus being, in fact, the innermost bed of
the series, which has become partially visible by the removal of the
protuberant portions of the outer layers.
To the north of Cromer are other fine illustrations of contorted drift
reposing on a floor of Chalk horizontally stratified and having a
level surface. These phenomena, in themselves sufficiently difficult
of explanation, are rendered still more anomalous by the occasional
enclosure in the drift of huge fragments of Chalk many yards in
diameter. One striking instance occurs west of Sheringham, where an
enormous pinnacle of Chalk, between 70 and 80 feet in height, is flanked
on both sides by vertical layers of loam, clay, and gravel (Figure 32).
[Illustration: Figure 32. Pinnacle of Chalk]
(FIGURE 32. INCLUDED PINNACLE OF CHALK AT OLD HYTHE POINT,
WEST OF SHERINGHAM.
d. Chalk with regular layers of flints.
c. Layer called "the pan," of Chalk, flints, and marine shells
of Recent species, cemented by oxide of iron.)
This chalky fragment is only one of many detached masses which have
been included in the drift, and forced along with it into their present
position. The level surface of the Chalk in situ (d) may be traced for
miles along the coast, where it has escaped the violent movements to
which the incumbent drift has been exposed.*
(* For a full account of the drift of East Norfolk, see a
paper by the author, "Philosophical Magazine" Number 104 May
1840.)
We are called upon, then, to explain how any force can have been exerted
against the upper masses, so as to produce movements in which the
subjacent strata have not participated. It may be answered that, if we
conceive the till and its boulders to have been drifted to their
present place by ice, the lateral pressure may have been supplied by
the stranding of ice-islands. We learn, from the observations of Messrs.
Dease and Simpson in the polar regions, that such islands, when they
run aground, push before them large mounds of shingle and sand. It
is therefore probable that they often cause great alterations in the
arrangement of pliant and incoherent strata forming the upper part of
shoals or submerged banks, the inferior portions of the same remaining
unmoved. Or many of the complicated curvatures of these layers of loose
sand and gravel may have been due to another cause, the melting on the
spot of ice-bergs and coast ice in which successive deposits of pebbles,
sand, ice, snow, and mud, together with huge masses of rock fallen from
cliffs, may have become interstratified. Ice-islands so constituted
often capsize when afloat, and gravel once horizontal may have assumed,
before the associated ice was melted, an inclined or vertical
position. The packing of ice forced up on a coast may lead to a similar
derangement in a frozen conglomerate of sand or shingle, and, as Mr.
Trimmer has suggested,* alternate layers of earthy matter may have sunk
down slowly during the liquefaction of the intercalated ice so as to
assume the most fantastic and anomalous positions, while the strata
below, and those afterwards thrown down above, may be perfectly
horizontal (see above).
(* "Quarterly Journal of the Geological Society" volume 7
1851 pages 22, 30.)
In most cases where the principal contortions of the layers of gravel
and sand have a decided correspondence with deep indentations in the
underlying till, the hypothesis of the melting of large lumps and masses
of ice once mixed up with the till affords the most natural explanation
of the phenomena. The quantity of ice now seen in the cliffs near
Behring's Straits, in which the remains of fossil elephants are common,
and the huge fragments of solid ice which Meyendorf discovered in
Siberia, after piercing through a considerable thickness of incumbent
soil, free from ice, is in favour of such an hypothesis, the partial
failure of support necessarily giving rise to foldings in the overlying
and previously horizontal layers, as in the case of creeps in coal
mines.*
(* See "Manual of Geology" by the author, page 51.)
In the diagram of the cliffs at page 167, the bent and contorted beds
Number 5, last alluded to, are represented as covered by undisturbed
beds of gravel and sand Number 6. These are usually destitute of organic
remains; but at some points marine shells of Recent species are said to
have been found in them. They afford evidence at many points of repeated
denudation and redeposition, and may be the monuments of a long series
of ages.
MUNDESLEY POST-GLACIAL FRESHWATER FORMATION.
In the range of cliffs above described at Mundesley, about 8 miles
south-east of Cromer, a fine example is seen of a freshwater formation,
newer than all those already mentioned, a deposit which has filled up a
depression hollowed out of all the older beds 3, 4, and 5 of the section
Figure 27.
[Illustration: Figure 33. Newer Freshwater Formation]
(FIGURE 33. SECTION OF THE NEWER FRESHWATER FORMATION I
N THE CLIFFS AT MUNDESLEY, EIGHT MILES SOUTH-EAST OF CROMER,
DRAWN UP BY THE REVEREND S.W. KING.
Height of cliff where lowest, 35 feet above high water.
OLDER SERIES.
1. Fundamental Chalk, below the beach line.
3. Forest bed, with elephant, rhinoceros, stag, etc., and with
tree roots and stumps, also below the beach line.
3 prime. Finely laminated sands and clays, with thin layer of
lignite, and shells of Cyclas and Valvata, and with Mytilus
in some beds.
4. Glacial boulder till.
5. Contorted drift.
6. Gravel overlying contorted drift.
N.B.--Number 2 of the section, Figure 27, is wanting here.
NEWER FRESHWATER BEDS.
A. Coarse river gravel, with shells of Anodon, Valvata, Cyclas,
Succinea, Limnaea, Paludina, etc., seeds of Ceratophyllum
demersum, Nuphar lutea, scales and bones of pike, perch,
salmon, etc., elytra of Donacia, Copris, Harpalus,
and other beetles.
C. Yellow sands.
D. Drift gravel.)
When I examined this line of coast in 1839, the section alluded to
was not so clearly laid open to view as it has been of late years, and
finding at that period not a few of the fossils in the lignite beds
Number 3 prime above the forest bed, identical in species with those
from the post-glacial deposits B C, I supposed the whole to have been of
contemporaneous origin, and so described them in my paper on the Norfolk
cliffs.*
(* "Philosophical Magazine" volume 16 1840 page 345.)
Mr. Gunn was the first to perceive this mistake, which he explained
to me on the spot when I revisited Mundesley in the autumn of 1859 in
company with Dr. Hooker and Mr. King. The last-named geologist has had
the kindness to draw up for me the annexed diagram (Figure 33) of the
various beds which he has recently studied in detail.*
(* Mr. Prestwich has given a correct account of this section
in a paper read to the British Association, Oxford, 1860.
See "The Geologist" volume 4 1861.)
The formations 3, 4, and 5 already described, Figure 27, were evidently
once continuous, for they may be followed for miles north-west and
south-east without a break, and always in the same order. A valley or
river channel was cut through them, probably during the gradual upheaval
of the country, and the hollow became afterwards the receptacle of
the comparatively modern freshwater beds A, B, C, and D. They may well
represent a silted up river-channel, which remained for a time in the
state of a lake or mere, and in which the black peaty mass B accumulated
by a very slow growth over the gravel of the river-bed A. In B we find
remains of some of the same plants which were enumerated as common
in the ancient lignite in 3 prime, such as the yellow water-lily and
hornwort, together with some freshwater shells which occur in the same
fluvio-marine series 3 prime.
[Illustration: Figure 34. Paludina marginata]
(FIGURE 34. Paludina marginata, Michaud (P. minuta, Strickland).
Hydrobia marginata.*
(* This shell is said to have a sub-spiral operculum (not a
concentric one, as in Paludina), and therefore to be
referable to the Hydrobia, a sub-genus of Rissoa. But
this species is always associated with freshwater shells,
while the Rissoae frequent marine and brackish waters.)
The middle figure is of the natural size.)
The only shell which I found not referable to a British species is the
minute Paludina, Figure 34, already alluded to.
When I showed the scales and teeth of the pike, perch, roach, and
salmon, which I obtained from this formation, to M. Agassiz, he thought
they varied so much from their nearest living representatives that they
might rank as distinct species; but Mr. Yarrell doubted the propriety
of so distinguishing them. The insects, like the shells and plants, are
identical, so far as they are known, with living British species. No
progress has yet been made at Mundesley in discovering the contemporary
mammalia.
By referring to the description and section before given of the
freshwater deposit at Hoxne, the reader will at once perceive the
striking analogy of the Mundesley and Hoxne deposits, the latter so
productive of flint implements of the Amiens type. Both of them, like
the Bedford gravel with flint tools and the bones of extinct mammalia,
are post-glacial. It will also be seen that a long series of events,
accompanied by changes in physical geography, intervened between
the "forest bed," Number 3, Figure 27, when the Elephas meridionalis
flourished, and the period of the Mundesley fluviatile beds A, B, C;
just as in France I have shown that the same E. meridionalis belonged to
a system of drainage different from and anterior to that with which the
flint implements of the old alluvium of the Somme and the Seine were
connected.
Before the growth of the ancient forest, Number 3, Figure 33, the
Mastodon arvernensis, a large proboscidian, characteristic of the
Norwich Crag, appears to have died out, or to have become scarce, as no
remains of it have yet been found in the Norfolk cliffs. There was, no
doubt, time for other modifications in the mammalian fauna between the
era of the marine beds, Number 2, Figure 27 (the shells of which imply
permanent submergence beneath the sea), and the accumulation of the
uppermost of the fluvio-marine, and lignite beds, Number 3 prime, which
overlie both Numbers 3 and 2, or the buried forest and the Crag. In the
interval we must suppose repeated oscillations of level, during which
land covered with trees, an estuary with its freshwater shells, and the
sea with its Mya truncata and other mollusca still retaining their erect
position, gained by turns the ascendency. These changes were accompanied
by some denudation followed by a grand submergence of several hundred
feet, probably brought about slowly, and when floating ice aided in
transporting erratic blocks from great distances. The glacial till
Number 4 then originated, and the gravel and sands Number 5 were
afterwards superimposed on the boulder clay, first in horizontal beds,
which became subsequently contorted. These were covered in their turn
by other layers of gravel and sand, Number 6, Figures 27 and 33, the
downward movement still continuing.
The entire thickness of the beds above the Chalk at some points near the
coast, and the height at which they now are raised, are such as to show
that the subsidence of the country after the growth of the forest bed
exceeded 400 feet. The re-elevation must have amounted to nearly as many
feet, as the site of the ancient forest, originally sub-aerial, has been
brought up again to within a few feet of high-water mark. Lastly, after
all these events, and probably during the final process of emergence,
the valley was scooped out in which the newer freshwater strata of
Mundesley, Figure 33, were gradually deposited.
Throughout the whole of this succession of geographical changes, the
flora and invertebrate fauna of Europe appear to have undergone no
important revolution in their specific characters. The plants of the
forest bed belonged already to what has been called the Germanic flora.
The mollusca, the insects, and even some of the mammalia, such as the
European beaver and roebuck, were the same as those now co-existing with
Man. Yet the oldest memorials of our species at present discovered in
Great Britain are post-glacial, or posterior in date to the boulder
clay, Number 4, Figures 27 and 33. The position of the Hoxne flint
implements corresponds with that of the Mundesley beds, from A to D,
Figure 33, and the most likely stratum in which to find hereafter
flint tools is no doubt the gravel A of that section, which has all the
appearance of an old river-bed. No flint tools have yet been observed
there, but had the old alluvium of Amiens or Abbeville occurred in the
Norfolk cliffs instead of the valley of the Somme, and had we depended
on the waves of the sea instead of the labour of many hundred workmen
continued for twenty years, for exposing the flint implements to view,
we might have remained ignorant to this day of the fossil relics brought
to light by M. Boucher de Perthes and those who have followed up his
researches.
Neither need we despair of one day meeting with the signs of Man's
existence in the forest bed Number 3, or in the overlying strata 3
prime, on the ground of any uncongeniality in the climate or incongruity
in the state of the animate creation with the well-being of our species.
For the present we must be content to wait and consider that we have
made no investigations which entitle us to wonder that the bones or
stone weapons of the era of the Elephas meridionalis have failed to come
to light. If any such lie hid in those strata, and should hereafter be
revealed to us, they would carry back the antiquity of Man to a distance
of time probably more than twice as great as that which separates
our era from that of the most ancient of the tool-bearing gravels yet
discovered in Picardy, or elsewhere. But even then the reader will
perceive that the age of Man, though pre-glacial, would be so modern
in the great geological calendar, as given in Chapter 1, that he would
scarcely date so far back as the commencement of the Pleistocene period.
CHAPTER 13. -- CHRONOLOGICAL RELATIONS OF THE GLACIAL PERIOD AND THE
EARLIEST SIGNS OF MAN'S APPEARANCE IN EUROPE.
Chronological Relations of the Close of the Glacial Period and
the earliest geological Signs of the Appearance of Man.
Effects of Glaciers and Icebergs in polishing and scoring Rocks.
Scandinavia once encrusted with Ice like Greenland.
Outward Movement of Continental Ice in Greenland.
Mild Climate of Greenland in the Miocene Period.
Erratics of Recent Period in Sweden.
Glacial State of Sweden in the Pleistocene Period.
Scotland formerly encrusted with Ice.
Its subsequent Submergence and Re-elevation.
Latest Changes produced by Glaciers in Scotland.
Remains of the Mammoth and Reindeer in Scotch Boulder Clay.
Parallel Roads of Glen Roy formed in Glacier Lakes.
Comparatively modern Date of these Shelves.
The chronological relations of the human and glacial periods were
frequently alluded to in the last chapter, and the sections obtained
near Bedford, and at Hoxne, in Suffolk, and a general view of the
Norfolk cliffs, have taught us that the earliest signs of Man's
appearance in the British isles, hitherto detected, are of post-glacial
date. We may now therefore inquire whether the peopling of Europe by
the human race and by the mammoth and other mammalia now extinct, was
brought about during the concluding phases of the glacial epoch.
Although it may be impossible in the present state of our knowledge to
come to a positive conclusion on this head, I know of no inquiry better
fitted to clear up our views respecting the geological state of the
northern hemisphere at the time when the fabricators of the flint
implements of the Amiens type flourished. I shall therefore now proceed
to consider the chronological relations of that ancient people with
the final retreat of the glaciers from the mountains of Scandinavia,
Scotland, Wales, and Switzerland.
SUPERFICIAL MARKINGS AND DEPOSITS LEFT BY GLACIERS AND ICEBERGS.
In order fully to discuss this question, I must begin by referring
to some of the newest theoretical opinions entertained on the glacial
question. When treating of this subject in the "Principles of Geology,"
chapter 15, and in the "Manual (or Elements) of Geology," chapter 11, I
have stated that the whole mass of the ice in a glacier is in constant
motion, and that the blocks of stone detached from boundary precipices,
and the mud and sand swept down by avalanches of snow, or by rain from
the surrounding heights, are lodged upon the surface and slowly borne
along in lengthened mounds, called in Switzerland moraines. These
accumulations of rocky fragments and detrital matter are left at the
termination of the glacier, where it melts in a confused heap called the
"terminal moraine," which is unstratified, because all the blocks, large
and small, as well as the sand and the finest mud, are carried to
equal distances and quietly deposited in a confused mass without being
subjected to the sorting power of running water, which would convey the
finer materials farther than the coarser ones, and would produce, as the
strength of the current varied from time to time in the same place, a
stratified arrangement.
In those regions where glaciers reach the sea, and where large masses of
ice break off and float away, moraines, such as I have just alluded to,
may be transported to indefinite distances, and may be deposited on the
bottom of the sea wherever the ice happens to melt. If the liquefaction
take place when the berg has run aground and is stationary, and if there
be no current, the heap of angular and rounded stones, mixed with sand
and mud, may fall to the bottom in an unstratified form called "till" in
Scotland, and which has been shown in the last chapter to abound in the
Norfolk cliffs; but should the action of a current intervene at certain
points or at certain seasons, then the materials will be sorted as they
fall, and arranged in layers according to their relative weight and
size. Hence there will be passages from till to stratified clay, gravel,
and sand.
Some of the blocks of stone with which the surfaces of glaciers are
loaded, falling occasionally through fissures in the ice, get fixed and
frozen into the bottom of the moving mass, and are pushed along under
it. In this position, being subjected to great pressure, they scoop
out long rectilinear furrows or grooves parallel to each other on the
subjacent solid rock. Smaller scratches and striae are made on the
polished surface by crystals or projecting edges of the hardest
minerals, just as a diamond cuts glass.
In all countries the fundamental rock on which the boulder formation
reposes, if it consists of granite, gneiss, marble, or other hard stone
capable of permanently retaining any superficial markings which may have
been imprinted upon it, is smoothed or polished, and exhibits parallel
striae and furrows having a determinate direction. This prevailing
direction, both in Europe and North America, is evidently connected with
the course taken by the erratic blocks in the same district, and is
very commonly from north to south, or if it be twenty or thirty or more
degrees to the east or west of north, still always corresponds to the
direction in which the large angular and rounded stones have travelled.
These stones themselves also are often furrowed and scratched on more
than one side, like those already spoken of as occurring in the glacial
drift of Bedford, and in that of Norfolk.
When we contemplate the area which is now exposed to the abrading action
of ice, or which is the receptacle of moraine matter thrown down from
melting glaciers or bergs, we at once perceive that the submarine area
is the most extensive of the two. The number of large icebergs
which float annually to great distances in the northern and southern
hemispheres is extremely great, and the quantity of stone and mud which
they carry about with them enormous. Some floating islands of ice have
been met with from 2 to 5 miles in length, and from 100 to 225 feet in
height above water, the submerged portion, according to the weight
of ice relatively to sea water, being from six to eight times more
considerable than the part which is visible. Such masses, when they run
aground on the bottom of the sea, must exert a prodigious mechanical
power, and may polish and groove the subjacent rocks after the manner of
glaciers on the land. Hence there will often be no small difficulty
in distinguishing between the effects of the submarine and supramarine
agency of ice.
SCANDINAVIA ONCE COVERED WITH ICE, AND A CENTRE OF DISPERSION OF
ERRATICS.
In the north of Europe, along the borders of the Baltic, where the
boulder formation is continuous for hundreds of miles east and west, it
has been long known that the erratic blocks, often of very large size,
are of northern origin. Some of them have come from Norway and Sweden,
others from Finland, and their present distribution implies that they
were carried southwards, for a part at least of their way, by floating
ice, at a time when much of the area over which they are scattered was
under water. But it appears from the observations of Boetlingk, in
1840, and those of more recent inquirers, that while many blocks have
travelled to the south, others have been carried northwards, or to the
shores of the Polar Sea, and others north-eastward, or to those of
the White Sea. In fact, they have wandered towards all points of
the compass, from the mountains of Scandinavia as a centre, and the
rectilinear furrows imprinted by them on the polished surfaces of the
mountains where the rocks are hard enough to retain such markings,
radiate in all directions, or point outwards from the highest land, in a
manner corresponding to the course of the erratics above mentioned.*
(* Sir R.I. Murchison, in his "Russia and the Ural
Mountains" (1845) has indicated on a map not only the
southern limits of the Scandinavian drift, but by arrows the
direction in which "it proceeded eccentrically from a common
central region.")
Before the glacial theory was adopted, the Swedish and Norwegian
geologists speculated on a great flood, or the sudden rush of an
enormous body of water charged with mud and stones, descending from the
central heights or watershed into the adjoining lower lands. The erratic
blocks were supposed in their downward passage to have smoothed and
striated the rock surfaces over which they were forced along.
It would be a waste of time, in the present state of science, to
controvert this hypothesis, as it is now admitted that even if the rush
of a diluvial current, invented for the occasion and wholly without
analogy in the known course of nature, be granted, it would be
inadequate to explain the uniformity, parallelism, persistency,
and rectilinearity of the so-called glacial furrows. It is moreover
ascertained that heavy masses of rock, not fixed in ice, and moving as
freely as they do when simply swept along by a muddy current, do not
give rise to such scratches and furrows.
M. Kjerulf of Christiania, in a paper lately communicated to the
Geological Society of Berlin,* has objected, and perhaps with reason,
to what he considers the undue extent to which I have, in some of
my writings, supposed the mountains of northern Europe, to have been
submerged during the glacial period.
(* "Zeitschrift der Deutschen Geologischen Gesellschaft"
Berlin 1860.)
He remarks that the signs of glacial action on the Scandinavian
mountains ascend as high as 6000 feet, whereas fossil marine shells of
the same period never reach elevations exceeding 600 feet. The land, he
says, may have been much higher than it now is, but it has evidently not
been much lower since the commencement of the glacial period, or marine
shells would be traceable to more elevated points. In regard to the
absence of marine shells, I shall point out in the sequel how small is
the dependence we can place on this kind of negative evidence, if we
desire to test by it the extent to which the land has been submerged.
I cannot therefore consent to limit the probable depression and
re-elevation of Scandinavia to 600 feet. But that the larger part of
the glaciation of that country has been supramarine, I am willing to
concede. In support of this view M. Kjerulf observes that the direction
of the furrows and striae, produced by glacial abrasion, neither
conforms to a general movement of floating ice from the Polar regions,
nor to the shape of the existing valleys, as it would do if it had been
caused by independent glaciers generated in the higher valleys after
the land had acquired its actual shape. Their general arrangement and
apparent irregularities are, he contends, much more in accordance with
the hypothesis of there having been at one time a universal covering
of ice over the whole of Norway and Sweden, like that now existing in
Greenland, which, being annually recruited by fresh falls of snow,
was continually pressing outwards and downwards to the coast and lower
regions, after crossing many of the lower ridges, and having no relation
to the minor depressions, which were all choked up with ice and reduced
to one uniform level.
CONTINENTAL ICE OF GREENLAND.
In support of this view, he appeals to the admirable description of
the continental ice of Greenland, lately published by Dr. H. Rink of
Copenhagen,* who resided three or four years in the Danish settlements
in Baffin's Bay, on the west coast of Greenland, between latitudes 69
and 73 degrees north.
(* "Journal of Royal Geographical Society" volume 23 1853
page 145.)
"In that country, the land," says Dr. Rink, "may be divided into two
regions, the 'inland' and the 'outskirts.' The 'inland,' which is 800
miles from west to east, and of much greater length from north to south,
is a vast unknown continent, buried under one continuous and colossal
mass of permanent ice, which is always moving seaward, but a small
proportion only of it in an easterly direction, since nearly the
whole descends towards Baffin's Bay." At the heads of the fjords which
intersect the coast, the ice is seen to rise somewhat abruptly from the
level of the sea to the height of 2000 feet, beyond which the ice of
the interior rises continuously as far as the eye can reach, and to
an unknown altitude. All minor ridges and valleys are levelled and
concealed, but here and there steep mountains protrude abruptly from the
icy slope, and a few superficial lines of stones or moraines are visible
at seasons when no recent snow has fallen. [23]
Although all the ice is moving seaward, the greatest quantity is
discharged at the heads of certain large fjords, usually about 4 miles
wide, which, if the climate were milder, would be the outlet of as many
great rivers. Through these the ice is now protruded in huge blocks,
several miles wide, and from 1000 to 1500 feet in height or thickness.
When these masses reach the fjords, they do not melt or break up into
fragments, but continue their course in a solid form in the salt water,
grating along the rocky bottom, which they must polish and score at
depths of hundreds and even of more than 1000 feet. At length, when
there is water enough to float them, huge portions, having broken off,
fill Baffin's Bay with icebergs of a size exceeding any which could
be produced by ordinary valley glaciers. Stones, sand, and mud are
sometimes included in these bergs which float down Baffin's Bay. At some
points, where the ice of the interior of Greenland reaches the coast,
Dr. Rink saw mighty springs of clayey water issuing from under the edge
of the ice even in winter, showing the grinding action of the glacial
mass mixed with sand on the subjacent surface of the rocks.
The "outskirts," where the Danish colonies are stationed, consist of
numerous islands, of which Disco island is the largest in latitude 70
degrees north, and of many peninsulas, with fjords from 50 to 100 miles
long, running into the land, and through which the ice above alluded
to passes on its way to the bay. This area is 30, 000 square miles in
extent, and contains in it some mountains 4000 feet to 5000 feet high.
The perpetual snow usually begins at the height of 2000 feet, below
which level the land is for the most part free from snow between June
and August, and supports a vegetation of several hundred species of
flowering plants, which ripen their seeds before the winter. There
are even some places where phanerogamous plants have been found at an
elevation of 4500 feet; a fact which, when we reflect on the immediate
vicinity of so large and lofty a region of continental ice in the same
latitude, well deserves the attention of the geologist, who should
also bear in mind, that while the Danes are settled to the west in the
"outskirts," there exists, due east of the most southern portion of this
ice-covered continent, at the distance of about 1200 miles, the home of
the Laplanders with their reindeer, bears, wolves, seals, walruses, and
whales. If, therefore, there are geological grounds for suspecting that
Scandinavia or Scotland or Wales was ever in the same glacial condition
as Greenland now is, we must not imagine that the contemporaneous
fauna and flora were everywhere poor and stunted, or that they may
not, especially at the distance of a few hundred miles in a SOUTHWARD
direction, have been very luxuriant. [24]
Another series of observations made by Captain Graah, during a survey of
Greenland between 1823 and 1829, and by Dr. Pingel in 1830-32, adds not
a little to the geological interest of the "outskirts," in their bearing
on glacial phenomena of ancient date. Those Danish investigators, with
one of whom, Dr. Pingel, I conversed at Copenhagen in 1834, ascertained
that the whole coast from latitude 60 to about 70 degrees north has been
subsiding for the last four centuries, so that some ancient piles driven
into the beach to support the boats of the settlers have been gradually
submerged, and wooden buildings have had to be repeatedly shifted
farther inland.*
(* "Principles of Geology" chapter 30.)
In Norway and Sweden, instead of such a subsiding movement, the land is
slowly rising; but we have only to suppose that formerly, when it was
covered like Greenland with continental ice, it sank at the rate of
several feet in a century, and we shall be able to explain why marine
deposits are found above the level of the sea, and why these generally
overlie polished and striated surfaces of rock.
We know that Greenland was not always covered with snow and ice, for
when we examine the Tertiary strata of Disco Island (of the Upper
Miocene period) we discover there a multitude of fossil plants, which
demonstrate that, like many other parts of the arctic regions, it
formerly enjoyed a mild and genial climate. Among the fossils brought
from that island, latitude 70 degrees north, Professor Heer has
recognised Sequoia Langsdorfii, a coniferous species which flourished
throughout a great part of Europe in the Miocene period, and is very
closely allied to the living Sequoia sempervirens of California. The
same plant has been found fossil by Sir John Richardson within the
arctic circle, far to the west on the Mackenzie River, near the entrance
of Bear River, also by some Danish naturalists in Iceland to the east.
The Icelandic surturbrand, or lignite, of this age has also yielded
a rich harvest of plants, more than thirty-one of them, according to
Steenstrup and Heer, in a good state of preservation, and no less than
fifteen specifically identical with Miocene plants of Europe. Thirteen
of the number are arborescent; and amongst others is a tulip-tree
(Liriodendron), with its fruit and characteristic leaves, a plane
(Platanus), a walnut, and a vine, affording unmistakable evidence of
a climate in the parallel of the arctic circle which precludes the
supposition of glaciers then existing in the neighbourhood, still less
any general crust of continental ice, like that of Greenland.*
(* Heer, "Recherches sur la Vegetation du Pays tertiaire"
etc. 1861 page 178.)
As the older Pliocene flora of the Tertiary strata of Italy, like the
shells of the Coralline Crag, before adverted to, Chapter 12, indicate
a temperature milder than that now prevailing in Europe, though not
so warm as that of the Upper Miocene period, it is probable that the
accumulation of snow and glaciers on the mountains and valleys of
Greenland did not begin till after the commencement of the Pliocene
period, and may not have reached its maximum until the close of that
period.
Norway and Sweden appear to have passed through all the successive
phases of glaciation which Greenland has experienced, and others which
that country will one day undergo, if the climate which it formerly
enjoyed should ever be restored to it. There must have been first a
period of separate glaciers in Scandinavia, then a Greenlandic state of
continental ice, and thirdly, when that diminished, a second period of
enormous separate glaciers filling many a valley now wooded with fir
and birch. Lastly, under the influence of the Gulf Stream, and various
changes in the height and extent of land in the arctic circle, a melting
of nearly all the permanent ice between latitudes 60 and 70 north,
corresponding to the parallels of the continental ice of Greenland,
has occurred, so that we have now to go farther north than latitude 70
degrees before we encounter any glacier coming down to the sea coast.
Among other signs of the last retreat of the extinct glaciers, Kjerulf
and other authors describe large transverse moraines left in many of the
Norwegian and Swedish glens.
CHRONOLOGICAL RELATIONS OF THE HUMAN AND GLACIAL PERIODS IN SWEDEN.
We may now consider whether any, and what part, of these changes in
Scandinavia may have been witnessed by Man. In Sweden, in the immediate
neighbourhood of Upsala, I observed, in 1834, a ridge of stratified
sand and gravel, in the midst of which occurs a layer of marl, evidently
formed originally at the bottom of the Baltic, by the slow growth of
the mussel, cockle, and other marine shells of living species intermixed
with some proper to fresh water. The marine shells are all of dwarfish
size, like those now inhabiting the brackish waters of the Baltic; and
the marl, in which myriads of them are embedded, is now raised more than
100 feet above the level of the Gulf of Bothnia. Upon the top of this
ridge (one of those called osars in Sweden) repose several huge erratics
consisting of gneiss, for the most part unrounded, from 9 to 16 feet in
diameter, and which must have been brought into their present position
since the time when the neighbouring gulf was already characterised by
its peculiar fauna. Here, therefore, we have proof that the transport of
erratics continued to take place, not merely when the sea was inhabited
by the existing Testacea, but when the north of Europe had already
assumed that remarkable feature of its physical geography, which
separates the Baltic from the North Sea, and causes the Gulf of Bothnia
to have only one-fourth of the saltness belonging to the ocean.
I cannot doubt that these large erratics of Upsala were brought into
their present position during the Recent period, not only because of
their moderate elevation above the sea-level in a country where the land
is now rising every century, but because I observed signs of a great
oscillation of level which had taken place at Sodertelje, south of
Stockholm (about 45 miles distant from Upsala), after the country had
been inhabited by Man. I described, in the "Philosophical Transactions"
for 1835, the section there laid open in digging a level in 1819,
which showed that a subsidence followed by a re-elevation of land, each
movement amounting to more than 60 feet, had occurred since the time
when a rude hut had been built on the ancient shore. The wooden frame
of the hut, with a ring of hearthstones on the floor, and much charcoal,
were found, and over them marine strata, more than 60 feet thick,
containing the dwarf variety of Mytilus edulis, and other brackish-water
shells of the Bothnian Gulf. Some vessels put together with wooden pegs,
of anterior date to the use of metals, were also embedded in parts of
the same marine formation, which has since been raised, so that the
upper beds are more than 60 feet above the sea-level, the hut being thus
restored to about its original position relatively to the sea.
We have seen in the account of the Danish kitchen-middens of the Recent
period that even at the comparatively late period of their origin the
waters of the Baltic had been rendered more salt than they are now. The
Upsala erratics may belong to nearly the same era as these. But were
we to go back to a long antecedent epoch, or to that of the Belgian and
British caves with their extinct animals, and the signs they afford of a
state of physical geography departing widely from the present, or to the
era of the implement-bearing alluvium of St. Acheul, we might expect
to find Scandinavia overwhelmed with glaciers, and the country
uninhabitable by Man. At a much remoter period the same country was in
the state in which Greenland now is, overspread with one uninterrupted
coating of continental ice, which has left its peculiar markings on the
highest mountains. This period, probably anterior to the earliest traces
yet brought to light of the human race, may have coincided with the
submergence of England, and the accumulation of the boulder-clay of
Norfolk, Suffolk, and Bedfordshire, before mentioned. It has already
been stated that the syenite and some other rocks of the Norfolk till
seem to have come from Scandinavia, and there is no era when icebergs
are so likely to have floated them so far south as when the whole of
Sweden and Norway were enveloped in a massive crust of ice; a state
of things the existence of which is deduced from the direction of the
glacial furrows, and their frequent unconformity to the shape of the
minor valleys.
GLACIAL PERIOD IN SCOTLAND [25].
Professor Agassiz, after his tour in Scotland in 1840, announced
the opinion that erratic blocks had been dispersed from the Scottish
mountains as from an independent centre, and that the capping of ice had
been of extraordinary thickness.*
(* Agassiz, "Proceedings of the Geological Society" 1840 and
"Edinburgh Philosophical Journal" 49 page 79.)
Mr. Robert Chambers, after visiting Norway and Sweden, and comparing the
signs of glacial action observed there with similar appearances in the
Grampians, came to the conclusion that the Highlands both of Scandinavia
and Scotland had once been "moulded in ice," and that the outward and
downward movement and pressure of the frozen mass had not only smoothed,
polished, and scratched the rocks, but had, in the course of ages,
deepened and widened the valleys, and produced much of that denudation
which has commonly been ascribed exclusively to aqueous action. The
glaciation of the Scotch mountains was traced by him to the height of at
least 3000 feet.*
(* "Ancient Sea Margins" Edinburgh 1848. Glacial Phenomena
"Edinburgh New Philosophical Journal" April 1853 and January
1855.)
Mr. T.F. Jamieson, of Ellon, in Aberdeenshire, has recently brought
forward an additional body of facts in support of this theory. According
to him the Grampians were at the period of extreme cold enveloped "in
one great winding sheet of snow and ice," which reached everywhere to
the coast-line, the land being then more elevated than it is now. He
describes the glacial furrows sculptured on the solid rocks as pointing
in Aberdeenshire to the south-east, those of the valley of the Forth at
Edinburgh, from west to east, and higher up the same valley at Stirling,
from north-west to south-east, as they should do if the ice had followed
the lines of what is now the principal drainage. The observations of Sir
James Hall, Mr. Maclaren, Mr. Chambers, and Dr. Fleming, are cited by
him in confirmation of this arrangement of the glacial markings, while
in Sutherland and Ross-shire he shows that the glacial furrows along the
north coast point northwards, and in Argyleshire westwards, always in
accordance with the direction of the principal glens and fjords.
Another argument is also adduced by him in proof of the ice having
exerted its mechanical force in a direction from the higher and more
inland country to the lower region and sea-coast. Isolated hills and
minor prominences of rock are often polished and striated on the land
side, while they remain rough and jagged on the side fronting the sea.
This may be seen both on the east and west coast. Mention is also
made of blocks of granite which have travelled from south to north
in Aberdeenshire, of which there would have been no examples had the
erratics been all brought by floating ice from the arctic regions
when Scotland was submerged. It is also urged against the doctrine of
attributing the general glaciation to submergence, that the glacial
grooves, instead of radiating as they do from a centre, would, if they
had been due to ice coming from the north, have been parallel to the
coast-line, to which they are now often almost at right angles. The
argument, moreover, which formerly had most weight in favour of floating
ice, namely, that it explained why so many of the stones did not conform
to the contour and direction of the minor hills and valleys, is now
brought forward, and with no small effect, in favour of the doctrine of
continental ice on the Greenlandic scale, which, after levelling up the
lesser inequalities, would occasionally flow in mighty ice-currents, in
directions often at a high angle to the smaller ridges and glens.
The application to Scandinavia and Scotland of this theory makes it
necessary to reconsider the validity of the proofs formerly relied on
as establishing the submergence of a great part of Scotland beneath
the sea, at some period subsequent to the commencement of the glacial
period. In all cases where marine shells overlie till, or rest on
polished and striated surfaces of rock, the evidence of the land having
been under water, and having been since upheaved, remains unshaken; but
this special proof rarely extends to heights exceeding 500 feet. In the
basin of the Clyde we have already seen that Recent strata occur 25 feet
above the sea-level, with existing species of marine testacea, and with
buried canoes, and other works of art. At the higher level of 50
feet occurs the well-known raised beach of the western coast, which,
according to Mr. Jamieson, contains, near Fort William and on Loch Fyne
and elsewhere, an assemblage of shells implying a colder climate than
that of the 25-foot terrace, or that of the present sea; just as, in the
valley of the Somme, the higher-level gravels are supposed to belong to
a colder period than the lower ones, and still more decidedly than that
of the present era. At still greater elevations, older beds containing
a still more arctic group of shells have been observed at Airdrie, 14
miles south-east of Glasgow, 524 feet above the level of the sea. They
were embedded in stratified clays, with the unstratified boulder till
both above and below them, and in the overlying unstratified drift were
some boulders of granite which must have come from distances of 60 miles
at the least.*
(* Smith of Jordanhill, "Quarterly Journal of the Geological
Society" volume 6 1850 page 387.)
The presence of Tellina calcarea, and several other northern shells,
implies a climate colder than that of the present Scottish seas. In the
north of Scotland, marine shells have been found in deposits of the same
age in Caithness and in Aberdeenshire at heights of 250 feet, and on the
shores of the Moray Firth, as at Gamrie in Banff, at an elevation of 350
feet; and the stratified sands and beds of pebbles which belong to the
same formation ascend still higher--to heights of 500 feet at least.*
(* Prestwich, "Proceedings of the Geological Society" volume
2 page 545; Jamieson, "Quarterly Journal of the Geological
Society" volume 16 1860.)
At much greater heights, stratified masses of drift occur in which
hitherto no organic remains, whether of marine or freshwater animals,
have ever been found. It is still an undecided question whether the
origin of all such deposits in the Grampians can be explained without
the intervention of the sea. One of the most conspicuous examples has
been described by Mr. Jamieson as resting on the flank of a hill called
Meal Uaine, in Perthshire, on the east side of the valley of the Tummel,
just below Killiecrankie. It consists of perfectly horizontal strata,
the lowest portion of them 300 feet above the river and 600 feet above
the sea. From this elevation to an altitude of nearly 1200 feet the
same series of strata is traceable, continuously, up the slope of the
mountain, and some patches are seen here and there even as high as 1550
feet above the sea. They are made up in great part of finely laminated
silt, alternating with coarser materials, through which stones from 4 to
5 feet in length are scattered. These large boulders, and some smaller
ones, are polished on one or more sides, and marked with glacial striae.
The subjacent rocks, also, of gneiss, mica slate, and quartz, are
everywhere grooved and polished as if by the passage of a glacier.*
(* Jamieson, "Quarterly Journal of the Geological Society"
volume 16 1860 page 360.)
At one spot a vertical thickness of 130 feet of this series of strata is
exposed to view by a mountain torrent, and in all more than 2000 layers
of clay, sand, and gravel were counted, the whole evidently accumulated
under water. Some beds consist of an impalpable mud, like putty,
apparently derived from the grinding down of felspar, and resembling the
mud produced by the grinding action of modern glaciers.
Mr. Jamieson, when he first gave an account of this drift, inferred, in
spite of the absence of marine shells, that it implied the submergence
of Scotland beneath the ocean after the commencement of the glacial
period, or after the era of continental ice indicated by the subjacent
floor of polished and grooved rock. This conclusion would require
a submergence of the land as far up as 1550 feet above the present
sea-level, after which a great re-upheaval must have occurred. But the
same author, having lately revisited the valley of the Tummel, suggests
another possible, and I think probable, explanation of the same
phenomena. The stratified drift in question is situated in a deep
depression between two buttresses of rock, and if an enormous glacier be
supposed to have once filled the valley of the Tummel to the height
of the stratified drift, it may have dammed up the mouth of a mountain
torrent by a transverse barrier, giving rise to a deep pond, in which
beds of clay and sand brought down by the waters of the torrent were
deposited. Charpentier in his work on the Swiss glaciers has described
many such receptacles of stratified matter now in progress, and due
to such blockages, and he has pointed out the remnants of ancient and
similar formations left by extinct glaciers of an earlier epoch. He
specially notices that angular stones of various dimensions, often
polished and striated, which rest on the glacier and are let fall when
the torrent undermines the side of the moving ice, descend into the
small lake and become interstratified with the gravel and fine sediment
brought down by the torrent into the same.*
(* Charpentier, "Essai sur les Glaciers" page 63 1841.)
The evidence of the former sojourn of the sea upon the land after the
commencement of the glacial period was formerly inferred from the height
to which erratic blocks derived from distant regions could be traced,
besides the want of conformity in the glacial furrows to the present
contours of many of the valleys. Some of these phenomena may now, as we
have seen, be accounted for by assuming that there was once a crust of
ice resembling that now covering Greenland.
The Grampians in Forfarshire and in Perthshire are from 3000 to
4000 feet high. To the southward lies the broad and deep valley of
Strathmore, and to the south of this again rise the Sidlaw Hills to the
height of 1500 feet and upwards. On the highest summits of this chain,
formed of sandstone and shale, and at various elevations, I have
observed huge angular fragments of mica-schist, some 3 and others 15
feet in diameter, which have been conveyed for a distance of at least
15 miles from the nearest Grampian rocks from which they could have been
detached. Others have been left strewed over the bottom of the large
intervening vale of Strathmore.*
(* "Proceedings of the Geological Society" volume 3 page
344.)
It may be argued that the transportation of such blocks may have been
due not to floating ice, but to a period when Strathmore was filled up
with land ice, a current of which extended from the Perthshire Highlands
to the summit of the Sidlaw Hills, and the total absence of marine or
freshwater shells from all deposits, stratified or unstratified, which
have any connection with these erratics in Forfarshire and Perthshire
may be thought to favour such a theory.
But the same mode of transport can scarcely be imagined for those
fragments of mica-schist, one of them weighing from 8 to 10 tons, which
were observed much farther south by Mr. Maclaren on the Pentland Hills,
near Edinburgh, at the height of 1100 feet above the sea, the nearest
mountain composed of this formation being 50 miles distant.*
(* Maclaren, "Geology of Fife" etc. page 220.)
On the same hills, also, at all elevations, stratified gravels occur
which, although devoid of shells, it seems hardly possible to refer to
any but a marine origin.
Although I am willing, therefore, to concede that the glaciation of the
Scotch mountains, at elevations exceeding 2000 feet, may be explained
by land ice, it seems difficult not to embrace the conclusion that a
subsidence took place not merely of 500 or 600 feet, as demonstrated by
the marine shells, but to a much greater amount, as shown by the present
position of erratics and some patches of stratified drift. The absence
of marine shells at greater heights than 525 feet above the sea, will be
treated of in a future chapter. It may in part, perhaps, be ascribed
to the action of glaciers, which swept out marine strata from all the
higher valleys, after the re-emergence of the land.
LATEST CHANGES PRODUCED BY GLACIERS IN SCOTLAND.
We may next consider the state of Scotland after its emergence from the
glacial sea, when we cannot fail to be approaching the time when Man
co-existed with the mammoth and other mammalia now extinct. In a paper
which I published in 1840, on the ancient glaciers of Forfarshire, I
endeavoured to show that some of these existed after the mountains and
glens had acquired precisely their present shape,* and had left moraines
even in the minor valleys, just where they would now leave them were the
snow and ice again to gain ground.
(* "Proceedings of the Geological Society" volume 3 page
337.)
I described also one remarkable transverse mound, evidently the terminal
moraine of a retreating glacier, which crosses the valley of the South
Esk, a few miles above the point where it issues from the Grampians, and
about 6 miles below the Kirktown of Clova. Its central part, at a place
called Glenarm, is 800 feet above the level of the sea. The valley is
about half a mile broad, and is bounded by steep and lofty mountains,
but immediately above the transverse barrier it expands into a wide
alluvial plain, several miles broad, which has evidently once been a
lake. The barrier itself, about 150 feet high, consists in its lower
part of till with boulders, 50 feet thick, precisely resembling the
moraine of a Swiss glacier, above which there is a mass of stratified
sand, varying in thickness from 50 to 100 feet, which has the appearance
of consisting of the materials of the moraine rearranged in a stratified
form, possibly by the waters of a glacier lake. The structure of the
barrier has been laid open by the Esk, which has cut through it a deep
passage about 400 yards wide.
I have also given an account of another striking feature in the physical
geography of Perthshire and Forfarshire, which I consider to belong
to the same period; namely, a continuous zone of boulder clay, forming
ridges and mounds from 50 to 70 feet high (the upper part of the mounds
usually stratified), enclosing numerous lakes, some of them several
miles long, and many ponds and swamps filled with shell-marl and peat.
This band of till, with Grampian boulders and associated river-gravel,
may be traced continuously for a distance of 34 miles, with a width of
3 1/2 miles, from near Dunkeld, by Coupar, to the south of Blairgowrie,
then through the lowest part of Strathmore, and afterwards in a straight
line through the greatest depression in the Sidlaw Hills, from Forfar to
Lunan Bay.
Although no great river now takes its course through this line of
ancient lakes, moraines, and river gravel, yet it evidently marks
an ancient line by which, first, a great glacier descended from the
mountains to the sea, and by which, secondly, at a later period, the
principal water drainage of this country was effected. The subsequent
modification in geography is comparable in amount to that which has
taken place since the higher level gravels of the valley of the Somme
were formed, or since the Belgian caves were filled with mud and
bone-breccia.
[Illustration: Figure 35. Oval And Flattish Pebbles In Deserted Channels]
(FIGURE 35. OVAL AND FLATTISH PEBBLES IN DESERTED CHANNELS.)
Mr. Jamieson has remarked, in reference to this and some other extinct
river-channels of corresponding date, that we have the means of
ascertaining the direction in which the waters flowed by observing the
arrangement of the oval and flattish pebbles in their deserted channels;
for in the bed of a fast-flowing river such pebbles are seen to dip
towards the current, as represented in Figure 35, such being the
position of greatest resistance to the stream.*
(* Jamieson, "Quarterly Journal of the Geological Society"
volume 16 1860 page 349.)
If this be admitted, it follows that the higher or mountainous country
bore the same relation to the lower lands, at the time when a great
river passed through this chain of lakes, as it does at present.
We also seem to have a test of the comparatively modern origin of the
mounds of till which surround the above-mentioned chain of lakes
(of which that of Forfar is one), in the species of organic remains
contained in the shell-marl deposited at their bottom. All the mammalia
as well as shells are of recent species. Unfortunately, we have no
information as to the fauna which inhabited the country at the time
when the till itself was formed. There seem to be only three or
four instances as yet known in all Scotland of mammalia having been
discovered in boulder clay.
Mr. R. Bald has recorded the circumstances under which a single
elephant's tusk was found in the unstratified drift of the valley of the
Forth, with the minuteness which such a discovery from its rarity well
deserved. He distinguishes the boulder clay, under the name of "the old
alluvial cover," from that more modern alluvium, in which the whales
of Airthrie, described in Chapter 3, were found. This cover he says is
sometimes 160 feet thick. Having never observed any organic remains in
it, he watched with curiosity and care the digging of the Union Canal
between Edinburgh and Falkirk, which passed for no less than 28
miles almost continuously through it. Mr. Baird, the engineer who
superintended the works, assisted in the inquiry, and at one place
only in this long section did they meet with a fossil, namely, at
Cliftonhall, in the valley of the Almond. It lay at a depth of between
15 and 20 feet from the surface, in very stiff clay, and consisted of an
elephant's tusk, 39 inches long and 13 in circumference, in so fresh
a state that an ivory turner purchased it and turned part of it into
chessmen before it was rescued from destruction. The remainder is still
preserved in the museum at Edinburgh, but by exposure to the air it has
shrunk considerably.*
(* "Memoirs of the Wernerian Society" Edinburgh volume 4
page 58.)
In 1817, two other tusks and some bones of the elephant, as we learn
from the same authority (Mr. Bald), were met with, 3 1/2 feet long and
13 inches in circumference, lying in an horizontal position, 17 feet
deep in clay, with marine shells, at Kilmaurs, in Ayrshire. The species
of shells are not given.*
(* Ibid. volume 4 page 63.)
In another excavation through the Scotch boulder clay, made in digging
the Clyde and Forth Junction Railway, the antlers of a reindeer were
found at Croftamie, in Dumbartonshire, in the basin of the river
Endrick, which flows into Loch Lomond. They had cut through 12 feet
of till with angular and rounded stones, some of large size, and then
through 6 feet of underlying clay, when they came upon the deer's horns,
18 feet from the surface, and within a foot of the sandstone on which
the till rested. At the distance of a few yards, and in the same
position, but a foot or two deeper, were observed marine shells, Cyprina
islandica, Astarte elliptica, A. compressa, Fusus antiquus, Littorina
littorea, and a Balanus. The height above the level of the sea was
between 100 and 103 feet. The reindeer's horn was seen by Professor
Owen, who considered it to be that of a young female of the large
variety, called by the Hudson's Bay trappers the caribou.
The remains of elephants, now in the museums of Glasgow and Edinburgh,
purporting to come from the superficial deposits of Scotland have been
referred to Elephas primigenius. In cases where tusks alone have been
found unaccompanied by molar teeth, such specific determinations may be
uncertain; but if any one specimen be correctly named, the occurrence
of the mammoth and reindeer in the Scotch boulder-clay, as both these
quadrupeds are known to have been contemporary with Man, favours the
idea which I have already expressed, that the close of the glacial
period in the Grampians may have coincided in time with the existence of
Man in those parts of Europe where the climate was less severe, as, for
example, in the basins of the Thames, Somme, and Seine, in which the
bones of many extinct mammalia are associated with flint implements of
the antique type.
PARALLEL ROADS OF GLEN ROY IN SCOTLAND.
[Illustration: Plate 2. Glen Roy and Glen Spean]
(PLATE 2. VIEW OF THE MOUTHS OF GLEN ROY AND GLEN SPEAN,
BY SIR T. DICK LAUDER.
VV. Hill of Bohuntine.
VVV. Glen Roy.
V(inverted)V. Mealderry.
V. Entrance of Glen Spean
VV(superscript)V. Point of division between Glens Roy
and Spean.)
Perhaps no portion of the superficial drift of Scotland can lay claim to
so modern an origin on the score of the freshness of its aspect, as that
which forms what are called the Parallel Roads of Glen Roy. If they do
not belong to the Recent epoch, they are at least posterior in date to
the present outline of mountain and glen, and to the time when every one
of the smaller burns ran in their present channels, though some of them
have since been slightly deepened. The almost perfect horizontality,
moreover, of the roads, one of which is continuous for about 20 miles
from east to west, and 12 miles from north to south, shows that since
the era of their formation no change has taken place in the relative
levels of different parts of the district.
[Illustration: Figure 36. Map of Glen Roy]
(FIGURE 36. MAP OF THE PARALLEL ROADS OF GLEN ROY OR LOCHABER.
A. five miles distant south-west from this point is
Fort William, where the Lochy joins an arm of the sea,
called Loch Eil.
Vertical lines. Cols or watersheds at the heads of the
glens--once the westward outlet of the lakes.
Dots. Conspicuous delta deposits as laid down by
Mr. T.F. Jamieson.)
Glen Roy is situated in the Western Highlands, about 10 miles
east-north-east of Fort William, near the western end of the great glen
of Scotland, or Caledonian Canal, and near the foot of the highest of
the Grampians, Ben Nevis. (See map, Figure 36.) Throughout nearly its
whole length, a distance of more than 10 miles, three parallel roads
or shelves are traced along the steep sides of the mountains, as
represented in the annexed view, Plate 2, by the late Sir T. Dick
Lauder, each maintaining a perfect horizontality, and continuing at
exactly the same level on the opposite sides of the glen. Seen at a
distance, they appear like ledges, or roads, cut artificially out of the
sides of the hills; but when we are upon them, we can scarcely recognise
their existence, so uneven is their surface, and so covered with
boulders. They are from 10 to 60 feet broad, and merely differ from the
side of the mountain by being somewhat less steep.
On closer inspection, we find that these terraces are stratified in
the ordinary manner of alluvial or littoral deposits, as may be seen at
those points where ravines have been excavated by torrents. The parallel
shelves, therefore, have not been caused by denudation, but by the
deposition of detritus, precisely similar to that which is dispersed in
smaller quantities over the declivities of the hills above. These hills
consist of clay-slate, mica schist, and granite, which rocks have been
worn away and laid bare at a few points immediately above the parallel
roads. The lowest of these roads is about 850 feet above the level of
the sea, the next about 212 feet higher, and the third 82 feet above
the second. There is a fourth shelf, which occurs only in a contiguous
valley called Glen Gluoy, which is 12 feet above the highest of all the
Glen Roy roads, and consequently about 1156 feet above the level of the
sea.*
(* Another detached shelf also occurs at Kilfinnan. (See
Map, Figure 36.))
One only, the lowest of the three roads of Glen Roy, is continued
throughout Glen Spean, a large valley with which Glen Roy unites. (See
Plate 2 and map, Figure 36.) As the shelves, having no slope towards
the sea like ordinary river terraces, are always at the same absolute
height, they become continually more elevated above the river in
proportion as we descend each valley; and they at length terminate very
abruptly, without any obvious cause, or any change either in the shape
of the ground or in the composition or hardness of the rocks.
I should exceed the limits of this work, were I to attempt to give a
full description of all the geographical circumstances attending these
singular terraces, or to discuss the ingenious theories which have been
severally proposed to account for them by Dr. Macculloch, Sir T. Lauder,
and Messrs. Darwin, Agassiz, Milne, and Chambers. There is one point,
however, on which all are agreed, namely, that these shelves are ancient
beaches, or littoral formations, accumulated round the edges of one or
more sheets of water which once stood for a long time successively at
the level of the several shelves.
[Illustration: Figure 37. Section Through Side of Loch]
(FIGURE 37. SECTION THROUGH SIDE OF LOCH.
AB. Supposed original surface of rock.
CD. Roads or shelves in the outer alluvial covering of the hill.)
It is well known, that wherever a lake or marine fjord exists surrounded
by steep mountains subject to disintegration by frost or the action of
torrents, some loose matter is washed down annually, especially during
the melting of snow, and a check is given to the descent of this
detritus at the point where it reaches the waters of the lake. The waves
then spread out the materials along the shore, and throw some of them
upon the beach; their dispersing power being aided by the ice, which
often adheres to pebbles during the winter months, and gives buoyancy
to them. The annexed diagram (Figure 37) illustrates the manner in which
Dr. MacCulloch and Mr. Darwin suppose "the roads" to constitute mere
excrescences of the superficial alluvial coating which rests upon the
hillside, and consists chiefly of clay and sharp unrounded stones.
Among other proofs that the parallel roads have really been formed along
the margin of a sheet of water, it may be mentioned, that wherever an
isolated hill rises in the middle of the glen above the level of any
particular shelf, as in Mealderry, Plate 2, a corresponding shelf is
seen at the same level passing round the hill, as would have happened if
it had once formed an island in a lake or fjord. Another very remarkable
peculiarity in these terraces is this; each of them comes in some
portion of its course to a col, or parting ridge, between the heads of
glens, the explanation of which will be considered in the sequel.
Those writers who first advocated the doctrine that the roads were the
ancient beaches of freshwater lakes, were unable to offer any probable
hypothesis respecting the formation and subsequent removal of barriers
of sufficient height and solidity to dam up the water. To introduce
any violent convulsion for their removal was inconsistent with the
uninterrupted horizontality of the roads, and with the undisturbed
aspect of those parts of the glens where the shelves come suddenly to an
end.
Mr. Agassiz and Dr. Buckland, desirous, like the defenders of the lake
theory, to account for the limitation of the shelves to certain glens,
and their absence in contiguous glens, where the rocks are of the same
composition, and the slope and inclination of the ground very similar,
first started the theory that these valleys were once blocked up by
enormous glaciers descending from Ben Nevis, giving rise to what are
called, in Switzerland and in the Tyrol, glacier-lakes. In corroboration
of this view, they contended that the alluvium of Glen Roy, as well as
of other parts of Scotland, agrees in character with the moraines of
glaciers seen in the Alpine valleys of Switzerland. It will readily be
conceded that this hypothesis was preferable to any previous lacustrine
theory, by accounting more easily for the temporary existence and entire
disappearance of lofty transverse barriers, although the height required
for the supposed dams of ice appeared very enormous.
Before the idea of glacier-lakes had been suggested by Agassiz, Mr.
Darwin examined Glen Roy, and came to the opinion that the shelves were
formed when the glens were still arms of the sea, and, consequently,
that there never were any seaward barriers. According to him, the
land emerged during a slow and uniform upward movement, like that now
experienced throughout a large part of Sweden and Finland; but there
were certain pauses in the upheaving process, at which times the waters
of the sea remained stationary for so many centuries as to allow of the
accumulation of an extraordinary quantity of detrital matter, and the
excavation, at many points immediately above the sea-level, of deep
notches and bare cliffs in the hard and solid rock.
This theory I adopted in 1841 ("Elements," 2nd edition), as appearing to
me less objectionable than any other then proposed. The phenomena most
difficult to reconcile with it are, first, the abrupt cessation of the
roads at certain points in the different glens; secondly, their unequal
number in different valleys connecting with each other, there being
three, for example, in Glen Roy, and only one in Glen Spean; thirdly,
the precise horizontality of level maintained by the same shelf over a
space many leagues in length, requiring us to assume, that during a
rise of 1156 feet no one portion of the land was raised even a few yards
above another; fourthly, the coincidence of level already alluded to of
each shelf with a col, or the point forming the head of two glens, from
which the rain-waters flow in opposite directions. This last-mentioned
feature in the physical geography of Lochaber Mr. Darwin endeavoured to
explain in the following manner. He called these cols "land-straits,"
and regarding them as having been anciently sounds or channels between
islands, he pointed out that there is a tendency in such sounds to be
silted up, and always the more so in proportion to their narrowness. In
a chart of the Falkland Islands, by Captain Sulivan, R.N., it appears
that there are several examples there of straits where the soundings
diminish regularly towards the narrowest part. One is so nearly dry that
it can be walked over at low water, and another, no longer covered by
the sea, is supposed to have recently dried up in consequence of a small
alteration in the relative level of sea and land. "Similar straits,"
observes Mr. Chambers, "hovering, in character, between sea and land,
and which may be called fords, are met with in the Hebrides. Such, for
example, is the passage dividing the islands of Lewis and Harris, and
that between North Uist and Benbecula, both of which would undoubtedly
appear as cols, coinciding with a terrace or raised beach, all round the
islands if the sea were to subside."*
(* R. Chambers, "Ancient Sea Margins" page 114.)
The first of the difficulties above alluded to, namely, the
non-extension of the shelves over certain parts of the glens, might
be explained, said Mr. Darwin, by supposing in certain places a quick
growth of green turf on a good soil, which prevented the rain from
washing away any loose materials lying on the surface. But wherever the
soil was barren, and where green sward took long to form, there may have
been time for the removal of the gravel. In one case an intermediate
shelf appears for a short distance (three quarters of a mile) on the
face of the mountain called Tombhran, between the two upper shelves,
and is seen nowhere else. It occurs where there was the longest space of
open water, and where the waves may have acquired a more than ordinary
power to heap up detritus.
The unequal number of the shelves in valleys communicating with each
other, and in which the boundary rocks are similar in composition, and
the general absence of any shelves at corresponding altitudes in glens
on the opposite watershed, like that of the Spey, and in valleys where
the waters flow eastward, are difficulties attending the marine theory
which have never yet been got over. Mr. T.F. Jamieson, before cited,
has, during a late visit to Lochaber, in 1861, observed many facts
highly confirmatory of the hypothesis of glacier-lakes which, as I have
already stated, was originally advanced by Mr. Agassiz. In the first
place, he found much superficial scoring and polishing of rocks, and
accumulation of boulders at those points where signs of glacial action
ought to appear, if ice had once dammed up the waters of the glens in
which the "roads" occur. Ben Nevis may have sent down its glaciers from
the south, and Glen Arkaig from the north, for the mountains at the head
of the last-mentioned glen are 3000 feet high, and may, together with
other tributary glens, have helped to choke up the great Caledonian
valley with ice, so as to block up for a time the mouths of the
Spean, Roy, and Gluoy. The temporary conversion of these glens into
glacier-lakes is the more conceivable, because the hills at their upper
ends not being lofty nor of great extent, they may not have been filled
with ice at a time when great glaciers were generated in other adjoining
and much higher regions.
Secondly. The shelves, says Mr. Jamieson, are more precisely defined
and unbroken than any of the raised beaches or acknowledged ancient
coast-lines visible on the west of Scotland, as in Argyllshire, for
example.
Thirdly. At the level of the lower shelf in Glen Roy, at points
where torrents now cut channels through the shelf as they descend the
hill-side, there are small delta-like extensions of the shelf, perfectly
preserved, as if the materials, whether fine or coarse, had originally
settled there in a placid lake, and had not been acted upon by tidal
currents, mingling them with the sediment of other streams. These deltas
are too entire to allow us to suppose that they have at any time since
their origin been exposed to the waves of the sea.
Fourthly. The alluvium on the cols or watersheds, before alluded to, is
such as would have been formed if the waters of the rivers had been made
to flow east, or out of the upper ends of the supposed glacier-lakes,
instead of escaping at the lower ends, in a westerly direction, where
the great blockages of ice are assumed to have occurred.
In addition to these arguments of Mr. Jamieson, I may mention that
in Switzerland, at present, no testacea live in the cold waters of
glacier-lakes; so that the entire absence of fossil shells, whether
marine or freshwater, in the stratified materials of each shelf, would
be accounted for if the theory above mentioned be embraced.
When I examined "the parallel roads" in 1825, in company with Dr.
Buckland, neither this glacier theory nor Mr. Darwin's suggestion of
ancient sea-margins had been proposed, and I have never since revisited
Lochaber. But I retain in my memory a vivid recollection of the
scenery and physical features of the district, and I now consider the
glacier-lake theory as affording by far the most satisfactory solution
of this difficult problem. The objection to it, which until lately
appeared to be the most formidable, and which led Mr. Robert Chambers
in his "Sea Margins," to reject it entirely, was the difficulty of
conceiving how the waters could be made to stand so high in Glen Roy as
to allow the uppermost shelf to be formed. Grant a barrier of ice in the
lower part of the glen of sufficient altitude to stop the waters from
flowing westward, still, what prevented them from escaping over the col
at the head of Glen Glaster? This col coincides exactly in level, as Mr.
Milne Home first ascertained, with the second or middle shelf of Glen
Roy. The difficulty here stated appears now to be removed by supposing
that the higher lines or roads were formed before the lower ones, and
when the quantity of ice was most in excess. We must imagine that at the
time when the uppermost shelf of Glen Roy was forming in a shallow lake,
the lower part of that glen was filled up with ice, and, according to
Mr. Jamieson, a glacier from Loch Treig then protruded itself across
Glen Spean and rested on the flank of the hill on the opposite side in
such a manner as effectually to prevent any water from escaping over the
Glen Glaster col. The proofs of such a glacier having actually existed
at the point in question consist, he says, in numerous cross striae
observable in the bottom of Glen Spean, and in the presence of moraine
matter in considerable abundance on the flanks of the hill extending
to heights above the Glen Glaster col. When the ice shrank into less
dimensions the second shelf would be formed, having its level determined
by the col last mentioned, Glen Spean in the meantime being filled with
a glacier. Finally, the ice blockage common to glens Roy, Spean, and
Laggan, which consisted probably of a glacier from Ben Nevis, gave rise
to the lowest and most extensive lake, the waters of which escaped over
the pass of Muckul or the col at the head of Loch Laggan, which, as Mr.
Jamieson has now ascertained: agrees precisely in level with the lowest
of all the shelves, and where there are unequivocal signs of a river
having flowed out for a considerable period.
Dr. Hooker has described some parallel terraces, very analogous in their
aspect to those of Glen Roy, as existing in the higher valleys of
the Himalaya, of which his pencil has given us several graphic
illustrations. He believes these Indian shelves to have originated on
the borders of glacier-lakes, the barriers of which were usually
formed by the ice and moraines of lateral or tributary glaciers, which
descended into and crossed the main valley, as we have supposed in the
case of Glen Roy; but others he ascribes to the terminal moraine of the
principal glacier itself, which had retreated during a series of milder
seasons, so as to leave an interval between the ice and the terminal
moraine. This interspace caused by the melting of ice becomes filled
with water and forms a lake, the drainage of which usually takes place
by percolation through the porous parts of the moraine, and not by a
stream overflowing that barrier. Such a glacier-lake Dr. Hooker actually
found in existence near the head of the Yangma valley in the Himalaya.
It was moreover partially bounded by recently formed marginal terraces
or parallel roads, implying changes of level in the barrier of ice and
moraine matter.*
(* Hooker, "Himalayan Journal" volume 1 page 242; 2 pages
119, 121, 166. I have also profited by the author's personal
explanations.)
It has been sometimes objected to the hypothesis of glacier-lakes, as
applied to the case of Glen Roy, that the shelves must have taken a very
long period for their formation. Such a lapse of time, it is said, might
be consistent with the theory of pauses or stationary periods in the
rise of the land during an intermittent upward movement, but it is
hardly compatible with the idea of so precarious and fluctuating
a barrier as a mass of ice. But the reader will have seen that the
permanency of level in such glacier-lakes has no necessary connection
with minor changes in the height of the supposed dam of ice. If a
glacier descending from higher mountains through a tributary glen enters
the main valley in which there happens to be no glacier, the river is
arrested in its course and a lake is formed. The dam may be constantly
repaired and may vary in height several hundreds of feet without
affecting the level of the lake, so long as the surplus waters escape
over a col or parting ridge of rock. The height at which the waters
remain stationary is determined solely by the elevation of the col, and
not by the barrier of ice, provided the barrier is higher than the col.
But if we embrace the theory of glacier-lakes, we must be prepared
to assume not only that the sea had nothing to do with the original
formation of the "parallel roads," but that it has never, since the
disappearance of the lakes, risen in any one of the glens up to the
level of the lowest shelf, which is about 850 feet high; for in that
case the remarkable persistency and integrity of the roads and deltas,
before described, must have been impaired.
We have seen that 50 miles to the south of Lochaber, the glacier
formations of Lanarkshire with marine shells of arctic character have
been traced to the height of 524 feet. About 50 miles to the south-east
in Perthshire are those stratified clays and sands, near Killiecrankie,
which were once supposed to be of submarine origin, and which in that
case would imply the former submergence of what is now dry land to the
extent of 1550 feet, or several hundred feet beyond the highest of the
parallel roads. Even granting that these laminated drifts may have had
a different origin, as above suggested, there are still many facts
connected with the distribution of erratics and the striation of rocks
in Scotland which are not easily accounted for without supposing the
country to have sunk, since the era of continental ice, to a greater
depth than 525 feet, the highest point to which marine shells have yet
been traced.
After what was said of the pressure and abrading power of a general
crust of ice, like that now covering Greenland, it is almost superfluous
to say that the parallel roads must have been of later date than such a
state of things, for every trace of them must have been obliterated
by the movement of such a mass of ice. It is no less clear that as no
glacier-lakes can now exist in Greenland [26], so there could have been
none in Scotland, when the mountains were covered with one great crust
of ice. It may, however, be contended that the parallel roads were
produced when the general crust of ice first gave place to a period
of separate glaciers, and that no period of deep submergence ever
intervened in Lochaber after the time of the lakes. Even in that case,
however, it is difficult not to suppose that the Glen Roy country
participated in the downward movement which sank part of Lanarkshire
525 feet beneath the sea, subsequently to the first great glaciation of
Scotland. Yet that amount of subsidence might have occurred, and even a
more considerable one, without causing the sea to rise to the level
of the lowest shelf, or to a height of 850 feet above the present
sea-level.
This is a question on which I am not prepared at present to offer a
decided opinion.
Whether the horizontality of the shelves or terrace-lines is really as
perfect as has been generally assumed is a point which will require to
be tested by a more accurate trigonometrical survey than has yet been
made. The preservation of precisely the same level in the lowest line
throughout the glens of Roy, Spean, and Laggan, for a distance of 20
miles east and west, and 10 or 12 miles north and south, would be very
wonderful if ascertained with mathematical precision. Mr. Jamieson,
after making in 1862 several measurements with a spirit-level, has been
led to suspect a rise in the lowest shelf of one foot in a mile in a
direction from west to east, or from the mouth of Glen Roy to a point
6 miles east of it in Glen Spean. To confirm such observations, and to
determine whether a similar rate of rise continues eastward, as far as
the pass of Muckul, would be most important.
On the whole, I conclude that the Glen Roy terrace-lines and those of
some neighbouring valleys, were formed on the borders of glacier-lakes,
in times long subsequent to the principal glaciation of Scotland. They
may perhaps have been nearly as late, especially the lowest of the
shelves, as that portion of the Pleistocene period in which Man
co-existed in Europe with the mammoth.
CHAPTER 14. -- CHRONOLOGICAL RELATIONS OF THE GLACIAL PERIOD AND THE
EARLIEST SIGNS OF MAN'S APPEARANCE IN EUROPE--CONTINUED.
Signs of extinct Glaciers in Wales.
Great Submergence of Wales during the Glacial Period proved by
Marine Shells.
Still greater Depression inferred from Stratified Drift.
Scarcity of Organic Remains in Glacial Formations.
Signs of extinct Glaciers in England.
Ice Action in Ireland.
Maps illustrating successive Revolutions in Physical Geography
during the Pleistocene Period.
Southernmost Extent of Erratics in England.
Successive Periods of Junction and Separation of England, Ireland,
and the Continent.
Time required for these Changes.
Probable Causes of the Upheaval and Subsidence of the Earth's Crust.
Antiquity of Man considered in relation to the Age of the existing
Fauna and Flora.
EXTINCT GLACIERS IN WALES.
The considerable amount of vertical movement in opposite directions,
which was suggested in the last chapter, as affording the most probable
explanation of the position of some of the stratified and fossiliferous
drifts of Scotland, formed since the commencement of the glacial
period, will appear less startling if it can be shown that independent
observations lead us to infer that a geographical revolution of still
greater magnitude accompanied the successive phases of glaciation
through which the Welsh mountains have passed.
That Wales was once an independent centre of the dispersion of erratic
blocks has long been acknowledged. Dr. Buckland published in 1842 his
reasons for believing that the Snowdonian mountains in Caernarvonshire
were formerly covered with glaciers, which radiated from the central
heights through the seven principal valleys of that chain, where striae
and flutings are seen on the polished rocks directed towards as many
different points of the compass. He also described the "moraines" of
the ancient glaciers, and the rounded masses of polished rock, called
in Switzerland "roches moutonnees." His views respecting the old extinct
glaciers of North Wales were subsequently confirmed by Mr. Darwin,
who attributed the transport of many of the larger erratic blocks to
floating ice. Much of the Welsh glacial drift had already been shown by
Mr. Trimmer to have had a submarine origin, and Mr. Darwin maintained
that when the land rose again to nearly its present height, glaciers
filled the valleys, and "swept them clean of all the rubbish left by the
sea."*
(* "Philosophical Magazine" series 3 volume 21 page 180.)
Professor Ramsay, in a paper read to the Geological Society in 1851,
and in a later work on the glaciation of North Wales, described three
successive glacial periods, during the first of which the land was much
higher than it now is, and the quantity of ice excessive; secondly, a
period of submergence when the land was 2300 feet lower than at present,
and when the higher mountain tops only stood out of the sea as a cluster
of low islands, which nevertheless were covered with snow; and lastly,
a third period when the marine boulder drift formed in the middle period
was ploughed out of the larger valleys by a second set of glaciers,
smaller than those of the first period. This last stage of glaciation
may have coincided with that of the parallel roads of Glen Roy,
spoken of in the last chapter. In Wales it was certainly preceded by
submergence, and the rocks had been exposed to glacial polishing and
friction before they sank.
Fortunately the evidence of the sojourn of the Welsh mountains beneath
the waters of the sea is not deficient, as in Scotland, in that complete
demonstration which the presence of marine shells affords. The late Mr.
Trimmer discovered such shells on Moel Tryfan, in North Wales, in drift
elevated more than 1300 feet above the level of the sea. It appears from
his observations, and those of the late Edward Forbes, corroborated by
others of Professor Ramsay and Mr. Prestwich, that about twelve species
of shells, including Fusus bamfius, F. antiquus, Venus striatula (Forbes
and Hanley), have been met with at heights of between 1000 and 1400
feet, in drift, reposing on a surface of rock which had been previously
exposed to glacial friction and striation.*
(* Ramsay, "Quarterly Journal of the Geological Society"
volume 8 1852 page 372.)
The shells, as a whole, are those of the glacial period, and not of the
Norwich Crag. Two localities of these shells in Wales, in addition
to that first pointed out by Mr. Trimmer, have since been observed
by Professor Ramsay, who, however, is of opinion that the amount of
submergence can by no means be limited to the extreme height to which
the shells happen to have been traced; for drift of the same character
as that of Moel Tryfan extends continuously to the height of 2300 feet.
[27]
RARITY OF ORGANIC REMAINS IN GLACIAL FORMATIONS.
The general dearth of shells in such formations, below as well as
above the level at which Mr. Trimmer first found them, deserves notice.
Whether we can explain it or not, it is a negative character which seems
to belong very generally to deposits formed in glacial seas. The porous
nature of the strata, and the length of time during which they have been
permeated by rain-water, may partly account, as we hinted in a former
chapter, for the destruction of organic remains. But it is also possible
that they were originally scarce, for we read of the waters of the
sea being so freshened and chilled by the melting of ice-bergs in some
Norwegian and Icelandic fjords, that the fish are driven away, and all
the mollusca killed. The moraines of glaciers are always from the first
devoid of shells, and if transported by ice-bergs to a distance,
and deposited where the ice melts, may continue as barren of every
indication of life as they were when they originated.
Nevertheless, it may be said, on the other hand, that herds of seals and
walruses crowd the floating ice of Spitzbergen in latitude 80 degrees
north, of which Mr. Lamont has recently given us a lively picture,*nand
huge whales fatten on myriads of pteropods in polar regions.
(* "Seasons with the Sea-Horses" 1861.)
It had been suggested that the bottom of the sea, at the era of extreme
submergence in Scotland and Wales, was so deep as to reach the zero
of animal life, which, in part of the Mediterranean (the Aegean,
for example), the late Edward Forbes fixed, after a long series of
dredgings, at 300 fathoms. But the shells of the glacial drift of
Scotland and Wales, when they do occur, are not always those of deep
seas; and, moreover, our faith in the uninhabitable state of the ocean
at great depths has been rudely shaken, by the recent discovery of
Captain McClintock and Dr. Wallich, of starfish in water more than
a thousand fathoms deep (7560 feet!), midway between Greenland and
Iceland. That these radiata were really dredged up from the bottom, and
that they had been living and feeding there, appeared from the fact
that their stomachs were full of Globigerina, of which foraminiferous
creatures, both living and dead, the oozy bed of the ocean at that vast
depth was found to be exclusively composed. [28]
Whatever may be the cause, the fact is certain, that over large areas
in Scotland, Ireland, and Wales, I might add throughout the northern
hemisphere on both sides of the Atlantic, the stratified drift of the
glacial period is very commonly devoid of fossils, in spite of the
occurrence here and there, at the height of 500, 700, and even
1400 feet, of marine shells. These, when met with, belong, with few
exceptions, to known living species. I am therefore unable to agree with
Mr. Kjerulf that the amount of former submergence can be measured by the
extreme height at which shells happen to have been found.
GLACIAL FORMATIONS IN ENGLAND.
[Illustration: Figure 38. Dome-shaped Rocks]
(FIGURE 38. DOME-SHAPED ROCKS, OR "ROCHES MOUTONEES," IN THE VALLEY
OF THE ROTHAY, NEAR AMBLESIDE, FROM A DRAWING BY E. HULL, F.G.S.*
(* "Edinburgh New Philosophical Journal" volume 11 Plate 1 page 31
1860.))
The mountains of Cumberland and Westmorland, and the English lake
district, afford equally unequivocal vestiges of ice-action not only
in the form of polished and grooved surfaces, but also of those rounded
bosses before mentioned as being so abundant in the Alpine valleys of
Switzerland, where glaciers exist, or have existed. Mr. Hall has
lately published a faithful account of these phenomena, and has given
a representation of some of the English "roches moutonnees," which
precisely resemble hundreds of dome-shaped protuberances in North Wales,
Sweden, and North America.*
(* Hull, "Edinburgh New Philosophical Journal" July 1860.)
The marks of glaciation on the rocks, and the transportation of erratics
from Cumberland to the eastward, have been traced by Professor Phillips
over a large part of Yorkshire, extending to a height of 1500 feet above
the sea; and similar northern drift has been observed in Lancashire,
Cheshire, Derbyshire, Shropshire, Staffordshire, and Worcestershire. It
is rare to find marine shells, except at heights of 200 or 300 feet;
but a few instances of their occurrence have been noticed, especially
of Turritella communis (a gregarious shell), far in the interior, at
elevations of 500 feet, and even of 700 in Derbyshire, and some adjacent
counties, as I learn from Mr. Binney and Mr. Prestwich.
Such instances are of no small theoretical interest, as enabling us
to account for the scattering of large erratic blocks at equal or
much greater elevations, over a large part of the northern and midland
counties, such as could only have been conveyed to their present sites
by floating ice. Of this nature, among others, is a remarkable angular
block of syenitic greenstone, 4 1/2 feet by 4 feet square, and 2 feet
thick, which Mr. Darwin describes as lying on the summit of Ashley
Heath, in Staffordshire, 803 feet above the sea, resting on New Red
Sandstone.*
(* Ancient Glaciers of Caernarvonshire, "Philosophical
Magazine" series 3, 21 page 180.)
SIGNS OF ICE-ACTION AND SUBMERGENCE IN IRELAND DURING THE GLACIAL
PERIOD.
In Ireland we encounter the same difficulty as in Scotland in
determining how much of the glaciation of the higher mountains should
be referred to land glaciers, and how much to floating ice, during
submergence. The signs of glacial action have been traced by Professor
Jukes to elevations of 2500 feet in the Killarney district, and to great
heights in other mountainous regions; but marine shells have rarely been
met with higher than 600 feet above the sea, and that chiefly in gravel,
clay, and sand in Wicklow and Wexford. They are so rare in the drift
east of the Wicklow mountains, that an exception to the rule, lately
observed at Ballymore Eustace, by Professor Jukes, is considered as a
fact of no small geological interest. The wide extent of drift of the
same character, spread over large areas in Ireland, shows that the
whole island was, in some part of the glacial period, an archipelago, as
represented in the maps, Figures 39 and 40.
Speaking of the Wexford drift, the late Professor E. Forbes states
that Sir H. James found in it, together with many of the usual glacial
shells, several species which are characteristic of the Crag; among
others the reversed variety of Fusus antiquus, called F. contrarius,
and the extinct species Nucula Cobboldiae, and Turritella incrassata.
Perhaps a portion of this drift of the south of Ireland may belong to
the close of the Pliocene period, and may be of a somewhat older date
than the shells of the Clyde, alluded to in Chapter 13. They may also
correspond still more nearly in age with the fauna of the uppermost
strata of the Norwich Crag, occurring at Chillesford. [29]
The scarcity of mammalian remains in the Irish drift favours the theory
of its marine origin. In the superficial deposits of the whole island,
I have only met with three recorded examples of the mammoth, one in
the south near Dungarvan, where the bones of Elephas primigenius, two
species of bear (Ursus arctos and Ursus spelaeus?), the reindeer, horse,
etc., were found in a cave;* another in the centre of the island near
Belturbet, in the county of Cavan.
(* E. Brenan and Dr. Carte, Dublin 1859.)
Perhaps the conversion into land of the bed of the glacial sea, and the
immigration into the newly upheaved region of the elephant, rhinoceros,
and hippopotamus, which co-existed with the fabricators of the St.
Acheul flint hatchets, were events which preceded in time the elevation
of the Irish drift, and the union of that island with England. Ireland
may have continued for a longer time in the state of an archipelago,
and was therefore for a much shorter time inhabited by the large extinct
Pleistocene pachyderms.
In one of the reports of the Geological Survey of Ireland, published in
1859, Professor Jukes, in explanation of sheet 184 of the maps, alludes
to beds of sand and gravel, and signs of the polishing and furrowing of
the rocks in the counties of Kerry and Killarney, as high as 2500 feet
above the sea, and supposes (perhaps with good reason) that the land
was depressed even to that extent. He observes that above that elevation
(2500 feet) the rocks are rough, and not smoothed, as if by ice. Some
of the drift was traced as high as 1500 feet, the highest hills there
exceeding 3400 feet. Mr. Jukes, however, is by no means inclined to
insist on submergence to the extent of 2500 feet, as he is aware that
ice, like that now prevailing in Greenland, might explain most, if not
all, the appearances of glaciation in the highest regions.
Although the course taken by the Irish erratics in general is such
that their transportation seems to have been due to floating ice or
coast-ice, yet some granite blocks have travelled from south to north,
as recorded by Sir R. Griffiths, namely, those of the Ox Mountains in
Sligo; a fact from which Mr. Jamieson infers that those mountains formed
at one time a centre of dispersion. In the same part of Ireland, the
general direction in which the boulders have travelled is everywhere
from north-west to south-east, a course directly at right angles to the
prevailing trend of the present mountain ridges.
MAPS ILLUSTRATING SUCCESSIVE REVOLUTIONS IN PHYSICAL GEOGRAPHY DURING
THE PLEISTOCENE PERIOD.
[Illustration: Figure 39. Map Of The British Isles]
(FIGURE 39. MAP OF THE BRITISH ISLES AND PART OF THE NORTH-WEST
OF EUROPE, SHOWING THE GREAT AMOUNT OF SUPPOSED SUBMERGENCE
OF LAND BENEATH THE SEA DURING PART OF THE GLACIAL PERIOD.
The submergence of Scotland is to the extent of 2000 feet,
and of other parts of the British Isles, 1300.
In the map, the dark shade expresses the land which alone
remained above water. The area shaded by diagonal lines is
that which cannot be shown to have been under water at the
period of floating ice by the evidence of erratics, or by
marine shells of northern species. How far the several parts
of the submerged area were simultaneously or successively laid
under water, in the course of the glacial period, cannot, in
the present state of our knowledge, be determined.)
[Illustration: Figure 40. Map British Islands]
(FIGURE 40. MAP SHOWING WHAT PARTS OF THE BRITISH ISLANDS
WOULD REMAIN ABOVE WATER AFTER A SUBSIDENCE OF THE AREA
TO THE EXTENT OF 600 FEET.
The authorities to whom I am indebted for the information
contained in this map are--for:
SCOTLAND:
A. Geikie, Esquire, F.G.S., and T.F. Jamieson, Esquire,
of Ellon, Aberdeenshire.
ENGLAND:
For the counties of:
Yorkshire, Lancashire, and Durham: Colonel Sir Henry James, R.E.
Dorsetshire, Hampshire, and Isle of Wight: H.W. Bristow, Esquire.
Gloucestershire, Somersetshire, and part of Devon: R. Etheridge,
Esquire.
Kent and Sussex: Frederick Drew, Esquire.
Isle of Man: W. Whitaker, Esquire.
IRELAND:
Reduced from a contour map constructed by Lieutenant Larcom,
R.E., in 1837, for the Railway Commissioners.)
[Illustration: Figure 41. Map Of Part Of The North-West Of Europe]
(FIGURE 41. MAP OF PART OF THE NORTH-WEST OF EUROPE, INCLUDING
THE BRITISH ISLES, SHOWING THE EXTENT OF SEA WHICH WOULD BECOME
LAND IF THERE WERE A GENERAL RISE OF THE AREA TO THE EXTENT
OF 600 FEET.
The darker shade expresses what is now land, the lighter shade
the space intervening between the present coastline and the
100 fathom line, which would be converted by such a movement
into land.
The original of this map will be found in Sir H. de la Beche's
"Theoretical Researches" page 190, 1834, but several important
corrections have been introduced into it from recently
published Admiralty Surveys, especially:
1st. A deep channel passing from the North Sea into the
entrance of the Baltic.
2nd. The more limited westerly extension of the West Coast
of Ireland.)
The late Mr. Trimmer, before referred to, has endeavoured to assist our
speculations as to the successive revolutions in physical geography,
through which the British Islands have passed since the commencement
of the glacial period, by four "sketch maps" as he termed them, in the
first of which he gave an ideal restoration of the original Continental
period, called by him the first elephantine period, or that of the
forest of Cromer, before described. He was not aware that the prevailing
elephant of that era (E. meridionalis) was distinct from the mammoth. At
this era he conceived Ireland and England to have been united with each
other and with France, but much of the area represented as land in the
map, Figure 41, was supposed to be under water. His second map, of the
great submergence of the glacial period, was not essentially different
from our map, Figure 39. His third map expressed a period of partial
re-elevation, when Ireland was reunited to Scotland and the north of
England; but England still separated from France. This restoration
appears to me to rest on insufficient data, being constructed to suit
the supposed area over which the gigantic Irish deer, or Megaceros,
migrated from east to west, also to explain an assumed submergence of
the district called the Weald, in the south-east of England, which had
remained land during the grand glacial submergence.
The fourth map is a return to nearly the same continental conditions
as the first--Ireland, England, and the Continent being united. This he
called the second elephantine period; and it would coincide very closely
with that part of the Pleistocene era in which Man co-existed with the
mammoth, and when, according to Mr. Trimmer's hypothesis previously
indicated by Mr. Godwin-Austen, the Thames was a tributary of the
Rhine.*
(* Joshua Trimmer, "Quarterly Journal of the Geological
Society" volume 9 1853, Plate 13, and Godwin-Austen, ibid.
volume 7 1851 page 134 and Plate 7.)
These geographical speculations were indulged in ten years after Edward
Forbes had published his bold generalisations on the geological changes
which accompanied the successive establishment of the Scandinavian,
Germanic, and other living floras and faunas in the British Islands,
and, like the theories of his predecessor, were the results of much
reflection on a vast body of geological facts. It is by repeated efforts
of this kind, made by geologists who are prepared for the partial
failure of some of their first attempts, that we shall ultimately arrive
at a knowledge of the long series of geographical revolutions which have
followed each other since the beginning of the Pleistocene period.
The map, Figure 39, will give some idea of the great extent of land
which would be submerged, were we to infer, as many geologists have
done, from the joint evidence of marine shells, erratics, glacial striae
and stratified drift at great heights, that Scotland was, during part of
the glacial period, 2000 feet below its present level, and other parts
of the British Isles, 1300 feet. A subsidence to this amount can be
demonstrated in the case of North Wales by marine shells. In the lake
district of Cumberland, in Yorkshire, and in Ireland, we must depend on
proofs derived from glacial striae and the transportation of erratics
for so much of the supposed submergence as exceeds 600 feet. As to
central England, or the country north of the Thames and Bristol Channel,
marine shells of the glacial period sometimes reach as high as 600 and
700 feet, and erratics still higher, as we have seen above. But this
region is of such moderate elevation above the sea, that it would be
almost equally laid under water, were there a sinking of no more than
600 feet.
To make this last proposition clear, I have constructed, from numerous
documents, many of them unpublished, the map, Figure 40, which shows how
that small amount of subsidence would reduce the whole of the British
Isles to an archipelago of very small islands, with the exception
of parts of Scotland, and the north of England and Wales, where four
islands of considerable dimensions would still remain.
The map does not indicate a state of things supposed to have prevailed
at any one moment of the past, because the district south of the Thames
and the Bristol Channel seems to have remained land during the whole of
the glacial period, at a time when the northern area was under water.
The map simply represents the effects of a downward movement of a
hundred fathoms, or 600 English feet, assumed to be uniform over the
whole of the British Isles. It shows the very different state of the
physical geography of the area in question, when contrasted with the
results of an opposite movement, or one of upheaval, to an equal amount,
of which Sir Henry de la Beche had already given us a picture, in his
excellent treatise called "Theoretical Researches."*
(* Also repeated in De la Beche's "Geological Observer.")
His map I have borrowed (Figure 41), after making some important
corrections in it.
If we are surprised when looking at the first map, Figure 40, at the
vast expanse of sea which so moderate a subsidence as 600 feet would
cause, we shall probably be still more astonished to perceive, in Figure
41, that a rise of the same number of feet would unite all the British
Isles, including the Hebrides, Orkneys, and Shetlands, with one another
and the Continent, and lay dry the sea now separating Great Britain from
Sweden and Denmark.
It appears from soundings made during various Admiralty surveys, that
the gained land thus brought above the level of the sea, instead of
presenting a system of hills and valleys corresponding with those
usually characterising the interior of most of our island, would form
a nearly level terrace, or gently inclined plane, sloping outwards
like those terraces of denudation and deposition which I have elsewhere
described as occurring on the coasts of Sicily and the Morea.*
(* "Manual of Geology" page 74.)
It seems that, during former and perhaps repeated oscillations of level
undergone by the British Isles, the sea has had time to cut back the
cliffs for miles in many places, while in others the detritus derived
from wasting cliffs drifted along the shores, together with the sediment
brought down by rivers and swept by currents into submarine valleys,
has exerted a levelling power, filling up such depressions as may have
pre-existed. Owing to this twofold action few marked inequalities of
level have been left on the sea-bottom, the "silver-pits" off the mouth
of the Humber offering a rare exception to the general rule, and even
there the narrow depression is less than 300 feet in depth.
Beyond the 100 fathom line, the submarine slope surrounding the British
coast is so much steeper that a second elevation of equal amount (or of
600 feet) would add but slightly to the area of gained land; in other
words, the 100 and 200 fathom lines run very near each other.*
(* De la Beche, "Geological Researches" page 191.)
The naturalist would have been entitled to assume the former union,
within the Pleistocene period, of all the British Isles with each other
and with the Continent, as expressed in the map, Figure 41, even if
there had been no geological facts in favour of such a junction. For in
no other way would he be able to account for the identity of the fauna
and flora found throughout these lands. Had they been separated ever
since the Miocene period, like Madeira, Porto Santo, and the Desertas,
constituting the small Madeiran Archipelago, we might have expected
to discover a difference in the species of land-shells, not only when
Ireland was compared to England, but when different islands of the
Hebrides were contrasted one with another, and each of them with
England. It would not, however, be necessary, in order to effect the
complete fusion of the animals and plants which we witness, to assume
that all parts of the area formed continuous land at one and the same
moment of time, but merely that the several portions were so joined
within the Pleistocene era as to allow the animals and plants to migrate
freely in succession from one district to another.
SOUTHERNMOST EXTENT OF ERRATICS IN ENGLAND.
In reference to that portion of the south of England which is marked by
diagonal lines in Figure 39, the theory of its having been an area of
dry land during the period of great submergence and floating ice does
not depend merely on negative evidence, such as the absence of the
northern drift or boulder clay on its surface; but we have also, in
favour of the same conclusion, the remarkable fact of the presence of
erratic blocks on the southern coast of Sussex, implying the existence
there of an ancient coast-line at a period when the cold must have been
at its height.
These blocks are to be seen in greatest number at Pagham and Selsea, 15
miles south of Chichester, in latitude 50 degrees 40 minutes north.
They consist of fragments of granite, syenite and greenstone, as well as
of Devonian and Silurian rocks, some of them of large size. I measured
one of granite at Pagham, 27 feet in circumference. They are not of
northern origin, but must have come from the coast of Normandy or
Brittany, or from land which may once have existed to the south-west, in
what is now the English Channel.
They were probably drifted into their present site by coast ice, and
the yellow clay and gravel in which they are embedded are a littoral
formation, as shown by the shells. Beneath the gravel containing these
large erratics, is a blue mud in which skeletons of Elephas antiquus,
and other mammalia, have been observed. Still lower occurs a sandy loam,
from which Mr. R.G. Austen* has collected thirty-eight species of marine
shells, all Recent, but forming an assemblage differing as a whole from
that now inhabiting the English Channel.
(* "Quarterly Journal of the Geological Society" volume 13
1857 page 50.)
The presence among them of Lutraria rugosa and Pecten polymorphus,
not known to range farther north in the actual seas than the coast of
Portugal, indicates a somewhat warmer temperature at the time when
they flourished. Subsequently, there must have been great cold when the
Selsea erratics were drifted into their present position, and this cold
doubtless coincided in time with a low temperature farther north. [30]
These transported rocks of Sussex are somewhat older than a sea-beach
with Recent marine shells which at Brighton is covered by Chalk rubble,
called the "elephant-bed" which I cannot describe in this place, but I
allude to it as one of many geological proofs of the former existence
of a seashore in this region, and of ancient cliffs bounding the channel
between France and England, all of older date than the close of the
glacial period. [31]
In order to form a connected view of the most simple series of changes
in physical geography which can possibly account for the phenomena of
the glacial period, and the period of the establishment of the present
provinces of animals and plants, the following geographical states of
the British and adjoining areas may be enumerated.
First, a continental period, towards the close of which the forest of
Cromer flourished: when the land was at least 500 feet above its present
level, perhaps much higher, and its extent probably greater than that
given in the map, Figure 41.
Secondly, a period of submergence, by which the land north of the Thames
and Bristol Channel, and that of Ireland, was gradually reduced to such
an archipelago as is pictured in map, Figure 40; and finally to such
a general prevalence of sea as is seen in map, Figure 39. This was the
period of great submergence and of floating ice, when the Scandinavian
flora, which occupied the lower grounds during the first continental
period, may have obtained exclusive possession of the only lands not
covered with perpetual snow.
Thirdly, a second continental period when the bed of the glacial sea,
with its marine shells and erratic blocks, was laid dry, and when
the quantity of land equalled that of the first period, and therefore
probably exceeded that represented in the map, Figure 41. During this
period there were glaciers in the higher mountains of Scotland and
Wales, and the Welsh glaciers, as we have seen, pushed before them and
cleared out the marine drift with which some valleys had been filled
during the period of submergence. The parallel roads of Glen Roy are
referable to some part of the same era.
As a reason for presuming that the land which in map, Figure 41, is only
represented as 600 feet above its present level, was during part of this
period much higher, Professor Ramsay has suggested that, as the previous
depression far exceeded 100 fathoms (amounting in Wales to 1400 feet,
as shown by marine shells, and to 2300, by stratified drift), it is not
improbable that the upward movement was on a corresponding scale.
In passing from the period of chief submergence to this second
continental condition of things, we may conceive a gradual change first
from that of Map 39 to Map 40, then from the latter phase to that of Map
41, and finally to still greater accessions of land. During this last
period the passage of the Germanic flora into the British area took
place, and the Scandinavian plants, together with northern insects,
birds, and quadrupeds, retreated into the higher grounds.
Judging from the evidence at present before us, the first appearance of
Man, when, together with the mammoth and woolly rhinoceros, or with the
Elephas antiquus, Rhinoceros hemitoechus, and Hippopotamus major, he
ranged freely from all parts of the Continent into the British area,
took place during this second continental period.
Fourthly, the next and last change comprised the breaking up of the
land of the British area once more into numerous islands, ending in
the present geographical condition of things. There were probably many
oscillations of level during this last conversion of continuous land
into islands, and such movements in opposite directions would account
for the occurrence of marine shells at moderate heights above the level
of the sea, notwithstanding a general lowering of the land. To the close
of this era belong the marine deposits of the Clyde and the Carses of
the Tay and Forth, before alluded to.
In a memoir by Professor E. Forbes, before cited, he observes, that the
land of passage by which the plants and animals migrated into Ireland
consisted of the upraised marine drift which had previously formed the
bottom of the glacial sea. Portions of this drift extend to the eastern
shores of Wicklow and Wexford, others are found in the Isle of Man full
of arctic shells, others on the British coast opposite Ireland. The
freshwater marl, containing numerous skeletons of the great deer,
or Megaceros, overlie in the Isle of Man that marine glacial drift.
Professor Forbes also remarks that the subsequent disjunction of Ireland
from England, or the formation of the Irish Channel, which is less than
400 feet in its greatest depth, preceded the opening of the Straits of
Dover, or the final separation of England from the Continent. This he
inferred from the present distribution of species both in the animal and
vegetable kingdoms. Thus, for example, there are twice as many reptiles
in Belgium as in England, and the number inhabiting England is twice
that found in Ireland. Yet the Irish species are all common to England,
and all the English to Belgium. It is therefore assumed that the
migration of species westward having been the work of time, there was
not sufficient lapse of ages to complete the fusion of the continental
and British reptilian fauna, before France was separated from England
and England from Ireland.
For the same reason there are also a great number of birds of short
flight, and small quadrupeds, inhabiting England which do not cross
to Ireland, the Irish Channel seeming to have arrested them in their
westward course.*
(* E. Forbes, Fauna and Flora of British Isles, "Memoir of
the Geological Survey" volume 1 1846 page 344.)
The depth of the Irish Channel in the narrower parts is only 360 feet,
and the English Channel between Dover and Calais less than 200, and
rarely anywhere more than 300 feet; so that vertical movements of slight
amount compared to some of those previously considered, with the aid of
denuding operations or the waste of sea cliffs, and the scouring out
of the channel, might in time effect the insulation of the lands above
alluded to.
TIME REQUIRED FOR SUCCESSIVE CHANGES IN PHYSICAL GEOGRAPHY IN THE
PLEISTOCENE PERIOD.
The time which it would require to bring about such changes of level,
according to the average rate assumed in Chapter 3, however vast, will
not be found to exceed that which would best explain the successive
fluctuations in terrestrial temperature, the glaciation of solid rocks,
the transportation of erratics above and below the sea-level, the height
of arctic shells above the sea, and last, not least, the migration of
the existing species of animals and plants into their actual stations,
and the extinction of some conspicuous forms which flourished during
the Pleistocene ages. When we duly consider all these changes which
have taken place since the beginning of the glacial epoch, or since the
forest of Cromer and the Elephas meridionalis flourished, we shall find
that the phenomena become more and more intelligible in proportion to
the slowness of the rate of elevation and depression which we assume.
The submergence of Wales to the extent of 1400 feet, as proved by
glacial shells, would require 56,000 years, at the rate of 2 1/2 feet
per century; but taking Professor Ramsay's estimate of 800 feet more,
that depression being implied by the position of some of the stratified
drift, we must demand an additional period of 32,000 years, amounting in
all to 88,000; and the same time would be required for the re-elevation
of the tract to its present height. But if the land rose in the second
continental period as much as 600 feet above its present level, as in
Figure 41, this 600 feet, first of rising and then of sinking,
would require 48,000 years more; the whole of the grand oscillation,
comprising the submergence and re-emergence, having taken about 224,000
years for its completion; and this, even if there were no pause or
stationary period, when the downward movement ceased, and before it was
converted into an upward one.
I am aware that it may be objected that the average rate here proposed
is a purely arbitrary and conjectural one, because, at the North Cape,
it is supposed that there has been a rise of about 5 feet in a century,
and at Spitsbergen, according to Mr. Lamont, a still faster upheaval
during the last 400 years.*
(* "Seasons with the Sea-Horses" page 202.)
But, granting that in these and some exceptional cases (none of them as
yet very well established) the rising or sinking has, for a time, been
accelerated, I do not believe the average rate of motion to exceed that
above proposed. Mr. Darwin, I find, considers that such a mean rate of
upheaval would be as high as we could assume for the west coast of South
America, where we have more evidence of sudden changes of level than
anywhere else. He has not, however, attempted to estimate the probable
rate of secular elevation in that or any other region.
Little progress has yet been made in divining the most probable causes
of these great movements of the earth's crust; yet what little we
know of the state of the interior leads us to expect that the gradual
expansion or contraction of large portions of the solid crust may be
the result of fluctuations in temperature, with which the existence
of hundreds of active and thousands of extinct volcanoes is probably
connected.
It is ascertained that solid rocks, such as granite and sandstone,
expand and contract annually, even under such a moderate range of
temperature as that of a Canadian winter and summer. If the heat should
go on increasing through a thickness, say only of 10 miles of the
earth's crust, the gradual upheaval of the incumbent mass may amount to
many hundreds of feet; and the elevation may be carried still farther,
by the complete fusion of part of the inferior rocks.
According to the experiments of Deville, the contraction of granite, in
passing from a melted, or as some would say its plastic condition, to a
solid state, must be more than 10 per cent.*
(* "Bull. Societe Geologique France" 2nd series volume 4
page 1312.)
So that we have at our command a source of depression on a grand scale,
at every period when granitic rocks have originated in the interior
of the earth's crust. All mineralogists are agreed that the passage of
voluminous masses, from a liquid or pasty to a solid and crystalline
state, must be an extremely slow process. It may often happen that, in
the same series of superimposed rocks, some are expanding while still
solid or while partially melting, while others are at the same time
crystallising and contracting; so that the alterations of level at
the surface may be the result of complicated and often of conflicting
agencies. The more gradually we conceive such changes to take place, the
more comprehensible they become in the eyes of the chemist and natural
philosopher who speculates on the changes of the earth's interior; and
the more fertile are they in the hands of the geologist in accounting
for revolutions on the habitable surface.
We may presume, that after the movement has gone on for a long time
in one determinate direction, whether of elevation or depression, the
change to an opposite movement, implying the substitution of a heating
for a refrigerating operation, or the reverse, would not take place
suddenly; but would be marked by a period of inaction, or of slight
movement, or such a state of quiescence, as prevails throughout large
areas of dry land in the normal condition of the globe.
I see no reason for supposing that any part of the revolutions in
physical geography, to which the maps above described have reference,
indicate any catastrophes greater than those which the present
generation has witnessed. If Man was in existence when the Cromer forest
was becoming submerged, he would have felt no more alarm than the Danish
settlers on the east coast of Baffin's Bay, when they found the poles,
which they had driven into the beach to secure their boats, had subsided
below their original level.
Already, perhaps, the melting ice has thrown down till and boulders
upon those poles, a counterpart of the boulder clay which overlies the
forest-bed on the Norfolk cliffs.
We have seen that all the plants and shells, marine and freshwater,
of the forest bed, and associated fluvio-marine strata of Norfolk,
are specifically identical with those of the living European flora and
fauna; so that if upon such a stratum a deposit of the present period,
whether freshwater or marine, should be thrown down, it might lie
conformably over it, and contain the same invertebrate fauna and flora.
The strata so superimposed would, in ordinary geological language, be
called contemporaneous, not only as belonging to the same epoch, but as
appertaining strictly to the same subdivision of one and the same
epoch; although they would in fact have been separated by an interval of
several hundred thousand years.
If, in the lower of the two formations, some of the mammalia of the
genera elephant and rhinoceros were found to be distinct in species
from those of the same genera in the upper or "recent" stratum, it might
appear as though there had been a sudden coming in of new forms, and a
sudden dying out of old ones; for there would not have been time in the
interval for any perceptible change in the invertebrate fauna, by which
alone we usually measure the lapse of time in the older formations.
When we are contrasting the vertebrate contents of two sets of
superimposed strata of the Cretaceous, Oolitic, or any other ancient
formation in which the shells are identical in species, we ought never
to lose sight of the possibility of their having been separated by such
intervals or by two or three thousand centuries. That number of years
may sometimes be of small moment in reference to the rate of fluctuation
of species in the lower animals, but very important when the succession
of forms in the highest classes of vertebrata is concerned.
If we reflect on the long series of events of the Pleistocene and Recent
periods contemplated in this chapter, it will be remarked that the
time assigned to the first appearance of Man, so far as our geological
inquiries have yet gone, is extremely modern in relation to the age
of the existing fauna and flora, or even to the time when most of the
living species of animals and plants attained their actual geographical
distribution. At the same time it will also be seen, that if the advent
of Man in Europe occurred before the close of the second continental
period, and antecedently to the separation of Ireland from England and
of England from the Continent, the event would be sufficiently remote to
cause the historical period to appear quite insignificant in duration,
when compared to the antiquity of the human race.
CHAPTER 15. -- EXTINCT GLACIERS OF THE ALPS AND THEIR CHRONOLOGICAL
RELATION TO THE HUMAN PERIOD.
Extinct Glaciers of Switzerland.
Alpine Erratic Blocks on the Jura.
Not transported by floating Ice.
Extinct Glaciers of the Italian Side of the Alps.
Theory of the Origin of Lake-Basins by the erosive Action of
Glaciers considered.
Successive phases in the Development of Glacial Action in the Alps.
Probable Relation of these to the earliest known Date of Man.
Correspondence of the same with successive Changes in the Glacial
Condition of the Scandinavian and British Mountains.
Cold Period in Sicily and Syria.
EXTINCT GLACIERS OF SWITZERLAND.
We have seen in the preceding chapters that the mountains of
Scandinavia, Scotland, and North Wales have served, during the glacial
period, as so many independent centres for the dispersion of erratic
blocks, just as at present the ice-covered continent of North Greenland
is sending down ice in all directions to the coast, and filling Baffin's
Bay with floating bergs, many of them laden with fragments of rocks.
Another great European centre of ice-action during the Pleistocene
period was the Alps of Switzerland, and I shall now proceed to consider
the chronological relations of the extinct Alpine glaciers to those of
more northern countries previously treated of. [32]
The Alps lie far south of the limits of the northern drift described in
the foregoing pages, being situated between the 44th and 47th degrees of
north latitude. On the flanks of these mountains, and on the sub-Alpine
ranges of hills or plains adjoining them, those appearances which have
been so often alluded to, as distinguishing or accompanying the drift,
between the 50th and 70th parallels of north latitude, suddenly reappear
and assume, in a southern region, a truly arctic development. Where the
Alps are highest, the largest erratic blocks have been sent forth; as,
for example, from the regions of Mont Blanc and Monte Rosa, into the
adjoining parts of Switzerland and Italy; while in districts where the
great chain sinks in altitude, as in Carinthia, Carniola, and elsewhere,
no such rocky fragments, or a few only and of smaller bulk, have been
detached and transported to a distance.
In the year 1821, M. Venetz first announced his opinion that the Alpine
glaciers must formerly have extended far beyond their present limits,
and the proofs appealed to by him in confirmation of this doctrine were
afterwards acknowledged by M. Charpentier, who strengthened them by new
observations and arguments, and declared in 1836 his conviction that the
glaciers of the Alps must once have reached as far as the Jura, and have
carried thither their moraines across the great valley of Switzerland.
M. Agassiz, after several excursions in the Alps with M. Charpentier,
and after devoting himself some years to the study of glaciers,
published in 1840 an admirable description of them and of the marks
which attest the former action of great masses of ice over the entire
surface of the Alps and the surrounding country.*
(* Agassiz, "Etudes sur les Glaciers et Systeme Glaciaire.")
He pointed out that the surface of every large glacier is strewed over
with gravel and stones detached from the surrounding precipices by
frost, rain, lightning, or avalanches. And he described more carefully
than preceding writers the long lines of these stones, which settle on
the sides of the glacier, and are called the lateral moraines; those
found at the lower end of the ice being called terminal moraines.
Such heaps of earth and boulders every glacier pushes before it when
advancing, and leaves behind it when retreating. When the Alpine glacier
reaches a lower and a warmer situation, about 3000 or 4000 feet above
the sea, it melts so rapidly that, in spite of the downward movement
of the mass, it can advance no farther. Its precise limits are variable
from year to year, and still more so from century to century; one
example being on record of a recession of half a mile in a single year.
We also learn from M. Venetz, that whereas, between the eleventh and
fifteenth centuries, all the Alpine glaciers were less advanced than
now, they began in the seventeenth and eighteenth centuries to push
forward, so as to cover roads formerly open, and to overwhelm forests of
ancient growth.
These oscillations enable the geologist to note the marks which a
glacier leaves behind it as it retrogrades; and among these the most
prominent, as before stated, are the terminal moraines, or mounds of
unstratified earth and stones, often divided by subsequent floods into
hillocks, which cross the valley like ancient earthworks, or embankments
made to dam up a river. Some of these transverse barriers were formerly
pointed out by Saussure below the glacier of the Rhone, as proving how
far it had once transgressed its present boundaries. On these moraines
we see many large angular fragments, which, having been carried along
the surface of the ice, have not had their edges worn off by friction;
but the greater number of the boulders, even those of large size, have
been well rounded, not by the power of water, but by the mechanical
force of the ice, which has pushed them against each other, or against
the rocks flanking the valley. Others have fallen down the numerous
fissures which intersect the glacier, where, being subject to the
pressure of the whole mass of ice, they have been forced along, and
either well rounded or ground down into sand, or even the finest mud, of
which the moraine is largely constituted.
As the terminal moraines are the most prominent of all the monuments
left by a receding glacier, so are they the most liable to obliteration;
for violent floods or debacles are sometimes occasioned in the Alps by
the sudden bursting of glacier-lakes, or those temporary sheets of water
before alluded to which are caused by the damming up of a river by a
glacier which has increased during a succession of cold seasons, and
descending from a tributary into the main valley, has crossed it from
side to side. On the failure of this icy barrier the accumulated waters,
being let loose, sweep away and level many a transverse mound of gravel
and loose boulders below, and spread their materials in confused and
irregular beds over the river-plain.
Another mark of the former action of glaciers in situations where they
exist no longer, is the polished, striated, and grooved surfaces of
rocks before described. Stones which lie underneath the glacier and are
pushed along by it sometimes adhere to the ice, and as the mass glides
slowly along at the rate of a few inches, or at the utmost 2 or 3 feet
per day, abrade, groove, and polish the rock, and the larger blocks are
reciprocally grooved and polished by the rock on their lower sides. As
the forces both of pressure and propulsion are enormous, the sand acting
like emery polishes the surface; the pebbles, like coarse gravers,
scratch and furrow it; and the large stones scoop out grooves in it.
Lastly, projecting eminences of rock, called "roches moutonnees," are
smoothed and worn into the shape of flattened domes where the glaciers
have passed over them.
Although the surface of almost every kind of rock when exposed to the
open air wastes away by decomposition, yet some retain for ages their
polished and furrowed exterior: and if they are well protected by
a covering of clay or turf, these marks of abrasion seem capable of
enduring for ever. They have been traced in the Alps to great heights
above the present glaciers, and to great horizontal distances beyond
them.
Another effect of a glacier is to lodge a ring of stones round the
summit of a conical peak which may happen to project through the ice.
If the glacier is lowered greatly by melting, these circles of large
angular fragments, which are called "perched blocks," are left in a
singular situation near the top of a steep hill or pinnacle, the lower
parts of which may be destitute of boulders.
ALPINE ERRATIC BLOCKS ON THE JURA.
Now some or all the marks above enumerated,--the moraines, erratics,
polished surfaces, domes, striae, and perched rocks--are observed in
the Alps at great heights above the present glaciers and far below their
actual extremities; also in the great valley of Switzerland, 50 miles
broad; and almost everywhere on the Jura, a chain which lies to the
north of this valley. The average height of the Jura is about one-third
that of the Alps, and it is now entirely destitute of glaciers; yet it
presents almost everywhere moraines, and polished and grooved surfaces
of rocks. The erratics, moreover, which cover it present a phenomenon
which has astonished and perplexed the geologist for more than half a
century. No conclusion can be more incontestable than that these angular
blocks of granite, gneiss, and other crystalline formations, came from
the Alps, and that they have been brought for a distance of 50 miles and
upwards across one of the widest and deepest valleys of the world; so
that they are now lodged on the hills and valleys of a chain composed
of limestone and other formations, altogether distinct from those of
the Alps. Their great size and angularity, after a journey of so many
leagues, has justly excited wonder, for hundreds of them are as large
as cottages; and one in particular, composed of gneiss, celebrated under
the name of Pierre a Bot, rests on the side of a hill about 900 feet
above the lake of Neufchatel, and is no less than 40 feet in diameter.
But there are some far-transported masses of granite and gneiss which
are still larger, and which have been found to contain 50,000 and 60,000
cubic feet of stone; and one limestone block at Devens, near Bex, which
has travelled 30 miles, contains 161,000 cubic feet, its angles being
sharp and unworn.
Von Buch, Escher, and Studer inferred, from an examination of the
mineral composition of the boulders, that those resting on the Jura,
opposite the lakes of Geneva and Neufchatel, have come from the region
of Mont Blanc and the Valais, as if they had followed the course of
the Rhone to the lake of Geneva, and had then pursued their way
uninterruptedly in a northerly direction.
M. Charpentier, who conceived the Alps in the period of greatest cold to
have been higher by several thousand feet than they are now, had already
suggested that the Alpine glaciers once reached continuously to the
Jura, conveying thither the large erratics in question.*
(* D'Archiac, "Histoire des Progres" etc. volume 2 page
249.)
M. Agassiz, on the other hand, instead of introducing distinct and
separate glaciers, imagined that the whole valley of Switzerland might
have been filled with ice, and that one great sheet of it extended from
the Alps to the Jura, the two chains being of the same height as
now relatively to each other. To this idea it was objected that the
difference of altitude, when distributed over a space of 50 miles, would
give an inclination of two degrees only, or far less than that of any
known glacier. In spite of this difficulty, the hypothesis has since
received the support of Professor James Forbes in his very able work on
the Alps published in 1843.
In 1841, I advanced jointly with Mr. Darwin* the theory that the
erratics may have been transferred by floating ice to the Jura, at the
time when the greater part of that chain and the whole of the Swiss
valley to the south was under the sea.
(* See "Elements of Geology" 2nd edition 1841.)
We pointed out that if at that period the Alps had attained only half
their present altitude they would yet have constituted a chain as lofty
as the Chilean Andes, which in a latitude corresponding to Switzerland
now send down glaciers to the head of every sound, from which icebergs
covered with blocks of granite are floated seaward. Opposite that part
of Chile where the glaciers abound is situated the island of Chiloe
100 miles in length with a breadth of 30 miles, running parallel to
the continent. The channel which separates it from the main land is of
considerable depth and 25 miles broad. Parts of its surface, like the
adjacent coast of Chile, are overspread with Recent marine shells,
showing an upheaval of the land during a very modern period; and beneath
these shells is a boulder deposit in which Mr. Darwin found large blocks
of granite and syenite which had evidently come from the Andes.
A continuance in future of the elevatory movement now observed to be
going on in this region of the Andes and of Chiloe might cause the
former chain to rival the Alps in altitude and give to Chiloe a height
equal to that of the Jura. The same rise might dry up the channel
between Chiloe and the main land so that it would then represent the
great valley of Switzerland.
Sir Roderick I. Murchison, after making several important geological
surveys of the Alps, proposed in 1849 a theory agreeing essentially with
that suggested by Mr. Darwin and myself, namely that the erratics were
transported to the Jura at a time when the great strath of Switzerland
and many valleys receding far into the Alps were under water. He thought
it impossible that the glacial detritus of the Rhone could ever have
been carried to the Lake of Geneva and beyond it by a glacier, or that
so vast a body of ice issuing from one narrow valley could have spread
its erratics over the low country of the cantons of Vaud, Fribourg,
Berne, and Soleure, as well as the slopes of the Jura, comprising a
region of about 100 miles in breadth from south-west to north-east, as
laid down in the map of Charpentier. He therefore imagined the granitic
blocks to have been translated to the Jura by ice-floats when the
intermediate country was submerged.*
(* "Quarterly Journal of the Geological Society" volume 6
1850 page 65.)
It may be remarked that this theory, provided the water be assumed to
have been salt or brackish, demands quite as great an oscillation in the
level of the land as that on which Charpentier had speculated, the only
difference being that the one hypothesis requires us to begin with a
subsidence of 2500 or 3000 feet, and the other with an elevation to the
same amount. We should also remember that the crests or watersheds of
the Alps and Jura are about 80 miles apart, and if once we suppose them
to have been in movement during the glacial period it is very probable
that the movements at such a distance may not have been strictly
uniform. If so the Alps may have been relatively somewhat higher, which
would have greatly facilitated the extension of Alpine glaciers to the
flanks of the less elevated chain.
Five years before the publication of the memoir last mentioned, M. Guyot
had brought forward a great body of new facts in support of the original
doctrine of Charpentier, that the Alpine glaciers once reached as far
as the Jura and that they had deposited thereon a portion of their
moraines.*
(* "Bulletin de la Societe des Sciences Naturelles de
Neufchatel" 1845.)
The scope of his observations and argument was laid with great clearness
before the British public in 1852 by Mr. Charles Maclaren, who had
himself visited Switzerland for the sake of forming an independent
opinion on a theoretical question of so much interest and on which so
many eminent men of science had come to such opposite conclusions.*
(* "Edinburgh New Philosophical Magazine" October 1852.)
M. Guyot had endeavoured to show that the Alpine erratics, instead
of being scattered at random over the Jura and the great plain of
Switzerland, are arranged in a certain determinate order strictly
analogous to that which ought to prevail if they had once constituted
the lateral, medial, and terminal moraines of great glaciers. The rocks
chiefly relied on as evidence of this distribution consist of three
varieties of granite, besides gneiss, chlorite-slate, euphotide,
serpentine, and a peculiar kind of conglomerate, all of them foreign
alike to the great Strath between the Alps and Jura and to the structure
of the Jura itself. In these two regions limestones, sandstones, and
clays of the Secondary and Tertiary formations alone crop out at the
surface, so that the travelled fragments of Alpine origin can easily be
distinguished and in some cases the precise localities pointed out from
whence they must have come.
[Illustration: Figure 42. Map of Ancient Glacier]
(FIGURE 42. MAP SHOWING THE SUPPOSED COURSE OF THE ANCIENT AND NOW
EXTINCT GLACIER OF THE RHONE, AND THE DISTRIBUTION OF THE ERRATIC
BLOCKS AND DRIFT CONVEYED BY IT TO THE GREAT VALLEY OF SWITZERLAND
AND THE JURA.)
The accompanying map or diagram (Figure 42) slightly altered from one
given by Mr. Maclaren will enable the reader more fully to appreciate
the line of argument relied on by M. Guyot. The dotted area is that over
which the Alpine fragments were spread by the supposed extinct glacier
of the Rhone. The site of the present reduced glacier of that name is
shown at A. From that point the boulders may first be traced to B, or
Martigny, where the valley takes an abrupt turn at right angles to its
former course. Here the blocks belonging to the right side of the river
or derived from c d e have not crossed over to the left side at B, as
they should have done had they been transported by floating ice, but
continue to keep to the side to which they belonged, assuming that they
once formed part of a right lateral moraine of a great extinct glacier.
That glacier, after arriving at the lower end of the long narrow valley
of the upper Rhone at F, filled the Lake of Geneva, F, I, with ice. From
F, as from a great vomitory, it then radiated in all directions bearing
along with it the moraines with which it was loaded and spreading them
out on all sides over the great plain. But the principal icy mass moved
straight onwards in a direct line towards the hill of Chasseron, G
(precisely opposite F), where the Alpine erratics attain their maximum
of height on the Jura, that is to say 2015 English feet above the level
of the Lake of Neufchatel or 3450 feet above the sea. The granite blocks
which have ascended to this eminence G came from the east shoulder of
Mont Blanc h, having travelled in the direction B, F, G.
When these and the accompanying blocks resting on the south-eastern
declivity of the Jura are traced from their culminating point G in
opposite directions, whether westward towards Geneva or eastwards
towards Soleure, they are found to decline in height from the middle of
the arc G towards the two extremities I and K, both of which are at a
lower level than G, by about 1500 feet. In other words the ice of the
extinct glacier, having mounted up on the sloping flanks of the Jura in
the line of greatest pressure to its highest elevation, began to decline
laterally in the manner of a pliant or viscous mass with a gentle
inclination till it reached two points distant from each other no less
than 100 miles. [33]
In further confirmation of this theory M. Guyot observed that fragments
derived from the right bank of the great valley of the Rhone c d e are
found on the right side of the great Swiss basin or Strath as at l and
m, while those derived from the left bank p h occur on the left side of
the basin or on the Jura between G and I; and those again derived from
places farthest up on the left bank and nearest the source of the Rhone,
as n o, occupy the middle of the great basin, constituting between m
and K what M. Guyot calls the frontal or terminal moraine of the eastern
prolongation of the old glacier.
A huge boulder of talcose granite, now at Steinhoff, 10 miles east from
K, or Soleure, containing 61,000 French cubic feet, or equal in bulk
to a mass measuring 40 feet in every direction, was ascertained by
Charpentier from its composition to have been derived from n, one of the
highest points on the left side of the Rhone valley far above Martigny.
From this spot it must have gone all round by F, which is the only
outlet to the deep valley, so as to have performed a journey of no less
than 150 miles!
GENERAL TRANSPORTATION OF ERRATICS IN SWITZERLAND DUE TO GLACIERS AND
NOT TO FLOATING ICE.
It is evident that the above described restriction of certain fragments
of peculiar lithological character to that bank of the Rhone where the
parent rocks are alone met with and the linear arrangement of the
blocks in corresponding order on the opposite side of the great plain of
Switzerland, are facts which harmonise singularly well with the theory
of glaciers while they are wholly irreconcilable with that of floating
ice. Against the latter hypothesis all the arguments which Charpentier
originally brought forward in opposition to the first popular doctrine
of a grand debacle or sudden flood rushing down from the Alps to the
Jura might be revived. Had there ever been such a rush of muddy water,
said he, the blocks carried down the basins of the principal Swiss
rivers, such as the Rhone, Aar, Reuss, and Limmat, would all have been
mingled confusedly together instead of having each remained in separate
and distinct areas as they do and should do according to the glacial
hypothesis.
M. Morlot presented me in 1857 with an unpublished map of Switzerland in
which he had embodied the results of his own observations and those
of MM. Guyot, Escher, and others, marking out by distinct colours the
limits of the ice-transported detritus proper to each of the great
river-basins. The arrangement of the drift and erratics thus
depicted accords perfectly well with Charpentier's views and is quite
irreconcilable with the supposition of the scattered blocks having been
dispersed by floating ice when Switzerland was submerged.
As opposed to the latter hypothesis, I may also state that nowhere as
yet have any marine shells or other fossils than those of a terrestrial
character, such as the bones of the mammoth and a few other mammalia
and some coniferous wood, been detected in those drifts, though they are
often many hundreds of feet in thickness.
A glance at M. Morlot's map, above mentioned,* will show that the two
largest areas, indicated by a single colour, are those over which the
Rhone and the Rhine are supposed to have spread out in ancient times
their enormous moraines.
(* See map, "Quarterly Journal of the Geological Society"
volume 18 1862 page 185 Plate 18.)
One of these only, that of the Rhone, has been exhibited in our diagram,
Figure 42. The distinct character of the drift in the two cases is such
as it would be if two colossal glaciers should now come down from the
higher Alps through the valleys traversed by those rivers, leaving their
moraines in the low country. The space occupied by the glacial drift of
the Rhine is equal in dimensions or rather exceeds that of the Rhone,
and its course is not interfered with in the least degree by the Lake
of Constance, 45 miles long, any more than is the dispersion of the
erratics of the Rhone by the Lake of Geneva, about 50 miles in length.
The angular and other blocks have in both instances travelled on
precisely as if those lakes had no existence, or as if, which was no
doubt the case, they had been filled with solid ice.
During my last visit to Switzerland in 1857, I made excursions, in
company with several distinguished geologists, for the sake of testing
the relative merits of the two rival theories above referred to, and I
examined parts of the Jura above Neufchatel in company with M. Desor,
the country round Soleure with M. Langen, the southern side of the great
strath near Lausanne with M. Morlot, the basin of the Aar around Berne
with M. Escher von der Linth; and having satisfied myself that all the
facts which I saw north of the Alps were in accordance with M. Guyot's
views, I crossed to the Italian side of the great chain and became
convinced that the same theory was equally applicable to the ancient
moraines of the plains of the Po.
M. Escher pointed out to me at Trogen in Appenzel on the left bank of
the Rhine fragments of a rock of a peculiar mineralogical character,
commonly called the granite of Pontelyas, the natural position of which
is well known near Trons, 100 miles from Trogen, on the left bank of the
Rhine about 30 miles from the source of that river. All the blocks of
this peculiar granite keep to the left bank, even where the valley turns
almost at right angles to its former course near Mayenfeld below Chur,
making a sharp bend resembling that of the valley of the Rhone at
Martigny. The granite blocks, where they are traced to the low country,
still keep to the left side of the Lake of Constance. That they should
not have crossed over to the opposite river-bank below Chur is quite
inexplicable if, rejecting the aid of land-ice, we appeal to floating
ice as the transporting power.
In M. Morlot's map already cited we behold between the areas occupied
by the glacial drift of the Rhine and Rhone three smaller yet not
inconsiderable spaces distinguished by distinct colours, indicating
the peculiar detritus brought down by the three great rivers, the Aar,
Reuss, and Limmat. The ancient glacier of the first of these, the
Aar, has traversed the lakes of Brienz and Thun and has borne angular,
polished, and striated blocks of limestone and other rocks as far as
Berne and somewhat below that city. The Reuss has also stamped the
lithological character of its own mountainous region upon the lower
part of its hydrographical basin by covering it with its peculiar Alpine
drift. In like manner the old extinct glacier of the Limmat during its
gradual retreat has left monuments of its course in the Lake of Zurich
in the shape of terminal moraines, one of which has almost divided that
great sheet of water into two lakes.
The ice-work done by the extinct glaciers, as contrasted with that
performed by their dwarfed representatives of the present day, is in due
proportion to the relative volume of the supposed glaciers, whether we
measure them by the distances to which they have carried erratic
blocks or the areas which they have strewed over with drift or the hard
surfaces of rock and number of boulders which they have polished and
striated. Instead of a length of 5, 10, or 20 miles and a thickness of
200, 300, or at the utmost 800 feet, those giants of the olden time must
have been from 50 to 150 miles long and between 1000 and 3000 feet deep.
In like manner the glaciation although identical in kind is on so small
a scale in the existing Alpine glaciers as at first sight to disappoint
a Swedish, Scotch, Welsh, or North American geologist. When I visited
the terminal moraine of the glacier of the Rhone in 1859 and tried
to estimate the number of angular or rounded pebbles and blocks which
exhibited glacial polishing or scratches as compared to those bearing no
such markings, I found that several thousand had to be reckoned before I
arrived at the first which was so striated or polished as to differ
from the stones of an ordinary torrent-bed. Even in the moraines of the
glaciers of Zermatt, Viesch, and others, in which fragments of limestone
and serpentine are abundant (rocks which most readily receive and most
faithfully retain the signs of glaciation), I found, for one which
displayed such indications, several hundreds entirely free from them.
Of the most opposite character were the results obtained by me from a
similar scrutiny of the boulders and pebbles of the terminal moraine
of one of the old extinct glaciers, namely, that of the Rhone in
the suburbs of Soleure. Thus at the point K in the map, Figure 42, I
observed a mass of unstratified clay or mud, through which a variety of
angular and rubbed stones were scattered and a marked proportion of the
whole were polished and scratched and the clay rendered so compact, as
if by the incumbent pressure of a great mass of ice, that it has been
found necessary to blow it up with gunpowder in making railway cuttings
through part of it. A limestone of the age of our Portland stone
on which this old moraine rests, has its surface polished like a
looking-glass, displaying beautiful sections of fossil shells of the
genera Nerinaea and Pteroceras, while occasionally, besides finer
striae, there are deep rectilinear grooves, agreeing in direction with
the course in which the extinct glacier would have moved according to
the theory of M. Guyot, before explained.
EXTINCT GLACIERS OF THE ITALIAN SIDE OF THE ALPS.
[Illustration: Figure 43. Map Of The Moraines Of Extinct Glaciers]
(FIGURE 43. MAP OF THE MORAINES OF EXTINCT GLACIERS
EXTENDING FROM THE ALPS INTO THE PLAINS OF THE PO NEAR TURIN.
From Map of the ancient Glaciers of the Italian side of the Alps
by Signor Gabriel de Mortillet.
A. Crest or watershed of the Alps.
B. Snow-covered Alpine summits which fed the ancient glaciers.
C. Moraines of ancient or extinct glaciers.)
To select another example from the opposite or southern side of the
Alps. It will be seen in the elaborate map recently executed by Signor
Gabriel de Mortillet of the ancient glaciers of the Italian flank of
the Alps that the old moraines descend in narrow strips from the
snow-covered ridges through the principal valleys to the great basin of
the Po, on reaching which they expand and cover large circular or oval
areas. Each of these groups of detritus is observed (see map, Figure 43)
to contain exclusively the wreck of such rocks as occur in situ on
the Alpine heights of the hydrographical basins to which the moraines
respectively belong.
I had an opportunity of verifying this fact, in company with Signor
Gastaldi as my guide, by examining the erratics and boulder formation
between Susa and Turin, on the banks of the Dora Riparia, which brings
down the waters from Mont Cenis and from the Alps south-west of it. I
there observed striated fragments of dolomite and gypsum, which had come
down from Mont Cenis and had travelled as far as Avigliana; also masses
of serpentine brought from less remote points, some of them apparently
exceeding in dimensions the largest erratics of Switzerland. I
afterwards visited, in company with Signori Gastaldi and Michelotti,
a still grander display of the work of a colossal glacier of the olden
time, 20 miles north-east of Turin, the moraine of which descended
from the two highest of the Alps, Mont Blanc and Monte Rosa, and after
passing through the valley of Aosta, issued from a narrow defile above
Ivrea (see map, Figure 43). From this vomitory the old glacier poured
into the plains of the Po that wonderful accumulation of mud, gravel,
boulders, and large erratics, which extend for 15 miles from above
Ivrea to below Caluso and which when seen in profile from Turin have the
aspect of a chain of hills. In many countries, indeed, they might rank
as an important range of hills, for where they join the mountains they
are more than 1500 feet high, and retain more than half that height for
a great part of their course, rising very abruptly from the plain, often
with a slope of from 20 to 30 degrees. This glacial drift reposes near
the mountains on ancient metamorphic rocks and farther from them on
marine Pliocene strata. Portions of the ridges of till and stratified
matter have been cut up into mounds and hillocks by the action of the
river, the Dora Baltea, and there are numerous lakes, so that the entire
moraine much resembles, except in its greater height and width, the line
of glacial drift of Perthshire and Forfarshire before described. Its
complicated structure can only be explained by supposing that the
ancient glacier advanced and retreated several times and left large
lateral moraines, the more modern mounds within the limits of the older
ones, and masses of till thrown down upon the rearranged and stratified
materials of the first set of moraines. Such appearances accord well
with the hypothesis of the successive phases of glacial action in
Switzerland, to which I shall presently advert.
CONTORTED STRATA OF GLACIAL DRIFT SOUTH OF IVREA.
At Mazze near Caluso (see Figure 43), the southern extremity of this
great moraine has recently been cut through in making a tunnel for the
railway which runs from Turin to Ivrea. In the fine section thus exposed
Signor Gastaldi and I had an opportunity of observing the internal
structure of the glacial formation. In close juxtaposition to a
great mass of till with striated boulders, we saw stratified beds of
alternating gravel, sand, and loam, which were so sharply bent that many
of them had been twice pierced through in the same vertical cutting.
Whether they had been thus folded by the mechanical power of an
advancing glacier, which had pushed before it a heap of stratified
matter, as the glacier of Zermatt has been sometimes known to shove
forward blocks of stone through the walls of houses, or whether the
melting of masses of ice, once interstratified with sand and gravel, had
given rise to flexures in the manner before suggested; it is at least
satisfactory to have detected this new proof of a close connection
between ice-action and contorted stratification, such as has been
described as so common in the Norfolk cliffs and which is also very
often seen in Scotland and North America, where stratified gravel
overlies till. I have little doubt that if the marine Pliocene strata
which underlie a great part of the moraine below Ivrea were exposed to
view in a vertical section, those fundamental strata would be found not
to participate in the least degree in the plications of the sands and
gravels of the overlying glacial drift.
To return to the marks of glaciation: in the moraine at Mazze there are
many large blocks of protogine and large and small ones of limestone
and serpentine which have been brought down from Monte Rosa, through
the gorge of Ivrea, after having travelled for a distance of 50
miles. Confining my attention to a part of the moraine where pieces of
limestone and serpentine were very numerous, I found that no less than
one-third of the whole number bore unequivocal signs of glacial action;
a state of things which seems to bear some relation to the vast volume
and pressure of the ice which once constituted the extinct glacier and
to the distance which the stones had travelled. When I separated the
pebbles of quartz, which were never striated, and those of granite,
mica-schist, and diorite, which do not often exhibit glacial markings,
and confined my attention to the serpentine alone I found no less than
nineteen in twenty of the whole number polished and scratched; whereas
in the terminal moraines of some modern glaciers, where the materials
have travelled not more than 10 or 15, instead of 100 miles, scarce
one in twenty even of the serpentine pebbles exhibit glacial polish and
striation.
THEORY OF THE ORIGIN OF LAKE-BASINS BY THE EROSIVE ACTION OF GLACIERS,
CONSIDERED.
Geologists are all agreed that the last series of movements to which the
Alps owe their present form and internal structure occurred after the
deposition of the Miocene strata; and it has been usual to refer the
origin of the numerous lake-basins of Alpine and sub-Alpine regions both
in Switzerland and Northern Italy to the same movements; for it
seemed not unnatural to suppose, that forces capable of modifying the
configuration of the greatest European chain, by uplifting some of its
component Tertiary strata (those of marine origin of the Miocene period)
several thousand feet above their former level, after throwing them
into vertical and contorted positions, must also have given rise to many
superficial inequalities, in some of which large bodies of water would
collect. M. Desor, in a memoir on the Swiss and Italian lakes, suggested
that they may have escaped being obliterated by sedimentary deposition
by having been filled with ice during the whole of the glacial period.
Subsequently to the retreat of the great glaciers we know that the
lake-basins have been to a certain extent encroached upon and turned
into land by river deltas; one of which, that of the Rhone at the head
of the Lake of Geneva, is no less than 12 miles long and several miles
broad, besides which there are many torrents on the borders of the same
lake, forming smaller deltas.
M. Gabriel de Mortillet after a careful study of the glacial formations
of the Alps agreed with his predecessors that the great lakes had
existed before the glacial period, but came to the opinion in 1859
that they had all been first filled up with alluvial matter and then
re-excavated by the action of ice, which during the epoch of intense
cold had by its weight and force of propulsion scooped out the loose
and incoherent alluvial strata, even where they had accumulated to a
thickness of 2000 feet. Besides this erosion, the ice had carried the
whole mass of mud and stones up the inclined planes, from the central
depths to the lower outlets of the lakes and sometimes far beyond them.
As some of these rock-basins are 500, others more than 2000 feet deep,
having their bottoms in some cases 500, in others 1000 feet below the
level of the sea, and having areas from 20 to 50 miles in length and
from 4 to 12 in breadth, we may well be startled at the boldness of this
hypothesis.
The following are the facts and train of reasoning which induced M. de
Mortillet to embrace these views. At the lower ends of the great
Italian lakes, such as Maggiore, Como, Garda, and others, there are vast
moraines which are proved by their contents to have come from the upper
Alpine valleys above the lakes. Such moraines often repose on an older
stratified alluvium, made up of rounded and worn pebbles of precisely
the same rocks as those forming the moraines, but not derived from them,
being small in size, never angular, polished, or striated, and the whole
having evidently come from a great distance. These older alluvial strata
must, according to M. de Mortillet, be of pre-glacial date and could
not have been carried past the sites of the lakes, unless each basin had
previously been filled and levelled up with mud, sand, and gravel,
so that the river channel was continuous from the upper to the lower
extremity of each basin.
Professor Ramsay, after acquiring an intimate knowledge of the glacial
phenomena of the British Isles, had taught many years before that small
tarns and shallow rock-basins such as we see in many mountain regions
owe their origin to glaciers which erode the softer rocks, leaving
the harder ones standing out in relief and comparatively unabraded.
Following up this idea after he had visited Switzerland and without
any communication with M. de Mortillet or cognisance of his views, he
suggested in 1859 that the lake-basins were not of pre-glacial date, but
had been scooped out by ice during the glacial period, the excavation
having for the most part been effected in Miocene sandstone,
provincially called, on account of its softness, "molasse." By this
theory he dispensed with the necessity of filling up pre-existing
cavities with stratified alluvium, in the manner proposed by M. de
Mortillet.
I will now explain to what extent I agree with, and on what points I
feel compelled to differ from the two distinguished geologists above
cited. First. It is no doubt true, as Professor Ramsay remarks, that
heavy masses of ice, creeping for ages over a surface of dry land
(whether this comprise hills, plateaus, and valleys, as in the case
of Greenland, before described, or be confined to the bottoms of great
valleys, as now in the higher Alps), must often by their grinding
action produce depressions, in consequence of the different degrees
of resistance offered by rocks of unequal hardness. Thus, for example,
where quartzose beds of mica-schist alternate with clay-slate, or where
trap-dykes, often causing waterfalls in the courses of torrents,
cut through sandstone or slate--these and innumerable other common
associations of dissimilar stony compounds must give rise to a very
unequal amount of erosion and consequently to lake-basins on a small
scale. But the larger the size of any lake, the more certain it will be
to contain within it rocks of every degree of hardness, toughness, and
softness; and if we find a gradual deepening from the head towards the
central parts and a shallowing again from the middle to the lower end,
as in several of the great Swiss and Italian lakes, which are 30 or
40 miles in length, we require a power capable of acting with a
considerable degree of uniformity on these masses of varying powers of
resistance.
Secondly. Several of the great lakes are by no means in the line of
direction which they ought to have taken had they been scooped out by
the pressure and onward movement of the extinct glaciers. The Lake
of Geneva, for instance, had it been the work of ice, would have been
prolonged from the termination of the upper valley of the Rhone towards
the Jura, in the direction from F to G of the map, Figure 42, instead of
running from F to I.
Thirdly. It has been ascertained experimentally, that in a glacier, as
in a river, the rate of motion is accelerated or lessened, according to
the greater or less slope of the ground; also, that the lower strata of
ice, like those of water, move more slowly than those above them. In the
Lago Maggiore, which is more than 2600 feet deep (797 metres), the ice,
says Professor Ramsay, had to descend a slope of about 3 degrees for
the first 25 miles, and then to ASCEND for the last 12 miles (from the
deepest part towards the outlet) at an angle of 5 degrees. It is for
those who are conversant with the dynamics of glacier motion to divine
whether in such a case the discharge of ice would not be entirely
effected by the superior and faster moving strata, and whether the
lowest would not be motionless or nearly so, and would therefore exert
very little, if any, friction on the bottom.
Fourthly. But the gravest objection to the hypothesis of glacial erosion
on so stupendous a scale is afforded by the entire absence of lakes of
the first magnitude in several areas where they ought to exist if the
enormous glaciers which once occupied those spaces had possessed the
deep excavating power ascribed to them. Thus in the area laid down on
the map, Figure 43, or that covered by the ancient moraine of the Dora
Baltea, we see the monuments of a colossal glacier derived from Mont
Blanc and Monte Rosa, which descended from points nearly 100 miles
distant, and then emerging from the narrow gorge above Ivrea deployed
upon the plains of the Po, advancing over a floor of marine Pliocene
strata of no greater solidity than the Miocene sandstone and
conglomerate in which the lake-basins of Geneva, Zurich, and some others
are situated. Why did this glacier fail to scoop out a deep and wide
basin rivalling in size the lakes of Maggiore or Como, instead of merely
giving rise to a few ponds above Ivrea, which may have been due to ice
action? There is one lake, it is true--that of Candia, near the southern
extremity of the moraine--which is larger; but even this, as will be
seen by the map, is quite of subordinate importance, and whether it is
situated in a rock basin or is simply caused by a dam of moraine matter
has not yet been fully made out.
There ought also to have been another great lake, according to the
theory under consideration, in the space now occupied by the moraine of
the Dora Riparia, between Susa and Turin (see map, Figure 43). Signor
Gastaldi has shown that all the ponds in that area consist exclusively
of what M. de Mortillet has denominated morainic lakes, i.e. caused by
barriers of glacier-mud and stones.
Fifthly. In proof of the great lakes having had no existence before the
glacial period, Professor Ramsay observes that we do not find in the
Alps any freshwater strata of an age intermediate between "the close of
the Miocenic and the commencement of the glacial epoch."*
(* "Quarterly Journal of the Geological Society" volume 18
1862.)
But although such formations are scarce, they are by no means wholly
wanting; and if it can be shown that any one of the principal lakes,
that of Zurich for example, existed prior to the glacial era it will
follow that in the Alps the erosive power of ice was not required to
produce lake-basins on a large scale. The deposits alluded to on the
borders of the Lake of Zurich are those of Utznach and Durnten, situated
each about 350 feet above the present level of the lake and containing
valuable beds of lignite.
The first of them, that of Utznach, is a delta formed at the head of
the ancient and once more extensive lake. The argillaceous and
lignite-bearing strata, more than 100 feet in thickness, rest
unconformably on highly inclined and sometimes vertical Miocene molasse.
These clays are covered conformably by stratified sand and gravel 60
feet thick, partly consolidated, in which the pebbles are of rocks
belonging to the upper valleys of the Limmat and its tributaries, all
of them small and not glacially striated and wholly without admixture
of large angular stones. On the top of all repose very large erratic
blocks, affording clear evidence that the colossal glacier which once
filled the valley of the Limmat covered the old littoral deposit. The
great age of the lignite is partly indicated by the bones of Elephas
antiquus found in it.
I visited Utznach in company with M. Escher von der Linth in 1857, and
during the same year examined the lignite of Durnten, many miles farther
down on the right bank of the lake, in company with Professor Heer and
M. Marcou. The beds there are of the same age and within a few feet of
the same height above the level of the lake. They might easily have
been overlooked or confounded with the general glacial drift of the
neighbourhood, had not the bed of lignite, which is from 5 to 12 feet
thick, been worked for fuel, during which operation many organic remains
came to light. Among these are the teeth of Elephas antiquus, determined
by Dr. Falconer, and Rhinoceros leptorhinus? (R. megarhinus, Christol),
the wild bull and red deer (Bos primigenius, Boj., and Cervus elaphus,
L.), the last two determined by Professor Rutimeyer. In the same beds I
found many freshwater shells of the genera Paludina, Limnaea, etc., all
of living species. The plants named by Professor Heer are also Recent
and agree singularly with those of the Cromer buried forest, before
described.
Among them are the Scotch and spruce firs, Pinus sylvestris and Pinus
abies, and the buckbean, or Menyanthes trifoliata, etc., besides the
common birch and other European plants.
Overlying this lignite are first, as at Utznach, stratified gravel not
of glacial origin, about 30 feet thick; and secondly, highest of all,
huge angular erratic blocks clearly indicating the presence of a great
glacier posterior in date to all the organic remains above enumerated.
If any one of the existing Swiss lakes were now lowered by deepening its
outlet, or by raising the higher portion of it relatively to the lower,
we should see similar deltas of comparatively modern date exposed to
view, some of them with embedded trunks of pines of the same species
drifted down during freshets. Such deposits would be most frequent at
the upper ends of the lakes, but a few would occur on either bank not
far from the shore where torrents once entered, agreeing in geographical
position with the lignite formations of Utznach and Durnten.
There are other freshwater formations with lignite, besides those on
the Lake of Zurich, as those of Wetzikon near the Pfaffikon Lake, of
Kaltbrunnen, of Buchberg, and that of Morschweil between St. Gall and
Rorschach, but none probably older than the Durnten beds. Like the
buried forest of Cromer they are all pre-glacial, yet they by no means
represent the older nor even the newer Pliocene period, but rather the
beginning of the Pleistocene. It is therefore true, as Professor Ramsay
remarks, that, as yet, no strata "of the age of the English Crag"
have been detected in any Alpine valley. In other words, there are no
freshwater formations yet known corresponding in date to the Pliocene
beds of the upper Val d'Arno, above Florence--a fact from which we may
infer (though with diffidence, as the inference is based on negative
evidence), that, although the great Alpine valleys were eroded in
Pliocene times, the lake-basins were, nevertheless, of Pleistocene
date--some of them formed before, others during, the glacial epoch.
Sixthly. In what manner then did the great lake-basins originate if they
were not hollowed out by ice? My answer is, they are all due to unequal
movements of upheaval and subsidence. We have already seen that the
buried forest of Cromer, which by its organic contents seems clearly to
be of the same age as the lignite of Durnten, was pre-glacial and that
it has undergone a great oscillation of level (about 500 feet in both
directions) since its origin, having first sunk to that extent below
the sea and then been raised up again to the sea-level. In the countless
Post-Miocene ages which preceded the glacial period there was ample time
for the slow erosion by water of all the principal hydrographical basins
of the Alps, and the sites of all the great lakes coincide, as Professor
Ramsay truly says, with these great lines of drainage. The lake-cavities
do not lie in synclinal troughs, following the strike and foldings of
the strata, but often, as the same geologist remarks, cross them at high
angles; nor are they due to rents or gaping fissures, although these,
with other accidents connected with the disturbing movements of the
Alps, may sometimes have determined originally the direction of the
valleys. The conformity of the lake-basins to the principal watercourses
is explicable if we assume them to have resulted from inequalities in
the upward and downward movements of the whole country in Pleistocene
times, after the valleys were eroded.
We know that in Sweden the rate of the rise of the land is far from
uniform, being only a few inches in a century near Stockholm, while
north of it and beyond Gefle it amounts to as many feet in the same
number of years. Let us suppose with Charpentier that the Alps gained
in height several thousand feet at the time when the intense cold of
the glacial period was coming on. This gradual rise would be an era of
aqueous erosion and of the deepening, widening, and lengthening of the
valleys. It is very improbable that the elevation would be everywhere
identical in quantity, but if it was never in excess in the outskirts as
compared to the central region or crest of the chain, it would not give
rise to lakes. When, however, the period of upheaval was followed by
one of gradual subsidence, the movement not being everywhere strictly
uniform, lake-basins would be formed wherever the rate of depression was
in excess in the upper country. Let the region, for example, near the
head waters of the great rivers sink at the rate of from 4 to 6 feet
per century, while only half as much subsidence occurs towards the
circumference of the mountains--the rate diminishing about an inch per
mile in a distance, say of 40 miles--this might convert many of the
largest and deepest valleys at their lower ends into lakes.
We have no certainty that such movements may not now be in progress in
the Alps; for if they are as slow as we have assumed, they would be as
insensible to the inhabitants as is the upheaval of Scandinavia or the
subsidence of Greenland to the Swedes and Danes who dwell there. They
only know of the progress of such geographical revolutions because a
slight change of level becomes manifest on the margin of the sea. The
lines of elevation or depression above supposed might leave no clear
geological traces of their action on the high ridges and table-lands
separating the valleys of the principal rivers; it is only when
they cross such valleys that the disturbance caused in the course of
thousands of years in the drainage becomes apparent. If there were no
ice, the sinking of the land might not give rise to lakes. To accomplish
this in the absence of ice, it is necessary that the rate of depression
should be sufficiently fast to make it impossible for the depositing
power of the river to keep pace with it, or in other words to fill
up the incipient cavity as fast as it begins to form. Such levelling
operations once complete, the running water, aided by sand and pebbles,
will gradually cut a gorge through the newly raised rock so as to
prevent it from forming a barrier. But if a great glacier fill the
lower part of the valley all the conditions of the problem are altered.
Instead of the mud, sand, and stones drifted down from the higher
regions being left behind in the incipient basin, they all travel
onwards in the shape of moraines on the top of the ice, passing over
and beyond the new depression, so that when at the end of fifty or
a thousand centuries the glacier melts, a large and deep basin
representing the difference in the movement of two adjoining mountain
areas--namely, the central and the circumferential--is for the first
time rendered visible.
By adopting this hypothesis, we concede that there is an intimate
connection between the glacial period and a predominance of lakes, in
producing which the action of ice is threefold; first, by its direct
power in scooping out shallow basins where the rocks are of unequal
hardness; an operation which can by no means be confined to the land,
for it must extend to below the level of high water a thousand feet
and more in such fjords as have been described as filled with ice in
Greenland.
Secondly. The ice will act indirectly by preventing cavities caused by
inequalities of subsidence or elevation from becoming the receptacles
first of water and then of sediment, by which the cavities would be
levelled up and the lakes obliterated.
Thirdly. The ice is also an indirect cause of lakes, by heaping up
mounds of moraine matter and thus giving rise to ponds and even to
sheets of water several miles in diameter.
The comparative scarcity, therefore, of lakes of Pleistocene date
in tropical countries, and very generally south of the fortieth and
fiftieth parallels of latitude, may be accounted for by the absence of
glacial action in such regions.
POST-GLACIAL LAKE-DWELLING IN THE NORTH OF ITALY.
We learn from M. de Mortillet that in the peat which has filled up one
of the "morainic lakes" formed by the ancient glacier of the Ticino, M.
Moro has discovered at Mercurago the piles of a lake-dwelling like those
of Switzerland, together with various utensils and a canoe hollowed out
of the trunk of a tree. From this fact we learn that south of the
Alps as well as north of them a primitive people having similar habits
flourished after the retreat of the great glaciers.
SUCCESSIVE PHASES OF GLACIAL ACTION IN THE ALPS, AND THEIR RELATION TO
THE HUMAN PERIOD [34].
According to the geological observations of M. Morlot, the following
successive phases in the development of ice-action in the Alps are
plainly recognisable:--
First. There was a period when the ice was in its greatest excess, when
the glacier of the Rhone not only reached the Jura, but climbed to the
height of 2015 feet above the Lake of Neufchatel, and 3450 feet above
the sea, at which time the Alpine ice actually entered the French
territory at some points, penetrating by certain gorges, as through the
defile of the Fort de l'Ecluse, among others.
Second. To this succeeded a prolonged retreat of the great glaciers,
when they evacuated not only the Jura and the low country between that
chain and the Alps, but retired some way back into the Alpine valleys.
M. Morlot supposes their diminution in volume to have accompanied a
general subsidence of the country to the extent of at least 1000 feet.
The geological formations of the second period consist of stratified
masses of sand and gravel, called the "ancient alluvium" by MM. Necker
and Favre, corresponding to the "older or lower diluvium" of some
writers. Their origin is evidently due to the action of rivers, swollen
by the melting of ice, by which the materials of parts of the old
moraines were rearranged and stratified and left usually at considerable
heights above the level of the present valley plains.
Third. The glaciers again advanced and became of gigantic dimensions,
though they fell far short of those of the first period. That of the
Rhone, for example, did not again reach the Jura, though it filled the
Lake of Geneva and formed enormous moraines on its borders and in many
parts of the valley between the Alps and Jura.
Fourth. A second retreat of the glaciers took place when they gradually
shrank nearly into their present limits, accompanied by another
accumulation of stratified gravels which form in many places a series of
terraces above the level of the alluvial plains of the existing rivers.
In the gorge of the Dranse, near Thonon, M. Morlot discovered no less
than three of these glacial formations in direct superposition, namely,
at the bottom of the section, a mass of compact till or boulder-clay
(Number 1) 12 feet thick, including striated boulders of Alpine
limestone, and covered by regularly stratified ancient alluvium (Number
2) 150 feet thick, made up of rounded pebbles in horizontal beds.
This mass is in its turn overlaid by a second formation (Number 3) of
unstratified boulder clay, with erratic blocks and striated pebbles,
which constituted the left lateral moraine of the great glacier of the
Rhone when it advanced for the second time to the Lake of Geneva. At a
short distance from the above section terraces (Number 4) composed of
stratified alluvium are seen at the heights of 20, 50, 100, and 150 feet
above the Lake of Geneva, which by their position can be shown to be
posterior in date to the upper boulder-clay and therefore belong to the
fourth period, or that of the last retreat of the great glaciers. In
the deposits of this fourth period the remains of the mammoth have
been discovered, as at Morges, for example, on the Lake of Geneva. The
conical delta of the Tiniere, mentioned in Chapter 2 as containing at
different depths monuments of the Roman as well as of the antecedent
bronze and stone ages, is the work of alluvial deposition going on when
the terrace of 50 feet was in progress. This modern delta is supposed
by M. Morlot to have required 10,000 years for its accumulation. At the
height of 150 feet above the lake, following up the course of the same
torrent, we come to a more ancient delta, about ten times as large,
which is therefore supposed to be the monument of about ten times as
many centuries, or 100,000 years, all referable to the fourth period
mentioned in the preceding page, or that which followed the last retreat
of the great glaciers.*
(* Morlot, Terrain quaternaire du Bassin de Leman "Bulletin
de la Societe Vaudoise des Sciences Naturelles" Number 44.)
If the lower flattened cone of Tiniere be referred in great part to
the age of the oldest lake-dwellings, the higher one might perhaps
correspond with the Pleistocene period of St. Acheul, or the era when
Man and the Elephas primigenius flourished together; but no human
remains or works of art have as yet been found in deposits of this
age or in any alluvium containing the bones of extinct mammalia in
Switzerland.
Upon the whole, it is impossible not to be struck with an apparent
correspondence in the succession of events of the glacial period of
Switzerland and that of the British Isles before described. The time
of the first Alpine glaciers of colossal dimensions, when that chain
perhaps was several thousand feet higher than now, may have agreed with
the first continental period when Scotland was invested with a universal
crust of ice. The retreat of the first Alpine glaciers, caused partly by
a lowering of that chain, may have been synchronous with the period of
great submergence and floating ice in England. The second advance of the
glaciers may have coincided in date with the re-elevation of the Alps,
as well as of the Scotch and Welsh mountains; and lastly, the final
retreat of the Swiss and Italian glaciers may have taken place when Man
and the extinct mammalia were colonising the north-west of Europe and
beginning to inhabit areas which had formed the bed of the glacial sea
during the era of chief submergence.
But it must be confessed that in the present state of our knowledge
these attempts to compare the chronological relations of the periods
of upheaval and subsidence of areas so widely separated as are the
mountains of Scandinavia, the British Isles, and the Alps, or the times
of the advance and retreat of glaciers in those several regions and
the greater or less intensity of cold, must be looked upon as very
conjectural.
We may presume with more confidence that when the Alps were highest
and the Alpine glaciers most developed, filling all the great lakes of
northern Italy and loading the plains of Piedmont and Lombardy with
ice, the waters of the Mediterranean were chilled and of a lower average
temperature than now. Such a period of refrigeration is required by the
conchologist to account for the prevalence of northern shells in the
Sicilian seas about the close of the Pliocene or commencement of the
Pleistocene period. For such shells as Cyprina islandica, Panopoea
norvegica (= P. bivonae, Philippi), Leda pygmaea, Munst, and some
others, enumerated among the fossils of the latest Tertiary formations
of Sicily by Philippi and Edward Forbes, point unequivocally to a former
more severe climate. Dr. Hooker also in his late journey to Syria (in
the autumn of 1860) found the moraines of extinct glaciers, on which the
whole of the ancient cedars of Lebanon grow, to descend 4000 feet below
the summit of that chain. The temperature of Syria is now so much milder
that there is no longer perpetual snow even on the summit of Lebanon,
the height of which was ascertained to be 10,200 feet above the
Mediterranean.*
(* Hooker, "Natural History Review" Number 5 January 1862
page 11.)
Such monuments of a cold climate in latitudes so far south as Syria and
the north of Sicily, between 33 and 38 degrees north, may be confidently
referred to an early part of the glacial period, or to times long
anterior to those of Man and the extinct mammalia of Abbeville and
Amiens.
CHAPTER 16. -- HUMAN REMAINS IN THE LOESS, AND THEIR PROBABLE AGE.
Nature, Origin, and Age of the Loess of the Rhine and Danube.
Impalpable Mud produced by the Grinding Action of Glaciers.
Dispersion of this Mud at the Period of the Retreat of the
great Alpine Glaciers.
Continuity of the Loess from Switzerland to the Low Countries.
Characteristic Organic Remains not Lacustrine.
Alpine Gravel in the Valley of the Rhine covered by Loess.
Geographical Distribution of the Loess and its Height above the Sea.
Fossil Mammalia.
Loess of the Danube.
Oscillations in the Level of the Alps and lower Country required to
explain the Formation and Denudation of the Loess.
More rapid Movement of the Inland Country.
The same Depression and Upheaval might account for the Advance
and Retreat of the Alpine Glaciers.
Himalayan Mud of the Plains of the Ganges compared to
European Loess.
Human Remains in Loess near Maestricht, and their probable
Antiquity.
NATURE AND ORIGIN OF THE LOESS.
Intimately connected with the subjects treated of in the last chapter,
is the nature, origin, and age of certain loamy deposits, commonly
called loess, which form a marked feature in the superficial deposits
of the basins of the Rhine, Danube, and some other large rivers draining
the Alps, and which extend down the Rhine into the Low Countries, and
were once perhaps continuous with others of like composition in the
north of France. [35]
It has been reported of late years that human remains have been detected
at several points in the loess of the Meuse around and below Maestricht.
I have visited the localities referred to; but, before giving an account
of them, it will be desirable to explain what is meant by the loess, a
step the more necessary as a French geologist for whose knowledge and
judgment I have great respect, tells me he has come to the conclusion
that "the loess" is "a myth," having no real existence in a geological
sense or as holding a definite place in the chronological series.
No doubt it is true that in every country, and at all geological
periods, rivers have been depositing fine loam on their inundated plains
in the manner explained above in Chapter 3, where the Nile mud was
spoken of. This mud of the plains of Egypt, according to Professor
Bischoff's chemical analysis agrees closely in composition with the
loess of the Rhine.*
(* "Chemical and Physical Geology" volume 1 page 132.)
I have also shown when speaking of the fossil man of Natchez, how
identical in mineral character and in the genera of its terrestrial and
amphibious shells is the ancient fluviatile loam of the Mississippi
with the loess of the Rhine. But granting that loam presenting the same
aspect has originated at different times and in distinct hydrographical
basins, it is nevertheless true that during the glacial period the Alps
were a great centre of dispersion, not only of erratics, as we have seen
in the last chapter, and of gravel which was carried farther than the
erratics, but also of very fine mud which was transported to still
greater distances and in greater volume down the principal river-courses
between the mountains and the sea.
MUD PRODUCED BY GLACIERS.
They who have visited Switzerland are aware that every torrent which
issues from an icy cavern at the extremity of a glacier is densely
charged with an impalpable powder, produced by the grinding action to
which the subjacent floor of rock and the stones and sand frozen into
the ice are exposed in the manner before described. We may therefore
readily conceive that a much greater volume of fine sediment was swept
along by rivers swollen by melting ice at the time of the retreat of the
gigantic glaciers of the olden time. The fact that a large proportion
of this mud, instead of being carried to the ocean where it might have
formed a delta on the coast or have been dispersed far and wide by the
tides and currents, has accumulated in inland valleys, will be found
to be an additional proof of the former occurrence of those grand
oscillations in the level of the Alps and parts of the adjoining
continent which were required to explain the alternate advance and
retreat of the glaciers, and the superposition of more than one boulder
clay and stratified alluvium.
The position of the loess between Basle and Bonn is such as to imply
that the great valley of the Rhine had already acquired its present
shape, and in some places, perhaps more than its actual depth and width,
previously to the time when it was gradually filled up to a great extent
with fine loam. The greater part of this loam has been since removed,
so that a fringe only of the deposit is now left on the flanks of the
boundary hills, or occasionally some outliers in the middle of the great
plain of the Rhine where it expands in width.
These outliers are sometimes on such a scale as to admit of minor hills
and valleys, having been shaped out of them by the action of rain and
small streamlets, as near Freiburg in the Breisgau and other districts.
FOSSIL SHELLS OF THE LOESS.
[Illustration: Figures 44, 45, and 46]
(FIGURE 44. Succinea oblonga.)
(FIGURE 45. Pupa muscorum.)
(FIGURE 46. Helix hispida, Lin.; H. plebeia, Drap.)
The loess is generally devoid of fossils, although in many places they
are abundant, consisting of land-shells, all of living species, and
comprising no small part of the entire molluscous fauna now inhabiting
the same region. The three shells most frequently met with are those
represented in the annexed figures (44, 45 and 46). The slug, called
Succinea, is not strictly aquatic, but lives in damp places, and may be
seen in full activity far from rivers, in meadows where the grass is wet
with rain or dew; but shells of the genera Limnaea, Planorbis, Paludina,
Cyclas, and others, requiring to be constantly in the water, are
extremely exceptional in the loess, occurring only at the bottom of the
deposit where it begins to alternate with ancient river-gravel on which
it usually reposes.
This underlying gravel consists in the valley of the Rhine for the most
part of pebbles and boulders of Alpine origin, showing that there was a
time when the rivers had power to convey coarse materials for hundreds
of miles northwards from Switzerland towards the sea; whereas at a later
period an entire change was brought about in the physical geography of
the same district, so that the same river deposited nothing but fine
mud, which accumulated to a thickness of 800 feet or more above the
original alluvial plain.
But although most of the fundamental gravel was derived from the Alps,
there has been observed in the neighbourhood of the principal mountain
chains bordering the great valley, such as the Black Forest, Vosges,
and Odenwald, an admixture of detritus characteristic of those several
chains. We cannot doubt therefore that as some of these mountains,
especially the Vosges, had during the glacial period their own glaciers,
a part of the fine mud of their moraines must have been mingled with
loess of Alpine origin; although the principal mass of the latter must
have come from Switzerland, and can in fact be traced continuously from
Basle to Belgium.
GEOGRAPHICAL DISTRIBUTION OF THE LOESS.
It was stated in the last chapter that at the time of the greatest
extension of the Swiss glaciers the Lake of Constance and all the other
great lakes were filled with ice, so that gravel and mud could pass
freely from the upper Alpine valley of the Rhine to the lower region
between Basle and the sea, the great lake intercepting no part of the
moraines whether fine or coarse. On the other hand the Aar with its
great tributaries the Limmat and the Reuss does not join the Rhine till
after it issues from the Lake of Constance; and by their channels a
large part of the Alpine gravel and mud could always have passed without
obstruction into the lower country, even after the ice of the great lake
had melted.
It will give the reader some idea of the manner in which the Rhenish
loess occurs, if he is told that some of the earlier scientific
observers imagined it to have been formed in a vast lake which occupied
the valley of the Rhine from Basle to Mayence, sending up arms or
branches into what are now the valleys of the Main, Neckar, and other
large rivers. They placed the barrier of this imaginary lake in the
narrow and picturesque gorge of the Rhine between Bingen and Coblenz:
and when it was objected that the lateral valley of the Lahn,
communicating with that gorge, had also been filled with loess, they
were compelled to transfer the great dam farther down and to place it
below Bonn. Strictly speaking it must be placed much farther north, or
in the 51st parallel of latitude, where the limits of the loess have
been traced out by MM. Omalius D'Halloy, Dumont, and others, running
east and west by Cologne, Juliers, Louvain, Oudenarde, and Courtrai in
Belgium to Cassel, near Dunkirk in France. This boundary line may not
indicate the original seaward extent of the formation, as it may have
stretched still farther north and its present abrupt termination may
only show how far it was cut back at some former period by the denuding
action of the sea.
Even if the imbedded fossil shells of the loess had been lacustrine,
instead of being, as we have seen, terrestrial and amphibious, the vast
height and width of the required barrier would have been fatal to
the theory of a lake: for the loess is met with in great force at
an elevation of no less than 1600 feet above the sea, covering the
Kaiserstuhl, a volcanic mountain which stands in the middle of the great
valley of the Rhine, near Freiburg in Breisgau. The extent to which the
valley has there been the receptacle of fine mud afterwards removed is
most remarkable.
The loess of Belgium was called "Hesbayan mud" in the geological map of
the late M. Dumont, who, I am told, recognised it as being in great
part composed of Alpine mud. M. d'Archiac, when speaking of the loess,
observes that it envelopes Hainault, Brabant, and Limburg like a mantle
everywhere uniform and homogeneous in character, filling up the lower
depressions of the Ardennes and passing thence into the north of France,
though not crossing into England. In France, he adds, it is found on
high plateaus 600 feet above some of the rivers, such as the Marne;
but as we go southwards and eastwards of the basin of the Seine, it
diminishes in quantity, and finally thins out in those directions.*
(* D'Archiac, "Histoire des Progres" volume 2 pages 169,
170.)
It may even be a question whether the "limon des plateaux," or upland
loam of the Somme valley, before alluded to,* may not be a part of the
same formation.
(* Number 4 Figure 7.)
As to the higher and lower level gravels of that valley, which, like
that of the Seine, contain no foreign rocks, we have seen that they are
each of them covered by deposits of loess or inundation-mud belonging
respectively to the periods of the gravels, whereas the upland loam is
of much older date, more widely spread, and occupying positions often
independent of the present lines of drainage. To restore in imagination
the geographical outline of Picardy, to which rivers charged with so
much homogeneous loam and running at such heights may once have belonged
is now impossible.*
(* See above, Chapter 8. )
In the valley of the Rhine, as I before observed, the body of the loess,
instead of having been formed at successively lower and lower levels as
in the case of the basin of the Somme, was deposited in a wide and deep
pre-existing basin, or strath, bounded by lofty mountain chains such
as the Black Forest, Vosges, and Odenwald. In some places the loam
accumulated to such a depth as first to fill the valley and then to
spread over the adjoining table-lands, as in the case of the Lower
Eifel, where it encircled some of the modern volcanic cones of loose
pumice and ashes. In these instances it does not appear to me that the
volcanoes were in eruption during the time of the deposition of the
loess, as some geologists have supposed. The interstratification of loam
and volcanic ejectamenta was probably occasioned by the fluviatile mud
having gradually enveloped the cones of loose scoriae after they were
completely formed. I am the more inclined to embrace this view after
having seen the junction of granite and loess on the steep slopes of
some of the mountains bounding the great plain of the Rhine on its
right bank in the Bergstrasse. Thus between Darmstadt and Heidelberg
perpendicular sections are seen of loess 200 feet thick, at various
heights above the river, some of them at elevations of 800 feet and
upwards. In one of these may be seen, resting on the hill side of
Melibocus in the Odenwald, the usual yellow loam free from pebbles at
its contact with a steep slope of granite, but divided into horizontal
layers for a short distance from the line of junction. In these layers,
which abut against the granite, a mixture of mica and of unrounded
grains of quartz and felspar occur, evidently derived from the
disintegration of the crystalline rock, which must have decomposed in
the atmosphere before the mud had reached this height. Entire shells of
Helix, Pupa, and Succinea, of the usual living species, are embedded in
the granitic mixture. We may therefore be sure that the valley bounded
by steep hills of granite existed before the tranquil accumulation of
this vast body of loess.
During the re-excavation of the basin of the Rhine successive deposits
of loess of newer origin were formed at various heights; and it is often
difficult to distinguish their relative ages, especially as fossils are
often entirely wanting, and the mineral composition of the formation is
so uniform.
The loess in Belgium is variable in thickness, usually ranging from
10 to 30 feet. It caps some of the highest hills or table-land around
Brussels at the height of 300 feet above the sea. In such places it
usually rests on gravel and rarely contains shells, but when they
occur they are of Recent species. I found the Succinea oblonga, before
mentioned, and Helix hispida in the Belgian loess at Neerepen, between
Tongres and Hasselt, where M. Bosquet had previously obtained remains
of an elephant referred to E. primigenius. This pachyderm and Rhinoceros
tichorhinus are cited as characterising the loess in various parts of
the valley of the Rhine. Several perfect skeletons of the marmot have
been disinterred from the loess of Aix-la-Chapelle. But much remains to
be done in determining the species of mammalia of this formation and the
relative altitudes above the valley-plain at which they occur.
If we ascend the basin of the Neckar, we find that it is filled with
loess of great thickness, far above its junction with the Rhine. At
Canstadt near Stuttgart, loess resembling that of the Rhine contains
many fossil bones, especially those of Elephas primigenius, together
with some of Rhinoceros tichorhinus, the species having been lately
determined by Dr. Falconer. At this place the loess is covered by a
thick bed of travertine, used as a building stone, the product of a
mineral spring. In the travertine are many fossil plants, all Recent
except two, an oak and poplar, the leaves of which Professor Heer has
not been able to identify with any known species.
Below the loess of Canstadt, in which bones of the mammoth are so
abundant, is a bed of gravel evidently an old river channel now many
feet above the level of the Neckar, the valley having there been
excavated to some depth below its ancient channel so as to lie in the
underlying red sandstone of Keuper. Although the loess, when traced from
the valley of the Rhine into that of the Neckar, or into any other
of its tributaries, often undergoes some slight alteration in its
character, yet there is so much identity of composition as to suggest
the idea that the mud of the main river passed far up the tributary
valleys, just as that of the Mississippi during floods flows far up the
Ohio, carrying its mud with it into the basin of that river. But
the uniformity of colour and mineral composition does not extend
indefinitely into the higher parts of every basin. In that of the
Neckar, for example, near Tubingen, I found the fluviatile loam or
brick-earth, enclosing the usual Helices and Succineae, together with
the bones of the mammoth, very distinct in colour and composition from
ordinary Rhenish loess, and such as no one could confound with Alpine
mud. It is mottled with red and green, like the New Red Sandstone or
Keuper, from which it has clearly been derived.
Such examples, however, merely show that where a basin is so limited
in size that the detritus is derived chiefly or exclusively from one
formation, the prevailing rock will impart its colour and composition
in a very decided manner to the loam; whereas, in the basin of a great
river which has many tributaries, the loam will consist of a mixture
of almost every variety of rock, and will therefore exhibit an average
result nearly the same in all countries. Thus, the loam which fills to
a great depth the wide valley of the Saone, which is bounded on the west
side by an escarpment of Inferior Oolite, and by the chain of the Jura
on the east, is very like the loess found in the continuation of the
same great basin after the junction of the Rhone, by which a large
supply of Alpine mud has been added and intermixed.
In the higher parts of the basin of the Danube, loess of the same
character as that of the Rhine, and which I believe to be chiefly of
Alpine origin, attains a far greater elevation above the sea than any
deposits of Rhenish loess; but the loam which, according to M. Stur,
fills valleys on the north slope of the Carpathians almost up to the
watershed between Galicia and Hungary, may be derived from a distinct
source.
OSCILLATIONS OF LEVEL REQUIRED TO EXPLAIN THE ACCUMULATION AND
DENUDATION OF THE LOESS.
A theory, therefore, which attempts to account for the position of the
loess cannot be satisfactory unless it be equally applicable to the
basins of the Rhine and Danube. So far as relates to the source of so
much homogeneous loam, there are many large tributaries of the Danube
which, during the glacial period, may have carried an ample supply
of moraine-mud from the Alps to that river; and in regard to grand
oscillations in the level of the land, it is obvious that the same
movements both downward and upward of the great mountain-chain would
be attended with analogous effects, whether the great rivers flowed
northwards or eastwards. In each case fine loam would be accumulated
during subsidence and removed during the upheaval of the land. Changes,
therefore, of level analogous to those on which we have been led to
speculate when endeavouring to solve the various problems presented by
the glacial phenomena, are equally available to account for the nature
and geological distribution of the loess. But we must suppose that
the amount of depression and re-elevation in the central region was
considerably in excess of that experienced in the lower countries, or
those nearer the sea, and that the rate of subsidence in the latter was
never so considerable as to cause submergence, or the admission of the
sea into the interior of the continent by the valleys of the principal
rivers.
We have already assumed that the Alps were loftier than now, when they
were the source of those gigantic glaciers which reached the flanks of
the Jura. At that time gravel was borne to the greatest distances from
the central mountains through the main valleys, which had a somewhat
steeper slope than now, and the quantity of river-ice must at that time
have aided in the transportation of pebbles and boulders. To this state
of things gradually succeeded another of an opposite character, when the
fall of the rivers from the mountains to the sea became less and less,
while the Alps were slowly sinking, and the first retreat of the great
glaciers was taking place. Suppose the depression to have been at the
rate of 5 feet in a century in the mountains and only as many inches in
the same time nearer the coast, still, in such areas as the eye could
survey at once, comprising a small part only of Switzerland or of the
basin of the Rhine, the movement might appear to be uniform and the
pre-existing valleys and heights might seem to remain relatively to each
other as before.
Such inequality in the rate of rising or sinking, when we contemplate
large continental spaces, is quite consistent with what we know of
the course of nature in our own times as well as at remote geological
epochs. Thus in Sweden, as before stated, the rise of land now in
progress is nearly uniform as we proceed from north to south for
moderate distances; but it greatly diminishes southwards if we compare
areas hundreds of miles apart; so that instead of the land rising about
5 feet in a hundred years as at the North Cape, it becomes less than
the same number of inches at Stockholm, and farther south the land is
stationary, or, if not, seems rather to be descending than ascending.*
(* "Principles of Geology" chapter 30 9th edition page 519
et seq.)
To cite an example of high geological antiquity, M. Hebert has
demonstrated that, during the Oolitic and Cretaceous periods, similar
inequalities in the vertical movements of the earth's crust took place
in Switzerland and France. By his own observations and those of M. Lory
he has proved that the area of the Alps was rising and emerging from
beneath the ocean towards the close of the Oolitic epoch, and was above
water at the commencement of the Cretaceous era; while, on the other
hand, the area of the Jura, about 100 miles to the north, was slowly
sinking at the close of the Oolitic period, and had become submerged at
the commencement of the Cretaceous. Yet these oscillations of level were
accomplished without any perceptible derangement in the strata, which
remained all the while horizontal, so that the Lower Cretaceous or
Neocomian beds were deposited conformably on the Oolitic.*
(* "Bulletin de la Societe Geologique de France" 2 series
volume 16 1859 page 596.)
Taking for granted then that the depression was more rapid in the more
elevated region, the great rivers would lose century after century some
portion of their velocity or carrying power, and would leave behind them
on their alluvial plains more and more of the moraine-mud with which
they were charged, till at length, in the course of thousands or some
tens of thousands of years, a large part of the main valleys would
begin to resemble the plains of Egypt where nothing but mud is deposited
during the flood season. The thickness of loam containing shells of land
and amphibious mollusca might in this way accumulate to any extent, so
that the waters might overflow some of the heights originally bounding
the valley and deposits of "platform mud," as it has been termed in
France, might be extensively formed. At length, whenever a re-elevation
of the Alps at the time of the second extension of the glaciers took
place, there would be renewed denudation and removal of such loess; and
if, as some geologists believe, there has been more than one oscillation
of level in the Alps since the commencement of the glacial period, the
changes would be proportionally more complicated and terraces of gravel
covered with loess might be formed at different heights and at different
periods.
HIMALAYAN MUD OF THE GANGES COMPARED TO EUROPEAN LOESS.
Some of the revolutions in physical geography above suggested for the
continent of Europe during the Pleistocene epoch, may have had their
counterparts in India in the Recent Period. The vast plains of Bengal
are overspread with Himalayan mud, which as we ascend the Ganges extends
inland for 1200 miles from the sea, continuing very homogeneous on the
whole, though becoming more sandy as it nears the hills. They who sail
down the river during a season of inundation see nothing but a sheet of
water in every direction, except here and there where the tops of trees
emerge above its level. To what depth the mud extends is not known, but
it resembles the loess in being generally devoid of stratification, and
of shells, though containing occasionally land shells in abundance, as
well as calcareous concretions, called kunkur, which may be compared to
the nodules of carbonate of lime sometimes observed to form layers in
the Rhenish loess. I am told by Colonel Strachey and Dr. Hooker that
above Calcutta, in the Hooghly, when the flood subsides, the Gangetic
mud may be seen in river cliffs 80 feet high, in which they were unable
to detect organic remains, a remark which I found to hold equally in
regard to the Recent mud of the Mississippi.
Dr. Wallich, while confirming these observations, informs me that at
certain points in Bengal, farther inland, he met with land-shells in the
banks of the great river. Borings have been made at Calcutta, beginning
not many feet above the sea-level, to the depth of 300 and 400 feet; and
wherever organic remains were found in the strata pierced through they
were of a fluviatile or terrestrial character, implying that during a
long and gradual subsidence of the country the sediment thrown down
by the Ganges and Brahmaputra had accumulated at a sufficient rate to
prevent the sea from invading that region.
At the bottom of the borings, after passing through much fine loam, beds
of pebbles, sand, and boulders were reached, such as might belong to an
ancient river channel; and the bones of a crocodile and the shell of
a freshwater tortoise were met with at the depth of 400 feet from the
surface. No pebbles are now brought down within a great distance of
this point, so that the country must once have had a totally different
character and may have had its valleys, hills, and rivers, before all
was reduced to one common level by the accumulation upon it of fine
Himalayan mud. If the latter were removed during a gradual re-elevation
of the country, many old hydrographical basins might reappear, and
portions of the loam might alone remain in terraces on the flanks of
hills, or on platforms, attesting the vast extent in ancient times
of the muddy envelope. A similar succession of events has, in all
likelihood, occurred in Europe during the deposition and denudation of
the loess of the Pleistocene period, which, as we have seen in a former
chapter, was long enough to allow of the gradual development of almost
any amount of such physical changes.
HUMAN REMAINS IN THE LOESS NEAR STRASBURG.
M. Ami Boue, well known by his numerous works on geology and a
well-practised observer in every branch of the science, disinterred in
the year 1823 with his own hands many bones of a human skeleton from
ancient undisturbed loess at Lahr, nearly opposite Strasburg, on the
right side of the great valley of the Rhine. No skull was detected, but
the tibia, fibula, and several other bones were obtained in a good state
of preservation and shown at the time to Cuvier, who pronounced them to
be human.
HUMAN REMAINS IN LOESS NEAR MAESTRICHT.
The banks of the Meuse at Maestricht, like those of the Rhine at Bonn
and Cologne, are slightly elevated above the level of the alluvial
plain. On the right bank of the Meuse, opposite Maestricht, the
difference of level is so marked that a bridge with many arches has been
constructed to keep up, during the flood season, a communication between
the higher parts of the alluvial plain and the hills or bluffs which
bound it. This plain is composed of modern loess, undistinguishable in
mineral character from that of higher antiquity, before alluded to,
and entirely without signs of successive deposition and devoid
of terrestrial or fluviatile shells. It is extensively worked for
brick-earth to the depth of about 8 feet. The bluffs before alluded to
often consist of a terrace of gravel, from 30 to 40 feet in thickness,
covered by an older loess, which is continuous as we ascend the valley
to Liege. In the suburbs of that city patches of loess are seen at the
height of 200 feet above the level of the Meuse. The table-land in that
region, composed of Carboniferous and Devonian rocks, is about 450 feet
high, and is not overspread with loess.
A terrace of gravel covered with loess has been mentioned as existing
on the right bank of the Meuse at Maestricht. Answering to it another
is also seen on the left bank below that city, and a promontory of
it projecting into the alluvial plain of the Meuse and approaching
to within a hundred yards of the river, was cut through during the
excavation of a canal running from Maestricht to Hocht, between the
years 1815 and 1823. This section occurs at the village of Smeermass,
and is about 60 feet deep, the lower 40 feet consisting of stratified
gravel and the upper of 20 feet of loess. The number of molars, tusks,
and bones (probably parts of entire skeletons) of elephants obtained
during these diggings, was extraordinary. Not a few of them are still
preserved in the museums of Maestricht and Leyden, together with some
horns of deer, bones of the ox-tribe and other mammalia, and a human
lower jaw, with teeth. According to Professor Crahay, who published an
account of it at the time, this jaw, which is now preserved at Leyden,
was found at the depth of 19 feet from the surface, where the loess
joins the underlying gravel, in a stratum of sandy loam resting on
gravel and overlaid by some pebbly and sandy beds. The stratum is said
to have been intact and undisturbed, but the human jaw was isolated,
the nearest tusk of an elephant being six yards removed from it in
horizontal distance.
Most of the other mammalian bones were found; like these human remains,
in or near the gravel, but some of the tusks and teeth of elephants were
met with much nearer the surface. I visited the site of these fossils in
1860 in company with M. van Binkhorst, and we found the description of
the ground, published by the late Professor Crahay of Louvain, to be
very correct.*
(* M. van Binkhorst has shown me the original manuscript
read to the Maestricht Athenaeum in 1823. The memoir was
published in 1836 in the "Bulletin de l'Academie Royale de
Belgique" volume 3 page 43.)
The projecting portion of the terrace, which was cut through in making
the canal, is called the hill of Caberg, which is flat-topped, 60 feet
high, and has a steep slope on both sides towards the alluvial plain.
M. van Binkhorst (who is the author of some valuable works on the
palaeontology of the Maestricht Chalk) has recently visited Leyden, and
ascertained that the human fossil above mentioned is still entire in the
museum of the University. Although we had no opportunity of verifying
the authenticity of Professor Crahay's statements, we could see no
reason for suspecting the human jaw to belong to a different geological
period from that of the extinct elephant. If this were granted, it might
have no claims to a higher antiquity than the human remains which Dr.
Schmerling disentombed from the Belgian caverns; but the fact of their
occurring in a Pleistocene alluvial deposit in the open plains, would be
one of the first examples of such a phenomenon. The top of the hill of
Caberg is not so high above the Meuse as is the terrace of St. Acheul
with its flint implements above the Somme, but at St. Acheul no human
bones have yet been detected.
In the museum at Maestricht are preserved a human frontal and a pelvic
bone, stained of a dark peaty colour; the frontal very remarkable
for its lowness and the prominence of the superciliary ridges, which
resemble those of the Borreby skull, Figure 5. These remains may be the
same as those alluded to by Professor Crahay in his memoir, where he
says that in a black deposit in the suburbs of Hocht were found leaves,
nuts, and freshwater shells in a very perfect state, and a human skull
of a dark colour. They were of an age long posterior to that of the
loess containing the bones of elephants and in which the human jaw now
at Leyden is said to have been embedded.
CHAPTER 17. -- POST-GLACIAL DISLOCATIONS AND FOLDINGS OF CRETACEOUS AND
DRIFT STRATA IN THE ISLAND OF MOEN, IN DENMARK.
Geological Structure of the Island of Moen.
Great Disturbances of the Chalk posterior in Date to the
Glacial Drift, with Recent Shells.
M. Puggaard's Sections of the Cliffs of Moen.
Flexures and Faults common to the Chalk and Glacial Drift.
Different Direction of the Lines of successive Movement,
Fracture, and Flexure.
Undisturbed Condition of the Rocks in the adjoining Danish Islands.
Unequal Movements of Upheaval in Finmark.
Earthquake of New Zealand in 1855.
Predominance in all Ages of uniform Continental Movements over
those by which the Rocks are locally convulsed.
In the preceding chapters I have endeavoured to show that the study of
the successive phases of the glacial period in Europe, and the enduring
marks which they have left on many of the solid rocks and on the
character of the superficial drift are of great assistance in enabling
us to appreciate the vast lapse of ages which are comprised in the
Pleistocene epoch. They enlarge at the same time our conception of the
antiquity, not only of the living species of animals and plants but
of their present geographical distribution, and throw light on the
chronological relations of these species to the earliest date yet
ascertained for the existence of the human race. That date, it will be
seen, is very remote if compared to the times of history and tradition,
yet very modern if contrasted with the length of time during which all
the living testacea, and even many of the mammalia, have inhabited the
globe.
In order to render my account of the phenomena of the glacial epoch
more complete, I shall describe in this chapter some other changes in
physical geography and in the internal structure of the earth's crust,
which have happened in the Pleistocene period, because they differ
in kind from any previously alluded to, and are of a class which were
thought by the earlier geologists to belong exclusively to epochs
anterior to the origin of the existing fauna and flora. Of this nature
are those faults and violent local dislocations of the rocks, and those
sharp bendings and foldings of the strata, which we so often behold in
mountain chains, and sometimes in low countries also, especially where
the rock-formations are of ancient date.
POST-GLACIAL DISLOCATIONS AND FOLDINGS OF CRETACEOUS AND DRIFT STRATA IN
THE ISLAND OF MOEN, DENMARK.
A striking illustration of such convulsions of Pleistocene date may
be seen in the Danish island of Moen, which is situated about 50 miles
south of Copenhagen. The island is about 60 miles in circumference, and
consists of white Chalk, several hundred feet thick, overlaid by
boulder clay and sand, or glacial drift which is made up of several
subdivisions, some unstratified and others stratified, the whole having
a mean thickness of 60 feet, but sometimes attaining nearly twice that
thickness. In one of the oldest members of the formation fossil marine
shells of existing species have been found.
Throughout the greater part of Moen the strata of the drift are
undisturbed and horizontal, as are those of the subjacent Chalk; but on
the north-eastern coast they have been throughout a certain area bent,
folded, and shifted, together with the beds of the underlying Cretaceous
formation. Within this area they have been even more deranged than is
the English Chalk-with-flints along the central axis of the Isle of
Wight in Hampshire, or of Purbeck in Dorsetshire. The whole displacement
of the Chalk is evidently posterior in date to the origin of the drift,
since the beds of the latter are horizontal where the fundamental
Chalk is horizontal, and inclined, curved, or vertical where the Chalk
displays signs of similar derangement. Although I had come to these
conclusions respecting the structure of Moen in 1835, after devoting
several days in company with Dr. Forchhammer to its examination,*
(* Lyell, "Geological Transactions" 2nd series volume 2 page
243.)
I should have hesitated to cite the spot as exemplifying convulsions on
so grand a scale, of such extremely modern date, had not the island been
since thoroughly investigated by a most able and reliable authority,
the Danish geologist, Professor Puggaard, who has published a series of
detailed sections of the cliffs.
These cliffs extend through the north-eastern coast of the island,
called Moens Klint,* where the Chalk precipices are bold and
picturesque, being 300 and 400 feet high, with tall beech-trees growing
on their summits, and covered here and there at their base with huge
taluses of fallen drift, verdant with wild shrubs and grass, by which
the monotony of a continuous range of white Chalk cliffs is prevented.
(* Puggaard, "Geologie d. Insel Moen" Bern 1851; and
"Bulletin de la Societe Geologique de France" 1851.)
[Illustration: Figure 47 and 48. Southern Extremity Of Moens Klint]
(FIGURE 47. SOUTHERN EXTREMITY OF MOENS KLINT (PUGGAARD).
A. Horizontal drift.
B. Chalk and overlying drift beginning to rise.
C. First flexure and fault. Height of cliff at this point,
180 feet.)
(FIGURE 48. SECTION OF MOENS KLINT (PUGGAARD), CONTINUED
FROM FIGURE 47.
S. Fossil shells of recent species in the drift at this point.
G. Greatest height near G, 280 feet.)
In the low part of the island, at A, Figure 47, or the southern
extremity of the line of section above alluded to, the drift is
horizontal, but when we reach B, a change, both in the height of the
cliffs and in the inclination of the strata, begins to be perceptible,
and the Chalk Number 1 soon makes its appearance from beneath the
overlying members of the drift Numbers 2, 3, 4, and 5.
This Chalk, with its layers of flints, is so like that of England as to
require no description. The incumbent drift consists of the following
subdivisions, beginning with the lowest:
Number 2. Stratified loam and sand, 5 feet thick, containing at one
spot near the base of the cliff, at s, Figure 48, Cardium edule, Tellina
solidula, and Turritella, with fragments of other shells. Between Number
2 and the Chalk Number 1, there usually intervenes a breccia of broken
flints.
Number 3. Unstratified blue clay or till, with small pebbles and
fragments of Scandinavian rocks occasionally scattered through it, 20
feet thick.
Number 4. A second unstratified mass of yellow and more sandy clay 40
feet thick, with pebbles and angular polished and striated blocks of
granite and other Scandinavian rocks, transported from a distance.
Number 5. Stratified sands and gravel, with occasionally large erratic
blocks; the whole mass varying from 40 to 100 feet in thickness, but
this only in a few spots.
The angularity of many of the blocks in Numbers 3 and 4, the glaciated
surfaces of others, and the transportation from a distance attested by
their crystalline nature, prove them to belong to the northern drift or
glacial period.
It will be seen that the four subdivisions 2, 3, 4, and 5 begin to rise
at B, Figure 47, and that at C, where the cliff is 180 feet high, there
is a sharp flexure shared equally by the Chalk and the incumbent drift.
Between D and G, Figure 48, we observe a great fracture in the rocks
with synclinal and anticlinal folds, exhibited in cliffs nearly 300 feet
high, the drift beds participating in all the bendings of the Chalk;
that is to say, the three lower members of the drift, including Number
2, which, at the point S in this diagram, contains the shells of Recent
species before alluded to.
Near the northern end of the Moens Klint, at a place called "Taler,"
more than 300 feet high, are seen similar folds, so sharp that there
is an appearance of four distinct alternations of the glacial and
Cretaceous formations in vertical or highly inclined beds; the Chalk at
one point bending over so that the position of all the beds is reversed.
[Illustration: Figure 49. Post-Glacial Disturbances]
(FIGURE 49. POST-GLACIAL DISTURBANCES OF VERTICAL, FOLDED,
AND SHIFTED STRATA OF CHALK AND DRIFT, IN THE DRONNINGESTOL,
MOEN, HEIGHT 400 FEET (PUGGAARD).
1. Chalk with flints.
2. Marine stratified loam, lowest member of glacial formation.
3. Blue clay or till, with erratic blocks unstratified.
4. Yellow sandy till, with pebbles and glaciated boulders.
5. Stratified sand and gravel with erratics.)
But the most wonderful shiftings and faultings of the beds are
observable in the Dronningestol part of the same cliff, 400 feet
in perpendicular height, where, as shown in Figure 49, the drift is
thoroughly entangled and mixed up with the dislocated Chalk.
If we follow the lines of fault, we may see, says M. Puggaard, along
the planes of contact of the shifted beds, the marks of polishing and
rubbing which the Chalk flints have undergone, as have many stones in
the gravel of the drift, and some of these have also been forced into
the soft Chalk. The manner in which the top of some of the arches of
bent Chalk have been cut off in this and several adjoining sections,
attests the great denudation which accompanied the disturbances,
portions of the bent strata having been removed, probably while they
were emerging from beneath the sea.
M. Puggaard has deduced the following conclusions from his study of
these cliffs.
First. The white Chalk, when it was still in horizontal stratification,
but after it had suffered considerable denudation, subsided gradually,
so that the lower beds of drift Number 2, with their littoral shells,
were superimposed on the Chalk in a shallow sea.
Second. The overlying unstratified boulder clays 3 and 4 were thrown
down in deeper water by the aid of floating ice coming from the north.
Third. Irregular subsidences then began, and occasionally partial
failures of support, causing the bending and sometimes the engulfment
of overlying masses both of the Chalk and drift, and causing the
various dislocations above described and depicted. The downward movement
continued till it exceeded 400 feet, for upon the surface even of Number
5, in some parts of the island, lie huge erratics 20 feet or more
in diameter, which imply that they were carried by ice in a sea of
sufficient depth to float large icebergs. But these big erratics, says
Puggaard, never enter into the fissures as they would have done had they
been of date anterior to the convulsions.
Fourth. After this subsidence, the re-elevation and partial denudation
of the Cretaceous and glacial beds took place during a general upward
movement, like that now experienced in parts of Sweden and Norway.
In regard to the lines of movement in Moen, M. Puggaard believes, after
an elaborate comparison of the cliffs with the interior of the island,
that they took at least three distinct directions at as many
successive eras, all of post-glacial date; the first line running from
east-south-east to west-north-west, with lines of fracture at
right angles to them; the second running from south-south-east to
north-north-west, also with fractures in a transverse direction; and
lastly, a sinking in a north and south direction, with other subsidences
of contemporaneous date running at right angles or east and west.
When we approach the north-west end of Moens Klint, or the range of
coast above described, the strata begin to be less bent and broken,
and after travelling for a short distance beyond we find the Chalk and
overlying drift in the same horizontal position as at the southern end
of the Moens Klint. What makes these convulsions the more striking is
the fact that in the other adjoining Danish islands, as well as in a
large part of Moen itself, both the Secondary and Tertiary formations
are quite undisturbed.
It is impossible to behold such effects of reiterated local movements,
all of post-Tertiary date, without reflecting that, but for the
accidental presence of the stratified drift, all of which might easily
have been missing, where there has been so much denudation, even if it
had once existed, we might have referred the verticality and flexures
and faults of the rocks to an ancient period, such as the era between
the Chalk with flints and the Maestricht Chalk, or to the time of the
latter formation, or to the Eocene, or Miocene, or Pliocene eras, even
the last of them long prior to the commencement of the glacial epoch.
Hence we may be permitted to suspect that in some other regions, where
we have no such means at our command for testing the exact date of
certain movements, the time of their occurrence may be far more modern
than we usually suppose. In this way some apparent anomalies in the
position of erratic blocks, seen occasionally at great heights above the
parent rocks from which they have been detached, might be explained, as
well as the irregular direction of certain glacial furrows like those
described by Professor Keilhau and Mr. Horbye on the mountains of
the Dovrefjeld in latitude 62 degrees north, where the striation and
friction is said to be independent of the present shape and slope of the
mountains.*
(* "Observations sur les Phenomenes d'Erosion en Norwege"
1857.)
Although even in such cases it remains to be proved whether a general
crust of continental ice, like that of Greenland described by Rink (see
above, Chapter 13), would not account for the deviation of the furrows
and striae from the normal directions which they ought to have followed
had they been due to separate glaciers filling the existing valleys.
It appears that in general the upward movements in Scandinavia, which
have raised sea-beaches containing marine shells of Recent species to
the height of several hundred feet, have been tolerably uniform over
very wide spaces; yet a remarkable exception to this rule was observed
by M. Bravais at Altenfjord in Finmark, between latitude 70 and 71
degrees north. An ancient water-level, indicated by a sandy deposit
forming a terrace and by marks of the erosion of the waves, can be
followed for 30 miles from south to north along the borders of a fjord
rising gradually from a height of 85 feet to an elevation of 220 feet
above the sea, or at the rate of about 4 feet in a mile.*
(* "Proceedings of the Geological Society" 1845 volume 4
page 94.)
To pass to another and very remote part of the world, we have witnessed
so late as January 1855 in the northern island of New Zealand a sudden
and permanent rise of land on the northern shores of Cook's Straits,
which at one point, called Muko-muka, was so unequal as to amount to
9 feet vertically, while it declined gradually from this maximum of
upheaval in a distance of about 23 miles north-west of the greatest
rise, to a point where no change of level was perceptible. Mr. Edward
Roberts of the Royal Engineers, employed by the British Government
at the time of the shock in executing public works on the coast,
ascertained that the extreme upheaval of certain ancient rocks followed
a line of fault running at least 90 miles from south to north into the
interior; and what is of great geological interest, immediately to the
east of this fault the country, consisting of Tertiary strata, remained
unmoved or stationary; a fact well established by the position of a line
of Nullipores marking the sea-level before the earthquake, both on the
surface of the Tertiary and Palaeozoic rocks.*
(* "Bulletin de la Societe Geologique de France" volume 13
1856 page 660, where I have described the facts communicated
to me by Messrs. Roberts and Walter Mantell.)
The repetition of such unequal movements, especially if they recurred at
intervals along the same lines of fracture, would in the course of ages
cause the strata to dip at a high angle in one direction, while towards
the opposite point of the compass they would terminate abruptly in a
steep escarpment.
But it is probable that the multiplication of such movements in the
post-Tertiary period has rarely been so great as to produce results like
those above described in Moen, for the principal movements in any given
period seem to be of a more uniform kind, by which the topography of
limited districts and the position of the strata are not visibly altered
except in their height relatively to the sea. Were it otherwise we
should not find conformable strata of all ages, including the primary
fossiliferous of shallow-water origin, which must have remained
horizontal throughout vast areas during downward movements of several
thousand feet going on at the period of their accumulation. Still less
should we find the same primary strata, such as the Carboniferous,
Devonian, or Silurian, still remaining horizontal over thousands of
square leagues, as in parts of North America and Russia, having escaped
dislocation and flexure throughout the entire series of epochs
which separate Palaeozoic from Recent times. Not that they have been
motionless, for they have undergone so much denudation, and of such
a kind, as can only be explained by supposing the strata to have been
subjected to great oscillations of level, and exposed in some cases
repeatedly to the destroying and planing action of the waves of the sea.
It seems probable that the successive convulsions in Moen were
contemporary with those upward and downward movements of the glacial
period which were described in the thirteenth and some of the following
chapters, and that they ended before the upper beds of Number 5, Figure
49, with its large erratic blocks, were deposited, as some of those
beds occurring in the disturbed parts of Moen appear to have escaped the
convulsions to which Numbers 2, 3, and 4 were subjected. If this be so,
the whole derangement, although Pleistocene, may have been anterior to
the human epoch, or rather to the earliest date to which the existence
of man has as yet been traced back.
CHAPTER 18. -- THE GLACIAL PERIOD IN NORTH AMERICA.
Post-glacial Strata containing Remains of Mastodon giganteus
in North America.
Scarcity of Marine Shells in Glacial Drift of Canada and the
United States.
Greater southern Extension of Ice-action in North America
than in Europe.
Trains of Erratic Blocks of vast Size in Berkshire, Massachusetts.
Description of their Linear Arrangement and Points of Departure.
Their Transportation referred to Floating and Coast Ice.
General Remarks on the Causes of former Changes of Climate at
successive geological Epochs.
Supposed Effects of the Diversion of the Gulf Stream in a
Northerly instead of North-Easterly Direction.
Development of extreme Cold on the opposite Sides of the Atlantic
in the Glacial period not strictly simultaneous.
Effect of Marine Currents on Climate.
Pleistocene Submergence of the Sahara.
On the North American continent, between the arctic circle and the 42nd
parallel of latitude, we meet with signs of ice-action on a scale as
grand as, if not grander than, in Europe; and there also the excess of
cold appears to have been first felt at the close of the Tertiary, and
to have continued throughout a large portion of the Pleistocene period.
[36]
The general absence of organic remains in the North American glacial
formation makes it as difficult as in Europe to determine what mammalia
lived on the continent at the time of the most intense refrigeration, or
when extensive areas were becoming strewed over with glacial drift and
erratic blocks, but it is certain that a large proboscidean now extinct,
the Mastodon giganteus, Cuv., together with many other quadrupeds, some
of them now living and others extinct, played a conspicuous part in the
post-glacial era. By its frequency as a fossil species, this pachyderm
represents the European Elephas primigenius, although the latter also
occurs fossil in the United States and Canada, and abounds, as I learn
from Sir John Richardson, in latitudes farther north than those to which
the mastodon has been traced.
In the state of New York, the mastodon is not unfrequently met with
in bogs and lacustrine deposits formed in hollows in the drift, and
therefore, in a geological position, much resembling that of Recent
peat and shell-marl in the British Isles, Denmark, or the valley of
the Somme, as before described. Sometimes entire skeletons have been
discovered within a few feet of the surface, in peaty earth at the
bottom of small ponds, which the agriculturists had drained. The shells
in these cases belong to freshwater genera, such as Limnaea, Physa,
Planorbis, Cyclas, and others, differing from European species, but
the same as those now proper to ponds and lakes in the same parts of
America.
I have elsewhere given an account of several of these localities which
I visited in 1842,* and can state that they certainly have a more modern
aspect than almost all the European deposits in which remains of the
mammoth occur, although a few instances are cited of Elephas Primigenius
having been dug out of peat in Great Britain.
(* "Travels in North America" volume 1 page 55 London 1845;
and "Manual of Geology" chapter 12 5th edition page 144.)
Thus I was shown a mammoth's tooth in the museum at Torquay in
Devonshire which is believed to have been dredged up from a deposit
of vegetable matter now partially submerged beneath the sea. A more
elevated part of the same peaty formation constitutes the bottom of
the valley in which Tor Abbey stands. This individual elephant must
certainly have been of more modern date than his fellows found fossil in
the gravel of the Brixham cave, before described, for it flourished when
the physical geography of Devonshire, unlike that of the cave period,
was almost identical with that now established.
I cannot help suspecting that many tusks and teeth of the mammoth, said
to have been found in peat, may be as spurious as are the horns of
the rhinoceros cited more than once in the "Memoirs of the Wernerian
Society" as having been obtained from shell-marl in Forfarshire and
other Scotch counties; yet, between the period when the mammoth was
most abundant and that when it died out, there must have elapsed a long
interval of ages when it was growing more and more scarce; and we may
expect to find occasional stragglers buried in deposits long subsequent
in date to others, until at last we may succeed in tracing a passage
from the Pleistocene to the Recent fauna, by geological monuments, which
will fill up the gap before alluded to as separating the era of the
flint tools of Amiens and Abbeville from that of the peat of the valley
of the Somme.
How far the lacustrine strata of North America above mentioned may help
to lessen this hiatus, and whether some individuals of the Mastodon
giganteus may have come down to the confines of the historical period,
is a question not so easily answered as might at first sight be
supposed. A geologist might naturally imagine that the fluviatile
formation of Goat Island, seen at the falls of Niagara, and at several
points below the falls,* was very modern, seeing that the fossil shells
contained in it are all of species now inhabiting the waters of the
Niagara, and seeing also that the deposit is more modern than the
glacial drift of the same locality.
(* "Travels in North America" by the author, volume 1
chapter 2 and volume 2 chapter 19.)
In fact, the old river bed, in which bones of the mastodon occur, holds
the same position relatively to the boulder formation as the strata
of shell-marl and bog-earth with bones of mastodon, so frequent in
the State of New York, bear to the glacial drift, and all may be of
contemporaneous date. But in the case of the valley of the Niagara
we happen to have a measure of time which is wanting in the other
localities, namely, the test afforded by the recession of the falls, an
operation still in progress, by which the deep ravine of the Niagara,
7 miles long, between Queenstown and Goat Island has been hollowed out.
This ravine is not only post-glacial, but also posterior in date to
the fluviatile or mastodon-bearing beds. The individual therefore found
fossil near Goat Island flourished before the gradual excavation of the
deep and long chasm, and we must reckon its antiquity, not by thousands,
but by tens of thousands of years, if I have correctly estimated
the minimum of time which was required for the erosion of that great
ravine.*
(* "Principles of Geology" 9th edition page 2; and "Travels
in North America" volume 1 page 32 1845.)
The stories widely circulated of bones of the mastodon having been
observed with their surfaces pierced as if by arrow-heads or bearing
the marks of wounds inflicted by some stone implement, must in future
be more carefully inquired into, for we can scarcely doubt that the
mastodon in North America lived down to a period when the mammoth
co-existed with Man in Europe. But I need say no more on this subject,
having already explained my views in regard to the evidence of the
antiquity of Man in North America when treating of the human bone
discovered at Natchez on the Mississippi.
In Canada and the United States we experience the same difficulty as
in Europe when we attempt to distinguish between glacial formations
of submarine and those of supra-marine origin. In the New World, as in
Scotland and England, marine shells of this era have rarely been traced
higher than 500 feet above the sea, and 700 feet seems to be the maximum
to which at present they are known to ascend. In the same countries,
erratic blocks have travelled from north to south, following the same
direction as the glacial furrows and striae imprinted almost everywhere
on the solid rocks underlying the drift. Their direction rarely deviates
more than fifteen degrees east or west of the meridian, so that we can
scarcely doubt, in spite of the general dearth of marine shells, that
icebergs floating in the sea and often running aground on its rocky
bottom were the instruments by which most of the blocks were conveyed to
southern latitudes.
There are, nevertheless, in the United States, as in Europe, several
groups of mountains which have acted as independent centres for the
dispersion of erratics, as, for example, the White Mountains, latitude
44 degrees north, the highest of which, Mount Washington, rises to about
6300 feet above the sea; and according to Professor Hitchcock some of
the loftiest of the hills of Massachusetts once sent down their glaciers
into the surrounding lower country.
GREAT SOUTHERN EXTENSION OF TRAINS OF ERRATIC BLOCKS IN BERKSHIRE,
MASSACHUSETTS, U.S., LATITUDE 42 DEGREES NORTH.
Having treated so fully in this volume of the events of the glacial
period, I am unwilling to conclude without laying before the reader the
evidence displayed in North America of ice-action in latitudes farther
south by about ten degrees than any seen on an equal scale in Europe.
This extension southwards of glacial phenomena in regions where there
are no snow-covered mountains like the Alps to explain the exception,
nor any hills of more than moderate elevation, constitutes a feature of
the western as compared to the eastern side of the Atlantic, and must be
taken into account when we speculate on the causes of the refrigeration
of the northern hemisphere during the Pleistocene period.
[Illustration: Figure 50. Erratic Blocks In Berkshire, Massachusetts]
(FIGURE 50. MAP SHOWING THE RELATIVE POSITION AND DIRECTION
OF SEVEN TRAINS OF ERRATIC BLOCKS IN BERKSHIRE, MASSACHUSETTS,
AND IN PART OF THE STATE OF NEW YORK.
Distance in a straight line, between the mountain ranges
A and C, about eight miles.
A. Canaan range, in the State of New York. The crest consists of
green chloritic rock.
B. Richmond range, the western division of which consists in
Merriman's Mount of the same green rock as A, but in a more
schistose form, while the eastern division is composed of
slaty limestone.
C. The Lenox range, consisting in part of mica-schist, and in some
districts of crystalline limestone.
d. Knob in the range A, from which most of the train Number 6 is
supposed to have been derived.
e. Supposed starting point of the train Number 5 in the range A.
f. Hiatus of 175 yards, or space without blocks.
g. Sherman's House.
h. Perry's Peak.
k. Flat Rock.
l. Merriman's Mount.
m. Dupey's Mount.
n. Largest block of train, Number 6. See Figures 51 and 52.
p. Point of divergence of part of the train Number 6, where a
branch is sent off to Number 5.
Number 1. The most southerly train examined by Messrs. Hall and
Lyell, between Stockbridge and Richmond, composed of blocks
of black slate, blue limestone and some of the green Canaan
rock, with here and there a boulder of white quartz.
Number 2. Train composed chiefly of large limestone masses, some
of them divided into two or more fragments by natural joints.
Number 3. Train composed of blocks of limestone and the green
Canaan rock; passes south of the Richmond Station on the Albany
and Boston railway; is less defined than Numbers 1 and 2.
Number 4. Train chiefly of limestone blocks, some of them thirty
feet in diameter, running to the north-west of the Richmond
Station, and passing south of the Methodist Meeting-house,
where it is intersected by a railway cutting.
Number 5. South train of Dr. Reid, composed entirely of large
blocks of the green chloritic Canaan rock; passes north of
the Old Richmond Meeting-house, and is three-quarters of a mile
north of the preceding train (Number 4).
Number 6. The great or principal train (north train of Dr. Reid),
composed of very large blocks of the Canaan rock, diverges at p,
and unites by a branch with train Number 5.
Number 7. A well-defined train of limestone blocks, with a few
of the Canaan rock, traced from the Richmond to the slope
of the Lenox range.)
In 1852, accompanied by Mr. James Hall, state geologist of New York,
author of many able and well-known works on geology and palaeontology,
I examined the glacial drift and erratics of the county of Berkshire,
Massachusetts, and those of the adjoining parts of the state of New
York, a district about 130 miles inland from the Atlantic coast and
situated due west of Boston in latitude 42 degrees 25 minutes north.
This latitude corresponds in Europe to that of the north of Portugal.
Here numerous detached fragments of rock are seen, having a linear
arrangement or being continuous in long parallel trains, running nearly
in straight lines over hill and dale for distances of 5, 10, and 20
miles, and sometimes greater distances. Seven of the more conspicuous
of these trains, from 1 to 7 inclusive, Figure 50, are laid down in the
accompanying map or ground plan.*
(* This ground plan, and a farther account of the Berkshire
erratics was given in an abstract of a lecture delivered by
me to the Royal Institution of Great Britain, April 27, 1855
and published in their Proceedings.)
It will be remarked that they run in a north-west and south-east
direction, or almost transversely to the ranges of hills A, B, and C,
which run north-north-east and south-south-west. The crests of these
chains are about 800 feet in height above the intervening valleys. The
blocks of the northernmost train, Number 7, are of limestone derived
from the calcareous chain B; those of the two trains next to the south,
Numbers 6 and 5, are composed exclusively in the first part of their
course of a green chloritic rock of great toughness, but after they have
passed the ridge B, a mixture of calcareous blocks is observed. After
traversing the valley for a distance of 6 miles these two trains pass
through depressions or gaps in the range C, as they had previously done
in crossing the range B, showing that the dispersion of the erratics
bears some relation to the acutal inequalities of the surface, although
the course of the same blocks is perfectly independent of the more
leading features of the geography of the country, or those by which
the present lines of drainage are determined. The greater number of the
green chloritic fragments in trains 5 and 6 have evidently come from the
ridge A, and a large proportion of the whole from its highest summit d,
where the crest of the ridge has been worn into those dome-shaped
masses called "roches moutonnees," already alluded to, and where several
fragments having this shape, some of them 30 feet long, are seen in
situ, others only slightly removed from their original position, as if
they had been just ready to set out on their travels. Although smooth
and rounded on their tops they are angular on their lower parts, where
their outline has been derived from the natural joints of the rock. Had
these blocks been conveyed from d by glaciers, they would have radiated
in all directions from a centre, whereas not one even of the smaller
ones is found to the westward of A, though a very slight force would
have made them roll down to the base of that ridge, which is very steep
on its western declivity. It is clear, therefore, that the propelling
power, whatever it may have been, acted exclusively in a south-easterly
direction. Professor Hall and I observed one of the green blocks--24
feet long, poised upon another about 19 feet in length. The largest of
all on the west flank of m, or Dupey's Mount, called the Alderman, is
above 90 feet in diameter, and nearly 300 feet in circumference. We
counted at some points between forty and fifty blocks visible at once,
the smallest of them larger than a camel.
[Illustration: Figure 51. Dome-Shaped Block]
(FIGURE 51. ERRATIC DOME-SHAPED BLOCK OF COMPACT CHLORITIC ROCK
(n in map in Figure 50), near the Richmond Meeting-house,
Berkshire, Massachusetts, latitude 42 degrees 25 minutes
North. Length, 52 feet; width, 40 feet; height above the
soil, 15 feet.)
The annexed drawing (Figure 51) represents one of the best known of
train Number 6, being that marked n on the map (Figure 50). According to
our measurement it is 52 feet long by 40 in width, its height above the
drift in which it is partially buried being 15 feet. At the distance
of several yards occurs a smaller block, 3 or 4 feet in height, 20 feet
long, and 14 broad, composed of the same compact chloritic rock, and
evidently a detached fragment from the bigger mass, to the lower and
angular part of which it would fit on exactly. This erratic n has a
regularly rounded top, worn and smoothed like the "roches moutonnees"
before mentioned, but no part of the attrition can have occurred since
it left its parent rock, the angles of the lower portion being quite
sharp and unblunted.
[Illustration: Figure 52. Position of Block in Figure 51]
(FIGURE 52. SECTION SHOWING THE POSITION OF THE BLOCK IN FIGURE 51.
a. The large block in Figure 51 and n in the map in Figure 50.
b. Fragment detached from the same.
c. Unstratified drift with boulders.
d. Silurian limestone in inclined stratification.)
From railway cuttings through the drift of the neighbourhood and other
artificial excavations, we may infer that the position of the block n,
if seen in a vertical section, would be as represented in Figure 52. The
deposit c in that section consists of sand, mud, gravel, and stones,
for the most part unstratified, resembling the till or boulder clay
of Europe. It varies in thickness from 10 to 50 feet, being of greater
depth in the valleys. The uppermost portion is occasionally, though
rarely, stratified. Some few of the imbedded stones have flattened,
polished, striated, and furrowed sides. They consist invariably, like
the seven trains above mentioned, of kinds of rock confined to the
region lying to the north-west, none of them having come from any other
quarter. Whenever the surface of the underlying rock has been exposed by
the removal of the superficial detritus, a polished and furrowed surface
is seen, like that underneath a glacier, the direction of the furrows
being from north-west to south-east, or corresponding to the course of
the large erratics.
As all the blocks, instead of being dispersed from a centre, have
been carried in one direction and across the ridges A, B, C and the
intervening valleys, the hypothesis of glaciers is out of the question.
I conceive, therefore, that the erratics were conveyed to the places
they now occupy by coast ice, when the country was submerged beneath the
waters of a sea cooled by icebergs coming annually from arctic regions.
[Illustration: Figure 53. Canaan And Richmond Valleys]
(FIGURE 53. SECTION THROUGH CANAAN AND RICHMOND VALLEYS AT A TIME
WHEN THEY WERE MARINE CHANNELS.
d, e. Masses of floating ice carrying fragments of rock.)
Suppose the highest peaks of the ridges A, B, C in the annexed diagram
(Figure 53) to be alone above water, forming islands, and d e to be
masses of floating ice, which drifted across the Canaan and Richmond
valleys at a time when they were marine channels, separating islands or
rather chains of islands, having a north-north-east and south-south-west
direction. A fragment of ice such as d, freighted with a block from A,
might run aground and add to the heap of erratics at the north-west base
of the island (now ridge) B, or, passing through a sound between B and
the next island of the same group, might float on till it reached the
channel between B and C. Year after year two such exposed cliffs in the
Canaan range as d and e of the map, Figure 50, undermined by the waves,
might serve as the points of departure of blocks, composing the trains
Numbers 5 and 6. It may be objected that oceanic currents could not
always have had the same direction; this may be true, but during a short
season of the year when the ice was breaking up the prevailing current
may have always run south-east.
If it be asked why the blocks of each train are not more scattered,
especially when far from their source, it may be observed that after
passing through sounds separating islands, they issued again from a
new and narrow starting-point; moreover, we must not exaggerate the
regularity of the trains, as their width is sometimes twice as great
in one place in as another; and Number 6 sends off a branch at p, which
joins Number 5. There are also stragglers, or large blocks here and
there in the spaces between the two trains. As to the distance to which
any given block would be carried, that must have depended on a variety
of circumstances; such as the strength of the current, the direction of
the wind, the weight of the block or the quantity and draught of the ice
attached to it. The smaller fragments would, on the whole, have the best
chance of going farthest; because, in the first place, they were more
numerous, and then, being lighter, they required less ice to float them,
and would not ground so readily on shoals, or if stranded, would be
more easily started again on their travels. Many of the blocks, which at
first sight seem to consist of single masses, are found when examined to
be made up of two, three, or more pieces divided by natural joints. In
the case of a second removal by ice, one or more portions would become
detached and be drifted to different points further on. Whenever this
happened, the original size would be lessened, and the angularity of
the block previously worn by the breakers would be restored, and this
tendency to split may explain why some of the far-transported fragments
remain very angular.
These various considerations may also account for the fact that the
average size of the blocks of all the seven trains laid down on the
plan, Figure 50, lessens sensibly in proportion as we recede from the
principal points of departure of particular kinds of erratics, yet not
with any regularity, a huge block now and then recurring when the rest
of the train consists of smaller ones.
All geologists acquainted with the district now under consideration are
agreed that the mountain ranges A, B, and c, as well as the adjoining
valleys, had assumed their actual form and position before the drift and
erratics accumulated on and in them and before the surface of the fixed
rocks was polished and furrowed. I have the less hesitation in ascribing
the transporting power to coast-ice, because I saw in 1852 an angular
block of sandstone, 8 feet in diameter, which had been brought down
several miles by ice only three years before to the mouth of the
Petitcodiac estuary, in Nova Scotia, where it joins the Bay of Fundy;
and I ascertained that on the shores of the same bay, at the South
Joggins, in the year 1850, much larger blocks had been removed by
coast-ice, and after they had floated half a mile, had been dropped in
salt water by the side of a pier built for loading vessels with coal,
so that it was necessary at low tide to blast these huge ice-borne
rocks with gunpowder in order that the vessels might be able to draw up
alongside the pier. These recent exemplifications of the vast carrying
powers of ice occurred in latitude 46 degrees north (corresponding to
that of Bordeaux), in a bay never invaded by icebergs.
I may here remark that a sheet of ice of moderate thickness, if it
extend over a wide area, may suffice to buoy up the largest erratics
which fall upon it. The size of these will depend, not on the intensity
of the cold but on the manner in which the rock is jointed, and the
consequent dimensions of the blocks into which it splits when falling
from an undermined cliff.
When I first endeavoured in the "Principles of Geology" in 1830,* to
explain the causes, both of the warmer and colder climates which have
at former periods prevailed on the globe, I referred to successive
variations in the height and position of the land and its extent
relatively to the sea in polar and equatorial latitudes--also to
fluctuations in the course of oceanic currents and other geographical
conditions, by the united influence of which I still believe the
principal revolutions in the meteorological state of the atmosphere at
different geological periods have been brought about.
(* 1st edition chapter 7; 9th edition ibid.)
The Gulf Stream was particularly alluded to by me as moderating the
winter climate of northern Europe and as depending for its direction
on temporary and accidental peculiarities in the shape of the land,
especially that of the narrow Straits of Bahama, which a slight
modification in the earth's crust would entirely alter.
Mr. Hopkins, in a valuable essay on the causes of former changes of
climate,*nhas attempted to calculate how much the annual temperature of
Europe would be lowered if this Gulf Stream were turned in some other
and new direction, and estimates the amount at about six or seven
degrees of Fahrenheit.
(* Hopkins, "Quarterly Journal of the Geological Society"
volume 8 1852 page 56.)
He also supposes that if at the same time a considerable part of
northern and central Europe were submerged, so that a cold current from
the arctic seas should sweep over it, an additional refrigeration of
three or four degrees would be produced. He has speculated in the
same essay on the effects which would be experienced in the eastern
hemisphere if the same mighty current of warm water, instead of crossing
the Atlantic, were made to run northwards from the Gulf of Mexico
through the region now occupied by the valley of the Mississippi, and so
onwards to the arctic regions.
After reflecting on what has been said in the thirteenth chapter of
the submergence and re-elevation of the British Isles and the adjoining
parts of Europe, and the rising and sinking of the Alps and the
basins of some of the great rivers flowing from that chain, since the
commencement of the glacial period, a geologist will not be disposed to
object to the theory above adverted to, on the score of its demanding
too much conversion of land into sea, or almost any amount of
geographical change in Pleistocene times. But a difficulty of another
kind presents itself. We have seen that, during the glacial period, the
cold in Europe extended much farther south than it does at present, and
in this chapter we have demonstrated that in North America the cold also
extended no less than 10 degrees of latitude still farther southwards
than in Europe; so that if a great body of heated water, instead of
flowing north-eastward, were made to pass through what is now the centre
of the American continent towards the Arctic Circle, it could not
fail to mitigate the severity of the winter's cold in precisely those
latitudes where the cold was greatest and where it has left monuments
of ice-action surpassing in extent any exhibited on the European side of
the ocean.
In the actual state of the globe, the isothermal lines, or lines of
equal winter temperature when traced westward from Europe to North
America bend 10 degrees south, there being a marked excess of winter
cold in corresponding latitudes west of the Atlantic. During the glacial
period, viewing it as a whole, we behold signs of a precisely similar
deflection of these same isothermal lines when followed from east to
west; so that if, in the hope of accounting for the former severity of
glacial action in Europe, we suppose the absence of the Gulf Stream and
imagine a current of equivalent magnitude to have flowed due north from
the Gulf of Mexico, we introduce, as we have just hinted, a source
of heat into precisely that part of the continent where the extreme
conditions of refrigeration are most manifest. Viewed in this light, the
hypothesis in question would render the glacial phenomena described in
the present chapter more perplexing and anomalous than ever. But here
another question arises, whether the eras at which the maximum of
cold was attained on the opposite sides of the Atlantic were really
contemporaneous? We have now discovered not only that the glacial period
was of vast duration, but that it passed through various phases and
oscillations of temperature; so that, although the chief polishing and
furrowing of the rocks and transportation of erratics in Europe and
North America may have taken place contemporaneously, according to the
ordinary language of geology, or when the same testacea and the
same Pleistocene assemblage of mammalia flourished, yet the extreme
development of cold on the opposite sides of the ocean may not have been
strictly simultaneous, but on the contrary the one may have preceded or
followed the other by a thousand or more than a thousand centuries.
It is probable that the greatest refrigeration of Norway, Sweden,
Scotland, Wales, the Vosges, and the Alps coincided very nearly in time;
but when the Scandinavian and Scotch mountains were encrusted with a
general covering of ice, similar to that now enveloping Greenland, this
last country may not have been in nearly so glacial a condition as now,
just as we find that the old icy crust and great glaciers, which
have left their mark on the mountains of Norway and Sweden, have
now disappeared, precisely at a time when the accumulation of ice in
Greenland is so excessive. In other words, we see that in the present
state of the northern hemisphere, at the distance of about 1500 miles,
two meridional zones enjoying very different conditions of temperature
may co-exist, and we are, therefore, at liberty to imagine some former
alternations of colder and milder climates on the opposite sides of the
ocean throughout the Pleistocene era of a compensating kind, the cold on
the one side balancing the milder temperature on the other. By assuming
such a succession of events we can more easily explain why there has not
been a greater extermination of species, both terrestrial and aquatic,
in polar and temperate regions during the glacial epoch, and why so many
species are common to pre-glacial and post-glacial times.
The numerous plants which are common to the temperate zones north and
south of the equator have been referred by Mr. Darwin and Dr. Hooker to
migrations which took place along mountain chains running from north to
south during some of the colder phases of the glacial epoch.*
(* Darwin, "Origin of Species" chapter 11 page 365; Hooker,
"Flora of Australia" Introduction page 18 1859.)
Such an hypothesis enables us to dispense with the doctrine that the
same species ever originated independently in two distinct and distant
areas; and it becomes more feasible if we admit the doctrine of the
co-existence of meridional belts of warmer and colder climate, instead
of the simultaneous prevalence of extreme cold both in the eastern and
western hemisphere. It also seems necessary, as colder currents of water
always flow to lower latitudes, while warmer ones are running towards
polar regions, that some such compensation should take place, and that
an increase of cold in one region must to a certain extent be balanced
by a mitigation of temperature elsewhere.
Sir John F. Herschel, in his recent work on "Physical Geography," when
speaking of the open sea which is caused in part of the polar regions
by the escape of ice through Behring's Straits, and the flow of warmer
water northwards through the same channel, observes that these straits,
by which the continents of Asia and North America are now parted, "are
only thirty miles broad where narrowest and only twenty-five fathoms
in their greatest depth." But "this narrow channel," he adds, "is yet
important in the economy of nature, inasmuch as it allows a portion
of the circulating water from a warmer region to find its way into the
polar basin, aiding thereby not only to mitigate the extreme rigour of
the polar cold, but to prevent in all probability a continual accretion
of ice, which else might rise to a mountainous height."*
(* Herschel's "Physical Geography" page 41 1861.)
Behring's Straits, here alluded to, happen to agree singularly in width
and depth with the Straits of Dover, the difference in depth not being
more than 3 or 4 feet; so that at the rate of upheaval, which is now
going on in many parts of Scandinavia, of 2 1/2 feet in a century, such
straits might be closed in 3000 years, and a vast accumulation of ice to
the northward commence forthwith.
But, on the other hand, although such an accumulation might spread
its refrigerating influence for many miles southwards beyond the new
barrier, the warm current which now penetrates through the straits, and
which at other times is chilled by floating ice issuing from them, would
when totally excluded from all communication with the icy sea have its
temperature raised and its course altered, so that the climate of some
other area must immediately begin to improve.
There is still another probable cause of a vast change in the
temperature of central Europe in comparatively modern times, to which no
allusion has yet been made; namely, the conversion of the great
desert of the Sahara from sea into land since the commencement of
the Pleistocene period. When that vast region was still submerged, no
sirocco blowing for days in succession carried its hot blasts from a
wide expanse of burning sand across the Mediterranean. The south winds
were comparatively cool, allowing the snows of the Alps to augment to an
extent which the colossal dimensions of the moraines of extinct glaciers
can alone enable us to estimate.
The scope and limits of this volume forbid my pursuing these
speculations and reasonings farther; but I trust I have said enough
to show that the monuments of the glacial period, when more thoroughly
investigated, will do much towards expanding our views as to the
antiquity of the fauna and flora now contemporary with Man, and will
therefore enable us the better to determine the time at which Man began
in the northern hemisphere to form part of the existing fauna. [37]
CHAPTER 19. -- RECAPITULATION OF GEOLOGICAL PROOFS OF MAN'S ANTIQUITY.
Recapitulation of Results arrived at in the earlier Chapters.
Ages of Stone and Bronze.
Danish Peat and Kitchen-Middens.
Swiss Lake-Dwellings.
Local Changes in Vegetation and in the wild and domesticated
Animals and in Physical Geography coeval with the Age of
Bronze and the later Stone Period.
Estimates of the positive Date of some Deposits of the later
Stone Period.
Ancient Division of the Age of Stone of St. Acheul and Aurignac.
Migrations of Man in that Period from the Continent to England
in Post-Glacial Times.
Slow Rate of Progress in barbarous Ages.
Doctrine of the superior Intelligence and Endowments of the
original Stock of Mankind considered.
Opinions of the Greeks and Romans, and their Coincidence with
those of the Modern Progressionist.
The ages of stone and bronze, so called by archaeologists, were spoken
of in the earlier chapters of this work. That of bronze has been traced
back to times anterior to the Roman occupation of Helvetia, Gaul, and
other countries north of the Alps. When weapons of that mixed metal were
in use, a somewhat uniform civilisation seems to have prevailed over
a wide extent of central and northern Europe, and the long duration
of such a state of things in Denmark and Switzerland is shown by the
gradual improvement which took place in the useful and ornamental arts.
Such progress is attested by the increasing variety of the forms,
and the more perfect finish and tasteful decoration of the tools and
utensils obtained from the more modern deposits of the bronze age, those
from the upper layers of peat, for example, as compared to those found
in the lower ones. The great number also of the Swiss lake-dwellings of
the bronze age (about seventy villages having been already discovered),
and the large population which some of them were capable of containing,
afford indication of a considerable lapse of time, as does the thickness
of the stratum of mud in which in some of the lakes the works of art
are entombed. The unequal antiquity, also, of the settlements is
occasionally attested by the different degrees of decay which the wooden
stakes or piles have undergone, some of them projecting more above the
mud than others, while all the piles of the antecedent age of stone have
rotted away quite down to the level of the mud, such part of them
only as was originally driven into the bed of the lake having escaped
decomposition.*
(* Troyon, "Habitations lacustres" Lausanne 1860.)
Among the monuments of the stone period, which immediately preceded that
of bronze, the polished hatchets called celts are abundant, and were
in very general use in Europe before metallic tools were introduced. We
learn, from the Danish peat and shell-mounds, and from the older Swiss
lake-settlements, that the first inhabitants were hunters who fed almost
entirely on game, but their food in after ages consisted more and more
of tamed animals and still later a more complete change to a pastoral
state took place, accompanied as population increased by the cultivation
of some cereals.
Both the shells and quadrupeds belonging to the later stone period
and to the age of bronze consist exclusively of species now living in
Europe, the fauna being the same as that which flourished in Gaul at the
time when it was conquered by Julius Caesar, even the Bos primigenius,
the only animal of which the wild type is lost, being still represented,
according to Cuvier, Bell, and Rutimeyer, by one of the domesticated
races of cattle now in Europe.
These monuments, therefore, whether of stone or bronze, belong to what I
have termed geologically the Recent period, the definition of which
some may think rather too dependent on negative evidence, or on the
non-discovery hitherto of extinct mammalia, such as the mammoth, which
may one day turn up in a fossil state in some of the oldest peaty
deposits, as indeed it is already said to have done at some spots,
though I have failed as yet to obtain authentic evidence of the fact.*
(* A molar of E. primigenius, in a very fresh state, in the
museum at Torquay, believed to have been washed up by the
waves of the sea out of the submerged mass of vegetable
matter at the extremity of the valley in which Tor Abbey
stands, is the best case I have seen. See above, Chapter
18.)
No doubt some such exceptional cases may be met with in the course of
future investigations, for we are still imperfectly acquainted with
the entire fauna of the age of stone in Denmark as we may infer from an
opinion expressed by Steenstrup, that some of the instruments exhumed by
antiquaries from the Danish peat are made of the bones and horns of
the elk and reindeer. Yet no skeleton or uncut bone of either of those
species has hitherto been observed in the same peat.
Nevertheless, the examination made by naturalists of the various Danish
and Swiss deposits of the Recent period has been so searching, that the
finding in them of a stray elephant or rhinoceros, should it ever occur,
would prove little more than that some few individuals lingered on, when
the species was on the verge of extinction, and such rare exceptions
would not render the classification above proposed inappropriate.
At the time when many wild quadrupeds and birds were growing scarce and
some of them becoming locally extirpated in Denmark, great changes were
taking place in the vegetation. The pine, or Scotch fir, buried in
the oldest peat, gave place at length to the oak, and the oak, after
flourishing for ages, yielded in its turn to the beech, the periods
when these three forest trees predominated in succession tallying pretty
nearly with the ages of stone, bronze, and iron in Denmark. In the same
country also, during the stone period, various fluctuations, as we have
seen, occurred in physical geography. Thus, on the ocean side of certain
islands, the old refuse-heaps, or "kitchen-middens," were destroyed
by the waves, the cliffs having wasted away, while on the side of the
Baltic, where the sea was making no encroachment or where the land was
sometimes gaining on the sea, such mounds remained uninjured. It was
also shown that the oyster, which supplied food to the primitive people,
attained its full size in parts of the Baltic where it cannot now
exist owing to a want of saltness in the water, and that certain marine
univalves and bivalves, such as the common periwinkle, mussel, and
cockle, of which the castaway shells are found in the mounds, attained
in the olden time their full dimensions, like the oysters, whereas the
same species, though they still live on the coast of the inland sea
adjoining the mounds, are dwarfed and never half their natural size, the
water being rendered too fresh for them by the influx of so many rivers.
Some archaeologists and geologists of merit have endeavoured to
arrive at positive dates, or an exact estimate of the minimum of time
assignable to the later age of stone. These computations have been
sometimes founded on changes in the level of the land, or on the
increase of peat, as in the Danish bogs, or on the conversion of water
into land by alluvial deposits, since certain lake-settlements in
Switzerland were abandoned. Alterations also in the geographical
distribution or preponderance of certain living species of animals and
plants have been taken into account in corroboration, as have the signs
of progress in human civilisation, as serving to mark the lapse of time
during the stone and bronze epochs.
M. Morlot has estimated with care the probable antiquity of three
superimposed vegetable soils cut open at different depths in the delta
of the Tiniere, each containing human bones or works of art, belonging
successively to the Roman, bronze, and later stone periods. According
to his estimate, an antiquity of 7000 years at least must be assigned
to the oldest of these remains, though believed to be long posterior in
date to the time when the mammoth and other extinct mammalia flourished
together with Man in Europe. Such computations of past time must be
regarded as tentative in the present state of our knowledge and much
collateral evidence will be required to confirm them; yet the results
appear to me already to afford a rough approximation to the truth.
Between the newer or Recent division of the stone period and the older
division, which has been called the Pleistocene, there was evidently a
vast interval of time--a gap in the history of the past, into which many
monuments of intermediate date will one day have to be intercalated. Of
this kind are those caves in the south of France, in which M. Lartet
has lately found bones of the reindeer, associated with works of art
somewhat more advanced in style than those of St. Acheul or of Aurignac.
In the valley of the Somme we have seen that peat exists of great
thickness, containing in its upper layers Roman and Celtic memorials,
the whole of which has been of slow growth, in basins or depressions
conforming to the present contour and drainage levels of the country,
and long posterior in date to older gravels, containing bones of the
mammoth and a large number of flint implements of a very rude and
antique type. Some of those gravels were accumulated in the channels
of rivers which flowed at higher levels by 100 feet than the present
streams, and before the valley had attained its present depth and form.
No intermixture has been observed in those ancient river beds of any of
the polished weapons, called "celts," or other relics of the more modern
times, or of the second or Recent stone period, nor any interstratified
peat; and the climate of those Pleistocene ages, when Man was a denizen
of the north-west of France and of southern and central England, appears
to have been much more severe in winter than it is now in the
same region, though far less cold than in the glacial period which
immediately preceded.
We may presume that the time demanded for the gradual dying out or
extirpation of a large number of wild beasts which figure in the
Pleistocene strata and are missing in the Recent fauna was of protracted
duration, for we know how tedious a task it is in our own times, even
with the aid of fire-arms, to exterminate a noxious quadruped, a wolf,
for example, in any region comprising within it an extensive forest or a
mountain chain. In many villages in the north of Bengal, the tiger still
occasionally carries off its human victims, and the abandonment of late
years by the natives of a part of the Sunderbunds or lower delta of the
Ganges, which they once peopled, is attributed chiefly to the ravages of
the tiger. It is probable that causes more general and powerful than the
agency of Man, alterations in climate, variations in the range of
many species of animals, vertebrate and invertebrate, and of plants,
geographical changes in the height, depth, and extent of land and sea,
some or all of these combined, have given rise in a vast series of
years to the annihilation, not only of many large mammalia, but to the
disappearance of the Cyrena fluminalis, once common in the rivers of
Europe, and to the different range or relative abundance of other shells
which we find in the European drifts.
That the growing power of Man may have lent its aid as the destroying
cause of many Pleistocene species, must, however, be granted; yet,
before the introduction of fire-arms, or even the use of improved
weapons of stone, it seems more wonderful that the aborigines were able
to hold their own against the cave-lion, hyaena, and wild bull, and
to cope with such enemies, than that they failed to bring about their
speedy extinction.
It is already clear that Man was contemporary in Europe with two species
of elephant, now extinct, E. primigenius and E. antiquus, two also of
rhinoceros, R. tichorhinus and R. hemitoechus (Falc.), at least one
species of hippopotamus, the cave-bear, cave-lion, and cave-hyaena,
various bovine, equine, and cervine animals now extinct, and many
smaller Carnivora, Rodentia, and Insectivora. While these were slowly
passing away, the musk ox, reindeer, and other arctic species which have
survived to our times were retreating northwards from the valleys of the
Thames and Seine to their present more arctic haunts.
The human skeletons of the Belgian caverns of times coeval with the
mammoth and other extinct mammalia do not betray any signs of a marked
departure in their structure, whether of skull or limb, from the
modern standard of certain living races of the human family. As to
the remarkable Neanderthal skeleton (Chapter 5), it is at present too
isolated and exceptional, and its age too uncertain, to warrant us
in relying on its abnormal and ape-like characters, as bearing on the
question whether the farther back we trace Man into the past, the more
we shall find him approach in bodily conformation to those species of
the anthropoid quadrumana which are most akin to him in structure.
In the descriptions already given of the geographical changes which
the British Isles have undergone since the commencement of the glacial
period (as illustrated by several maps, Figures 39 to 41), it has been
shown that there must have been a free communication by land between the
Continent and these islands, and between the several islands themselves,
within the Pleistocene epoch, in order to account for the Germanic fauna
and flora having migrated into every part of the area, as well as for
the Scandinavian plants and animals to have retreated into the
higher mountains. During some part of the Pleistocene ages, the large
pachyderms and accompanying beasts of prey, now extinct, wandered from
the Continent to England; and it is highly probable that France was
united with some part of the British Isles as late as the period of the
gravels of St. Acheul and the era of those engulfed rivers which, in
the basin of the Meuse near Liege, swept into many a rent and cavern
the bones of Man and of the mammoth and cave-bear. There have been vast
geographical revolutions in the times alluded to, and oscillations of
land, during which the English Channel, which can be shown by the Pagham
erratics and the old Brighton beach (Chapter 14), to be of very ancient
origin, may have been more than once laid dry and again submerged.
During some one of these phases, Man may have crossed over, whether by
land or in canoes, or even on the ice of a frozen sea (as Mr. Prestwich
has hinted), for the winters of the period of the higher-level gravels
of the valley of the Somme were intensely cold.
The primitive people, who co-existed with the elephant and rhinoceros
in the valley of the Ouse at Bedford, and who made use of flint tools of
the Amiens type, certainly inhabited part of England which had already
emerged from the waters of the glacial sea and the fabricators of
the flint tools of Hoxne, in Suffolk, were also, as we have seen,
post-glacial. We may likewise presume that the people of Pleistocene
date, who have left their memorials in the valley of the Thames, were of
corresponding antiquity, posterior to the boulder clay but anterior to
the time when the rivers of that region had settled into their present
channels.
The vast distance of time which separated the origin of the higher and
lower gravels of the valley of the Somme, both of them rich in flint
implements of similar shape (although those of oval form predominate in
the newer gravels), leads to the conclusion that the state of the arts
in those early times remained stationary for almost indefinite periods.
There may, however, have been different degrees of civilisation and in
the art of fabricating flint tools, of which we cannot easily detect the
signs in the first age of stone, and some contemporary tribes may have
been considerably in advance of others. Those hunters, for example, who
feasted on the rhinoceros and buried their dead with funeral rites at
Aurignac may have been less barbarous than the savages of St. Acheul,
as some of their weapons and utensils have been thought to imply. To
a European who looks down from a great eminence on the products of the
humble arts of the aborigines of all times and countries, the stone
knives and arrows of the Red Indian of North America, the hatchets
of the native Australian, the tools found in the ancient Swiss
lake-dwellings or those of the Danish kitchen-middens and of St. Acheul,
seem nearly all alike in rudeness and very uniform in general character.
The slowness of the progress of the arts of savage life is manifested
by the fact that the earlier instruments of bronze were modelled on the
exact plan of the stone tools of the preceding age, although such shapes
would never have been chosen had metals been known from the first. The
reluctance or incapacity of savage tribes to adopt new inventions has
been shown in the East by their continuing to this day to use the same
stone implements as their ancestors, after that mighty empires, where
the use of metals in the arts was well known, had flourished for three
thousand years in their neighbourhood.
We see in our own times that the rate of progress in the arts and
sciences proceeds in a geometrical ratio as knowledge increases, and so
when we carry back our retrospect into the past, we must be prepared to
find the signs of retardation augmenting in a like geometrical ratio; so
that the progress of a thousand years at a remote period may correspond
to that of a century in modern times, and in ages still more remote Man
would more and more resemble the brutes in that attribute which causes
one generation exactly to imitate in all its ways the generation which
preceded it.
The extent to which even a considerably advanced state of civilisation
may become fixed and stereotyped for ages, is the wonder of Europeans
who travel in the East. One of my friends declared to me, that whenever
the natives expressed to him a wish "that he might live a thousand
years," the idea struck him as by no means extravagant, seeing that if
he were doomed to sojourn for ever among them, he could only hope to
exchange in ten centuries as many ideas, and to witness as much progress
as he could do at home in half a century.
It has sometimes happened that one nation has been conquered by another
less civilised though more warlike, or that during social and political
revolutions, people have retrograded in knowledge. In such cases, the
traditions of earlier ages, or of some higher and more educated caste
which has been destroyed, may give rise to the notion of degeneracy from
a primaeval state of superior intelligence, or of science supernaturally
communicated. But had the original stock of mankind been really endowed
with such superior intellectual powers and with inspired knowledge and
had possessed the same improvable nature as their posterity, the point
of advancement which they would have reached ere this would have been
immeasurably higher. We cannot ascertain at present the limits,
whether of the beginning or the end, of the first stone period when Man
co-existed with the extinct mammalia, but that it was of great duration
we cannot doubt. During those ages there would have been time for
progress of which we can scarcely form a conception, and very different
would have been the character of the works of art which we should now
be endeavouring to interpret--those relics which we are now disinterring
from the old gravel-pits of St. Acheul, or from the Liege caves. In
them, or in the upraised bed of the Mediterranean, on the south coast of
Sardinia, instead of the rudest pottery or flint tools so irregular
in form as to cause the unpractised eye to doubt whether they afford
unmistakable evidence of design, we should now be finding sculptured
forms surpassing in beauty the masterpieces of Phidias or Praxiteles;
lines of buried railways or electric telegraphs from which the
best engineers of our day might gain invaluable hints; astronomical
instruments and microscopes of more advanced construction than any known
in Europe, and other indications of perfection in the arts and sciences
such as the nineteenth century has not yet witnessed. Still farther
would the triumphs of inventive genius be found to have been carried,
when the later deposits, now assigned to the ages of bronze and iron,
were formed. Vainly should we be straining our imaginations to guess
the possible uses and meaning of such relics--machines, perhaps,
for navigating the air or exploring the depths of the ocean, or
for calculating arithmetical problems beyond the wants or even the
conception of living mathematicians.
The opinion entertained generally by the classical writers of Greece and
Rome, that Man in the first stage of his existence was but just removed
from the brutes, is faithfully expressed by Horace in his celebrated
lines, which begin:--
Quum prorepserunt primis animalia terris.--Sat. lib. 1, 3, 99.
The picture of transmutation given in these verses, however severe
and contemptuous the strictures lavishly bestowed on it by Christian
commentators, accords singularly with the train of thought which the
modern doctrine of progressive development has encouraged.
"When animals," he says, "first crept forth from the newly formed earth,
a dumb and filthy herd, they fought for acorns and lurking-places with
their nails and fists, then with clubs, and at last with arms, which,
taught by experience, they had forged. They then invented names for
things and words to express their thoughts, after which they began to
desist from war, to fortify cities and enact laws." They who in
later times have embraced a similar theory, have been led to it by no
deference to the opinions of their pagan predecessors, but rather in
spite of very strong prepossessions in favour of an opposite hypothesis,
namely, that of the superiority of their original progenitors, of whom
they believe themselves to be the corrupt and degenerate descendants.
So far as they are guided by palaeontology, they arrive at this result
by an independent course of reasoning; but they have been conducted
partly to the same goal as the ancients by ethnological considerations
common to both, or by reflecting in what darkness the infancy of
every nation is enveloped and that true history and chronology are the
creation, as it were, of yesterday.
CHAPTER 20. -- THEORIES OF PROGRESSION AND TRANSMUTATION.
Antiquity and Persistence in Character of the existing Races
of Mankind.
Theory of their Unity of Origin considered.
Bearing of the Diversity of Races on the Doctrine of Transmutation.
Difficulty of defining the Terms "Species" and "Race."
Lamarck's Introduction of the Element of Time into the
Definition of a Species.
His Theory of Variation and Progression.
Objections to his Theory, how far answered.
Arguments of modern Writers in favour of Progression in the
Animal and Vegetable World.
The old Landmarks supposed to indicate the first Appearance of Man,
and of different Classes of Animals, found to be erroneous.
Yet the Theory of an advancing Series of Organic Beings not
inconsistent with Facts.
Earliest known Fossil Mammalia of low Grade.
No Vertebrata as yet discovered in the oldest Fossiliferous Rocks.
Objections to the Theory of Progression considered.
Causes of the Popularity of the Doctrine of Progression as compared
to that of Transmutation.
When speaking in a former work of the distinct races of mankind,* I
remarked that, "if all the leading varieties of the human family sprang
originally from a single pair" (a doctrine, to which then, as now,
I could see no valid objection), "a much greater lapse of time was
required for the slow and gradual formation of such races as the
Caucasian, Mongolian, and Negro, than was embraced in any of the popular
systems of chronology."
(* "Principles of Geology" 7th edition page 637, 1847; see
also 9th edition page 660.)
In confirmation of the high antiquity of two of these, I referred to
pictures on the walls of ancient temples in Egypt, in which, a thousand
years or more before the Christian era, "the Negro and Caucasian
physiognomies were portrayed as faithfully, and in as strong contrast,
as if the likenesses of these races had been taken yesterday." In
relation to the same subject, I dwelt on the slight modification which
the Negro has undergone, after having been transported from the tropics
and settled for more than two centuries in the temperate climate of
Virginia. I therefore concluded that, "if the various races were
all descended from a single pair, we must allow for a vast series of
antecedent ages, in the course of which the long-continued influence
of external circumstances gave rise to peculiarities increased in many
successive generations and at length fixed by hereditary transmission."
So long as physiologists continued to believe that Man had not existed
on the earth above six thousand years, they might with good reason
withhold their assent from the doctrine of a unity of origin of so many
distinct races but the difficulty becomes less and less, exactly in
proportion as we enlarge our ideas of the lapse of time during which
different communities may have spread slowly, and become isolated,
each exposed for ages to a peculiar set of conditions, whether of
temperature, or food, or danger, or ways of living. The law of the
geometrical rate of the increase of population which causes it always
to press hard on the means of subsistence, would ensure the migration in
various directions of offshoots from the society first formed abandoning
the area where they had multiplied. But when they had gradually
penetrated to remote regions by land or water--drifted sometimes
by storms and currents in canoes to an unknown shore--barriers of
mountains, deserts, or seas, which oppose no obstacle to mutual
intercourse between civilised nations, would ensure the complete
isolation for tens or thousands of centuries of tribes in a primitive
state of barbarism.
Some modern ethnologists, in accordance with the philosophers of
antiquity, have assumed that men at first fed on the fruits of the
earth, before even a stone implement or the simplest form of canoe had
been invented. They may, it is said, have begun their career in some
fertile island in the tropics, where the warmth of the air was such that
no clothing was needed and where there were no wild beasts to endanger
their safety. But as soon as their numbers increased they would be
forced to migrate into regions less secure and blest with a less genial
climate. Contests would soon arise for the possession of the most
fertile lands, where game or pasture abounded and their energies and
inventive powers would be called forth, so that at length they would
make progress in the arts.
But as ethnologists have failed, as yet, to trace back the history
of any one race to the area where it originated, some zoologists of
eminence have declared their belief that the different races, whether
they be three, five, twenty, or a much greater number (for on this point
there is an endless diversity of opinion),* have all been primordial
creations, having from the first been stamped with the characteristic
features, mental and bodily, by which they are now distinguished, except
where intermarriage has given rise to mixed or hybrid races.
(* See "Transactions of the Ethnological Society" volume 1
1861.)
Were we to admit, say they, a unity of origin of such strongly marked
varieties as the Negro and European, differing as they do in colour and
bodily constitution, each fitted for distinct climates and exhibiting
some marked peculiarities in their osteological, and even in some
details of cranial and cerebral conformation, as well as in their
average intellectual endowments--if, in spite of the fact that all these
attributes have been faithfully handed down unaltered for hundreds of
generations, we are to believe that, in the course of time, they have
all diverged from one common stock, how shall we resist the arguments
of the transmutationist, who contends that all closely allied species of
animals and plants have in like manner sprung from a common parentage,
albeit that for the last three or four thousand years they may have been
persistent in character? Where are we to stop, unless we make our stand
at once on the independent creation of those distinct human races, the
history of which is better known to us than that of any of the inferior
animals?
So long as Geology had not lifted up a part of the veil which formerly
concealed from the naturalist the history of the changes which the
animate creation had undergone in times immediately antecedent to
the Recent period, it was easy to treat these questions as too
transcendental, or as lying too far beyond the domain of positive
science to require serious discussion. But it is no longer possible
to restrain curiosity from attempting to pry into the relations which
connect the present state of the animal and vegetable worlds, as well as
of the various races of mankind, with the state of the fauna and flora
which immediately preceded.
In the very outset of the inquiry, we are met with the difficulty
of defining what we mean by the terms "species" and "race;" and the
surprise of the unlearned is usually great, when they discover how wide
is the difference of opinion now prevailing as to the significance of
words in such familiar use. But, in truth, we can come to no agreement
as to such definitions, unless we have previously made up our minds
on some of the most momentous of all the enigmas with which the human
intellect ever attempted to grapple.
It is now thirty years since I gave an analysis in the first edition of
my "Principles of Geology" (volume 2 1832) of the views which had been
put forth by Lamarck, in the beginning of the century, on this subject.
In that interval the progress made in zoology and botany, both in
augmenting the number of known animals and plants, and in studying their
physiology and geographical distribution and above all in examining and
describing fossil species, is so vast that the additions made to our
knowledge probably exceed all that was previously known; and what
Lamarck then foretold has come to pass; the more new forms have been
multiplied, the less are we able to decide what we mean by a variety,
and what by a species. In fact, zoologists and botanists are not only
more at a loss than ever how to define a species, but even to determine
whether it has any real existence in nature, or is a mere abstraction of
the human intellect, some contending that it is constant within certain
narrow and impassable limits of variability, others that it is capable
of indefinite and endless modification.
Before I attempt to explain a great step, which has recently been made
by Mr. Darwin and his fellow-labourers in this field of inquiry, I think
it useful to recapitulate in this place some of the leading features of
Lamarck's system, without attempting to adjust the claims of some of
his contemporaries (Geoffroy St. Hilaire in particular) to share in the
credit of some of his original speculations.
From the time of Linnaeus to the commencement of the present century,
it seemed a sufficient definition of the term species to say that
"a species consisted of individuals all resembling each other, and
reproducing their like by generation." But Lamarck after having
first studied botany with success, had then turned his attention to
conchology, and soon became aware that in the newer (or Tertiary) strata
of the earth's crust there were a multitude of fossil species of shells,
some of them identical with living ones, others simply varieties of the
living, and which as such were entitled to be designated, according
to the ordinary rules of classification, by the same names. He also
observed that other shells were so nearly allied to living forms that
it was difficult not to suspect that they had been connected by a common
bond of descent. He therefore proposed that the element of time should
enter into the definition of a species, and that it should run thus:
"A species consists of individuals all resembling each other, and
reproducing their like by generation, SO LONG AS THE SURROUNDING
CONDITIONS DO NOT UNDERGO CHANGES SUFFICIENT TO CAUSE THEIR HABITS,
CHARACTERS, AND FORMS TO VARY." He came at last to the conclusion that
none of the animals and plants now existing were primordial creations,
but were all derived from pre-existing forms, which, after they may have
gone on for indefinite ages reproducing their like, had at length, by
the influence of alterations in climate and in the animate world been
made to vary gradually, and adapt themselves to new circumstances, some
of them deviating in the course of ages so far from their original type
as to have claims to be regarded as new species.
In support of these views, he referred to wild and cultivated plants and
to wild and domesticated animals, pointing out how their colour, form,
structure, physiological attributes and even instincts were gradually
modified by exposure to new soils and climates, new enemies, modes of
subsistence, and kinds of food.
Nor did he omit to notice that the newly acquired peculiarities may
be inherited by the offspring for an indefinite series of generations,
whether they be brought about naturally--as when a species, on the
extreme verge of its geographical range, comes into competition with
new antagonists and is subjected to new physical conditions; or
artificially--as when by the act of the breeder or horticulturist
peculiar varieties of form or disposition are selected.
But Lamarck taught not only that species had been constantly undergoing
changes from one geological period to another, but that there also had
been a progressive advance of the organic world from the earliest to
the latest times, from beings of the simplest to those of more and more
complex structure, and from the lowest instincts up to the highest,
and finally from brute intelligence to the reasoning powers of Man. The
improvement in the grade of being had been slow and continuous, and the
human race itself was at length evolved out of the most highly organised
and endowed of the inferior mammalia.
In order to explain how, after an indefinite lapse of ages, so many of
the lowest grades of animal or plant still abounded, he imagined that
the germs or rudiments of living things, which he called monads, were
continually coming into the world and that there were different kinds
of these monads for each primary division of the animal and vegetable
kingdoms. This last hypothesis does not seem essentially different from
the old doctrine of equivocal or spontaneous generation; it is wholly
unsupported by any modern experiments or observation, and therefore
affords us no aid whatever in speculating on the commencement of vital
phenomena on the earth.
Some of the laws which govern the appearance of new varieties were
clearly pointed out by Lamarck. He remarked, for example, that as the
muscles of the arm become strengthened by exercise or enfeebled by
disuse, some organs may in this way, in the course of time, become
entirely obsolete, and others previously weak become strong and play a
new or more leading part in the organisation of a species. And so
with instincts, where animals experience new dangers they become more
cautious and cunning, and transmit these acquired faculties to their
posterity. But not satisfied with such legitimate speculations, the
French philosopher conceived that by repeated acts of volition animals
might acquire new organs and attributes, and that in plants, which
could not exert a will of their own, certain subtle fluids or organising
forces might operate so as to work out analogous effects.
After commenting on these purely imaginary causes, I pointed out in
1832, as the two great flaws in Lamarck's attempt to explain the origin
of species, first, that he had failed to adduce a single instance of
the initiation of a new organ in any species of animal or plant; and
secondly, that variation, whether taking place in the course of nature
or assisted artificially by the breeder and horticulturist, had never
yet gone so far as to produce two races sufficiently remote from each
other in physiological constitution as to be sterile when intermarried,
or, if fertile, only capable of producing sterile hybrids, etc.*
(* "Principles of Geology" 1st edition volume 2 chapter 2.)
To this objection Lamarck would, no doubt, have answered that there had
not been time for bringing about so great an amount of variation;
for when Cuvier and some other of his contemporaries appealed to the
embalmed animals and plants taken from Egyptian tombs, some of them 3000
years old, which had not experienced in that long period the slightest
modification in their specific characters, he replied that the climate
and soil of the valley of the Nile had not varied in the interval, and
that there was therefore no reason for expecting that we should be able
to detect any change in the fauna and flora. "But if," he went on to
say, "the physical geography, temperature, and other conditions of life
had been altered in Egypt as much as we know from geology has happened
in other regions, some of the same animals and plants would have
deviated so far from their pristine types as to be thought entitled to
take rank as new and distinct species."
Although I cited this answer of Lamarck in my account of his theory,*
I did not at the time fully appreciate the deep conviction which it
displays of the slow manner in which geological changes have taken place
and the insignificance of thirty or forty centuries in the history of
a species, and that, too, at a period when very narrow views were
entertained of the extent of past time by most of the ablest geologists,
and when great revolutions of the earth's crust, and its inhabitants,
were generally attributed to sudden and violent catastrophes.
(* Ibid. page 587.)
While in 1832 I argued against Lamarck's doctrine of the gradual
transmutation of one species into another, I agreed with him in
believing that the system of changes now in progress in the organic
world would afford, when fully understood, a complete key to the
interpretation of all the vicissitudes of the living creation in past
ages. I contended against the doctrine, then very popular, of the sudden
destruction of vast multitudes of species and the abrupt ushering into
the world of new batches of plants and animals.
I endeavoured to sketch out (and it was, I believe, the first systematic
attempt to accomplish such a task) the laws which govern the extinction
of species, with a view of showing that the slow but ceaseless
variations now in progress in physical geography, together with the
migration of plants and animals into new regions, must in the course
of ages give rise to the occasional loss of some of them and eventually
cause an entire fauna and flora to die out; also that we must infer from
geological data that the places thus left vacant from time to time
are filled up without delay by new forms adapted to new conditions,
sometimes by immigration from adjoining provinces, sometimes by new
creations. Among the many causes of extinction enumerated by me were the
power of hostile species, diminution of food, mutations in climate, the
conversion of land into sea and of sea into land, etc. I firmly opposed
Brocchi's hypothesis of a decline in the vital energy of each species;*
maintaining that there was every reason to believe that the reproductive
powers of the last surviving representatives of a species were as
vigorous as those of their predecessors, and that they were as capable,
under favourable circumstances, of repeopling the earth with their kind.
(* "Principles of Geology" 1st edition volume 2 chapter 8;
and 9th edition page 668.)
The manner in which some species are now becoming scarce and dying out,
one after the other, appeared to me to favour the doctrine of the fixity
of the specific character, showing a want of pliancy and capability of
varying, which ensured their annihilation whenever changes adverse
to their well-being occurred; time not being allowed for such a
transformation as might be conceived capable of adapting them to the new
circumstances, and of converting them into what naturalists would call
new species.*
(* Laws of Extinction, "Principles of Geology" 1st edition
1832 volume 2 chapters 5 to 11 inclusive; and 9th edition
chapters 37 to 42 inclusive 1853.)
But while rejecting transmutation, I was equally opposed to the popular
theory that the creative power had diminished in energy, or that it
had been in abeyance ever since Man had entered upon the scene. That a
renovating force which had been in full operation for millions of years
should cease to act while the causes of extinction were still in full
activity, or even intensified by the accession of Man's destroying
power, seemed to me in the highest degree improbable. The only point on
which I doubted was whether the force might not be intermittent instead
of being, as Lamarck supposed, in ceaseless operation. Might not the
births of new species, like the deaths of old ones, be sudden? Might
they not still escape our observation? If the coming in of one new
species, and the loss of one other which had endured for ages, should
take place annually, still, assuming that there are a million of animals
and plants living on the globe, it would require, I observed, a million
of years to bring about a complete revolution in the fauna and flora. In
that case, I imagined that, although the first appearance of a new form
might be as abrupt as the disappearance of an old one, yet naturalists
might never yet have witnessed the first entrance on the stage of a
large and conspicuous animal or plant, and as to the smaller kinds, many
of them may be conceived to have stolen in unseen, and to have spread
gradually over a wide area, like species migrating into new provinces.*
(* "Principles of Geology" 1st edition 1832 volume 2 chapter
11; and 9th edition page 706.)
It may now be useful to offer some remarks on the very different
reception which the twin branches of Lamarck's development theory,
namely, progression and transmutation, have met with, and to inquire
into the causes of the popularity of the one and the great unpopularity
of the other. We usually test the value of a scientific hypothesis by
the number and variety of the phenomena of which it offers a fair or
plausible explanation. If transmutation, when thus tested, has decidedly
the advantage over progression and yet is comparatively in disfavour,
we may reasonably suspect that its reception is retarded, not so much by
its own inherent demerits, as by some apprehended consequences which
it is supposed to involve and which run counter to our preconceived
opinions.
THEORY OF PROGRESSION.
In treating of this question, I shall begin with the doctrine of
progression, a concise statement of which, so far as it relates to the
animal kingdom, was thus given twelve years ago by Professor Sedgwick,
in the preface to his "Discourse on the Studies of the University of
Cambridge."
"There are traces," he says, "among the old deposits of the earth of an
organic progression among the successive forms of life. They are to
be seen in the absence of mammalia in the older, and their very
rare appearance in the newer Secondary groups; in the diffusion of
warm-blooded quadrupeds (frequently of unknown genera) in the older
Tertiary system, and in their great abundance (and frequently of known
genera) in the upper portions of the same series; and lastly, in the
recent appearance of Man on the surface of the earth."
"This historical development," continues the same author, of the forms
and functions of organic life during successive epochs, "seems to mark
a gradual evolution of creative power, manifested by a gradual ascent
towards a higher type of being." "But the elevation of the fauna of
successive periods was not made by transmutation, but by creative
additions; and it is by watching these additions that we get some
insight into Nature's true historical progress, and learn that there
was a time when Cephalopoda were the highest types of animal life, the
primates of this world; that Fishes next took the lead, then Reptiles;
and that during the secondary period they were anatomically raised far
above any forms of the reptile class now living in the world. Mammals
were added next, until Nature became what she now is, by the addition of
Man."*
(* Professor Sedgwick's "Discourse on the Studies of the
University of Cambridge" Preface to 5th edition pages 44,
154, 216, 1850.)
Although in the half century which has elapsed between the time of
Lamarck and the publication of the above summary, new discoveries have
caused geologists to assign a higher antiquity both to Man and the
oldest fossil mammalia, fish, and reptiles than formerly, yet the
generalisation, as laid down by the Woodwardian Professor, as to
progression, still holds good in all essential particulars.
The progressive theory was propounded in the following terms by the late
Hugh Miller in his "Footprints of the Creator."
"It is of itself an extraordinary fact without reference to other
considerations, that the order adopted by Cuvier in his "Animal
Kingdom," as that in which the four great classes of vertebrate animals,
when marshalled according to their rank and standing, naturally range,
should be also that in which they occur in order of time. The brain,
which bears an average proportion to the spinal cord of not more than
two to one, comes first--it is the brain of the fish; that which bears
to the spinal cord an average proportion of two and a half to one
succeeded it--it is the brain of the reptile; then came the brain
averaging as three to one--it is that of the bird. Next in succession
came the brain that averages as four to one--it is that of the mammal;
and last of all there appeared a brain that averages as twenty-three to
one--reasoning, calculating Man had come upon the scene."*
(* "Footprints of the Creator" Edinburgh 1849 page 283.)
M. Agassiz, in his "Essay on Classification," has devoted a chapter to
the "Parallelism between the Geological Succession of Animals and
Plants and their present relative Standing;" in which he has expressed a
decided opinion that within the limits of the orders of each great class
there is a coincidence between their relative rank in organisation and
the order of succession of their representatives in time.*
(* "Contributions to the Natural History of the United
States" Part 1.--Essay on Classification page 108.)
Professor Owen, in his Palaeontology, has advanced similar views, and
has remarked, in regard to the vertebrata that there is much positive
as well as negative evidence in support of the doctrine of an advance in
the scale of being, from ancient to more modern geological periods. We
observe, for example, in the Triassic, Oolitic, and Cretaceous
strata, not only an absence of placental mammalia, but the presence
of innumerable reptiles, some of large size, terrestrial and aquatic,
herbivorous and predaceous, fitted to perform the functions now
discharged by the mammalia.
The late Professor Bronn, of Heidelberg, after passing in review more
than 24,000 fossil animals and plants, which he had classified
and referred each to their geological position in his "Index
Palaeontologicus," came to the conclusion that, in the course of time,
there had been introduced into the earth more and more highly organised
types of animal and vegetable life; the modern species being, on the
whole, more specialised, i.e. having separate organs, or parts of the
body, to perform different functions, which, in the earlier periods and
in beings of simpler structure, were discharged in common by a single
part or organ.
Professor Adolphe Brongniart, in an essay published in 1849 on the
botanical classification and geological distribution of the genera of
fossil plants,* arrives at similar results as to the progress of the
vegetable world from the earliest periods to the present.
(* Tableau des Genres de Vegetaux fossiles, etc.
"Dictionnaire Universel d'Histoire Naturelle" Paris 1849.)
He does not pretend to trace an exact historical series from the
sea-weed to the fern, or from the fern again to the conifers and
cycads, and lastly from those families to the palms and oaks, but he,
nevertheless, points out that the cryptogamic forms, especially the
acrogens, predominate among the fossils of the primary formations,
the Carboniferous especially, while the gymnosperms or coniferous and
cycadeous plants abound in all the strata, from the Trias to the Wealden
inclusive; and lastly, the more highly developed angiosperms, both
monocotyledonous and dicotyledonous, do not become abundant until the
Tertiary period. It is a remarkable fact, as he justly observes,
that the angiospermous exogens, which comprise four-fifths of living
plants--a division to which all our native European trees, except the
Coniferae, belong, and which embrace all the Compositae, Leguminosae,
Umbelliferae, Cruciferae, Heaths, and so many other families--are wholly
unrepresented by any fossils hitherto discovered in the Primary and
Secondary formations from the Silurian to the Oolitic inclusive. It is
not till we arrive at the Cretaceous period that they begin to appear,
sparingly at first, and only playing a conspicuous part, together with
the palms and other endogens, in the Tertiary epoch.
When commenting on the eagerness with which the doctrine of progression
was embraced from the close of the last century to the time when I first
attempted, in 1830, to give some account of the prevailing theories in
geology, I observed that far too much reliance was commonly placed on
the received dates of the first appearances of certain orders or classes
of animals or plants, such dates being determined by the age of the
stratum in which we then happened to have discovered the earliest
memorials of such types. At that time (1830), it was taken for granted
that Man had not co-existed with the mammoth and other extinct mammalia,
yet now that we have traced back the signs of his existence to the
Pleistocene era, and may anticipate the finding of his remains on some
future day in the Pliocene period, the theory of progression is not
shaken; for we cannot expect to meet with human bones in the Miocene
formations, where all the species and nearly all the genera of mammalia
belong to types widely differing from those now living; and had some
other rational being, representing Man, then flourished, some signs
of his existence could hardly have escaped unnoticed, in the shape of
implements of stone or metal, more frequent and more durable than the
osseous remains of any of the mammalia.
In the beginning of this century it was one of the canons of the popular
geological creed that the first warm-blooded quadrupeds which had
inhabited this planet were those derived from the Eocene gypsum of
Montmartre in the suburbs of Paris, almost all of which Cuvier had shown
to belong to extinct genera. This dogma continued in force for more than
a quarter of a century, in spite of the discovery in 1818 of a marsupial
quadruped in the Stonesfield strata, a member of the Lower Oolite,
near Oxford. Some disputed the authority of Cuvier himself as to the
mammalian character of the fossil; others, the accuracy of those who had
assigned to it so ancient a place in the chronological series of rocks.
In 1832 I pointed out that the occurrence of this single fossil in
the Oolite was "fatal to the theory of successive development" as then
propounded.*
(* "Principles of Geology" 2nd edition 1 173.)
Since that period great additions have been made to our knowledge of
the existence of land quadrupeds in the olden times. We have ascertained
that, in Eocene strata older than the gypsum of Paris, no less than
four distinct sets of placental mammalia have flourished; namely, first,
those of the Headon series in the Isle of Wight, from which fourteen
species have been procured; secondly, those of the antecedent
Bagshot and Bracklesham beds, which have yielded, together with the
contemporaneous "calcaire grossier" of Paris, twenty species; thirdly,
the still older beds of Kyson, near Ipswich, and those of Herne Bay,
at the mouth of the Thames, in which seven species have been found;
and fourthly, the Woolwich and Reading beds, which have supplied ten
species.*
(* Lyell's supplement to 5th edition of "Elements" 1857.)
We can scarcely doubt that we should already have traced back the
evidence of this class of fossils much farther had not our inquiries
been arrested, first by the vast gap between the Tertiary and Secondary
formations, and then by the marine nature of the Cretaceous rocks.
The mammalia next in antiquity, of which we have any cognisance, are
those of the Upper Oolite of Purbeck, discovered between the years 1854
and 1857, and comprising no less than fourteen species, referable
to eight or nine genera; one of them, Plagiaulax, considered by Dr.
Falconer to have been a herbivorous marsupial. The whole assemblage
appear, from the joint observations of Professor Owen and Dr. Falconer,
to indicate a low grade of quadruped, probably of the marsupial type.
They were, for the most part, diminutive, the two largest not much
exceeding our common hedgehog and polecat in size.
Next anterior in age are the mammalia of the Lower Oolite of
Stonesfield, of which four species are known, also very small and
probably marsupial, with one exception, the Stereognathus ooliticus,
which, according to Professor Owen's conjecture, may have been a hoofed
quadruped and placental, though, as we have only half of the lower jaw
with teeth, and the molars are unlike any living type, such an opinion
is of course hazarded with due caution.
Still older than the above are some fossil quadrupeds of small size,
found in the Upper Trias of Stuttgart in Germany, and more lately by Mr.
C. Moore in beds of corresponding age near Frome, which are also of a
very low grade, like the living Myrmecobius of Australia. Beyond this
limit our knowledge of the highest class of vertebrata does not as
yet extend into the past, but the frequent shifting back of the old
landmarks, nearly all of them once supposed in their turn to indicate
the date of the first appearance of warm-blooded quadrupeds on this
planet, should serve as a warning to us not to consider the goal at
present reached by palaeontology as one beyond which they who come after
us are never destined to pass.
On the other hand, it may be truly said in favour of progression that
after all these discoveries the doctrine is not gainsaid, for the less
advanced marsupials precede the more perfect placental mammalia in the
order of their appearance on the earth.
If the three localities where the most ancient mammalia have been
found--Purbeck, Stonesfield, and Stuttgart--had belonged all of them to
formations of the same age, we might well have imagined so limited an
area to have been peopled exclusively with pouched quadrupeds, just
as Australia now is, while other parts of the globe were inhabited by
placentals, for Australia now supports one hundred and sixty species of
marsupials, while the rest of the continents and islands are tenanted by
about seventeen hundred species of mammalia, of which only forty-six
are marsupial, namely, the opossums of North and South America. But the
great difference of age of the strata in each of these three localities
seems to indicate the predominance throughout a vast lapse of time (from
the era of the Upper Trias to that of the Purbeck beds) of a low grade
of quadrupeds; and this persistency of similar generic and ordinal types
in Europe while the species were changing, and while the fish, reptiles,
and mollusca were undergoing vast modifications, raises a strong
presumption that there was also a vast extension in space of the same
marsupial forms during that portion of the Secondary epoch which has
been termed "the age of reptiles."
As to the class Reptilia, some of the orders which prevailed when
the Secondary rocks were formed are confessedly much higher in their
organisation than any of the same class now living. If the less perfect
ophidians, or snakes, which now abound on the earth had taken the lead
in those ancient days among the land reptiles, and the Deinosaurians
had been contemporary with Man, there can be no doubt that the
progressionist would have seized upon this fact with unfeigned
satisfaction as confirmatory of his views. Now that the order of
succession is precisely reversed, and that the age of the Iguanodon was
long anterior to that of the Eocene Palaeophis and living boa, while the
crocodile is in our own times the highest representative of its class, a
retrograde movement in this important division of the vertebrata must be
admitted. It may perhaps be accounted for by the power acquired by the
placental mammalia, when they became dominant, a power before which
the class of vertebrata next below them, as coming most directly in
competition with them, may more than any other have given way.
For no less than thirty-four years it had been a received axiom in
palaeontology that reptiles had never existed before the Permian or
Magnesian Limestone period, when at length in 1844 this supposed barrier
was thrown down, and Carboniferous reptiles, terrestrial and aquatic, of
several genera were brought to light; and discussions are now going
on as to whether some remains of an Enaliosaur (perhaps a large
Labyrinthodon) have not been detected in the coal of Nova Scotia, and
whether certain sandstones near Elgin in Scotland, containing the bones
of lacertian, crocodilian, and rhynchosaurian reptiles, may not be
referable to the "Old Red" or Devonian group. Still, no traces of this
class have yet been detected in rocks as ancient as those in which the
oldest fish have been found. [38]
As to fossil representatives of the ichthyic type, the most ancient were
not supposed before 1838 to be of a date anterior to the Coal, but they
have since been traced back, first to the Devonian, and then to the
Silurian rocks. No remains, however, of them or of any vertebrate animal
have yet been discovered in the Ordovician strata, rich as these are in
invertebrate fossils, nor in the still older Cambrian; so that we seem
authorised to conclude, though not without considerable reserve, that
the vertebrate type was extremely scarce, if not wholly wanting,
in those epochs often spoken of as "primitive," but which, if the
Development Theory be true, were probably the last of a long series of
antecedent ages in which living beings flourished.
As to the Mollusca, which afford the most unbroken series of geological
medals, the highest of that class, the Cephalopoda, abounded in
older Silurian times, comprising several hundred species of chambered
univalves. Had there been strong prepossessions against the progressive
theory, it would probably have been argued that when these cephalopods
abounded, and the siphonated gasteropods were absent, a higher order of
zoophagous mollusca discharged the functions afterwards performed by an
inferior order in the Secondary, Tertiary, and Post-Tertiary seas. But
I have never seen this view suggested as adverse to the doctrine of
progress, although much stress has been laid on the fact that the
Silurian Brachiopoda, creatures of a lower grade, formerly discharged
the functions of the existing lamellibranchiate bivalves, which are
higher in the scale.
It is said truly that the Ammonite, Orthoceras, and Nautilus of these
ancient rocks were of the tetrabranchiate division, and none of them
so highly organised as the Belemnite and other dibranchiate cephalopods
which afterwards appeared, and some of which now flourish in our seas.
Therefore, we may infer that the simplest forms of the Cephalopoda took
precedence of the more complex in time. But if we embrace this view, we
must not forget that there are living Cephalopoda, such as the Octopods,
which are devoid of any hard parts, whether external or internal, and
which could leave behind them no fossil memorials of their existence,
so that we must make a somewhat arbitrary assumption, namely, that at
a remote era, no such Dibranchiata were in being, in order to avail
ourselves of this argument in favour of progression. On the other
hand, it is true that in the Lower Cambrian not even the shell-bearing
tetrabranchiates have yet been discovered.
In regard to plants, although the generalisation above cited of M.
Adolphe Brongniart is probably true, there has been a tendency in the
advocates of progression to push the inferences deducible from known
facts, in support of their favourite dogma, somewhat beyond the limits
which the evidence justifies. Dr. Hooker observes, in his recent
"Introductory Essay to the Flora of Australia," that it is impossible
to establish a parallel between the successive appearances of vegetable
forms in time, and their complexity of structure or specialisation of
organs as represented by the successively higher groups in the natural
method of classification. He also adds that the earliest recognisable
Cryptogams are not only the highest now existing, but have more highly
differentiated vegetative organs than any subsequently appearing, and
that the dicotyledonous embryo and perfect exogenous wood, with the
highest specialised tissue known (the coniferous with glandular tissue),
preceded the monocotyledonous embryo and endogenous wood in date
of appearance on the globe--facts wholly opposed to the doctrine of
progression, and which can only be set aside on the supposition that
they are fragmentary evidence of a time farther removed from the origin
of vegetation than from the present day.*
(* "Introductory Essay to the Flora of Australia," page 31
London 1859. Published separately.) [39]
It would be an easy task to multiply objections to the theory now under
consideration; but from this I refrain, as I regard it not only as a
useful, but rather in the present state of science as an indispensable
hypothesis, and one which though destined hereafter to undergo many and
great modifications will never be overthrown.
It may be thought almost paradoxical that writers who are most in favour
of transmutation (Mr. C. Darwin and Dr. J. Hooker, for example) are
nevertheless among those who are most cautious, and one would say timid,
in their mode of espousing the doctrine of progression; while, on the
other hand, the most zealous advocates of progression are oftener than
not very vehement opponents of transmutation. We might have anticipated
a contrary leaning on the part of both, for to what does the theory
of progression point? It supposes a gradual elevation in grade of the
vertebrate type in the course of ages from the most simple ichthyic form
to that of the placental mammalia and the coming upon the stage last in
the order of time of the most anthropomorphous mammalia, followed by
the human race--this last thus appearing as an integral part of the same
continuous series of acts of development, one link in the same chain,
the crowning operation as it were of one and the same series of
manifestations of creative power. If the dangers apprehended from
transmutation arise from the too intimate connection which it tends to
establish between the human and merely animal natures, it might
have been expected that the progressive development of organisation,
instinct, and intelligence might have been unpopular, as likely to
pioneer the way for the reception of the less favoured doctrine. But the
true explanation of the seeming anomaly is this, that no one can believe
in transmutation who is not profoundly convinced that all we know in
palaeontology is as nothing compared with what we have yet to learn, and
they who regard the record as so fragmentary, and our acquaintance
with the fragments which are extant as so rudimentary, are apt to be
astounded at the confidence placed by the progressionists in data which
must be defective in the extreme. But exactly in proportion as the
completeness of the record and our knowledge of it are overrated,
in that same degree are many progressionists unconscious of the goal
towards which they are drifting. Their faith in the fullness of
the annals leads them to regard all breaks in the series of organic
existence, or in the sequence of the fossiliferous rocks, as proofs
of original chasms and leaps in the course of nature--signs of the
intermittent action of the creational force, or of catastrophes which
devastated the habitable surface. They do not doubt that there is a
continuity of plan, but they believe that it exists in the Divine mind
alone, and they are therefore without apprehension that any facts
will be discovered which would imply a material connection between the
outgoing organisms and the incoming ones.
CHAPTER 21. -- ON THE ORIGIN OF SPECIES BY VARIATION AND NATURAL
SELECTION.
Mr. Darwin's Theory of the Origin of Species by Natural Selection.
Memoir by Mr. Wallace.
Manner in which favoured Races prevail in the Struggle for Existence.
Formation of new Races by breeding.
Hypotheses of definite and indefinite Modifiability equally arbitrary.
Competition and Extinction of Races.
Progression not a necessary Accompaniment of Variation.
Distinct Classes of Phenomena which Natural Selection explains.
Unity of Type, Rudimentary Organs, Geographical Distribution,
Relation of the extinct to the living Fauna and Flora, and
mutual Relations of successive Groups of Fossil Forms.
Light thrown on Embryological Development by Natural Selection.
Why large Genera have more variable Species than small ones.
Dr. Hooker on the Evidence afforded by the Vegetable Kingdom
in favour of Creation by Variation.
Steenstrup on alternation of Generations.
How far the Doctrine of Independent Creation is opposed to the
Laws now governing the Migration of Species.
For many years after the promulgation of Lamarck's doctrine of
progressive development, geologists were much occupied with the question
whether the past changes in the animate and inanimate world were brought
about by sudden and paroxysmal action, or gradually and continuously, by
causes differing neither in kind nor degree from those now in operation.
The anonymous author of "The Vestiges of Creation" published in 1844
a treatise, written in a clear and attractive style, which made
the English public familiar with the leading views of Lamarck on
transmutation and progression, but brought no new facts or original
line of argument to support those views, or to combat the principal
objections which the scientific world entertained against them.
No decided step in this direction was made until the publication in 1858
of two papers, one by Mr. Darwin and another by Mr. Wallace, followed in
1859 by Mr. Darwin's celebrated work on "The Origin of Species by Means
of Natural Selection; or, the Preservation of favoured Races in the
Struggle for Life." The author of this treatise had for twenty previous
years strongly inclined to believe that variation and the ordinary laws
of reproduction were among the secondary causes always employed by the
Author of nature, in the introduction from time to time of new species
into the world, and he had devoted himself patiently to the collecting
of facts and making of experiments in zoology and botany, with a view
of testing the soundness of the theory of transmutation. Part of the
manuscript of his projected work was read to Dr. Hooker as early as 1844
and some of the principal results were communicated to me on several
occasions. [40] Dr. Hooker and I had repeatedly urged him to publish
without delay, but in vain, as he was always unwilling to interrupt the
course of his investigations; until at length Mr. Alfred R. Wallace, who
had been engaged for years in collecting and studying the animals of the
East Indian archipelago, thought out independently for himself one of
the most novel and important of Mr. Darwin's theories. This he embodied
in an essay "On the Tendency of Varieties to depart indefinitely from
the original Type." It was written at Ternate in February 1858, and sent
to Mr. Darwin with a request that it might be shown to me if thought
sufficiently novel and interesting. Dr. Hooker and I were of opinion
that it should be immediately printed, and we succeeded in persuading
Mr. Darwin to allow one of the manuscript chapters of his "Origin of
Species," entitled "On the Tendency of Species to form Varieties, and
on the Perpetuation of Species and Varieties by natural Means of
Selection," to appear at the same time.*
(* See "Proceedings of the Linnaean Society" 1858.)
By reference to these memoirs it will be seen that both writers begin by
applying to the animal and vegetable worlds the Malthusian doctrine of
population, or its tendency to increase in a geometrical ratio, while
food can only be made to augment even locally in an arithmetical one.
There being therefore no room or means of subsistence for a large
proportion of the plants and animals which are born into the world, a
great number must annually perish. Hence there is a constant struggle
for existence among the individuals which represent each species and
the vast majority can never reach the adult state, to say nothing of
the multitudes of ova and seeds which are never hatched or allowed to
germinate. Of birds it is estimated that the number of those which die
every year equals the aggregate number by which the species to which
they respectively belong is on the average permanently represented.
The trial of strength which must decide what individuals are to survive
and what to succumb occurs in the season when the means of subsistence
are fewest, or enemies most numerous, or when the individuals are
enfeebled by climate or other causes; and it is then that those
varieties which have any, even the slightest, advantage over others come
off victorious. They may often owe their safety to what would seem to a
casual observer a trifling difference, such as a darker or lighter shade
of colour rendering them less visible to a species which preys upon
them, or sometimes to attributes more obviously advantageous, such as
greater cunning or superior powers of flight or swiftness of foot. These
peculiar qualities and faculties, bodily and instinctive, may enable
them to outlive their less favoured rivals, and being transmitted by the
force of inheritance to their offspring will constitute new races, or
what Mr. Darwin calls "incipient species." If one variety, being
in other respects just equal to its competitors, happens to be more
prolific, some of its offspring will stand a greater chance of being
among those which will escape destruction, and their descendants, being
in like manner very fertile, will continue to multiply at the expense of
all less prolific varieties.
As breeders of domestic animals, when they choose certain varieties in
preference to others to breed from, speak technically of their method as
that of "selecting," Mr. Darwin calls the combination of natural causes,
which may enable certain varieties of wild animals or plants to prevail
over others of the same species, "natural selection."
A breeder finds that a new race of cattle with short horns or without
horns may be formed in the course of several generations by choosing
varieties having the most stunted horns as his stock from which to
breed; so nature, by altering in the course of ages, the conditions
of life, the geographical features of a country, its climate, the
associated plants and animals, and consequently the food and enemies
of a species and its mode of life, may be said, by this means to select
certain varieties best adapted for the new state of things. Such
new races may often supplant the original type from which they
have diverged, although that type may have been perpetuated without
modification for countless anterior ages in the same region, so long as
it was in harmony with the surrounding conditions then prevailing.
Lamarck, when speculating on the origin of the long neck of the giraffe,
imagined that quadruped to have stretched himself up in order to reach
the boughs of lofty trees, until by continued efforts and longing to
reach higher he obtained an elongated neck. Mr. Darwin and Mr. Wallace
simply suppose that, in a season of scarcity, a longer-necked variety,
having the advantage in this respect over most of the herd, as being
able to browse on foliage out of their reach, survived them and
transmitted its peculiarity of cervical conformation to its successors.
By the multiplying of slight modifications in the course of thousands of
generations and by the handing down of the newly-acquired peculiarities
by inheritance, a greater and greater divergence from the original
standard is supposed to be effected, until what may be called a new
species, or in a greater lapse of time a new genus will be the result.
Every naturalist admits that there is a general tendency in animals and
plants to vary; but it is usually taken for granted, though he have
no means of proving the assumption to be true, that there are certain
limits beyond which each species cannot pass under any circumstances or
in any number of generations. Mr. Darwin and Mr. Wallace say that the
opposite hypothesis, which assumes that every species is capable
of varying indefinitely from its original type, is not a whit more
arbitrary, and has this manifest claim to be preferred, that it will
account for a multitude of phenomena which the ordinary theory is
incapable of explaining.
We have no right, they say, to assume, should we find that a variable
species can no longer be made to vary in a certain direction, that it
has reached the utmost limit to which it might under more favourable
conditions or if more time were allowed be made to diverge from the
parent type.
Hybridisation is not considered by Mr. Darwin as a cause of new species,
but rather as tending to keep variation within bounds. Varieties which
are nearly allied cross readily with each other, and with the parent
stock, and such crossing tends to keep the species true to its type,
while forms which are less nearly related, although they may intermarry,
produce no mule offspring capable of perpetuating their kind.
The competition of races and species, observes Mr. Darwin, is always
most severe between those which are most closely allied and which
fill nearly the same place in the economy of nature. Hence when the
conditions of existence are modified the original stock runs great risk
of being superseded by some one of its modified offshoots. The new race
or species may not be absolutely superior in the sum of its powers and
endowments to the parent stock, and may even be more simple in structure
and of a lower grade of intelligence, as well as of organisation,
provided on the whole it happens to have some slight advantage over
its rivals. Progression, therefore, is not a necessary accompaniment
of variation and natural selection, though when a higher organisation
happens to be coincident with superior fitness to new conditions, the
new species will have greater power and a greater chance of permanently
maintaining and extending its ground. One of the principal claims of Mr.
Darwin's theory to acceptance is that it enables us to dispense with a
law of progression as a necessary accompaniment of variation. It will
account equally well for what is called degradation, or a retrograde
movement towards a simpler structure, and does not require Lamarck's
continual creation of monads; for this was a necessary part of his
system, in order to explain how, after the progressive power had been
at work for myriads of ages, there were as many beings of the simplest
structure in existence as ever.
Mr. Darwin argues, and with no small success, that all true
classification in zoology and botany is in fact genealogical, and that
community of descent is the hidden bond which naturalists have been
unconsciously seeking, while they often imagined that they were looking
for some unknown plan of creation.
As the "Origin of Species"* is in itself a condensed abstract of a much
larger work not yet published [41] I could not easily give an analysis
of its contents within narrower limits than those of the original, but
it may be useful to enumerate briefly some of the principal classes of
phenomena on which the theory of "natural selection" would throw light.
(* "Origin of Species" page 121.)
In the first place it would explain, says Mr. Darwin, the unity of type
which runs through the whole organic world, and why there is sometimes a
fundamental agreement in structure in the same class of beings which is
quite independent of their habits of life, for such structure, derived
by inheritance from a remote progenitor, has been modified in the course
of ages in different ways according to the conditions of existence.
It would also explain why all living and extinct beings are united, by
complex radiating and circuitous lines of affinity with one another into
one grand system;* also, there having been a continued extinction of old
races and species in progress and a formation of new ones by variation,
why in some genera which are largely represented, or to which a great
many species belong, many of these are closely but unequally related;
also, why there are distinct geographical provinces of species of
animals and plants, for after long isolation by physical barriers each
fauna and flora by varying continually must become distinct from its
ancestral type, and from the new forms assumed by other descendants
which have diverged from the same stock.
(* "Origin" page 498.)
The theory of indefinite modification would also explain why rudimentary
organs are so useful in classification, being the remnants preserved
by inheritance of organs which the present species once used--as in the
case of the rudiments of eyes in insects and reptiles inhabiting dark
caverns, or of the wings of birds and beetles which have lost all
power of flight. In such cases the affinities of species are often more
readily discerned by reference to these imperfect structures than
by others of much more physiological importance to the individuals
themselves.
The same hypothesis would explain why there are no mammalia in islands
far from continents, except bats, which can reach them by flying; and
also why the birds, insects, plants, and other inhabitants of islands,
even when specifically unlike, usually agree generically with those of
the nearest continent, it being assumed that the original stock of such
species came by migration from the nearest land.
Variation and natural selection would also afford a key to a multitude
of geological facts otherwise wholly unaccounted for, as for example why
there is generally an intimate connection between the living animals
and plants of each great division of the globe and the extinct fauna and
flora of the Post-Tertiary or Tertiary formations of the same region;
as, for example, in North America, where we not only find among the
living mollusca peculiar forms foreign to Europe, such as Gnathodon
and Fulgur (a subgenus of Fusus), but meet also with extinct species of
those same genera in the Tertiary fauna of the same part of the world.
In like manner, among the mammalia we find in Australia not only living
kangaroos and wombats, but fossil individuals of extinct species of the
same genera. So also there are recent and fossil sloths, armadilloes
and other Edentata in South America, and living and extinct species
of elephant, rhinoceros, tiger, and bear in the great Europeo-Asiatic
continent. The theory of the origin of new species by variation will
also explain why a species which has once died out never reappears
and why the fossil fauna and flora recede farther and farther from the
living type in proportion as we trace them back to remoter ages. It
would also account for the fact that when we have to intercalate a new
set of fossiliferous strata between two groups previously known, the
newly discovered fossils serve to fill up gaps between specific or
generic types previously familiar to us, supplying often the missing
links of the chain, which, if transmutation is accepted, must once have
been continuous.
One of the most original speculations in Mr. Darwin's work is derived
from the fact that, in the breeding of animals, it is often observed
that at whatever age any variation first appears in the parent, it tends
to reappear at a corresponding age in the offspring. Hence the young
individuals of two races which have sprung from the same parent stock
are usually more like each other than the adults. Thus the puppies
of the greyhound and bull-dog are much more nearly alike in their
proportions than the grown-up dogs, and in like manner the foals of the
carthorse and racehorse than the adult individuals. For the same reason
we may understand why the species of the same genus, or genera of the
same family, resemble each other more nearly in their embryonic than in
their more fully developed state, or how it is that in the eyes of
most naturalists the structure of the embryo is even more important in
classification than that of the adult, "for the embryo is the animal in
its less modified state, and in so far it reveals the structure of its
progenitor. In two groups of animals, however much they may at present
differ from each other in structure and habits, if they pass through
the same or similar embryonic stages, we may feel assured that they
have both descended from the same or nearly similar parents, and are
therefore in that degree closely related. Thus community in embryonic
structure reveals community of descent, however much the structure of
the adult may have been modified."*
(* Darwin, "Origin" etc. page 448.)
If then there had been a system of progressive development, the
successive changes through which the embryo of a species of a high
class, a mammifer for example, now passes, may be expected to present us
with a picture of the stages through which, in the course of ages, that
class of animals has successively passed in advancing from a lower to a
higher grade. Hence the embryonic states exhibited one after the other
by the human individual bear a certain amount of resemblance to those
of the fish, reptile, and bird before assuming those of the highest
division of the vertebrata.
Mr. Darwin, after making a laborious analysis of many floras, found that
those genera which are represented by a large number of species contain
a greater number of variable species, relatively speaking, than the
smaller genera or those less numerously represented. This fact he
adduces in support of his opinion that varieties are incipient species,
for he observes that the existence of the larger genera implies that
the manufacturing of species has been active in the period immediately
preceding our own, in which case we ought generally to find the same
forces still in full activity, more especially as we have every reason
to believe the process by which new species are produced is a slow one.*
(* "Origin of Species" chapter 2 page 56.)
Dr. Hooker tells us that he was long disposed to doubt this result,
as he was acquainted with so many variable small genera, but after
examining Mr. Darwin's data, he was compelled to acquiesce in his
generalisation.*
(* "Introductory Essay to the Flora of Australia" page 6.)
It is one of those conclusions, to verify which requires the
investigation of many thousands of species, and to which exceptions may
easily be adduced both in the animal and vegetable kingdoms, so that
it will be long before we can expect it to be thoroughly tested, and
if true, fairly appreciated. Among the most striking exceptions will
be some genera still large, but which are beginning to decrease, the
conditions favourable to their former predominance having already
begun to change. To many, this doctrine of "natural selection," or
"the preservation of favoured races in the struggle for life," seems so
simple, when once clearly stated, and so consonant with known facts and
received principles, that they have difficulty in conceiving how it can
constitute a great step in the progress of science. Such is often the
case with important discoveries, but in order to assure ourselves that
the doctrine was by no means obvious, we have only to refer back to the
writings of skilful naturalists who attempted in the earlier part of the
nineteenth century to theorise on this subject, before the invention of
this new method of explaining how certain forms are supplanted by new
ones and in what manner these last are selected out of innumerable
varieties and rendered permanent.
DR. HOOKER ON THE THEORY OF "CREATION BY VARIATION" AS APPLIED TO THE
VEGETABLE KINGDOM.
Of Dr. Hooker, whom I have often cited in this chapter, Mr. Darwin has
spoken in the Introduction to his "Origin of Species," as one "who had,
for fifteen years, aided him in every possible way, by his large stores
of knowledge, and his excellent judgment." This distinguished botanist
published his "Introductory Essay to the Flora of Australia" in December
1859, the year after the memoir on "Natural Selection" was communicated
to the Linnaean Society, and a month after the appearance of the "Origin
of Species."
Having, in the course of his extensive travels, studied the botany of
arctic, temperate, and tropical regions, and written on the flora of
India, which he had examined at all heights above the sea from the
plains of Bengal to the limits of perpetual snow in the Himalaya, and
having specially devoted his attention to "geographical varieties," or
those changes of character which plants exhibit when traced over wide
areas and seen under new conditions; being also practically versed in
the description and classification of new plants, from various parts of
the world, and having been called upon carefully to consider the
claims of thousands of varieties to rank as species, no one was better
qualified by observation and reflection to give an authoritative opinion
on the question, whether the present vegetation of the globe is or is
not in accordance with the theory which Mr. Darwin has proposed. We
cannot but feel, therefore, deeply interested when we find him making
the following declaration:
"The mutual relations of the plants of each great botanical province,
and, in fact, of the world generally, is just such as would have
resulted if variation had gone on operating throughout indefinite
periods, in the same manner as we see it act in a limited number of
centuries, so as gradually to give rise in the course of time, to the
most widely divergent forms."
In the same essay, this author remarks, "The element of mutability
pervades the whole Vegetable Kingdom; no class, nor order, nor genus of
more than a few species claims absolute exemption from it, whilst the
grand total of unstable forms, generally assumed to be species, probably
exceeds that of the stable." Yet he contends that species are neither
visionary, nor even arbitrary creations of the naturalist, but
realities, though they may not remain true for ever. The majority
of them, he remarks, are so far constant, "within the range of our
experience," and their forms and characters so faithfully handed down
through thousands of generations, that they admit of being treated as if
they were permanent and immutable. But the range of "our experience" is
so limited, that it will "not account for a single fact in the present
geographical distribution, or origin of any one species of plant, nor
for the amount of variation it has undergone, nor will it indicate the
time when it first appeared, nor the form it had when created."*
(* Hooker, "Introductory Essay to the Flora of Australia.")
To what an extent the limits of species are indefinable, is evinced, he
says, by the singular fact that, among those botanists who believe them
to be immutable, the number of flowering plants is by some assumed to be
80,000, and by others over 150,000. The general limitation of species
to certain areas suggests the idea that each of them, with all their
varieties, have sprung from a common parent and have spread in various
directions from a common centre. The frequency also of the grouping of
genera within certain geographical limits is in favour of the same
law, although the migration of species may sometimes cause apparent
exceptions to the rule and make the same types appear to have originated
independently at different spots.*
(* Ibid. page 13.)
Certain genera of plants, which, like the brambles, roses, and willows
in Europe, consist of a continuous series of varieties between the terms
of which no intermediate forms can be intercalated, may be supposed
to be newer types and on the increase, and therefore undergoing much
variation; whereas genera which present no such perplexing gradations
may be of older date and may have been losing species and varieties by
extinction. In this case, the annihilation of intermediate forms which
once existed makes it an easy task to distinguish those which remain.
It had usually been supposed by the advocates of the immutability of
species that domesticated races, if allowed to run wild, always revert
to their parent type. Mr. Wallace had said in reply that a domesticated
species, if it loses the protection of Man, can only stand its ground
in a wild state by resuming those habits and recovering those attributes
which it may have lost when under domestication. If these faculties are
so much enfeebled as to be irrecoverable it will perish; if not and if
it can adapt itself to the surrounding conditions, it will revert to the
state in which Man first found it: for in one, two, or three thousand
years, which may have elapsed since it was originally tamed, there will
not have been time for such geographical, climatal, and organic changes
as would only be suited to a new race or a new and allied species.
But in regard to plants Dr. Hooker questions the fact of reversion.
According to him, species in general do not readily vary, but when they
once begin to do so the new varieties, as every horticulturist knows,
show a great inclination to go on departing more and more from the
old stock. As the best marked varieties of a wild species occur on the
confines of the area which it inhabits, so the best marked varieties of
a cultivated plant are those last produced by the gardener. Cabbages,
for example, wall fruits, and cereal, show no disposition, when
neglected, to assume the characters of the wild states of these plants.
Hence the difficulty of determining what are the true parent species of
most of our cultivated plants. Thus the finer kinds of apples, if grown
from seed, degenerate and become crabs, but in so doing they do not
revert to the original wild crab-apple, but become crab states of the
varieties to which they belong.*
(* "Introductory Essay to the Flora of Australia" page 9.)
It would lead me into too long a digression were I to attempt to give a
fuller analysis of this admirable essay; but I may add that none of
the observations are more in point, as bearing on the doctrine of what
Hooker terms "creation by variation," than the great extent to which
the internal characters and properties of plants, or their physiological
constitution, are capable of being modified, while they exhibit
externally no visible departure from the normal form. Thus, in one
region a species may possess peculiar medicinal qualities which it wants
in another, or it may be hardier and better able to resist cold. The
average range in altitude, says Hooker, of each species of flowering
plant in the Himalayan Mountains, whether in the tropical, temperate,
or Alpine region, is 4000 feet, which is equivalent to twelve degrees
of isothermals of latitude. If an individual of any of these species be
taken from the upper limits of its range and carried to England, it is
found to be better able to stand our climate than those from the lower
or warmer stations. When several of these internal or physiological
modifications are accompanied by variation in size, habits of growth,
colour of the flowers, and other external characters, and these are
found to be constant in successive generations, botanists may well begin
to differ in opinion as to whether they ought to regard them as distinct
species or not.
ALTERNATION OF GENERATIONS.
Hitherto, no rival hypothesis has been proposed as a substitute for the
doctrine of transmutation; for what we term "independent creation," or
the direct intervention of the Supreme Cause, must simply be considered
as an avowal that we deem the question to lie beyond the domain of
science.
The discovery by Steenstrup of alternate generation enlarges our views
of the range of metamorphosis through which a species may pass, so
that some of its stages (as when a Sertularia and a Medusa interchange)
deviate so far from others as to have been referred by able zoologists
to distinct genera, or even families. But in all these cases the
organism, after running through a certain cycle of change, returns to
the exact point from which it set out, and no new form or species is
thereby introduced into the world. The only secondary cause therefore
which has as yet been even conjecturally brought forward, to explain how
in the ordinary course of nature a new specific form may be generated
is, as Lamarck declared, "variation," and this has been rendered a far
more probable hypothesis by the way in which "natural selection" is
shown to give intensity and permanency to certain varieties.
INDEPENDENT CREATION.
When I formerly advocated the doctrine that species were primordial
creations and not derivative, I endeavoured to explain the manner of
their geographical distribution, and the affinity of living forms to
the fossil types nearest akin to them in the Tertiary strata of the
same part of the globe, by supposing that the creative power, which
originally adapts certain types to aquatic and others to terrestrial
conditions, has at successive geological epochs introduced new forms
best suited to each area and climate, so as to fill the places of those
which may have died out.
In that case, although the new species would differ from the old (for
these would not be revived, having been already proved by the fact of
their extinction to be incapable of holding their ground), still they
would resemble their predecessors generically. For, as Mr. Darwin states
in regard to new races, those of a dominant type inherit the advantages
which made their parent species flourish in the same country, and they
likewise partake in those general advantages which made the genus to
which the parent species belonged a large genus in its own country.
We might therefore, by parity of reasoning, have anticipated that the
creative power, adapting the new types to the new combination of organic
and inorganic conditions of a given region, such as its soil,
climate, and inhabitants, would introduce new modifications of the old
types--marsupials, for example, in Australia, new sloths and armadilloes
in South America, new heaths at the Cape, new roses in the northern
and new calceolarias in the southern hemisphere. But to this line of
argument Mr. Darwin and Dr. Hooker reply that when animals or plants
migrate into new countries, whether assisted by man or without his aid,
the most successful colonisers appertain by no means to those types
which are most allied to the old indigenous species. On the contrary it
more frequently happens that members of genera, orders, or even classes,
distinct and foreign to the invaded country, make their way most rapidly
and become dominant at the expense of the endemic species. Such is the
case with the placental quadrupeds in Australia, and with horses and
many foreign plants in the pampas of South America, and numberless
instances in the United States and elsewhere which might easily be
enumerated. Hence the transmutationists infer that the reason why these
foreign types, so peculiarly fitted for these regions, have never
before been developed there is simply that they were excluded by natural
barriers. But these barriers of sea or desert or mountain could never
have been of the least avail had the creative force acted independently
of material laws or had it not pleased the Author of Nature that the
origin of new species should be governed by some secondary causes
analogous to those which we see preside over the appearance of new
varieties, which never appear except as the offspring of a parent stock
very closely resembling them.
CHAPTER 22. -- OBJECTIONS TO THE HYPOTHESIS OF TRANSMUTATION CONSIDERED.
Statement of Objections to the Hypothesis of Transmutation
founded on the Absence of Intermediate Forms.
Genera of which the Species are closely allied.
Occasional Discovery of the missing Links in a Fossil State.
Davidson's Monograph on the Brachiopoda.
Why the Gradational Forms, when found, are not accepted as
Evidence of Transmutation.
Gaps caused by Extinction of Races and Species.
Vast Tertiary Periods during which this Extinction has been going
on in the Fauna and Flora now existing.
Genealogical Bond between Miocene and Recent Plants and Insects.
Fossils of Oeningen.
Species of Insects in Britain and North America represented by
distinct Varieties.
Falconer's Monograph on living and fossil Elephants.
Fossil Species and Genera of the Horse Tribe in North and
South America.
Relation of the Pliocene Mammalia of North America, Asia,
and Europe.
Species of Mammalia, though less persistent than the Mollusca,
change slowly.
Arguments for and against Transmutation derived from the Absence
of Mammalia in Islands.
Imperfection of the Geological Record.
Intercalation of newly discovered Formation of intermediate Age
in the chronological Series.
Reference of the St. Cassian Beds to the Triassic Periods.
Discovery of new organic Types.
Feathered Archaeopteryx of the Oolite.
THEORY OF TRANSMUTATION--ABSENCE OF INTERMEDIATE LINKS.
The most obvious and popular of the objections urged against the theory
of transmutation may be thus expressed: If the extinct species of plants
and animals of the later geological periods were the progenitors of
the living species, and gave origin to them by variation and natural
selection, where are all the intermediate forms, fossil and living,
through which the lost types must have passed during their conversion
into the living ones? And why do we not find almost everywhere passages
between the nearest allied species and genera, instead of such strong
lines of demarcation and often wide intervening gaps?
We may consider this objection under two heads:--
First. To what extent are the gradational links really wanting in the
living creation or in the fossil world, and how far may we expect to
discover such as are missing by future research?
Secondly. Are the gaps more numerous than we ought to anticipate,
allowing for the original defective state of the geological records,
their subsequent dilapidation and our slight acquaintance with
such parts of them as are extant, and allowing also for the rate of
extinction of races and species now going on, and which has been going
on since the commencement of the Tertiary period?
First. As to the alleged absence of intermediate varieties connecting
one species with another, every zoologist and botanist who has engaged
in the task of classification has been occasionally thrown into this
dilemma--if I make more than one species in this group, I must, to be
consistent, make a great many. Even in a limited region like the British
Isles this embarrassment is continually felt.
Scarcely any two botanists, for example, can agree as to the number of
roses, still less as to how many species of bramble we possess. Of the
latter genus, Rubus, there is one set of forms respecting which it is
still a question whether it ought to be regarded as constituting three
species or thirty-seven. Mr. Bentham adopts the first alternative and
Mr. Babington the second, in their well-known treatises on British
plants.
We learn from Dr. Hooker that at the antipodes, both in New Zealand and
Australia, this same genus Rubus is represented by several species rich
in individuals and remarkable for their variability. When we consider
how, as we extend our knowledge of the same plant over a wider area, new
geographical varieties commonly present themselves, and then endeavour
to imagine the number of forms of the genus Rubus which may now exist,
or probably have existed, in Europe and in regions intervening between
Europe and Australia, comprehending all which may have flourished in
Tertiary and Post-Tertiary periods, we shall perceive how little stress
should be laid on arguments founded on the assumed absence of missing
links in the flora as it now exists.
If in the battle of life the competition is keenest between closely
allied varieties and species, as Mr. Darwin contends, many forms can
never be of long duration, nor have a wide range, and these must often
pass away without leaving behind them any fossil memorials. In this
manner we may account for many breaks in the series which no future
researches will ever fill up.
DAVIDSON ON FOSSIL BRACHIOPODA.
It is from fossil conchology more than from any other department of the
organic world that we may hope to derive traces of a transition from
certain types to others, and fossil memorials of all the intermediate
shades of form. We may especially hope to gain this information from the
study of some of the lower groups, such as the Brachiopoda, which are
persistent in type, so that the thread of our inquiry is less likely to
be interrupted by breaks in the sequence of the fossiliferous rocks.
The splendid monograph just concluded by Mr. Davidson on the British
Brachiopoda, illustrates, in the first place, the tendency of certain
generic forms in this division of the mollusca to be persistent
throughout the whole range of geological time yet known to us; for
the four genera, Rhynchonella, Crania, Discina, and Lingula, have been
traced through the Silurian, Devonian, Carboniferous, Permian, Jurassic,
Cretaceous, Tertiary, and Recent periods, and still retain in the
existing seas the identical shape and character which they exhibited in
the earliest formations. On the other hand, other Brachiopoda have gone
through in shorter periods a vast series of transformations, so that
distinct specific and even generic names have been given to the same
varying form, according to the different aspects and characters it has
put on in successive sets of strata.
In proportion as materials of comparison have accumulated, the
necessity of uniting species previously regarded as distinct under
one denomination has become more and more apparent. Mr. Davidson,
accordingly, after studying not less than 260 reputed species from the
British Carboniferous rocks, has been obliged to reduce that number to
100, to which he has added 20 species either entirely new or new to the
British strata; but he declares his conviction that, when our knowledge
of these 120 Brachiopoda is more complete, a further reduction of
species will take place.
Speaking of one of these forms, which he calls Spirifer trigonalis,
he says that it is so dissimilar to another extreme of the series, S.
crassa, that in the first part of his memoir (published some ten years
ago) he described them as distinct, and the idea of confounding them
together must, he admits, appear absurd to those who have never seen the
intermediate links, such as are presented by S. bisulcata, and at
least four others with their varieties, most of them shells formerly
recognised as distinct by the most eminent palaeontologists, but
respecting which these same authorities now agree with Mr. Davidson in
uniting them into one species.*
(* "Monograph on British Brachiopoda" Palaeontographical
Society page 222.)
The same species has sometimes continued to exist under slightly
modified forms throughout the whole of the Ordovician and Silurian as
well as the entire Devonian and Carboniferous periods, as in the case of
the shell generally known as Leptaena rhomboidalis, Wahlenberg. No less
than fifteen commonly received species are demonstrated by Mr. Davidson
by the aid of a long series of transitional forms, to appertain to this
one type; and it is acknowledged by some of the best writers that they
were induced on purely theoretical grounds to give distinct names to
some of the varieties now suppressed, merely because they found them in
rocks so widely remote in time that they deemed it contrary to
analogy to suppose that the same species could have endured so long:
a fallacious mode of reasoning, analogous to that which leads some
zoologists and botanists to distinguish by specific names slight
varieties of living plants and animals met with in very remote
countries, as in Europe and Australia, for example; it being assumed
that each species has had a single birthplace or area of creation, and
that they could not by migration have gone from the northern to the
southern hemisphere across the intervening tropics.
Examples are also given by Mr. Davidson of species which pass from the
Devonian into the Carboniferous, and from that again into the Permian
rocks. The vast longevity of such specific forms has not been generally
recognised in consequence of the change of names which they have
undergone when derived from such distant formations, as when Atrypa
unguicularis assumes, when derived from a Carboniferous rock, the name
of Spirifer Urei, besides several other synonyms, and then, when it
reaches the Permian period, takes the name of Spirifer Clannyana, King;
all of which forms the author of the monograph, now under consideration,
asserts to be one and the same.
No geologist will deny that the distance of time which separates some
of the eras above alluded to, or the dates of the earliest and latest
appearances of some of the fossils above mentioned, must be reckoned by
millions of years. According to Mr. Darwin's views, it is only by having
at our command the records of such enormous periods that we can expect
to be able to point out the gradations which unite very distinct
specific forms. But the advocate of transmutation must not be
disappointed if, when he has succeeded in obtaining some of the proofs
which he was challenged to produce, they make no impression on the mind
of his opponent. All that will be conceded is that specific variation
in the Brachiopoda, at least, has a wider range than was formerly
suspected. So long as several allied species were brought nearer and
nearer to each other, considerable uneasiness might have been felt as
to the reality of species in general, but when fifteen or more are
once fairly merged in one group, constituting in the aggregate a single
species, one and indivisible, and capable of being readily distinguished
from every other group at present known, all misgivings are at an end.
Implicit trust in the immutability of species is then restored, and the
more insensible the shades from one extreme to the other, in a word,
the more complete the evidence of transition, the more nugatory does the
argument derived from it appear. It then simply resolves itself into one
of those exceptional instances of what is called a protean form.
Thirty years ago a great London dealer in shells, himself an able
naturalist, told me that there was nothing he had so much reason to
dread, as tending to depreciate his stock in trade, as the appearance of
a good monograph on some large genus of mollusca; for, in proportion as
the work was executed in a philosophical spirit, it was sure to injure
him, every reputed species pronounced to be a mere variety becoming from
that time unsaleable. Fortunately, so much progress has since been
made in England in estimating the true ends and aims of science, that
specimens indicating a passage between forms usually separated by wide
gaps, whether in the Recent or fossil fauna, are eagerly sought for, and
often more prized than the mere normal or typical forms.
It is clear that the more ancient the existing mollusca, or the farther
back into the past we can trace the remains of shells still living, the
more easy it becomes to reconcile with the doctrine of transmutation the
distinctness in character of the majority of living species. For, what
we want is time, first, for the gradual formation, and then for the
extinction of races and allied species, occasioning gaps between the
survivors.
In the year 1830 I announced, on the authority of M. Deshayes, that
about one-fifth of the mollusca of the Falunian or Upper Miocene strata
of Europe, belonged to living species. Although the soundness of that
conclusion was afterwards called in question by two or three eminent
conchologists (and by the late M. Alcide d'Orbigny among others), it has
since been confirmed by the majority of living naturalists and is well
borne out by the copious evidence on the subject laid before the public
in the magnificent work edited by Dr. Hoernes, and published under the
auspices of the Austrian Government, "On the Fossil Shells of the Vienna
Basin."
The collection of Tertiary shells from which those descriptions and
beautiful figures were taken is almost unexampled for the fine state of
preservation of the specimens, and the care with which all the varieties
have been compared. It is now admitted that about one-third of these
Miocene forms, univalves and bivalves included, agree specifically with
living mollusca, so that much more than the enormous interval which
divides the Miocene from the Recent period must be taken into our
account when we speculate on the origin by transmutation of the
shells now living, and the disappearance by extinction of intermediate
varieties and species.
MIOCENE PLANTS AND INSECTS RELATED TO RECENT SPECIES.
Geologists were acquainted with about three hundred species of marine
shells from the Falunian strata on the banks of the Loire, before they
knew anything of the contemporary insects and plants. At length, as if
to warn us against inferring from negative evidence the poverty of any
ancient set of strata in organic remains proper to the land, a rich
flora and entomological fauna was suddenly revealed to us characteristic
of Central Europe during the Upper Miocene period. This result
followed the determination of the true position of the Oeningen beds in
Switzerland, and of certain formations of "Brown Coal" in Germany.
Professor Heer, who has described nearly five hundred species of fossil
plants from Oeningen, besides many more from other Miocene localities
in Switzerland,* estimates the phanerogamous species which must have
flourished in Central Europe at that time at 3000, and the insects as
having been more numerous in the same proportion as they now exceed the
plants in all latitudes.
(* Heer, "Flora tertiaria Helvetiae" 1859; and Gaudin's
French translation, with additions, 1861.)
This European Miocene flora was remarkable for the preponderance of
arborescent and shrubby evergreens, and comprised many generic types
no longer associated together in any existing flora or geographical
province. Some genera, for example, which are at present restricted to
America, co-existed in Switzerland with forms now peculiar to Asia, and
with others at present confined to Australia.
Professor Heer has not ventured to identify any of this vast assemblage
of Miocene plants and insects with living species, so far at least as to
assign to them the same specific names, but he presents us with a list
of what he terms homologous forms, which are so like the living ones
that he supposes the one to have been derived genealogically from the
others. He hesitates indeed as to the manner of the transformation
or the precise nature of the relationship, "whether the changes were
brought about by some influence exerted continually for ages, or whether
at some given moment the old types were struck with a new image."
Among the homologous plants alluded to are forty species, of which both
the leaves and fruits are preserved, and thirty others, known at present
by their leaves only. In the first list we find many American types,
such as the tulip tree (Liriodendron), the deciduous cypress (Taxodium),
the red maple and others, together with Japanese forms, such as a
cinnamon, which is very abundant. And what is worthy of notice, some of
these fossils so closely allied to living plants occur not only in
the Upper, but even some few of them as far back in time as the Lower
Miocene formations of Switzerland and Germany, which are probably as
distant from the Upper Miocene or Oeningen beds as are the latter from
our own era.
Some of the fossil plants to which Professor Heer has given new names
have been regarded as Recent species by other eminent naturalists. Thus,
one of the trees allied to the elm Unger had called Planera Richardi, a
species which now flourishes in the Caucasus and Crete. Professor Heer
had attempted to distinguish it from the living tree by the greater size
of its fruit, but this character he confessed did not hold good, when he
had an opportunity (1861) of comparing all the varieties of the living
Planera Richardi which Dr. Hooker laid before him in the rich herbarium
of Kew.
As to the "homologous insects" of the Upper Miocene period in
Switzerland, we find among them, mingled with genera now wholly foreign
to Europe, some very familiar forms, such as the common glowworm,
Lampyris noctiluca, Linn., the dung-beetle, Geotrupes stercorarius,
Linn., the ladybird, Coccinella septempunctata, Linn., the ear-wig,
Forficula auricularia, Linn., some of our common dragon-flies, as
Libellula depressa, Linn., the honey-bee, Apis mellifera, Linn., the
cuckoo spittle insect, Aphrophora spumaria, Linn., and a long catalogue
of others, to all of which Professor Heer had given new names, but which
some entomologists may regard as mere varieties until some stronger
reasons are adduced for coming to a contrary opinion.
Several of the insects above enumerated, like the common ladybird, are
well known at present to have a very wide range over nearly the whole
of the Old World, for example, without varying, and might therefore be
expected to have been persistent throughout many successive changes of
the earth's surface and climate. Yet we may fairly anticipate that
even the most constant types will have undergone some modifications in
passing from the Miocene to the Recent epoch, since in the former period
the geography and climate of Europe, the height of the Alps, and the
general fauna and flora were so different from what they now are. But
the deviation may not exceed that which would generally be expressed by
what is called a well-marked variety.
Before I pass on to another topic, it may be well to answer a question
which may have occurred to the reader; how it happens that we remained
so long ignorant of the vegetation and insects of the Upper Miocene
period in Europe? The answer may be instructive to those who are in the
habit of underrating the former richness of the organic world wherever
they happen to have no evidence of its condition. A large part of
the Upper Miocene insects and plants alluded to have been met with at
Oeningen, near the Lake of Constance, in two or three spots embedded in
thinly laminated marls, the entire thickness of which scarcely exceeds
3 or 4 feet, and in two quarries of very limited dimensions. The
rare combination of causes which seems to have led to the faithful
preservation of so many treasures of a perishable nature in so small an
area, appear to have been the following: first, a river flowing into a
lake; secondly, storms of wind, by which leaves and sometimes the boughs
of trees were torn off and floated by the stream into the lake; thirdly,
mephitic gases rising from the lake, by which insects flying over its
surface were occasionally killed: and fourthly, a constant supply of
carbonate of lime in solution from mineral springs, the calcareous
matter when precipitated to the bottom mingling with fine mud and thus
forming the fossiliferous marls.
SPECIES OF INSECTS IN BRITAIN AND NORTH AMERICA, REPRESENTED BY DISTINCT
VARIETIES.
If we compare the living British insects with those of the American
continent, we frequently find that even those species which are
considered to be identical, are nevertheless varieties of the European
types. I have noticed this fact when speaking of the common English
butterfly, Vanessa atalanta, or "red admiral," which I saw flying
about the woods of Alabama in mid-winter. I was unable to detect any
difference myself, but all the American specimens which I took to
the British Museum were observed by Mr. Doubleday to exhibit a slight
peculiarity in the colouring of a minute part of the anterior wing,* a
character first detected by Mr. T.F. Stephens, who has also discovered
that similar slight, but equally constant variations, distinguish other
Lepidoptera now inhabiting the opposite sides of the Atlantic, insects
which, nevertheless, he and Mr. Westwood and the late Mr. Kirby, have
always agreed to regard as mere varieties of the same species.
(* Lyell's "Second Visit to the United States" volume 2 page
293.)
Mr. T.V. Wollaston, in treating of the variation of insects in maritime
situations and small islands, has shown how the colour, growth of
the wings, and many other characters, undergo modification under the
influence of local conditions, continued for long periods of time;* and
Mr. Brown has lately called our attention to the fact that the insects
of the Shetland Isles present slight deviations from the corresponding
types occurring in Great Britain, but far less marked than those which
distinguish the American from the European varieties.** In the case of
Shetland, Mr. Brown remarks, a land communication may well be supposed
to have prevailed with Scotland at a more modern era than that between
Europe and America. In fact, we have seen that Shetland can hardly fail
to have been united with Scotland after the commencement of the glacial
period (see map, Figure 41); whereas a communication between the north
of Europe by Iceland and Greenland (which, as before stated, once
enjoyed a genial climate) must have been anterior to the glacial epoch.
A much larger isolation, and the impossibility of varieties formed
in the two separated areas crossing with each other, would account,
according to Mr. Darwin's theory, for the much wider divergence observed
in the specific types of the two regions.
(* Wollaston, "On the Variation of Species" etc. London
1856.)
(** "Transactions of Northern Entomological Society" 1862.)
The reader will remember that at the commencement of the Glacial period
there was scarcely any appreciable difference between the molluscous
fauna and that now living. When therefore the events of the Glacial
period, as described in the earlier part of this volume, are duly
pondered on, and when we reflect that in the Upper Miocene period the
living species of mollusca constitute only one-third of the whole fauna,
we see clearly by how high a figure we must multiply the time in order
to express the distance between the Miocene period and our own days.
SPECIES OF MAMMALIA RECENT AND FOSSIL--PROBOSCIDIANS.
But it may perhaps be said that the mammalia afford more conspicuous
examples than do the mollusca, insects, or plants of the wide gaps which
separate species and genera, and that if in this higher class such a
multitude of transitional forms had ever existed as would be required
to unite the Tertiary and Recent species into one series or net-work of
allied or transitional forms, they could not so entirely have escaped
observation whether in the fossil or living fauna. A zoologist who
entertains such an opinion would do well to devote himself to the
study of some one genus of mammalia, such as the elephant, rhinoceros,
hippopotamus, bear, horse, ox, or deer; and after collecting all the
materials he can get together respecting the extinct and Recent species,
decide for himself whether the present state of science justifies his
assuming that the chain could never have been continuous, the number of
the missing links being so great.
Among the extinct species formerly contemporary with man, no fossil
quadruped has so often been alluded to in this work as the mammoth,
Elephas primigenius. From a monograph on the proboscidians by Dr.
Falconer, it appears that this species represents one extreme of a type
of which the Pliocene Mastodon borsoni represents the other. Between
these extremes there are already enumerated by Dr. Falconer no less
than twenty-six species, some of them ranging as far back in time as the
Miocene period, others still living, like the Indian and African forms.
Two of these species, however, he has always considered as doubtful,
Stegodon ganesa, probably a mere variety of one of the others, and
Elephas priscus of Goldfuss, founded partly on specimens of the African
elephant, assumed by mistake to be fossil, and partly on some aberrant
forms of E. antiquus.
The first effect of the intercalation of so many intermediate forms
between the two most divergent types, has been to break down almost
entirely the generic distinction between Mastodon and Elephas. Dr.
Falconer, indeed, observes that Stegodon (one of several subgenera which
he has founded) constitutes an intermediate group, from which the other
species diverge through their dental characters, on the one side into
the mastodons, and on the other into the Elephants.*
(* "Quarterly Journal of the Geological Society" volume 13
1857 page 314.)
The next result is to diminish the distance between the several members
of each of these groups.
Dr. Falconer has discovered that no less than four species of
elephant were formerly confounded together under the title of Elephas
primigenius, whence its supposed ubiquity in Pleistocene times, or its
wide range over half the habitable globe. But even when this form
has been thus restricted in its specific characters, it has still its
geographical varieties; for the mammoth's teeth brought from America
may in most instances, according to Dr. Falconer, be distinguished from
those proper to Europe. On this American variety Dr. Leidy has conferred
the name of E. americanus. Another race of the same mammoth (as
determined by Dr. Falconer) existed, as we have seen, before the Glacial
period, or at the time when the buried forest of Cromer and the Norfolk
cliffs was deposited; and the Swiss geologists have lately found remains
of the mammoth in their country, both in pre-glacial and post-glacial
formations.
Since the publication of Dr. Falconer's monograph, two other species of
elephant, F. mirificus, Leidy, and F. imperator, have been obtained
from the Pliocene formations of the Niobrara Valley in Nebraska, one
of which, however, may possibly be found hereafter to be the same as E.
columbi, Falc. A remarkable dwarf species also (Elephas melitensis) has
been discovered, belonging, like the existing E. africanus, to the group
Loxodon. This species has been established by Dr. Falconer on remains
found by Captain Spratt R.N. in a cave in Malta.*
(* "Proceedings of the Geological Society" London 1862.)
How much the difficulty of discriminating between the fossil
representatives of this genus may hereafter augment, when all the
species with their respective geographical varieties are known, may be
inferred from the following fact--Professor H. Schlegel, in a recently
published memoir, endeavours to show that the living elephant of Sumatra
agrees with that of Ceylon, but is a distinct species from that of
Continental India, being distinguishable by the number of its dorsal
vertebrae and ribs, the form of its teeth, and other characteristics.*
(* Schlegel, "Natural History Review" Number 5 1862 page
72.)
Dr. Falconer, on the other hand, considers these two living species
as mere geographical varieties, the characters referred to not being
constant, as he has ascertained, on comparing different individuals
of E. indicus in different parts of Bengal in which the ribs vary from
nineteen to twenty, and different varieties of E. africanus in which
they vary from twenty to twenty-one.
An inquiry into the various species of the genus Rhinoceros, recent and
fossil, has led Dr. Falconer to analogous results, as might be inferred
from what was said in Chapter 10, and as a forthcoming memoir by the
same writer will soon more fully demonstrate.
Among the fossils brought in 1858 by Mr. Hayden from the Niobrara
Valley, Dr. Leidy describes a rhinoceros so like the Asiatic species,
R. indicus, that he at first referred it to the same, and, what is most
singular, he remarks generally of the Pliocene fauna of that part
of North America that it is far more related in character to the
Pleistocene and Recent fauna of Europe than to that now inhabiting the
American continent.
It seems indeed more and more evident that when we speculate in future
on the pedigree of any extinct quadruped which abounds in the drift or
caverns of Europe, we shall have to look to North and South America as
a principal source of information. Thirty years ago, if we had been
searching for fossil types which might fill up a gap between two species
or genera of the horse tribe (or great family of the Solipedes), we
might have thought it sufficient to have got together as ample materials
as we could obtain from the continents of Europe, Africa, and Asia.
We might have presumed that as no living representative of the equine
family, whether horse, ass, zebra, or quagga, had been furnished
by North or South America when those regions were first explored by
Europeans, a search in the transatlantic world for fossil species might
be dispensed with. But how different is the prospect now opening before
us! Mr. Darwin first detected the remains of a fossil horse during his
visit to South America, since which two other species have been met
with on the same continent, while in North America, in the valley of the
Nebraska alone, Mr. Hayden, besides a species not distinguishable
from the domestic horse, has obtained, according to Dr. Leidy,
representatives of five other fossil genera of Solipedes. These he
names, Hipparion, Protohippus, Merychippus, Hypohippus, and Parahippus.
On the whole, no less than twelve equine species, belonging to seven
genera (including the Miocene Anchitherium of Nebraska), being already
detected in the Tertiary and Post-Tertiary formations of the United
States.*
(* "Proceedings of the Academy of Natural Science"
Philadelphia for 1858 page 89.)
Professors Unger* and Heer** have advocated, on botanical grounds,
the former existence of an Atlantic continent during some part of the
Tertiary period, as affording the only plausible explanation that can be
imagined, of the analogy between the Miocene flora of Central Europe and
the existing flora of Eastern America. Professor Oliver, on the other
hand, after showing how many of the American types found fossil in
Europe are common to Japan, inclines to the theory, first advanced by
Dr. Asa Gray, that the migration of species, to which the community of
types in the eastern states of North America and the Miocene flora of
Europe is due, took place when there was an overland communication from
America to eastern Asia between the fiftieth and sixtieth parallels of
latitude, or south of Behring Straits, following the direction of the
Aleutian islands.*** By this course they may have made their way, at any
epoch, Miocene, Pliocene, or Pleistocene, antecedently to the glacial
epoch, to Mongolia, on the east coast of northern Asia.
(* "Die versunkene Insel Atlantis.")
(** "Flora tertiaria Helvetiae.")
(*** Oliver, Lecture at the Royal Institution, March 7, 1862.)
We have already seen that a large proportion of the living quadrupeds of
Mongolia (34 out of 48) are specifically identical with those at present
inhabiting the continent of Western Europe and the British Isles.
A monograph on the hippopotamus, bear, ox, stag, or any other genus of
mammalia common in the European drift or caverns, might equally well
illustrate the defective state of the materials at present at our
command. We are rarely in possession of one perfect skeleton of any
extinct species, still less of skeletons of both sexes, and of different
ages. We usually know nothing of the geographical varieties of the
Pleistocene and Pliocene species, least of all, those successive changes
of form which they must have undergone in the preglacial epoch between
the Upper Miocene and Pleistocene eras. Such being the poverty of
our palaeontological data, we cannot wonder that osteologists are at
variance as to whether certain remains found in caverns are of the same
species as those now living; whether, for example, the Talpa fossilis
is really the common mole, the Meles morreni the common badger, Lutra
antiqua the otter of Europe, Sciurus priscus the squirrel, Arctomys
primigenia the marmot, Myoxus fossilis the dormouse, Schmerling's Felis
engihoulensis the European lynx, or whether Ursus spelaeus and Ursus
priscus are not extinct races of the living brown bear (Ursus arctos).
If at some future period all the above-mentioned species should be
united with their allied congeners, it cannot fail to enlarge our
conception of the modifications which a species is capable of undergoing
in the course of time, although the same form may appear absolutely
immutable within the narrow range of our experience.
LONGEVITY OF SPECIES IN THE MAMMALIA.
In the "Principles of Geology," in 1833,* I stated that the longevity of
species in the class mollusca exceeded that in the mammalia. It has been
since found that this generalisation can be carried much farther, and
that in fact the law which governs the changes in organic being is such
that the lower their place in a graduated scale, or the simpler their
structure, the more persistent are they in form and organisation. I soon
became aware of the force of this rule in the class mollusca, when I
first attempted to calculate the numerical proportion of Recent species
in the Newer Pliocene formations as compared to the Older Pliocene, and
of them again as contrasted with the Miocene; for it appeared invariably
that a greater number of the lamellibranchs could be identified with
living species than of the gasteropods, and of these last a greater
number in the lower division, that of entire-mouthed univalves, than in
that of the siphonated. In whatever manner the changes have been brought
about, whether by variation and natural selection, or by any other
causes, the rate of change has been greater where the grade of
organisation is higher.
(* 1st edition volume 3 pages 48 and 140.)
It is only, therefore, where there is a full representation of all the
principal orders of mollusca, or when we compare those of corresponding
grade, that we can fully rely on the percentage test, or on the
proportion of Recent to extinct species as indicating the relation of
two groups to the existing fauna.
The foraminifera which exemplify the lowest stage of animal existence
exhibit, as we learn from the researches of Dr. Carpenter and of Messrs.
Jones and Parker, extreme variability in their specific forms, and
yet these same forms are persistent throughout vast periods of time,
exceeding, in that respect, even the brachiopods before mentioned.
Dr. Hooker observes, in regard to plants of complex floral structure,
that they manifest their physical superiority in a greater extent of
variation and in thus better securing a succession of race, an attribute
which in some senses he regards as of a higher order than that indicated
by mere complexity or specialisation of organ.*
(* "Introductory Essay to the Flora of Australia" page 7.)
As one of the consequences of this law, he says that species, genera,
and orders are, on the whole, best limited in plants of higher grade,
the dicotyledons better than the monocotyledons, and the Dichlamydeae
better than the Achlamydeae.
Mr. Darwin remarks, "We can, perhaps, understand the apparently quicker
rate of change in terrestrial, and in more highly organised productions,
compared with marine and lower productions, by the more complex
relations of the higher beings to their organic and inorganic conditions
of life."*
(* "Origin of Species" 3rd edition page 340.)
If we suppose the mammalia to be more sensitive than are the inferior
classes of the vertebrata, to every fluctuation in the surrounding
conditions, whether of the animate or inanimate world, it would follow
that they would oftener be called upon to adapt themselves by variation
to new conditions, or if unable to do so, to give place to other types.
This would give rise to more frequent extinction of varieties, species,
and genera, whereby the surviving types would be better limited, and the
average duration of the same unaltered specific types would be lessened.
ABSENCE OF MAMMALIA IN ISLANDS CONSIDERED IN REFERENCE TO TRANSMUTATION.
But if mammalia vary upon the whole at a more rapid rate than animals
lower in the scale of being, it must not be supposed that they can alter
their habits and structures readily, or that they are convertible in
short periods into new species. The extreme slowness with which such
changes of habits and organisation take place, when new conditions
arise, appears to be well exemplified by the absence even of small
warm-blooded quadrupeds in islands far from continents, however well
such islands may be fitted by their dimensions to support them.
Mr. Darwin has pointed to this absence of mammalia as favouring his
views, observing that bats, which are the only exceptions to the rule,
might have made their way to distant islands by flight, for they are
often met with on the wing far out at sea. Unquestionably, the total
exclusion of quadrupeds in general, which could only reach such isolated
habitations by swimming, seems to imply that nature does not dispense
with the ordinary laws of reproduction when she peoples the earth with
new forms; for if causes purely immaterial were alone at work, we
might naturally look for squirrels, rabbits, polecats, and other small
vegetable feeders and beasts of prey, as often as for bats, in the spots
alluded to.
On the other hand, I have found it difficult to reconcile the antiquity
of certain islands, such as those of the Madeiran Archipelago, and those
of still larger size in the Canaries, with the total absence of small
indigenous quadrupeds, for, judging by ancient deposits of littoral
shells, now raised high above the level of the sea, several of these
volcanic islands (Porto Santo and the Grand Canary among others) must
have existed ever since the Upper Miocene period. But, waiving all such
claims to antiquity, it is at least certain that since the close of the
Newer Pliocene period, Madeira, and Porto Santo have constituted two
separate islands, each in sight of the other, and each inhabited by an
assemblage of land shells (Helix, Pupa, Clausilia, etc.), for the most
part different or proper to each island. About thirty-two fossil species
have been obtained in Madeira, and forty-two in Porto Santo, only
five of the whole being common to both islands. In each the living
land-shells are equally distinct, and correspond, for the most part,
with the species found fossil in each island respectively.
Among the fossil species, one or two appear to be entirely extinct,
and a larger number have disappeared from the fauna of the Madeiran
Archipelago, though still extant in Africa and Europe. Many which were
amongst the most common in the Pliocene period, have now become
the scarcest, and others formerly scarce, are now most numerously
represented. The variety-making force has been at work with such
energy--perhaps we ought to say, has had so much time for its
development--that almost every isolated rock within gun-shot of the
shores has its peculiar living forms, or those very marked races to
which Mr. Lowe, in his excellent description of the fauna, has given the
name of "sub-species."
Since the fossil shells were embedded in sand near the coast, these
volcanic islands have undergone considerable alterations in size
and shape by the wasting action of the waves of the Atlantic beating
incessantly against the cliffs, so that the evidence of a vast lapse of
time is derivable from inorganic as well as from organic phenomena.
During this period no mammalia, not even of small species, excepting
bats, have made their appearance, whether in Madeira and Porto-Santo or
in the larger and more numerous islands of the Canarian group. It might
have been expected, from some expressions met with here and there in the
"Origin of Species," though not perhaps from a fair interpretation
of the whole tenor of the author's reasoning, that this dearth of the
highest class of vertebrata is inconsistent with the powers of mammalia
to accommodate their habits and structures to new conditions. Why did
not some of the bats, for example, after they had greatly multiplied,
and were hard pressed by a scarcity of insects on the wing, betake
themselves to the ground in search of prey, and, gradually losing their
wings, become transformed into non-volant Insectivora? Mr. Darwin tells
me that he has learnt that there is a bat in India which has been known
occasionally to devour frogs. One might also be tempted to ask, how it
has happened that the seals which swarmed on the shores of Madeira and
the Canaries, before the European colonists arrived there, were never
induced, when food was scarce in the sea, to venture inland from the
shores, and begin in Teneriffe, and the Grand Canary especially, and
other large islands, to acquire terrestrial habits, venturing first
a few yards inland, and then farther and farther until they began to
occupy some of the "places left vacant in the economy of nature." During
these excursions, we might suppose some varieties, which had the skin
of the webbed intervals of their toes less developed, to succeed best in
walking on the land, and in the course of several generations they might
exchange their present gait or manner of shuffling along and jumping by
aid of the tail and their fin-like extremities, for feet better adapted
for running.
It is said that one of the bats in the island of Palma (one of the
Canaries) is of a peculiar species, and that some of the Cheiroptera
of the Pacific islands are even of peculiar genera. If so, we seem, on
organic as well as on geological grounds, to be precluded from arguing
that there has not been time for great divergence of character. We seem
also entitled to ask why the bats and rodents of Australia, which are
spread so widely among the marsupials over that continent, have never,
under the influence of the principle of progression, been developed
into higher placental types, since we have now ascertained that that
continent was by no means unfitted to sustain such mammalia, for these
when once introduced by Man have run wild and become naturalised in
many parts. The following answers may perhaps be offered to the above
criticisms of some of Mr. Darwin's theoretical views.
First, as to the bats and seals: they are what zoologists call aberrant
and highly specialised types, and therefore precisely those which
might be expected to display a fixity and want of pliancy in their
organisation, or the smallest possible aptitude for deviating in new
directions towards new structures, and the acquisition of such altered
habits as a change from aquatic to terrestrial or from Volant to
non-volant modes of living would imply.
Secondly, the same powers of flight which enabled the first bats to
reach Madeira or the Canaries, would bring others from time to time
from the African continent, which, mixing with the first emigrants and
crossing with them, would check the formation of new races, or keep
them true to the old types, as is found to be actually the case with the
birds of Madeira and the Bermudas.
This would happen the more surely, if, as Mr. Darwin has endeavoured to
prove, the offspring of races slightly varying are usually more
vigorous than the progeny of parents of the same race, and would be more
prolific, therefore, than the insular stock which had been for a long
time breeding in and in.
The same cause would tend in a still more decided manner to prevent the
seals from diverging into new races or "incipient species," because
they range freely over the wide ocean, and, may therefore have continual
intercourse with all other individuals of their species.
Thirdly, as to peculiar species, and even genera of bats in islands, we
are perhaps too little acquainted at present with all the species and
genera of the neighbouring continents to be able to affirm, with any
degree of confidence, that the forms supposed to be peculiar do not
exist elsewhere: those of the Canaries in Africa, for example. But
what is still more important, we must bear in mind how many species and
genera of Pleistocene mammalia have everywhere become extinct by causes
independent of Man. It is always possible, therefore, that some types
of Cheiroptera, originally derived from the main land, have survived in
islands, although they have gradually died out on the continents from
whence they came; so that it would be rash to infer that there has been
time for the creation, whether by variation or other agency, of new
species or genera in the islands in question.
As to the Rodents and Cheiroptera of Australia, we are as yet too
ignorant of the Pleistocene and Pliocene fauna of that part of the
world, to be able to decide whether the introduction of such forms dates
from a remote geological time. We know, however, that, before the Recent
period, that continent was peopled with large kangaroos, and other
herbivorous and carnivorous marsupials, of species long since extinct,
their remains having been discovered in ossiferous caverns. The
preoccupancy of the country by such indigenous tribes may have checked
the development of the placental Rodents and Cheiroptera, even were we
to concede the possibility of such forms being convertible by variation
and progressive development into higher grades of mammalia.
IMPERFECTION OF THE GEOLOGICAL RECORD [42].
When treating in the eighth chapter of the dearth of human bones in
alluvium containing flint implements in abundance, I pointed out that it
is not part of the plan of Nature to write everywhere, and at all times,
her autobiographical memoirs. On the contrary, her annals are local and
exceptional from the first, and portions of them are afterwards ground
into mud, sand, and pebbles, to furnish materials for new strata. Even
of those ancient monuments now forming the crust of the earth, which
have not been destroyed by rivers and the waves of the sea, or which
have escaped being melted by volcanic heat, three-fourths lie submerged
beneath the ocean, and are inaccessible to Man; while of those which
form the dry land, a great part are hidden for ever from our observation
by mountain masses, thousands of feet thick, piled over them.
Mr. Darwin has truly said that the fossiliferous rocks known to
geologists consist, for the most part, of such as were formed when the
bottom of the sea was subsiding. This downward movement protects the
new deposits from denudation, and allows them to accumulate to a great
thickness; whereas sedimentary matter, thrown down where the sea-bottom
is rising, must almost invariably be swept away by the waves as fast as
the land emerges.
When we reflect, therefore, on the fractional state of the annals
which are handed down to us, and how little even these have as yet been
studied, we may wonder that so many geologists should attribute every
break in the series of strata and every gap in the past history of the
organic world to catastrophes and convulsions of the earth's crust or
to leaps made by the creational force from species to species, or from
class to class. For it is clear that, even had the series of monuments
been perfect and continuous at first (an hypothesis quite opposed to the
analogy of the working of causes now in action), it could not fail to
present itself to our eyes in a broken and disconnected state.
Those geologists who have watched the progress of discovery during the
last half century can best appreciate the extent to which we may still
hope by future exertion to fill up some of the wider chasms which
now interrupt the regular sequence of fossiliferous rocks. The
determination, for example, of late years of the true place of the
Hallstadt and St. Cassian beds on the north and south flanks of the
Austrian Alps, has revealed to us, for the first time, the marine fauna
of a period (that of the Upper Trias) of which, until lately, but little
was known. In this case, the palaeontologist is called upon suddenly to
intercalate about 800 species of Mollusca and Radiata, between the fauna
of the Lower Lias and that of the Middle Trias. The period in question
was previously believed, even by many a philosophical geologist, to
have been comparatively barren of organic types. In England, France,
and northern Germany, the only known strata of Upper Triassic date had
consisted almost entirely of fresh or brackish-water beds, in which
the bones of terrestrial and amphibious reptiles were the most
characteristic fossils. The new fauna was, as might have been expected,
in part peculiar, not a few of the species of Mollusca being referable
to new genera; while some species were common to the older, and some
to the newer rocks. On the whole, the new forms have helped greatly to
lessen the discordance, not only between the Lias and Trias, but also
generally between Palaeozoic and Mesozoic formations. Thus the genus
Orthoceras has been for the first time recognised in a Mesozoic deposit,
and with it we find associated, for the first time, large Ammonites
with foliated lobes, a form never seen before below the Lias; also the
Ceratites, a family of Cephalopods never before met with in the Upper
Trias, and never before in the same stratum with such lobed Ammonites.
We can now no longer doubt that should we hereafter have an opportunity
of studying an equally rich marine fauna of the age of the Lower Trias
(or Bunter Sandstein), the marked hiatus which still separates the
Triassic and Permian eras would almost disappear.
Archaeopteryx macrurus, Owen.
I could readily add a copious list of minor deposits, belonging to the
Primary, Secondary and Tertiary series, which we have been called upon
in like manner to intercalate in the course of the last quarter of a
century into the chronological series previously known; but it would
lead me into too long a digression. I shall therefore content myself
with pointing out that it is not simply new formations which are brought
to light from year to year, reminding us of the elementary state of
our knowledge of palaeontology, but new types also of structure are
discovered in rocks whose fossil contents were supposed to be peculiarly
well known.
The last and most striking of these novelties is "the feathered fossil"
from the lithographic stone of Solenhofen.
Until the year 1858, no well-determined skeleton of a bird had been
detected in any rocks older than the Tertiary. In that year, Mr. Lucas
Barrett found in the Cambridge Greensand of the Cretaceous series, the
femur, tibia, and some other bones of a swimming bird, supposed by him
to be of the gull tribe. His opinion as to the ornithic character of the
remains was afterwards confirmed by Professor Owen.
The Archaeopteryx macrurus, Owen, recently acquired by the British
Museum, affords a second example of the discovery of the osseous remains
of a bird in strata older than the Eocene. It was found in the great
quarries of lithographic limestone at Solenhofen in Bavaria, the rock
being a member of the Upper Oolite.
It was at first conjectured in Germany, before any experienced
osteologist had had an opportunity of inspecting the original specimen,
that this fossil might be a feathered Pterodactyl (flying reptiles
having been often met with in the same stratum), or that it might at
least supply some connecting links between a reptile and a bird. But
Professor Owen, in a memoir lately read to the Royal Society (November
20, 1862), has shown that it is unequivocally a bird, and that such of
its characters as are abnormal are by no means strikingly reptilian. The
skeleton was lying on its back when embedded in calcareous sediment, so
that the ventral part is exposed to view. It is about 1 foot 8 inches
long, and 1 foot across, from the apex of the right to that of the left
wing. The furculum, or merry-thought, which is entire, marks the fore
part of the trunk; the ischium, scapula, and most of the wing and leg
bones are preserved, and there are impressions of the quill feathers and
of down on the body. The vanes and shafts of the feathers can be seen by
the naked eye. Fourteen long quill feathers diverge on each side of the
metacarpal and phalangial bones, and decrease in length from 6 inches
to 1 inch. The wings have a general resemblance to those of gallinaceous
birds. The tarso-metatarsal, or drumstick, exhibits at its distal end
a trifid articular surface supporting three toes, as in birds. The
furculum, pelvis, and bones of the tail are in their natural position.
The tail consists of twenty vertebrae, each of which supports a pair of
plumes. The length of the tail with its feathers is 11 1/2 inches, and
its breadth 3 1/2. It is obtusely truncated at the end. In all living
birds the tail-feathers are arranged in fan-shaped order and attached
to a coccygean bone, consisting of several vertebrae united together,
whereas in the embryo state these same vertebrae are distinct. The
greatest number is seen in the ostrich, which has eighteen caudal
vertebrae in the foetal state, which are reduced to nine in the adult
bird, many of them having been anchylosed together. Professor Owen
therefore considers the tail of the Archaeopteryx as exemplifying the
persistency of what is now an embryonic character. The tail, he
remarks, is essentially a variable organ; there are long-tailed bats
and short-tailed bats, long-tailed rodents and short-tailed rodents,
long-tailed pterodactyls and short-tailed pterodactyls.
The Archaeopteryx differs from all known birds, not only in the
structure of its tail, but in having two, if not three, digits in the
hand; but there is no trace of the fifth digit of the winged reptile.
The conditions under which the skeleton occurs are such, says Professor
Owen, as to remind us of the carcass of a gull which has been a prey to
some Carnivore, which had removed all the soft parts, and perhaps
the head, nothing being left but the bony legs and the indigestible
quill-feathers. But since Professor Owen's paper was read, Mr. John
Evans, whom I have often had occasion to mention in the earlier chapters
of this work, seems to have found what may indicate a part of the
missing cranium. He has called our attention to a smooth protuberance
on the otherwise even surface of the slab of limestone which seems to
be the cast of the brain or interior of the skull. Some part even of the
cranial bone itself appears to be still buried in the matrix. Mr. Evans
has pointed out the resemblance of this cast to one taken by himself
from the cranium of a crow, and still more to that of a jay, observing
that in the fossil the median line which separates the two hemispheres
of the brain is visible.
To conclude, we may learn from this valuable relic how rashly the
existence of Birds at the epoch of the Secondary rocks has been
questioned, simply on negative evidence, and secondly, how many new
forms may be expected to be brought to light in strata with which we
are already best acquainted, to say nothing of the new formations which
geologists are continually discovering.
CHAPTER 23. -- ORIGIN AND DEVELOPMENT OF LANGUAGES AND SPECIES COMPARED
[43].
Aryan Hypothesis and Controversy.
The Races of Mankind change more slowly than their Languages.
Theory of the gradual Origin of Languages.
Difficulty of defining what is meant by a Language as distinct
from a Dialect.
Great Number of extinct and living Tongues.
No European Language a Thousand Years old.
Gaps between Languages, how caused.
Imperfection of the Record.
Changes always in Progress.
Struggle for Existence between rival Terms and Dialects.
Causes of Selection.
Each Language formed slowly in a single Geographical Area.
May die out gradually or suddenly.
Once lost can never be revived.
Mode of Origin of Languages and Species a Mystery.
Speculations as to the Number of original Languages or Species
unprofitable.
The supposed existence, at a remote and unknown period, of a language
conventionally called the Aryan, has of late years been a favourite
subject of speculation among German philologists, and Professor Max
Muller has given us lately the most improved version of this theory,
and has set forth the various facts and arguments by which it may be
defended, with his usual perspicuity and eloquence. He observes that if
we know nothing of the existence of Latin--if all historical documents
previous to the fifteenth century had been lost--if tradition even was
silent as to the former existence of a Roman empire, a mere comparison
of the Italian, Spanish, Portuguese, French, Wallachian, and Rhaetian
dialects would enable us to say that at some time there must have been
a language from which these six modern dialects derive their origin in
common. Without this supposition it would be impossible to account for
their structure and composition, as, for example, for the forms of the
auxiliary verb "to be," all evidently varieties of one common type,
while it is equally clear that no one of the six affords the original
form from which the others could have been borrowed. So also in none
of the six languages do we find the elements of which these verbal and
other forms could have been composed; they must have been handed down as
relics from a former period, they must have existed in some antecedent
language, which we know to have been the Latin.
But, in like manner, he goes on to show, that Latin itself, as well as
Greek, Sanscrit, Zend (or Bactrian), Lithuanian, old Sclavonic, Gothic,
and Armenian are also eight varieties of one common and more ancient
type, and no one of them could have been the original from which the
others were borrowed. They have all such an amount of mutual resemblance
as to point to a more ancient language, the Aryan, which was to them
what Latin was to the six Romance languages. The people who spoke this
unknown parent speech, of which so many other ancient tongues were
off-shoots, must have migrated at a remote era to widely separated
regions of the old world, such as Northern Asia, Europe, and India south
of the Himalaya.*
(* Max Muller, "Comparative Mythology" Oxford Essays 1856.)
The soundness of some parts of this Aryan hypothesis has lately been
called in question by Mr. Crawfurd, on the ground that the Hindoos,
Persians, Turks, Scandinavians, and other people referred to as having
derived not only words but grammatical forms from an Aryan source,
belong each of them to a distinct race, and all these races have, it is
said, preserved their peculiar characters unaltered from the earliest
dawn of history and tradition. If, therefore, no appreciable change has
occurred in three or four thousand years, we should be obliged to assume
a far more remote date for the first branching off of such races from a
common stock than the supposed period of the Aryan migrations, and the
dispersion of that language over many and distant countries.
But Mr. Crawfurd has, I think, himself helped us to remove this
stumbling-block, by admitting that a nation speaking a language allied
to the Sanscrit (the oldest of the eight tongues alluded to), once
probably inhabited that region situated to the north-west of India,
which within the period of authentic history has poured out its
conquering hordes over a great extent of Western Asia and Eastern
Europe. The same people, he says, may have acted the same part in the
long, dark night which preceded the dawn of tradition.*
(* Crawfurd, "Transactions of the Ethnological Society"
volume 1 1861.)
These conquerors may have been few in number when compared to the
populations which they subdued. In such cases the new settlers, although
reckoned by tens of thousands, might merge in a few centuries into the
millions of subjects which they ruled. It is an acknowledged fact that
the colour and features of the Negro or European are entirely lost in
the fourth generation, provided that no fresh infusion of one or
other of the two races takes place. The distinctive physical features,
therefore, of the Aryan conquerors might soon wear out and be lost in
those of the nations they overran; yet many of the words, and, what is
more in point, some of the grammatical forms of their language, might
be retained by the masses which they had governed for centuries, these
masses continuing to preserve the same features of race which had
distinguished them long before the Aryan invasions.
There can be no question that if we could trace back any set of cognate
languages now existing to some common point of departure, they would
converge and meet sooner in some era of the past than would the existing
races of mankind; in other words, races change much more slowly than
languages. But, according to the doctrine of transmutation, to form a
new species would take an incomparably longer period than to form a new
race. No language seems ever to last for a thousand years, whereas
many a species seems to have endured for hundreds of thousands. A
philologist, therefore, who is contending that all living languages are
derivative and not primordial, has a great advantage over a naturalist
who is endeavouring to inculcate a similar theory in regard to species.
It may not be uninstructive, in order fairly to appreciate the vast
difficulty of the task of those who advocate transmutation in natural
history, to consider how hard it would be even for a philologist to
succeed, if he should try to convince an assemblage of intelligent
but illiterate persons that the language spoken by them, and all those
talked by contemporary nations, were modern inventions, moreover that
these same forms of speech were still constantly undergoing change, and
none of them destined to last for ever.
We will suppose him to begin by stating his conviction, that the living
languages have been gradually derived from others now extinct, and
spoken by nations which had immediately preceded them in the order of
time, and that those again had used forms of speech derived from still
older ones. They might naturally exclaim, "How strange it is that you
should find records of a multitude of dead languages, that a part of the
human economy which in our own time is so remarkable for its stability,
should have been so inconstant in bygone ages! We all speak as our
parents and grandparents spoke before us, and so, we are told, do the
Germans and French. What evidence is there of such incessant variation
in remoter times? and, if it be true, why not imagine that when one form
of speech was lost, another was suddenly and supernaturally created by
a gift of tongues or confusion of languages, as at the building of
the Tower of Babel? Where are the memorials of all the intermediate
dialects, which must have existed, if this doctrine of perpetual
fluctuation be true? And how comes it that the tongues now spoken do not
pass by insensible gradations the one into the other, and into the dead
languages of dates immediately antecedent?
"Lastly, if this theory of indefinite modifiability be sound, what
meaning can be attached to the term language, and what definition can be
given of it so as to distinguish a language from a dialect?"
In reply to this last question, the philologist might confess that the
learned are not agreed as to what constitutes a language as distinct
from a dialect. Some believe that there are 4000 living languages,
others that there are 6000, so that the mode of defining them is clearly
a mere matter of opinion. Some contend, for example, that the Danish,
Norwegian, and Swedish form one Scandinavian tongue, others that
they constitute three different languages, others that the Danish and
Norwegian are one--mere dialects of the same language, but that Swedish
is distinct.
The philologist, however, might fairly argue that this very ambiguity
was greatly in favour of his doctrine, since if languages had all been
constantly undergoing transmutation, there ought often to be a want of
real lines of demarcation between them. He might, however, propose that
he and his pupils should come to an understanding that two languages
should be regarded as distinct whenever the speakers of them are unable
to converse together, or freely to exchange ideas, whether by word
or writing. Scientifically speaking, such a test might be vague
and unsatisfactory, like the test of species by their capability of
producing fertile hybrids; but if the pupil is persuaded that there
are such things in nature as distinct languages, whatever may have been
their origin, the definition above suggested might be of practical use,
and enable the teacher to proceed with his argument.
He might begin by undertaking to prove that none of the languages of
modern Europe were a thousand years old. No English scholar, he might
say, who has not specially given himself up to the study of Anglo-Saxon,
can interpret the documents in which the chronicles and laws of England
were written in the days of King Alfred, so that we may be sure that
none of the English of the nineteenth century could converse with the
subjects of that monarch if these last could now be restored to life.
The difficulties encountered would not arise merely from the intrusion
of French terms, in consequence of the Norman conquest, because that
large portion of our language (including the articles, pronouns, etc.),
which is Saxon has also undergone great transformations by abbreviation,
new modes of pronunciation, spelling, and various corruptions, so as to
be unlike both ancient and modern German. They who now speak German, if
brought into contact with their Teutonic ancestors of the ninth century,
would be quite unable to converse with them, and, in like manner, the
subjects of Charlemagne could not have exchanged ideas with the Goths of
Alaric's army, or with the soldiers of Arminius in the days of Augustus
Caesar. So rapid indeed has been the change in Germany, that the
epic poem called the Nibelungen Lied, once so popular, and only seven
centuries old, cannot now be enjoyed, except by the erudite.
If we then turn to France, we meet again with similar evidence of
ceaseless change. There is a treaty of peace still extant a thousand
years old, between Charles the Bald and King Louis of Germany (dated
A.D. 841), in which the German king takes an oath in what was the French
tongue of that day, while the French king swears in the German of the
same era, and neither of these oaths would now convey a distinct meaning
to any but the learned in these two countries. So also in Italy, the
modern Italian cannot be traced back much beyond the time of Dante, or
some six centuries before our time. Even in Rome, where there had been
no permanent intrusion of foreigners, such as the Lombard settlers of
German origin in the plains of the Po, the common people of the year
1000 spoke quite a distinct language from that of their Roman ancestors
or their Italian descendants, as is shown by the celebrated chronicle
of the monk Benedict, of the convent of St. Andrea on Mount Soracte,
written in such barbarous Latin, and with such strange grammatical
forms, that it requires a profoundly skilled linguist to decipher it.*
(* See G. Pertz, "Monumenta Germanica" volume 3.)
Having thus established the preliminary fact, that none of the tongues
now spoken were in existence ten centuries ago, and that the ancient
languages have passed through many a transitional dialect before they
settled into the forms now in use, the philologist might bring forward
proofs of the great numbers both of lost and living forms of speech.
Strabo tells us that in his time, in the Caucasus alone (a chain of
mountains not longer than the Alps, and much narrower), there were
spoken at least seventy languages. At the present period the number, it
is said, would be still greater if all the distinct dialects of those
mountains were reckoned. Several of these Caucasian tongues admit of no
comparison with any known living or lost Asiatic or European language.
Others which are not peculiar are obsolete forms of known languages,
such as the Georgian, Mongolian, Persian, Arabic, and Tartarian. It
seems that as often as conquering hordes swept over that part of Asia,
always coming from the north and east, they drove before them the
inhabitants of the plains, who took refuge in some of the retired
valleys and high mountain fastnesses, where they maintained their
independence, as do the Circassians in our time in spite of the power of
Russia.
In the Himalayan Mountains, from Assam to its extreme north-western
limit, and generally in the more hilly parts of British India, the
diversity of languages is surprisingly great, impeding the advance of
civilisation and the labours of the missionary. In South America and
Mexico, Alexander Humboldt reckoned the distinct tongues by hundreds,
and those of Africa are said to be equally numerous. Even in China, some
eighteen provincial dialects prevail, almost all deviating so much from
others that the speakers are not mutually intelligible, and besides
these there are other distinct forms of speech in the mountains of the
same empire.
The philologist might next proceed to point out that the geographical
relations of living and dead languages favour the hypothesis of the
living ones having been derived from the extinct, in spite of our
inability, in most instances, to adduce documentary evidence of the
fact or to discover monuments of all the intermediate and transitional
dialects which must have existed. Thus he would observe that the modern
Romance languages are spoken exactly where the ancient Romans once lived
or ruled, and the Greek of our days where the older classical Greek was
formerly spoken. Exceptions to this rule might be detected, but they
would be explicable by reference to colonisation and conquest.
As to the many and wide gaps sometimes encountered between the dead and
living languages, we must remember that it is not part of the plan of
any people to preserve memorials of their forms of speech expressly for
the edification of posterity. Their manuscripts and inscriptions serve
some present purpose, are occasional and imperfect from the first,
and are rendered more fragmentary in the course of time, some being
intentionally destroyed, others lost by the decay of the perishable
materials on which they are written; so that to question the theory of
all known languages being derivative on the ground that we can rarely
trace a passage from the ancient to the modern through all the dialects
which must have flourished one after the other in the intermediate ages,
implies a want of reflection on the laws which govern the recording as
well as the obliterating processes.
But another important question still remains to be considered, namely,
whether the trifling changes which can alone be witnessed by a single
generation, can possibly represent the working of that machinery
which, in the course of many centuries, has given rise to such mighty
revolutions in the forms of speech throughout the world. Everyone
may have noticed in his own lifetime the stealing in of some slight
alterations of accent, pronunciation or spelling, or the introduction of
some words borrowed from a foreign language to express ideas of which no
native term precisely conveyed the import. He may also remember hearing
for the first time some cant terms or slang phrases, which have since
forced their way into common use, in spite of the efforts of the purist.
But he may still contend that "within the range of his experience," his
language has continued unchanged, and he may believe in its immutability
in spite of minor variations. The real question, however, at issue
is, whether there are any limits to this variability. He will find on
farther investigation, that new technical terms are coined almost daily
in various arts, sciences, professions, and trades, that new names must
be found for new inventions, that many of these acquire a metaphorical
sense, and then make their way into general circulation, as
"stereotyped," for instance, which would have been as meaningless to the
men of the seventeenth century as would the new terms and images derived
from steamboat and railway travelling to the men of the eighteenth.
If the numerous words, idioms, and phrases, many of them of ephemeral
duration, which are thus invented by the young and old in various
classes of society, in the nursery, the school, the camp, the fleet, the
courts of law and the study of the man of science or literature, could
all be collected together and put on record, their number in one or
two centuries might compare with the entire permanent vocabulary of the
language. It becomes, therefore, a curious subject of inquiry, what are
the laws which govern not only the invention, but also the "selection"
of some of these words or idioms, giving them currency in preference to
others?--for as the powers of the human memory are limited, a check must
be found to the endless increase and multiplication of terms, and
old words must be dropped nearly as fast as new ones are put into
circulation. Sometimes the new word or phrase, or a modification of
the old ones, will entirely supplant the more ancient expressions, or,
instead of the latter being discarded, both may flourish together, the
older one having a more restricted use.
Although the speakers may be unconscious that any great fluctuation is
going on in their language--although when we observe the manner in which
new words and phrases are thrown out, as if at random or in sport, while
others get into vogue, we may think the process of change to be the
result of mere chance--there are nevertheless fixed laws in action, by
which, in the general struggle for existence, some terms and dialects
gain the victory over others. The slightest advantage attached to some
new mode of pronouncing or spelling, from considerations of brevity or
euphony, may turn the scale, or more powerful causes of selection may
decide which of two or more rivals shall triumph and which succumb.
Among these are fashion, or the influence of an aristocracy, whether of
birth or education, popular writers, orators, preachers--a centralised
government organising its schools expressly to promote uniformity of
diction, and to get the better of provincialisms and local dialects.
Between these dialects, which may be regarded as so many "incipient
languages," the competition is always keenest when they are most nearly
allied, and the extinction of any one of them destroys some of the links
by which a dominant tongue may have been previously connected with
some other widely distinct one. It is by the perpetual loss of such
intermediate forms of speech that the great dissimilarity of the
languages which survive is brought about. Thus, if Dutch should become a
dead language, English and German would be separated by a wider gap.
Some languages which are spoken by millions, and spread over a wide
area, will endure much longer than others which have never had a wide
range, especially if the tendency to incessant change in one of these
dominant tongues is arrested for a time by a standard literature.
But even this source of stability is insecure, for popular writers
themselves are great innovators, sometimes coining new words, and
still oftener new expressions and idioms, to embody their own original
conceptions and sentiments, or some peculiar modes of thought and
feeling characteristic of their age. Even when a language is regarded
with superstitious veneration as the vehicle of divine truths and
religious precepts, and which has prevailed for many generations, it
will be incapable of permanently maintaining its ground. Hebrew had
ceased to be a living language before the Christian era. Sanscrit, the
sacred language of the Hindoos, shared the same fate, in spite of the
veneration in which the Vedas are still held, and in spite of many a
Sanscrit poem once popular and national.
The Christians of Constantinople and the Morea still hear the New
Testament and their liturgy read in ancient Greek, while they speak a
dialect in which Paul might have preached in vain at Athens. So in
the Catholic Church, the Italians pray in one tongue and talk another.
Luther's translation of the Bible acted as a powerful cause of
"selection," giving at once to one of many competing dialects (that of
Saxony) a prominent and dominant position in Germany; but the style
of Luther has, like that of our English Bible, already become somewhat
antiquated.
If the doctrine of gradual transmutation be applicable to languages, all
those spoken in historical times must each of them have had a
closely allied prototype; and accordingly, whenever we can thoroughly
investigate their history, we find in them some internal evidence of
successive additions by the invention of new words or the modification
of old ones. Proofs also of borrowing are discernible, letters being
retained in the spelling of some words which have no longer any meaning
as they are now pronounced--no connection with any corresponding sounds.
Such redundant or silent letters, once useful in the parent speech,
have been aptly compared by Mr. Darwin to rudimentary organs in living
beings, which, as he interprets them, have at some former period been
more fully developed, having had their proper functions to perform in
the organisation of a remote progenitor.
If all known languages are derivative and not primordial creations, they
must each of them have been slowly elaborated in a single geographical
area. No one of them can have had two birthplaces. If one were carried
by a colony to a distant region, it would immediately begin to vary
unless frequent intercourse was kept up with the mother country. The
descendants of the same stock, if perfectly isolated, would in five or
six centuries, perhaps sooner, be quite unable to converse with those
who remained at home, or with those who may have migrated to some
distant region, where they were shut out from all communication with
others speaking the same tongue.
A Norwegian colony which settled in Iceland in the ninth century,
maintained its independence for about 400 years, during which time the
old Gothic which they at first spoke became corrupted and considerably
modified. In the meantime the natives of Norway, who had enjoyed much
commercial intercourse with the rest of Europe, acquired quite a new
speech, and looked on the Icelandic as having been stationary, and
as representing the pure Gothic original of which their own was an
offshoot.
A German colony in Pennsylvania was cut off from frequent communication
with Europe for about a quarter of a century, during the wars of the
French Revolution between 1792 and 1815. So marked had been the effect
even of this brief and imperfect isolation, that when Prince Bernhard of
Saxe-Weimar travelled among them a few years after the peace, he found
the peasants speaking as they had done in Germany in the preceding
century,*) and retaining a dialect which at home had already become
obsolete.
(* "Travels of Prince Bernhard of Saxe-Weimar, in North
America, in 1825 and 1826", page 123.)
Even after the renewal of the German emigration from Europe, when I
travelled in 1841 among the same people in the retired valleys of the
Alleghenies, I found the newspapers full of terms half English and
half German, and many an Anglo-Saxon word, which had assumed a Teutonic
dress, as "fencen," to fence, instead of umzaunen, "flauer" for flour,
instead of mehl, and so on. What with the retention of terms no longer
in use in the mother country, and the borrowing of new ones from
neighbouring states, there might have arisen in Pennsylvania in five or
six generations, but for the influx of newcomers from Germany, a mongrel
speech equally unintelligible to the Anglo-Saxon and to the inhabitants
of the European fatherland.
If languages resemble species in having had each their "specific centre"
or single area of creation, in which they have been slowly formed, so
each of them is alike liable to slow or to sudden extinction. They may
die out very gradually in consequence of transmutation, or abruptly by
the extermination of the last surviving representatives of the unaltered
type. We know in what century the last Dodo perished, and we know
that in the seventeenth century the language of the Red Indians of
Massachusetts, into which Father Eliot had translated the Bible, and
in which Christianity was preached for several generations, ceased to
exist, the last individuals by whom it was spoken having at that period
died without issue.*
(* Lyell, "Travels in North America" volume 1 page 260
1845.)
But if just before that event the white man had retreated from the
continent, or had been swept off by an epidemic, those Indians might
soon have repeopled the wilderness, and their copious vocabulary
and peculiar forms of expression might have lasted without important
modification to this day. The extinction, however, of languages in
general is not abrupt, any more than that of species. It will also be
evident from what has been said, that a language which has once died out
can never be revived, since the same assemblage of conditions can never
be restored even among the descendants of the same stock, much less
simultaneously among all the rounding nations with whom they may be in
contact.
We may compare the persistency of languages, or the tendency of each
generation to adopt without change the vocabulary of its predecessor,
to the force of inheritance in the organic world, which causes the
offspring to resemble its parents. The inventive power which coins new
words or modifies old ones, and adapts them to new wants and conditions
as often as these arise, answers to the variety-making power in the
animate creation.
Progressive improvement in language is a necessary consequence of
the progress of the human mind from one generation to another. As
civilisation advances, a greater number of terms are required to express
abstract ideas, and words previously used in a vague sense, so long
as the state of society was rude and barbarous, gradually acquire more
precise and definite meanings, in consequence of which several terms
must be employed to express ideas and things, which a single word had
before signified, though somewhat loosely and imperfectly.
The farther this subdivision of function is carried, the more complete
and perfect the language becomes, just as species of higher grade have
special organs, such as eyes, lungs, and stomach, for seeing, breathing,
and digesting, which in simple organisms are all performed by one and
the same part of the body.*
(* See Herbert Spencer's "Psychology" and "Scientific
Essays.")
When we had satisfied ourselves that all the existing languages, instead
of being primordial creations, or the direct gifts of a supernatural
Power, have been slowly elaborated, partly by the modification of
pre-existing dialects, partly by borrowing terms at successive periods
from numerous foreign sources, and partly by new inventions made some of
them deliberately, and some casually and as it were fortuitously--when
we have discovered the principal causes of selection, which have guided
the adoption or rejection of rival names for the same things and ideas,
rival modes of pronouncing the same words and provincial dialects
competing one with another--we are still very far from comprehending all
the laws which have governed the formation of each language.
It was a profound saying of William Humboldt, that "Man is Man only by
means of speech, but in order to invent speech he must be already Man."
Other animals may be able to utter sounds more articulate and as varied
as the click of the Bushman, but voice alone can never enable brute
intelligence to acquire language.
When we consider the complexity of every form of speech spoken by a
highly civilised nation, and discover that the grammatical rules and
the inflections which denote number, time, and equality are usually the
product of a rude state of society--that the savage and the sage, the
peasant and man of letters, the child and the philosopher, have worked
together, in the course of many generations, to build up a fabric
which has been truly described as a wonderful instrument of thought, a
machine, the several parts of which are so well adjusted to each other
as to resemble the product of one period and of a single mind--we cannot
but look upon the result as a profound mystery, and one of which the
separate builders have been almost as unconscious as are the bees in
a hive of the architectural skill and mathematical knowledge which is
displayed in the construction of the honeycomb.
In our attempts to account for the origin of species, we find ourselves
still sooner brought face to face with the working of a law of
development of so high an order as to stand nearly in the same relation
as the Deity himself to man's finite understanding, a law capable of
adding new and powerful causes, such as the moral and intellectual
faculties of the human race, to a system of nature which had gone on for
millions of years without the intervention of any analogous cause. If we
confound "Variation" or "Natural Selection" with such creational laws,
we deify secondary causes or immeasurably exaggerate their influence.
Yet we ought by no means to undervalue the importance of the step which
will have been made, should it hereafter become the generally received
opinion of men of science (as I fully expect it will), that the past
changes of the organic world have been brought about by the subordinate
agency of such causes as "Variation" and "Natural Selection." All our
advances in the knowledge of Nature have consisted of such steps as
these, and we must not be discouraged because greater mysteries remain
behind wholly inscrutable to us.
If the philologist is asked whether in the beginning of things there
was one or five, or a greater number of languages, he may answer that,
before he can reply to such a question, it must be decided whether the
origin of Man was single, or whether there were many primordial races.
But he may also observe, that if mankind began their career in a rude
state of society, their whole vocabulary would be limited to a
few words, and that if they then separated into several isolated
communities, each of these would soon acquire an entirely distinct
language, some roots being lost and others corrupted and transformed
beyond the possibility of subsequent identification, so that it might
be hopeless to expect to trace back the living and dead languages to one
starting point, even if that point were of much more modern date than
we have now good reason to suppose. In like manner it may be said of
species, that if those first formed were of very simple structure, and
they began to vary and to lose some organs by disuse and acquire
new ones by development, they might soon differ as much as so many
distinctly created primordial types. It would therefore be a waste of
time to speculate on the number of original monads or germs from which
all plants and animals were subsequently evolved, more especially as the
oldest fossiliferous strata known to us may be the last of a long series
of antecedent formations, which once contained organic remains. It was
not till geologists ceased to discuss the condition of the original
nucleus of the planet, whether it was solid or fluid, and whether it
owed its fluidity to aqueous or igneous causes, that they began to
achieve their great triumphs; and the vast progress which has recently
been made in showing how the living species may be connected with the
extinct by a common bond of descent, has been due to a more careful
study of the actual state of the living world, and to those monuments of
the past in which the relics of the animate creation of former ages are
best preserved and least mutilated by the hand of time.
CHAPTER 24. -- BEARING OF THE DOCTRINE OF TRANSMUTATION ON THE ORIGIN OF
MAN, AND HIS PLACE IN THE CREATION.
Whether Man can be regarded as an Exception to the Rule if the
Doctrine of Transmutation be embraced for the rest of the
Animal Kingdom.
Zoological Relations of Man to other Mammalia.
Systems of Classification.
Term Quadrumanous, why deceptive.
Whether the Structure of the Human Brain entitles Man to form a
distinct Sub-class of the Mammalia.
Intelligence of the lower Animals compared to the Intellect and
Reason of Man.
Grounds on which Man has been referred to a distinct Kingdom of
Nature.
Immaterial Principle common to Man and Animals.
Non-discovery of intermediate Links among Fossil Anthropomorphous
Species.
Hallam on the compound Nature of Man, and his Place in the Creation.
Great Inequality of mental Endowment in different Human Races
and Individuals developed by Variation and ordinary Generation.
How far a corresponding Divergence in physical Structure may result
from the Working of the same Causes.
Concluding remarks.
Some of the opponents of transmutation, who are well versed in Natural
History, admit that though that doctrine is untenable, it is not
without its practical advantages as a "useful working hypothesis," often
suggesting good experiments and observations and aiding us to retain in
the memory a multitude of facts respecting the geographical distribution
of genera and species, both of animals and plants, the succession in
time of organic remains, and many other phenomena which, but for such a
theory, would be wholly without a common bond of relationship.
It is in fact conceded by many eminent zoologists and botanists, as
before explained, that whatever may be the nature of the species-making
power or law, its effects are of such a character as to imitate the
results which variation, guided by natural selection, would produce,
if only we could assume with certainty that there are no limits to the
variability of species. But as the anti-transmutationists are persuaded
that such limits do exist, they regard the hypothesis as simply a
provisional one, and expect that it will one day be superseded by
another cognate theory, which will not require us to assume the former
continuousness of the links which have connected the past and present
states of the organic world, or the outgoing with the incoming species.
In like manner, many of those who hesitate to give in their full
adhesion to the doctrine of progression, the other twin branch of the
development theory, and who even object to it, as frequently tending to
retard the reception of new facts supposed to militate against opinions
solely founded on negative evidence, are nevertheless agreed that on
the whole it is of great service in guiding our speculations. Indeed it
cannot be denied that a theory which establishes a connection between
the absence of all relics of vertebrata in the oldest fossiliferous
rocks, and the presence of man's remains in the newest, which affords a
more than plausible explanation of the successive appearance in strata
of intermediate age of the fish, reptile, bird, and mammal, has no
ordinary claims to our favour as comprehending the largest number of
positive and negative facts gathered from all parts of the globe, and
extending over countless ages, that science has perhaps ever attempted
to embrace in one grand generalisation.
But will not transmutation, if adopted, require us to include the human
race in the same continuous series of developments, so that we must hold
that Man himself has been derived by an unbroken line of descent from
some one of the inferior animals? We certainly cannot escape from such
a conclusion without abandoning many of the weightiest arguments which
have been urged in support of variation and natural selection considered
as the subordinate causes by which new types have been gradually
introduced into the earth. Many of the gaps which separate the most
nearly allied genera and orders of mammalia are, in a physical point of
view, as wide as those which divide Man from the mammalia most nearly
akin to him, and the extent of his isolation, whether we regard his
whole nature or simply his corporeal attributes, must be considered
before we can discuss the bearing of transmutation upon his origin and
place in the creation.
SYSTEMS OF CLASSIFICATION.
In order to qualify ourselves to judge of the degree of affinity in
physical organisation between Man and the lower animals, we cannot
do better than study those systems of classification which have been
proposed by the most eminent teachers of natural history. Of these an
elaborate and faithful summary has recently been drawn up by the late
Isidore Geoffroy St. Hilaire, which the reader will do well to consult.*
(* "Histoire Naturale Generale des Regnes organiques" Paris
volume 2 1856.)
He begins by passing in review numerous schemes of classification, each
of them having some merit, and most of them having been invented with a
view of assigning to Man a separate place in the system of Nature, as,
for example, by dividing animals into rational and irrational, or the
whole organic world into three kingdoms, the human, the animal, and the
vegetable--an arrangement defended on the ground that Man is raised
as much by his intelligence above the animals as are these by their
sensibility above plants. Admitting that these schemes are not
unphilosophical, as duly recognising the double nature of Man (his moral
and intellectual, as well as his physical attributes), Isidore G. St.
Hilaire observes that little knowledge has been imparted by them. We
have gained, he says, much more from those masters of the science who
have not attempted any compromise between two distinct orders of ideas,
the physical and psychological, and who have confined their attention
strictly to Man's physical relation to the lower animals.
Linnaeus led the way in this field of inquiry by comparing Man and the
apes, in the same manner as he compared these last with the carnivores,
ruminants, rodents, or any other division of warm-blooded quadrupeds.
After several modifications of his original scheme, he ended by placing
Man as one of the many genera in his order Primates, which embraced not
only the apes and lemurs, but the bats also, as he found these last to
be nearly allied to some of the lowest forms of the monkeys. But all
modern naturalists, who retain the order Primates, agree to exclude from
it the bats or Cheiroptera; and most of them class Man as one of
several families of the order Primates. In this, as in most systems
of classification, the families of modern zoologists and botanists
correspond with the genera of Linnaeus.
Blumenbach, in 1779, proposed to deviate from this course, and to
separate Man from the apes as an order apart, under the name of Bimana,
or two-handed. In making this innovation he seems at first to have
felt that it could not be justified without calling in psychological
considerations to his aid, to strengthen those which were purely
anatomical; for, in the earliest edition of his "Manual of Natural
History," he defined Man to be "animal rationale, loquens, erectum,
bimanum," whereas in later editions he restricted himself entirely to
the two last characters, namely, the erect position and the two hands,
or "animal erectum, bimanum."
The terms "bimanous" and "quadrumanous" had been already employed by
Buffon in 1766, but not applied in a strict zoological classification
till so used by Blumenbach. Twelve years later, Cuvier adopted the same
order Bimana for the human family, while the apes, monkeys, and lemurs
constituted a separate order called Quadrumana.
Respecting this last innovation, Isidore G. St. Hilaire asks, "How could
such a division stand, repudiated as it was by the anthropologists in
the name of the moral and intellectual supremacy of Man; and by the
zoologists, on the ground of its incompatibility with natural affinities
and with the true principles of classification? Separated as a group of
ordinal value, placed at the same distance from the ape as the latter
from the carnivore, Man is at once too near and too distant from
the higher mammalia--too near if we take into account those elevated
faculties, which, raising Man above all other organised beings, accord
to him not only the first, but a separate place in the creation--too far
if we merely consider the organic affinities which unite him with the
quadrumana; with the apes especially, which, in a purely physical point
of view, approach Man more nearly than they do the lemurs."
"What, then, is this order of Bimana of Blumenbach and Cuvier? An
impracticable compromise between two opposite and irreconcilable
systems--between two orders of ideas which are clearly expressed in the
language of natural history by these two words: the human KINGDOM and
the human FAMILY. It is one of those would-be via media propositions
which, once seen through, satisfy no one, precisely because they
are intended to please everybody; half-truths, perhaps, but also
half-falsehoods; for what, in science, is a half-truth but an error?"
Isidore G. St. Hilaire then proceeds to show how, in spite of the
great authority of Blumenbach and Cuvier, a large proportion of modern
zoologists of note have rejected the order Bimana, and have regarded Man
simply as a family of one and the same order, Primates.
TERM "QUADRUMANOUS," WHY DECEPTIVE.
Even the term "Quadrumanous" has lately been shown by Professor Huxley,
in a lecture delivered by him in the spring of 1860-61, which I had
the good fortune to hear, to have proved a fertile source of popular
delusion, conveying ideas which the great anatomists Blumenbach and
Cuvier never entertained themselves, namely, that in the so-called
Quadrumana the extremities of the hind-limbs bear a real resemblance to
the human hands, instead of corresponding anatomically with the human
feet.
As this subject bears very directly on the question, how far Man is
entitled, in a purely zoological classification, to rank as an order
apart, I shall proceed to cite, in an abridged form, the words of the
lecturer above alluded to.*
(* Professor Huxley's third lecture "On the Motor Organs of
Man compared with those of other Animals," delivered in the
Royal School of Mines, in Jermyn Street (March 1861) has
been embodied with the rest of the course in his work
entitled "Evidence as to Man's Place in Nature.")
"To gain," he observes, "a precise conception of the resemblances and
differences of the hand and foot, and of the distinctive characters of
each, we must look below the skin, and compare the bony framework and
its motor apparatus in each.
"The foot of Man is distinguished from his hand by:--
"1. The arrangement of the tarsal bones.
"2. By having a short flexor and a short extensor muscle of the digits.
"3. By possessing the muscle termed peronaeus longus.
"And if we desire to ascertain whether the terminal division of a limb
in other animals is to be called a foot or a hand, it is by the presence
or absence of these characters that we must be guided, and not by the
mere proportions, and greater or lesser mobility of the great toe,
which may vary indefinitely without any fundamental alteration in the
structure of the foot. Keeping these considerations in mind, let us now
turn to the limbs of the Gorilla. The terminal division of the fore-limb
presents no difficulty--bone for bone, and muscle for muscle, are found
to be arranged precisely as in Man, or with such minute differences as
are found as varieties in Man. The Gorilla's hand is clumsier, heavier,
and has a thumb somewhat shorter in proportion than that of Man; but no
one has ever doubted its being a true hand.
"At first sight, the termination of the hind-limb of the Gorilla looks
very hand-like, and as it is still more so in the lower apes, it is not
wonderful that the appellation 'Quadrumana,' or four-handed creatures,
adopted from the older anatomists by Blumenbach, and unfortunately
rendered current by Cuvier, should have gained such wide acceptance as a
name for the ape order. But the most cursory anatomical investigation at
once proves that the resemblance of the so-called 'hindhand' to a
true hand is only skin deep, and that, in all essential respects, the
hind-limb of the Gorilla is as truly terminated by a foot as that
of Man. The tarsal bones, in all important circumstances of number,
disposition, and form, resemble those of Man. The metatarsals and
digits, on the other hand, are proportionally longer and more slender,
while the great toe is not only proportionally shorter and weaker,
but its metatarsal bone is united by a far more movable joint with the
tarsus. At the same time, the foot is set more obliquely upon the leg
than in Man.
"As to the muscles, there is a short flexor, a short extensor, and a
peronaeus longus, while the tendons of the long flexors of the great toe
and of the other toes are united together and into an accessory fleshy
bundle.
"The hind-limb of the Gorilla, therefore, ends in a true foot with a
very movable great toe. It is a prehensile foot, if you will, but is
in no sense a hand: it is a foot which differs from that of Man in no
fundamental character, but in mere proportions--degree of mobility--and
secondary arrangement of its parts.
"It must not be supposed, however, that because I speak of these
differences as not fundamental, that I wish to underrate their value.
They are important enough in their way, the structure of the foot being
in strict correlation with that of the rest of the organism; but after
all, regarded anatomically, the resemblances between the foot of Man
and the foot of the Gorilla are far more striking and important than the
differences."*
(* Professor Huxley, ibid.)
After dwelling on some points of anatomical detail, highly
important, but for which I have not space here, the Professor
continues--"Throughout all these modifications, it must be recollected
that the foot loses no one of its essential characters. Every monkey and
lemur exhibits the characteristic arrangement of tarsal bones, possesses
a short flexor and short extensor muscle, and a peronaeus longus. Varied
as the proportions and appearance of the organ may be, the terminal
division of the hind-limb remains in plan and principle of construction
a foot, and never in the least degree approaches a hand."*
(* Ibid.)
For these reasons, Professor Huxley rejects the term "Quadrumana," as
leading to serious misconception, and regards Man as one of the families
of the Primates. This method of classification he shows to be equally
borne out by an appeal to another character on which so much reliance
has always been placed in classification, as affording in the mammalia
the most trustworthy indications of affinity, namely, the dentition.
"The number of teeth in the Gorilla and all the Old World monkeys,
except the lemurs, is thirty-two, the same as in Man, and the general
pattern of their crowns the same. But besides other distinctions, the
canines in all but Man project in the upper or lower jaws almost like
tusks. But all the American apes have four more teeth in their permanent
set, or thirty-six in all, so that they differ in this respect more from
the Old World apes than do these last from Man."
If therefore, by reference to this character, we place Man in a separate
order, we must make several orders for the apes, monkeys, and lemurs,
and so, in regard to the structure of the hands and feet before alluded
to, "the Gorilla differs far more from some of the quadrumana than he
differs from Man." Indeed, Professor Huxley contends that there is more
difference between the hand and foot of the Gorilla and those of the
Orang, one of the anthropomorphous apes, than between those of the
Gorilla and Man, for "the thumb of the Orang differs by its shortness
and by the absence of any special long flexor muscle from that of the
Gorilla more than it differs from that of Man." The carpus also of the
Orang, like that of most lower apes, contains nine bones, while in the
Gorilla, as in Man and the Chimpanzee, there are only eight." Other
characters are also given to show that the Orang's foot separates it
more widely from the Gorilla than that of the Gorilla separates that ape
from Man. In some of the lower apes, the divergence from the human
type of hand and foot, as well as from those of the Gorilla, is still
greater, as, for example, in the spider-monkey and marmoset."*
(* Huxley, ibid. page 29.)
If the muscles, viscera, or any other part of the animal fabric,
including the brain, be compared, the results are declared to be
similar.
WHETHER THE STRUCTURE OF THE HUMAN BRAIN ENTITLES MAN TO FORM A DISTINCT
SUB-CLASS OF THE MAMMALIA.
In consequence of these and many other zoological considerations, the
order Bimana had already been declared, in 1856, by Isidore G. St.
Hilaire in his history of the science above quoted "to have become
obsolete," even though sanctioned by the great names of Blumenbach and
Cuvier. But in opposition to the new views Professor Owen announced, the
year after the publication of G. St. Hilaire's work, that he had been
led by purely anatomical considerations to separate Man from the other
Primates and from the mammalia generally as a distinct SUB-CLASS, thus
departing farther from the classification of Blumenbach and Cuvier than
they had ventured to do from that of Linnaeus.
The proposed innovation was based chiefly on three cerebral characters
belonging, it was alleged, exclusively to Man and thus described in the
following passages of a memoir communicated to the Linnaean Society in
1857, in which all the mammalia were divided, according to the structure
of the brain, into four sub-classes, represented by the kangaroo, the
beaver, the ape, and Man respectively:--
"In Man, the brain presents an ascensive step in development, higher
and more strongly marked than that by which the preceding sub-class
was distinguished from the one below it. Not only do the cerebral
hemispheres overlap the olfactory lobes and cerebellum, but they extend
in advance of the one and farther back than the other. Their posterior
development is so marked that anatomists have assigned to that part the
character of a third lobe; it is peculiar to the genus Homo, and equally
peculiar is the 'posterior horn of the lateral ventricle' and
the 'hippocampus minor' which characterises the hind-lobe of each
hemisphere. The superficial grey matter of the cerebrum, through the
number and depth of its convolutions, attains its maximum of extent in
Man.
"Peculiar mental powers are associated with this highest form of brain,
and their consequences wonderfully illustrate the value of the cerebral
character; according to my estimate of which I am led to regard the
genus Homo as not merely a representative of a distinct order, but of
a distinct sub-class of the mammalia, for which I propose the name of
'Archencephala.'"*
(* Owen, "Proceedings of the Linnaean Society" London volume
8 page 20.)
The above definition is accompanied in the same memoir by the following
note:--"Not being able to appreciate, or conceive, of the distinction
between the psychical phenomena of a chimpanzee and of a Boschisman,
or of an Aztec with arrested brain-growth, as being of a nature so
essential as to preclude a comparison between them, or as being other
than a difference of degree, I cannot shut my eyes to the significance
of that all-pervading similitude of structure--every tooth, every bone,
strictly homologous--which makes the determination of the difference
between Homo and Pithecus the anatomist's difficulty; and therefore,
with every respect for the author of the Records of Creation,* I follow
Linnaeus and Cuvier in regarding mankind as a legitimate subject of
zoological comparison and classification."
(* The late Archbishop of Canterbury, Dr. Sumner.)
[Illustration: Figure 54, 55 and 56. Brain Of Chimpanzee]
(FIGURE 54. UPPER SURFACE OF BRAIN OF CHIMPANZEE, DISTORTED (FROM
SCHROEDER VAN DER KOLK AND VROLIK.)
Scale half the diameter of the natural size.
A. Left cerebral hemisphere.
B. Right cerebral hemisphere.
C. Cerebellum displaced.)
(FIGURE 55. SIDE VIEW OF BRAIN OF CHIMPANZEE, DISTORTED (FROM
SCHROEDER VAN DER KOLK AND VROLIK.)
Scale half the diameter of the natural size.
e. The extension of the displaced cerebellum beyond the
cerebrum at d.)
(FIGURE 56. CORRECT SIDE VIEW OF CHIMPANZEE'S BRAIN (FROM
GRATIOLET).
Scale half the diameter of the natural size.
d. Backward extension of the cerebrum, beyond the cerebellum at e.
f. Fissure of Sylvius.)
[Illustration: Figure 57 and 58. Chimpanzee and Human Brain]
(FIGURE 57. CORRECT VIEW OF UPPER SURFACE OF CHIMPANZEE'S BRAIN
(FROM GRATIOLET),
in which the cerebrum covers and conceals the cerebellum.
Scale half the diameter of the natural size.)
(FIGURE 58. SIDE VIEW OF HUMAN BRAIN (FROM GRATIOLET), NAMELY,
THAT OF THE BUSHWOMAN CALLED THE HOTTENTOT VENUS.
Scale half the diameter of the natural size.
A. Left cerebral hemisphere.
C. Cerebellum.
ff. Fissure of Sylvius.)
To illustrate the difference between the human and Simian brain,
Professor Owen gave figures of the negro's brain as represented by
Tiedemann, an original one of a South American monkey, Midas rufimanus,
and one of the chimpanzee (Figure 54), from a memoir published in 1849
by MM. Schroeder van der Kolk and M. Vrolik.*
(* "Comptes rendus de l'Academie Royale des Sciences"
Amsterdam volume 13.)
The selection of Figure 54 was most unfortunate, for three years before,
M. Gratiolet, the highest authority in cerebral anatomy of our age, had,
in his splendid work on "The Convolutions of the Brain in Man and
the Primates" (Paris, 1854), pointed out that, though this engraving
faithfully expressed the cerebral foldings as seen on the surface, it
gave a very false idea of the relative position of the several parts
of the brain, which, as very commonly happens in such preparations, had
shrunk and greatly sunk down by their own weight.*
(* Gratiolet's words are: "Les plis cerebraux du chimpanze y
sont fort bien etudies, malheureusement le cerveau qui leur
a servi de modele etait profondement affaisse, aussi la
forme generale du cerveau est-elle rendue, dans leurs
planches, d'une maniere tout-a-fait fausse." Ibid. page 18.)
Anticipating the serious mistakes which would arise from this inaccurate
representation of the brain of the ape, published under the auspices of
men so deserving of trust as the two above-named Dutch anatomists, M.
Gratiolet thought it expedient, by way of warning to his readers, to
repeat their incorrect figures (Figures 54 and 55), and to place by the
side of them two correct views (Figures 56 and 57) of the brain of the
same ape. By reference to these illustrations, as well as to Figure 58,
the reader will see not only the contrast of the relative position of
the cerebrum and cerebellum, as delineated in the natural as well as
in the distorted state, but also the remarkable general correspondence
between the chimpanzee brain and that of the human subject in everything
save in size. The human brain (Figure 58) here given, by Gratiolet,
is that of an African bushwoman, called the Hottentot Venus, who was
exhibited formerly in London, and who died in Paris.
Respecting this striking analogy of cerebral structure in Man and the
apes, Gratiolet says, in the work above cited: "The convoluted brain
of Man and the smooth brain of the marmoset resemble each other by the
quadruple character of a rudimentary olfactory lobe, a posterior lobe
COMPLETELY COVERING THE CEREBELLUM, a well-defined fissure of Sylvius
(ff, Figure 56), and lastly a posterior horn in the lateral ventricle.
These characters are not met with together except in Man and the apes."*
(* Gratiolet, ibid. Avant-propos page 2 1854.)
In reference to the other figure of a monkey given by Professor Owen,
namely, that of the Midas, one of the marmosets, he states, in 1857 as
he had done in 1837, that the posterior part of the cerebral hemispheres
"extends, as in most of the quadrumana, over the greater part of the
cerebellum."*
(* "Proceedings of the Linnaean Society" 1857 page 18 note,
and "Philosophical Transactions" 1837 page 93.)
In 1859, in his Rede Lecture, delivered to the University of Cambridge,
the same illustrations of the ape's brain were given, namely, that of
the Midas and the distorted one of the Dutch anatomists already cited
(Figure 54).*
(* See Appendix M.)
Two years later, Professor Huxley, in a memoir "On the Zoological
Relations of Man with the Lower Animals," took occasion to refer to
Gratiolet's warning, and to cite his criticism on the Dutch plates;* but
this reminder appears to have been overlooked by Professor Owen, who six
months later came out with a new paper on "The Cerebral Character of
Man and the Ape," in which he repeated the incorrect representation
of Schroeder van der Kolk and Vrolik, associating it with Tiedemann's
figure of a negro's brain, expressly to show the relative and different
extent to which the cerebellum is overlapped by the cerebrum in the two
cases respectively.** In the ape's brain as thus depicted, the portion
of the cerebellum left uncovered is greater than in the lemurs, the
lowest type of Primates, and almost as large as in the rodentia, or some
of the lowest grades of the mammalia.
(* Huxley, "Natural History Review" January 7, 1861 page
76.)
(** "Annals and Magazine of Natural History" volume 7 1861
page 456 and Plate 20.)
When the Dutch naturalists above mentioned found their figures so often
appealed to as authority, by one the weight of whose opinion on such
matters they well knew how to appreciate, they resolved to do their
best towards preventing the public from being misled. Accordingly, they
addressed to the Royal Academy of Amsterdam a memoir "On the brain of
an Orang-outang" which had just died in the Zoological Gardens of that
city.*
(* This paper is reprinted in the original French in the
"Natural History Review" volume 2 1862 page 111.)
The dissection of this ape, in 1861, fully bore out the general
conclusions at which they had previously arrived in 1849, as to
the existence both in the human and the simian brain of the three
characters, which Professor Owen had represented as exclusively
appertaining to Man, namely, the occipital or posterior lobe, the
hippocampus minor, and the posterior cornu. These last two features
consist of certain cavities and furrows in the posterior lobes, which
are caused by the foldings of the brain, and are only visible when it is
dissected. MM. Schroeder van der Kolk and Vrolik took this opportunity
of candidly confessing that M. Gratiolet's comments on the defects of
their two figures (Figures 54 and 55) were perfectly just, and they
expressed regret that Professor Owen should have overstated the
differences existing between the brain of Man and the Quadrumana, "led
astray, as they supposed, by his zeal to combat the Darwinian theory
respecting the transformation of species," a doctrine against which
they themselves protested strongly, saying that it belongs to a class
of speculations which are sure to be revived from time to time, and are
always "peculiarly seductive to young and sanguine minds."*
(* Ibid. page 114.)
As the two memoirs before alluded to by us, the one by Mr. Darwin on
"Natural Selection," and the other by Mr. Wallace "On the Tendency of
Varieties to depart indefinitely from the original Type," did not appear
till 1858, a year after Professor Owen's classification of the mammalia,
and as Darwin's "Origin of Species" was not published till another year
had elapsed, we cannot accept the explanation above offered to us of the
causes which led the founder of the sub-class Archencephala to seek for
new points of distinction between the human and simian brains; but the
Dutch anatomists may have fallen into this anachronism by having just
read, in the paper by Professor Owen in the "Annals," some prefatory
allusions to "the Vestiges of Creation," "Natural Selection, and the
question whether man be or be not a descendant of the ape."
The number of original and important memoirs to which this discussion on
the cerebral relations of Man to the Primates has already given rise in
less than five years, must render the controversy for ever memorable in
the history of Comparative Anatomy.*
(* Rolleston, "Natural History Review" April 1861. Huxley,
on "Brain of Ateles" "Proceedings of the Zoological Society"
1861. Flower, "Posterior Lobe in Quadrumana" etc.,
"Philosophical Transactions" 1862. Id. "Javan Loris"
"Proceedings of the Zoological Society" 1862. Id. on
"Anatomy of Pithecia" ibid. 1862.)
In England alone, no less than fifteen genera of the Primates (the
subjects having been almost all furnished by that admirable institution
the Zoological Gardens of London) have been anatomically examined, and
they include nearly all the leading types of structure of the Old
and New World apes and monkeys, from the most anthropoid form to that
farthest removed from Man; in other words, from the Chimpanzee to the
Lemur. These are:--
Troglodytes (Chimpanzee).
Pithecus (Orang).
Hylobates (Gibbon).
Semnopithecus.
Cercopithecus.
Macacus.
Cynocephalus (Baboon).
Ateles (Spider Monkey).
Cebus (Capuchin Monkey).
Pithecia (Saki).
Nyctipithecus (Douricouli).
Hapale (Marmoset).
Otolicnus.
Stenops.
Lemur.
In July 1861 Mr. Marshall, in a paper on the brain of a young
Chimpanzee, which he had dissected immediately after its death, gave a
series of photographic drawings, showing that when the parts are all
in a fresh state, the posterior lobe of the cerebrum, instead of simply
covering the cerebellum, is prolonged backwards beyond it even to a
greater extent than in Gratiolet's figure, 56, and, what is more in
point, in a greater degree relatively speaking (at least in the young
state of the animal) than in Man. In fact, "the projection is to the
extent of about one-ninth of the total length of the cerebrum, whereas
the average excess of overlapping is only one-eleventh in the human
brain."*
(* Marshall, "Natural History Review" July 1861. See also on
this subject Professor Rolleston on the slight degree of
backward extension of the cerebrum in some races of Man.
"Medical Times" October 1862, page 419.)
The same author gives an instructive account of the manner in which
displacement and distortion take place when such brains are preserved in
spirits as in the ordinary preparations of the anatomist.
Mr. Flower, in a recent paper on the posterior lobe of the cerebrum in
the Quadrumana,* remarks, that although Tiedemann had declared himself
unable in 1821 to detect the hippocampus minor or the posterior cornu
of the lateral ventricle in the brain of a Macacus dissected by him,
Cuvier, nevertheless, mentions the latter as characteristic of Man and
the apes, and M. Serres in his well-known work on the brain in 1826,
has shown in at least four species of apes the presence of both the
hippocampus minor and the posterior cornu.
(* "Philosophical Transactions" 1862 page 185.)
Tiedemann had expressly stated that "the third or hinder lobe in the ape
covered the cerebellum as in Man,"* and as to his negative evidence in
respect to the internal structure of that lobe, it can have no weight
whatever against the positive proofs obtained to the contrary by a host
of able observers. Even before Tiedemann's work was published, Kuhl had
dissected, in 1820, the brain of the spider-monkey (Ateles beelzebuth),
and had given a figure of a long posterior cornu to the lateral
ventricle, which he had described as such.**
(* Tiedemann, "Icones cerebri Simiarum" etc. page 48.)
(** "Beitrage zur Zoologie" etc. Frankfurt am Main 1820.)
The general results arrived at by the English anatomists already cited,
and by Professor Rolleston in various papers on the same subject, have
thus been briefly stated by Professor Huxley:--
"Every lemur which has yet been examined has its cerebellum partially
visible from above, and its posterior lobe, with the contained posterior
cornu and hippocampus minor, more or less rudimentary. Every marmoset,
American monkey, Old World monkey, baboon, or man-like ape, on the
contrary, has its cerebellum entirely hidden, and possesses a large
posterior cornu, with a well-developed hippocampus minor.
"In many of these creatures, such as the Saimiri (Chrysothrix), the
cerebral lobes overlap and extend much farther behind the cerebellum in
proportion than they do in Man."*
(* Huxley, "Evidence as to Man's place in Nature" page 97.)
It is by no means pretended that these conclusions of British observers
as to the affinity in cerebral structure of Man and the Primates are
new, but on the contrary that they confirm the inductions previously
made by the principal continental teachers of the last and present
generations, such as Tiedemann, Cuvier, Serres, Leuret, Wagner,
Schroeder van der Kolk, Vrolik, Gratiolet, and others.
At a late meeting of the British Association (1862), Professor Owen read
a paper "On the brain and limb characters of the Gorilla as contrasted
with those of Man"* in which, he observes, that in the gorilla the
cerebrum "extends over the cerebellum, not beyond it."
(* Medical Times and Gazette" October 1862 page 373.)
This statement, although slightly at variance with one published the
year before (1861) by Professor Huxley, who maintains that it does
project beyond, is interesting as correcting the description of the same
brain given by Professor Owen in that year, in a lecture to the Royal
Institution, in which a considerable part of the cerebellum of the
gorilla was represented as uncovered.*
(* "Athenaeum" Report of Royal Institution Lecture, March
23, 1861, and reference to it by Professor Owen as to
Gorilla, ibid. March 30 page 434.)
In the same memoir, it is remarked that in the Maimon Baboon the
cerebrum not only covers but "extends backwards even beyond the
cerebellum."*
(* For Report of Professor Owen's Cambridge British
Association paper see "Medical Times" October 11, 1862 page
373.)
This baboon, therefore, possesses a posterior lobe, according to every
description yet given of such a lobe, including a new definition of
the same lately proposed by Professor Owen. For the posterior lobe was
formerly considered to be that part of the cerebrum which covers the
cerebellum, whereas Professor Owen defines it as that part which covers
the posterior third of the cerebellum, and extends beyond it.
We may, therefore, consider the attempt to distinguish the brain of
Man from that of the ape on the ground of newly-discovered cerebral
characters, presenting differences in kind, as virtually abandoned by
its originator, and if the sub-class Archencephala is to be retained, it
must depend on differences in degree, as, for example, the vast increase
of the brain in Man, as compared with that of the highest ape, "in
absolute size, and the still greater superiority in relative size to the
bulk and weight of the body."*
(* Owen, ibid. page 373.)
If we ask why this character, though well known to Cuvier and other
great anatomists before our time, was not considered by them to entitle
Man, physically considered, to claim a more distinct place in the group
called Primates than that of a separate order, or, according to others,
a separate genus or family only, we shall find the answer thus concisely
stated by Professor Huxley in his new work, before cited:--
"So far as I am aware, no human cranium belonging to an adult man has
yet been observed with a less cubical capacity than 62 cubic inches, the
smallest cranium observed in any race of men, by Morton, measuring 63
cubic inches; while on the other hand, the most capacious gorilla skull
yet measured has a content of not more than 34 1/2 cubic inches. Let us
assume for simplicity's sake, that the lowest man's skull has twice
the capacity of the highest gorilla's. No doubt this is a very striking
difference, but it loses much of its apparent systematic value,
when viewed by the light of certain other equally indubitable facts
respecting cranial capacities.
"The first of these is, that the difference in the volume of the cranial
cavity of different races of mankind is far greater, absolutely, than
that between the lowest man and the highest ape, while, relatively,
it is about the same; for the largest human skull measured by Morton
contained 114 cubic inches, that is to say, had very nearly double the
capacity of the smallest, while its absolute preponderance of over 50
cubic inches is far greater than that by which the lowest adult male
human cranium surpasses the largest of the gorillas (62 minus 34 1/2 =
27 1/2). Secondly, the adult crania of gorillas which have as yet been
measured, differ among themselves by nearly one-third, the maximum
capacity being 34.5 cubic inches, the minimum 24 cubic inches; and,
thirdly, after making all due allowance for difference of size, the
cranial capacities of some of the lower apes fall nearly as much
relatively below those of the higher apes, as the latter fall below
Man."*
(* Huxley, "Evidence as to Man's place in Nature" London
1863 page 78. )
Are we then to conclude that differences in mental power have no
intimate connection with the comparative volume of the brain? We cannot
draw such an inference, because the highest and most civilised races of
Man exceed in the average of their cranial capacity the lowest races,
the European brain, for example, being larger than that of the negro,
and somewhat more convoluted and less symmetrical, and those apes, on
the other hand, which approach nearest to Man in the form and volume
of their brain being more intelligent than the Lemurs, or still lower
divisions of the mammalia, such as the Rodents and Marsupials, which
have smaller brains. But the extraordinary intelligence of the elephant
and dog, so far exceeding that of the larger part of the Quadrumana,
although their brains are of a type much more remote from the human, may
serve to convince us how far we are as yet from understanding the
real nature of the dependence of intellectual superiority on cerebral
structure.
Professor Rolleston, in reference to this subject, remarks, that "even
if it were to be proved that the differences between Man's brain and
that of the ape are differences entirely of quantity, there is
no reason, in the nature of things, why so many and such weighty
differences in degree should not amount to a difference in kind.
"Differences of degree and differences of kind are, it is true, mutually
exclusive terms in the language of the schools; but whether they are so
also in the laboratory of Nature, we may very well doubt."*
(* Report of a Lecture delivered at the Royal Institution by
Professor George Rolleston "On the Brain of Man and Animals"
"Medical Gazette" March 15, 1862 page 262.)
The same physiologist suggests, that as there is considerable plasticity
in the human frame, not only in youth and during growth, but even in the
adult, we ought not always to take for granted, as some advocates of
the development theory seem to do, that each advance in psychical power
depends on an improvement in bodily structure, for why may not the soul,
or the higher intellectual and moral faculties, play the first instead
of the second part in a progressive scheme?
INTELLIGENCE OF THE LOWER ANIMALS COMPARED TO THAT OF MAN.
Ever since the days of Leibnitz, metaphysicians who have attempted to
draw a line of demarcation between the intelligence of the lower animals
and that of Man, or between instinct and reason, have experienced
difficulties analogous to those which the modern anatomist encounters
when he tries to distinguish the brain of an ape from that of Man by
some characters more marked than those of mere size and weight, which
vary so much in individuals of the same species, whether simian or
human.
Professor Agassiz, after declaring that as yet we scarcely possess the
most elementary information requisite for a scientific comparison of the
instincts and faculties of animals with those of Man, confesses that he
cannot say in what the mental faculties of a child differ from those of
a young chimpanzee. He also observes, that "the range of the passions of
animals is as extensive as that of the human mind, and I am at a loss to
perceive a difference of kind between them, however much they may differ
in degree and in the manner in which they are expressed. The gradations
of the moral faculties among the higher animals and Man are, moreover,
so imperceptible, that to deny to the first a certain sense of
responsibility and consciousness would certainly be an exaggeration of
the difference between animals and Man. There exists, besides, as much
individuality within their respective capabilities among animals as
among Man, as every sportsman, or every keeper of menageries, or every
farmer and shepherd can testify, who has had a large experience with
wild, or tamed, or domesticated animals. This argues strongly in favour
of the existence in every animal of an immaterial principle, similar
to that which, by its excellence and superior endowments, places Man so
much above animals. Yet the principle exists unquestionably, and whether
it be called soul, reason, or instinct, it presents, in the whole range
of organised beings, a series of phenomena closely linked together, and
upon it are based not only the higher manifestations of the mind, but
the very permanence of the specific differences which characterise every
organ. Most of the arguments of philosophy in favour of the immortality
of Man apply equally to the permanency of this principle in other living
beings."*
(* Contributions to the "Natural History of the United
States of North America" volume 1 part 1 pages 60 and 64.)
Professor Huxley, when commenting on a passage in Professor Owen's
memoir, above cited, argues that there is a unity in psychical as in
physical plan among animated beings, and adds, that although he cannot
go so far as to say that "the determination of the difference between
Homo and Pithecus is the anatomist's difficulty," yet no impartial judge
can doubt that the roots, as it were, of those great faculties which
confer on Man his immeasurable superiority above all other animate
things are traceable far down into the animate world. The dog, the cat,
and the parrot, return love for our love and hatred for our hatred. They
are capable of shame and of sorrow, and though they may have no logic
nor conscious ratiocination, no one who has watched their ways can
doubt that they possess that power of rational cerebration which evolves
reasonable acts from the premises furnished by the senses--a process
which takes fully as large a share as conscious reason in human
activity.*
(* "Natural History Review" Number 1 January 1861 page 68.)
GROUNDS FOR REFERRING MAN TO A DISTINCT KINGDOM OF NATURE.
Few if any of the authors above cited, while they admit so fully the
analogy which exists between the faculties of Man and the inferior
animals, are disposed to underrate the enormous gap which separates Man
from the brutes, and if they scarcely allow him to be referable to
a distinct order, and much less to a separate sub-class, on purely
physical grounds, it does not follow that they would object to the
reasoning of M. Quatrefages, who says, in his work on the "Unity of
the Human Species," that Man must form a kingdom by himself if once we
permit his moral and intellectual endowments to have their due weight in
classification.
As to his organisation, he observes, "We find in the mammalia nearly
absolute identity of anatomical structure, bone for bone, muscle for
muscle, nerve for nerve--similar organs performing like functions. It is
not by a vertical position on his feet, the os sublime of Ovid, which he
shares with the penguin, nor by his mental faculties, which, though more
developed, are fundamentally the same as those of animals, nor by his
powers of perception, will, memory, and a certain amount of reason, nor
by articulate speech, which he shares with birds and some mammalia,
and by which they express ideas comprehended not only by individuals of
their own species but often by Man, nor is it by the faculties of the
heart, such as love and hatred, which are also shared by quadrupeds and
birds, but it is by something completely foreign to the mere animal, and
belonging exclusively to Man, that we must establish a separate kingdom
for him (page 21). These distinguishing characters," he goes on to say,
"are the abstract notion of good and evil, right and wrong, virtue and
vice, or the moral faculty, and a belief in a world beyond ours, and in
certain mysterious beings, or a Being of a higher nature than ours,
whom we ought to fear or revere; in other words, the religious
faculty."--page 23.
By these two attributes the moral and the religious, not common to man
and the brutes, M. Quatrefages proposes to distinguish the human from
the animal kingdom.
But he omits to notice one essential character, which Dr. Sumner, the
late Archbishop of Canterbury, brought out in strong relief fifty years
ago in his "Records of Creation." "There are writers," he observes, "who
have taken an extraordinary pleasure in levelling the broad distinction
which separates Man from the Brute Creation. Misled to a false
conclusion by the infinite variety of Nature's productions, they have
described a chain of existence connecting the vegetable with the animal
world, and the different orders of animals one with another, so as to
rise by an almost imperceptible gradation from the tribe of Simiae
to the lowest of the human race, and from these upwards to the most
refined. But if a comparison were to be drawn, it should be taken, not
from the upright form, which is by no means confined to mankind, nor
even from the vague term reason, which cannot always be accurately
separated from instinct, but from that power of progressive and
improvable reason, which is Man's peculiar and exclusive endowment."
"It has been sometimes alleged, and may be founded on fact, that there
is less difference between the highest brute animal and the lowest
savage than between the savage and the most improved Man. But, in order
to warrant the pretended analogy, it ought to be also true that this
lowest savage is no more capable of improvement than the Chimpanzee or
Orang-outang."
"Animals," he adds, "are born what they are intended to remain. Nature
has bestowed upon them a certain rank, and limited the extent of their
capacity by an impassable decree. Man she has empowered and obliged
to become the artificer of his own rank in the scale of beings by the
peculiar gift of improvable reason."*
(* "Records of Creation" volume 2 chapter 2 2nd edition
1816.)
We have seen that Professor Agassiz, in his "Essay on Classification,"
above cited, speaks of the existence in every animal of "an immaterial
principle similar to that which, by its excellence and superior
endowments, places man so much above animals;" and he remarks, "that
most of the arguments of philosophy in favour of the immortality of
Man, apply equally to the permanency of this principle in other living
beings."
Although the author has no intention by this remark to impugn the truth
of the great doctrine alluded to, it may be well to observe, that if
some of the arguments in favour of a future state are applicable in
common to Man and the lower animals, they are by no means those which
are the weightiest and most relied on. It is no doubt true that, in
both, the identity of the individual outlasts many changes of form and
structure which take place during the passage from the infant to the
adult state, and from that to old age, and the loss again and again
of every particle of matter which had entered previously into the
composition of the body during its growth, and the substitution of new
elements in their place, while the individual remains always the same,
carries the analogy a step farther. But beyond this we cannot push the
comparison. We cannot imagine this world to be a place of trial and
moral discipline for any of the inferior animals, nor can any of them
derive comfort and happiness from faith in a hereafter. To Man alone is
given this belief, so consonant to his reason, and so congenial to the
religious sentiments implanted by nature in his soul, a doctrine which
tends to raise him morally and intellectually in the scale of being, and
the fruits of which are, therefore, most opposite in character to those
which grow out of error and delusion.
The opponents of the theory of transmutation sometimes argue that, if
there had been a passage by variation from the lower Primates to Man,
the geologist ought ere this to have detected some fossil remains of the
intermediate links of the chain. But what we have said respecting the
absence of gradational forms between the Recent and Pliocene mammalia
may serve to show the weakness in the present state of science of any
argument based on such negative evidence, especially in the case of Man,
since we have not yet reached those pages of the great book of nature,
in which alone we have any right to expect to find records of the
missing links alluded to. The countries of the anthropomorphous apes are
the tropical regions of Africa, and the islands of Borneo and Sumatra,
lands which may be said to be quite unknown in reference to their
Pliocene and Pleistocene mammalia. Man is an old-world type, and it is
not in Brazil, the only equatorial region where ossiferous caverns have
yet been explored, that the discovery, in a fossil state, of extinct
forms allied to the human, could be looked for. Lund, a Danish
naturalist, found in Brazil, not only extinct sloths and armadilloes,
but extinct genera of fossil monkeys, but all of the American type, and,
therefore, widely departing in their dentition and some other characters
from the Primates of the old world.
At some future day, when many hundred species of extinct quadrumana may
have been brought to light, the naturalist may speculate with advantage
on this subject; at present we must be content to wait patiently, and
not to allow our judgment respecting transmutation to be influenced by
the want of evidence, which it would be contrary to analogy to look for
in Pleistocene deposits in any districts, which as yet we have carefully
examined. For, as we meet with extinct kangaroos and wombats in
Australia, extinct llamas and sloths in South America, so in equatorial
Africa, and in certain islands of the East Indian Archipelago, may
we hope to meet hereafter with lost types of the anthropoid Primates,
allied to the gorilla, chimpanzee, and orang-outang. [44]
Europe, during the Pliocene period, seems not to have enjoyed a climate
fitting it to be the habitation of the quadrumanous mammalia; but we no
sooner carry back our researches into Miocene times, where plants and
insects, like those of Oeningen, and shells, like those of the Faluns of
the Loire, would imply a warmer temperature both of sea and land, than
we begin to discover fossil apes and monkeys north of the Alps and
Pyrenees. Among the few species already detected, two at least belong to
the anthropomorphous class. One of these, the Dryopithecus of Lartet, a
gibbon or long-armed ape, about equal to man in stature, was obtained
in the year 1856 in the Upper Miocene strata at Sansan, near the foot
of the Pyrenees in the South of France, and one bone of the same ape is
reported to have been since procured from a deposit of corresponding age
at Eppelsheim, near Darmstadt, in a latitude answering to that of the
southern counties of England.*
(* Owen, "Geologist" November 1862.)
But according to the doctrine of progression it is not in these
Miocene strata, but in those of Pliocene and Pleistocene date, in
more equatorial regions, that there will be the greatest chance of
discovering hereafter some species more highly organised than the
gorilla and chimpanzee.
The only reputed fossil monkey of Eocene date, namely, that found in
1840 at Kyson, in Suffolk, and so determined by Professor Owen, has
recently been pronounced by the same anatomist, after re-examination,
and when he had ampler materials at his command, to be a pachyderm.
M. Rutimeyer,* however, an able osteologist, referred to in the earlier
chapters of this work, has just announced the discovery in Eocene
strata, in the Swiss Jura, of a monkey allied to the lemurs, but as
he has only obtained as yet a small fragment of a jaw with three molar
teeth, we must wait for fuller information before we confidently rely
on the claims of his Coenopithecus lemuroides to take rank as one of the
Primates.
(* Rutimeyer, "Eocene Saugethiere" Zurich 1862.)
HALLAM ON MAN'S PLACE IN THE CREATION.
Hallam, in his "Literature of Europe," after indulging in some profound
reflections on "the thoughts of Pascal," and the theological dogmas of
his school respecting the fallen nature of Man, thus speaks of Man's
place in the creation--"It might be wandering from the proper subject
of these volumes if we were to pause, even shortly, to inquire whether,
while the creation of a world so full of evil must ever remain the most
inscrutable of mysteries, we might not be led some way in tracing the
connection of moral and physical evil in mankind, with his place in that
creation, and especially, whether the law of continuity, which it has
not pleased his Maker to break with respect to his bodily structure, and
which binds that, in the unity of one great type, to the lower forms of
animal life by the common conditions of nourishment, reproduction, and
self-defence, has not rendered necessary both the physical appetites
and the propensities which terminate in self; whether again the superior
endowments of his intellectual nature, his susceptibility of
moral emotion, and of those disinterested affections which, if
not exclusively, he far more intensely possesses than an inferior
being--above all, the gifts of conscience and a capacity to know God,
might not be expected, even beforehand, by their conflict with the
animal passions, to produce some partial inconsistencies, some anomalies
at least, which he could not himself explain in so compound a being.
Every link in the long chain of creation does not pass by easy
transition into the next. There are necessary chasms, and, as it were,
leaps from one creature to another, which, though no exceptions to the
law of continuity, are accommodations of it to a new series of being.
If Man was made in the image of God, he was also made in the image of an
ape. The framework of the body of him who has weighed the stars and made
the lightning his slave, approaches to that of a speechless brute, who
wanders in the forests of Sumatra. Thus standing on the frontier land
between animal and angelic natures, what wonder that he should partake
of both!"*
(* Hallam, "Introduction to the Literature of Europe" etc.
volume 4 page 162.)
The law of continuity here spoken of, as not being violated by
occasional exceptions, or by leaps from one creature to another, is not
the law of variation and natural selection above explained (Chapter 21),
but that unity of plan supposed to exist in the Divine Mind, whether
realised or not materially and in the visible creation, of which the
"links do not pass by an easy transition" the one into the other, at
least as beheld by us.
Dr. Asa Gray, an eminent American botanist, to whom we are indebted
for a philosophical essay of great merit on the "Origin of Species by
Variation and Natural Selection," has well observed, when speaking of
the axiom of Leibnitz, "Natura non agit saltatim," that nature secures
her ends and makes her distinctions, on the whole, manifest and real,
but without any important breaks or long leaps. "We need not wonder that
gradations between species and varieties should occur, or that genera
and other groups should not be absolutely limited, though they are
represented to be so in our systems. The classifications of the
naturalist define abruptly where nature more or less blends. Our systems
are nothing if not definite."
The same writer reminds us that "plants and animals are so different,
that the difficulty of the ordinary observer would be to find points of
comparison, whereas, with the naturalist, it is all the other way.
All the broad differences vanish one by one as we approach the
lower confines of the animal and vegetable kingdoms, and no absolute
distinction whatever is now known between them."*
(* Gray, "Natural Selection not inconsistent with Natural
Theology" Trubner & Co. London 1861 page 55.)
The author of an elaborate review of Darwin's "Origin of Species,"
himself an accomplished geologist, declares that if we embrace the
doctrine of the continuous variation of all organic forms from the
lowest to the highest, including Man as the last link in the chain of
being, there must have been a transition from the instinct of the brute
to the noble mind of Man; and in that case, "where," he asks, "are the
missing links, and at what point of his progressive improvement did Man
acquire the spiritual part of his being, and become endowed with the
awful attribute of immortality?"*
(* Physical Theories of the Phenomena of Life "Fraser's
Magazine" July 1860 page 88.)
Before we raise objections of this kind to a scientific hypothesis,
it would be well to pause and inquire whether there are no analogous
enigmas in the constitution of the world around us, some of which
present even greater difficulties than that here stated. When we
contemplate, for example, the many hundred millions of human beings who
now people the earth, we behold thousands who are doomed to helpless
imbecility, and we may trace an insensible gradation between them
and the half-witted, and from these again to individuals of perfect
understanding, so that tens of thousands must have existed in the course
of ages, who in their moral and intellectual condition, have exhibited
a passage from the irrational to the rational, or from the irresponsible
to the responsible. Moreover we may infer from the returns of the
Registrar General of births and deaths in Great Britain, and from
Quetelet's statistics of Belgium, that one-fourth of the human race die
in early infancy, nearly one-tenth before they are a month old; so that
we may safely affirm that millions perish on the earth in every century,
in the first few hours of their existence. To assign to such individuals
their appropriate psychological place in the creation is one of the
unprofitable themes on which theologians and metaphysicians have
expended much ingenious speculation.
The philosopher, without ignoring these difficulties, does not allow
them to disturb his conviction that "whatever is, is right," nor do they
check his hopes and aspirations in regard to the high destiny of his
species; but he also feels that it is not for one who is so often
confounded by the painful realities of the present, to test the
probability of theories respecting the past, by their agreement or want
of agreement with some ideal of a perfect universe which those who are
opposed to opinions may have pictured to themselves.
We may also demur to the assumption that the hypothesis of variation
and natural selection obliges us to assume that there was an absolutely
insensible passage from the highest intelligence of the inferior
animals to the improvable reason of Man. The birth of an individual
of transcendent genius, of parents who have never displayed any
intellectual capacity above the average standard of their age or race,
is a phenomenon not to be lost sight of, when we are conjecturing
whether the successive steps in advance by which a progressive scheme
has been developed may not admit of occasional strides, constituting
breaks in an otherwise continuous series of psychical changes.
The inventors of useful arts, the poets and prophets of the early stages
of a nation's growth, the promulgators of new systems of religion,
ethics, and philosophy, or of new codes of laws, have often been looked
upon as messengers from Heaven, and after their death have had divine
honours paid to them, while fabulous tales have been told of the
prodigies which accompanied their birth. Nor can we wonder that such
notions have prevailed when we consider what important revolutions
in the moral and intellectual world such leading spirits have brought
about; and when we reflect that mental as well as physical attributes
are transmissible by inheritance, so that we may possibly discern in
such leaps the origin of the superiority of certain races of mankind.
In our own time the occasional appearance of such extraordinary
mental powers may be attributed to atavism; but there must have been
a beginning to the series of such rare and anomalous events. If, in
conformity with the theory of progression, we believe mankind to have
risen slowly from a rude and humble starting point, such leaps may have
successively introduced not only higher and higher forms and grades of
intellect, but at a much remoter period may have cleared at one bound
the space which separated the highest stage of the unprogressive
intelligence of the inferior animals from the first and lowest form of
improvable reason manifested by Man.
To say that such leaps constitute no interruption to the ordinary course
of nature is more than we are warranted in affirming. In the case of the
occasional birth of an individual of superior genius there is certainly
no break in the regular genealogical succession; and when all the mists
of mythological fiction are dispelled by historical criticism, when it
is acknowledged that the earth did not tremble at the nativity of the
gifted infant and that the face of heaven was not full of fiery shapes,
still a mighty mystery remains unexplained, and it is the ORDER of the
phenomena, and not their CAUSE, which we are able to refer to the usual
course of nature.
Dr. Asa Gray, in the excellent essay already cited, has pointed out that
there is no tendency in the doctrine of Variation and Natural Selection
to weaken the foundations of Natural Theology, for, consistently with
the derivative hypothesis of species, we may hold any of the popular
views respecting the manner in which the changes of the natural world
are brought about. We may imagine "that events and operations in general
go on in virtue simply of forces communicated at the first, and without
any subsequent interference, or we may hold that now and then, and only
now and then, there is a direct interposition of the Deity; or, lastly,
we may suppose that all the changes are carried on by the immediate
orderly and constant, however infinitely diversified, action of the
intelligent, efficient Cause." They who maintain that the origin of
an individual, as well as the origin of a species or a genus, can be
explained only by the direct action of the creative cause, may retain
their favourite theory compatibly with the doctrine of transmutation.
Professor Agassiz, having observed that, "while human thought is
consecutive, divine thought is simultaneous," Dr. Asa Gray has replied
that, "if divine thought is simultaneous, we have no right to affirm the
same of divine action."
The whole course of nature may be the material embodiment of a
preconcerted arrangement; and if the succession of events be explained
by transmutation, the perpetual adaptation of the organic world to new
conditions leaves the argument in favour of design, and therefore of a
designer, as valid as ever; "for to do any work by an instrument must
require, and therefore presuppose, the exertion rather of more than of
less power, than to do it directly."*
(* Asa Gray, "Natural Selection not inconsistent with
Natural Theology" Trubner & Co. London 1861 page 55.)
As to the charge of materialism brought against all forms of the
development theory, Dr. Gray has done well to remind us that "of the
two great minds of the seventeenth century, Newton and Leibnitz, both
profoundly religious as well as philosophical, one produced the
theory of gravitation, the other objected to that theory, that it was
subversive of natural religion."*
(* Ibid. page 31.)
It may be said that, so far from having a materialistic tendency, the
supposed introduction into the earth at successive geological periods
of life--sensation--instinct--the intelligence of the higher mammalia
bordering on reason--and lastly the improvable reason of Man himself,
presents us with a picture of the ever-increasing dominion of mind over
matter.
NOTES.
[Footnote 1: The classification of the strata above the Chalk, as at
present employed by the majority of British geologists, is merely a
slight modification of that proposed by Lyell in 1833. The subdivisions
generally recognised are as follows (Lake and Rastall, "Textbook of
Geology," London, 1910, page 438):--
Neogene:
Pleistocene
Pliocene
Miocene.
Palaeogene:
Oligocene
Eocene.
This differs chiefly from Lyell's classification in the introduction of
the term Oligocene for the upper part of the original Eocene, which was
somewhat unwieldy. In the earlier editions of the "Antiquity of Man" and
of the "Principles of Geology," the strata here classed as Pleistocene
were designated as Post-pliocene. The term "diluvium," now obsolete
in Britain but still lingering on the Continent, is equivalent to
Pleistocene. This subdivision is still sometimes separated from the
Tertiary, as the Quaternary epoch. This, however, is unnecessary and
indeed objectionable, as attributing too great importance to
relatively insignificant deposits. There is no definite break, either
stratigraphical or palaeontological, at the top of the Pliocene, and
it is most natural to regard the Tertiary epoch as still in progress.
Equally unnecessary is the separation of the post-glacial deposits
as "Recent," a distinction which still prevails in many quarters,
apparently with the sole object of adding another name to an already
over-burdened list.]
[Footnote 2: The table of strata here printed is not that given by
Lyell in the later editions of the "Antiquity of Man." This would have
required so much explanation in the light of modern work that it was
thought better to abolish it altogether and to substitute an entirely
new table, which is to some extent a compromise between the numerous
classifications now in vogue. In this form it is only strictly
applicable to the British Isles, though the divisions adopted in other
countries are generally similar, and in many cases identical.]
[Footnote 3: A similar succession of forest-beds, five in number, has
been observed in the peat of the Fenland, near Ely. Each bed consists
for the most part of a single species of tree, and a definite succession
of oak, yew, Scotch fir, alder, and willow has been made out. The forest
beds are supposed to indicate temporarily drier conditions, due either
to changes of climate or to slight uplift of the land, the growth of
peat being renewed during periods of damp climate or of depression of
the land. (See Clement Reid, "Submerged Forests," Cambridge, 1913.)]
[Footnote 4: Since the "Stone Age," in the sense in which the term is
here employed, obviously occupied an enormous lapse of time and embraced
very different stages of culture, it has been found convenient to
subdivide it into two primary subdivisions. For these Lord Avebury
proposed in 1865 the terms Palaeolithic and Neolithic. (" Prehistoric
Times," London, 1865, page 60.) The first comprises the ages during
which man fabricated flint implements solely by chipping, whereas
the implements of Neolithic Age are polished by rubbing. But there
is another and more fundamental distinction. Palaeolithic man was
exclusively a hunter, and consequently nomadic in his habits; Neolithic
man possessed domesticated animals and cultivated crops. A pastoral
and agricultural life implies a settled abode, and these are found, for
example, in the lake-villages of Switzerland. The "kitchen-middens" of
Denmark also indicate long continuance in one place, in this instance
the seashore.]
[Footnote 5: The famous case of the so-called Temple of Serapis at
Pozzuoli, has given rise to a considerable literature. The subject is
discussed by Suess at length ("Des Antlitz der Erde," Vienna, 1888,
volume 2 page 463, or English translation, "The Face of the Earth,"
Oxford, 1904). This author shows that the whole region is highly
volcanic, and consequently very liable to disturbance, much relative
movement of land and sea having occurred within historic times. Hence
the facts here observed cannot be taken as evidence for any general
upward or downward movement of wide-spread or universal extent.]
[Footnote 6: Darwin, "Voyage of the Beagle," chapter 14, and a much
fuller account in the same author's "Geological Observations on the
Volcanic Islands and Parts of South America Visited during the Voyage of
H.M.S. Beagle," chapter 9.]
[Footnote 7: For a full discussion of the evidence for and against
continental elevation and subsidence in general, and as affecting
the British Isles and Scandinavia in particular, see Sir A. Geikie's
Presidential Address to the Geological Society for 1904 (" Proceedings
of the Geological Society"' volume 60, 1904, pages 80 to 104.). Here it
is shown that the oldest raised beaches of Scotland are pre-glacial, and
the same also holds for the south of Ireland.]
[Footnote 8: The argument here employed is fallacious, since the mere
existence of a distinct beach implies a pause in the movement and a long
continuance at one level. It is impossible to form any estimate of the
lapse of time necessary for the building up of a beach-terrace. We can
only, in some cases, obtain a measure of the time that elapsed between
the formation of two successive beaches, as in this instance.]
[Footnote 9: The "strand lines," or raised beaches of Norway, have given
rise to much discussion, of which a summary will be found in the address
cited in Note 7.]
[Footnote 10: A considerable number of skulls and skeletons of the
Neanderthal type have now been found in different parts of Southern
Europe, extending from Belgium to Gibraltar and Croatia, and it is now
known that this type of skull is associated with flint implements of
Mousterian Age. (See Note 12.)]
[Footnote 11: The most important discovery of recent years in this
connection is that made in Sussex by Mr. C. Dawson and Dr. A. Smith
Woodward; this find is described in great detail in the "Quarterly
Journal of the Geological Society," volume 69, 1913, pages 117 to 151.
At a height of about 80 feet above the present level of the River Ouse,
at Piltdown, near Uckfield, is a gravel, containing many brown flints of
peculiar character, some of which are implements of Chellean or earlier
type, associated with some remains of Pleistocene animals and a few of
older date, derived from Pliocene deposits. Embedded in this gravel were
found fragments of a human skull and lower jaw of very remarkable type,
showing in some respects distinctly simian characters, while in other
respects it is less ape-like than the Mousterian skulls of Neanderthal
and other localities. For this form the name of Eoanthropus has been
proposed, thus constituting a new genus of the Hominidae.]
[Footnote 12: It will be well at this point to give a brief summary of
the modern classification of the Palaeolithic implement-bearing
deposits of Europe. From the labours of many geologists and prehistoric
archaeologists, especially in France, a definite succession of types
of implement has been established, and in some cases it has been found
possible to correlate these with actual human remains and with certain
well-marked events in the physical history of Pleistocene times,
especially with the advance and retreat of ice-sheets. The present state
of our knowledge is admirably summarised by Professor Sollas ("Ancient
Hunters," London, 1911), and from that work the following note is
condensed.
The stages of Palaeolithic culture now recognised are as follows:--
Azilian
Magdalenian
Solutrean
Aurignacian
Mousterian
Acheulean
Chellean
Strepyan
Mesvinian.
Below the Mesvinian comes the nebulous region of "eoliths," which are
not yet definitely proved to be of human workmanship. The Neanderthal
skull belongs to the Mousterian stage, but the oldest known definitely
human remain, the jaw from the Mauer sands near Heidelberg, may be
older than any of these, indeed by some it is assigned to the first
interglacial period of Penck and Bruckner (see Note 32). For figures
of the types of implement characterising each period, see "Guide to the
Antiquities of the Stone Age in the Department of British and Medieval
Antiquities," British Museum, 2nd edition, London, 1911, pages 1 to 74.
This publication gives an admirable summary of recent knowledge on this
subject. For an excellent and critical summary of the latest researches
on Palaeolithic man up till the end of the Aurignacian period, see
Duckworth, "Prehistoric Man," Cambridge, 1912. See also note 44.]
[Footnote 13: Sir John Evans, K.C.B. (1823-1908), was one of the
foremost authorities on prehistoric archaeology and a prolific writer
on the subject. His best known work is "The Ancient Stone Implements,
Weapons, and Ornaments of Great Britain," 2nd edition, 1897.]
[Footnote 14: By the expression "Celtic weapons of the stone period" is
presumably meant Neolithic implements, with polished surfaces.]
[Footnote 15: It has recently been shown that the growth of peat is a
very slow process, and at the present time it is in many places either
at a standstill or even in a state of retrogression. In the peat-mosses
of Scotland, Lewis has traced nine successive layers, marked by
different floras. The lowest of these and another at a higher level are
distinctly of an arctic character, the intermediate forest beds, on the
other hand, indicate periods of milder climate, when the limit of the
growth of trees was at a higher level in Scotland than is now the case.
From these facts it is certain that the peat-mosses of Scotland and
northern England date back at least as far as the later stages of the
glacial period, and indicate at least one mild interglacial episode,
when the climate was somewhat warmer than it now is. (See Lewis,
"Science Progress," volume 2, 1907, page 307.) Hence the statements of
the French workmen, here quoted, do not possess much significance.]
[Footnote 16: Cyrena fluminalis is very abundant in the gravels of an
old terrace of the River Cam, at Barnwell, in the suburbs of Cambridge,
and also in glacial gravels at Kelsey Hill in Holderness. It is a very
remarkable fact that this shell, now an inhabitant of warm regions,
should be so abundant in these Pleistocene deposits, in close
association with glacial accumulations.]
[Footnote 17: The implement-bearing deposits of Hoxne, in Suffolk, were
investigated with great care by a committee of the British Association,
and the results were published in a special and detailed report ("The
Relation of Palaeolithic Man to the Glacial Epoch," "Report of the
British Association," Liverpool, 1896, pages 400 to 415). The deposit
consists of a series of lacustrine or fluviatile strata with plant
remains, some being arctic in character, resting on Chalky Boulder Clay,
and this again on sand. The Palaeolithic deposits are all clearly later
than the latest boulder-clay of East Anglia, and between their formation
and that of the glacial deposits at least two important climatic changes
took place, indicating a very considerable lapse of time.
Mention may conveniently be made here of the supposed discovery of the
remains of pre-glacial man at Ipswich, which appears to be founded
on errors of observation. The boulder-clay above the interment is,
according to the best authorities, merely a landslip or flow.]
[Footnote 18: It has been suggested with a considerable degree of
probability, that in Auvergne volcanic eruptions persisted even into
historic times. The subject is obscure, depending on the interpretation
of difficult passages in two Latin chronicles of the fifth century. The
most obvious meaning of both passages would certainly appear to be the
occurrence of volcanic eruptions and earthquakes, but attempts have
been made to explain them as referring to some artificial conflagration,
possibly the burning of a town by an invader. (See Bonney, "Volcanoes,"
3rd edition, London, 1913, page 129.)]
[Footnote 19: In the early days of glacial geology in Britain, it
was commonly accepted that the phenomena could be most satisfactorily
explained on the hypothesis of a general submergence of the northern
parts of the country to a depth of many hundreds of feet, and this in
spite of the original comparison by Agassiz of the glacial deposits
of Britain to those of the Alps. In later times, however, a school of
geologists arose who attributed the glaciation of Britain to land-ice
of the Continental or Greenland type. Of late years this school has been
dominant in British geology, with a few notable exceptions, of whom the
most important is Professor Bonney. The difficulties presented by both
theories are almost equally great, and at the present time, in spite of
the vehemence of the supporters of the land-ice theory, it is impossible
to hold any dogmatic views on the subject. Against the doctrine of
submergence is the absence of glacial deposits in places where they
would naturally be expected to occur if the whole of the British Isles
north of the Thames and Bristol Channel had been covered by the sea,
together with the very general absence of sea-shells in the deposits.
The objections to the land-ice hypothesis are largely of a mechanical
nature. If we take into account the lateral extent and the thickness
that can be assigned to the ice-sheet, we are at once confronted by very
considerable difficulties as to the sufficiency of the driving-power
behind the ice. Another great difficulty is the shallowness of the North
Sea, in which a comparatively thin mass of ice would run aground at
almost any point. It has been calculated that the maximum slope of the
surface of the ice from Norway to the English coast could not exceed
half a degree, and it is therefore difficult to see what force could
compel it to move forward at all, much less to climb steep slopes in the
way postulated by the extremists of this school.]
[Footnote 20: The most complete account of the geology of the Norfolk
coast is contained in "The Geology of Cromer," by Clement Reid ("Memoir
of the Geological Survey"). (See also Harmer, "The Pleistocene Period
in the Eastern Counties of England," "Geology in the Field, the Jubilee
Volume of the Geologists Association," 1909, chapter 4.). Above the
Norwich Crag several more subdivisions are now recognised, and the
complete succession of the Pliocene and Pleistocene strata of East
Anglia may be summarised as follows:--
Pleistocene:
Peat and Alluvium
Gravel Terraces of the present river systems
Gravels of the old river-systems
Plateau gravels
Chalky boulder-clay
Interglacial sands and gravels and Contorted Drift
Cromer Till
Arctic Plant Bed.
Pliocene:
Cromer Forest Series
Weybourn Crag
Chillesford Crag
Norwich Crag
Red Crag
Coralline Crag.
[Footnote 21: It is now generally agreed that the tree-stumps in the
Cromer Forest bed are not in the position of growth. Many of them are
upside down or lying on their sides, and they were probably floated into
their present position by the waters of a river flowing to the north.
This river was a tributary of the Rhine which then flowed for several
hundred miles over a plain now forming the bed of the North Sea,
collecting all the drainage of eastern England, and debouching into the
North Atlantic somewhere to the south of the Faroe Isles. (See Harmer,
"The Pleistocene Period in the Eastern Counties of England," "Geological
Association Jubilee Volume," London, 1909, pages 103 to 123.)]
[Footnote 22: Of late years an enormous number of characteristic rocks
from Norway and Sweden have been recognised in the drifts of Eastern
England, as far south as Essex and Middlesex. One of the most easily
identifiable types is the well-known Rhombporphyry of the Christiania
Fjord, a rock which occurs nowhere else in the world, and is quite
unmistakable in appearance. Along with it are many of the distinctive
soda-syenites found in the same district, the granites of southern
Sweden, and many others. The literature of the subject is very large,
but many details may be found in the annual reports of the British
Association for the last twenty years.]
From a study of these erratics it has been found possible to draw
important conclusions as to the direction and sequence of the ice
streams which flowed over these regions during the different stages of
the glacial period.]
[Footnote 23: During his first crossing of Greenland from east to west,
Nansen attained a height of 9000 feet on a vast expanse of frozen snow,
and it is believed that towards the north the surface of this great
snow-plateau rises to even greater elevations. The surface of the snow
is perfectly clean and free from moraine-material. No rock in situ has
been seen in the interior of Greenland at a distance greater than 75
miles from the coast.
A great amount of valuable information concerning the glacial conditions
of Greenland is to be found in the "Meddelelser om Gronland," a Danish
publication, but containing many summaries in French or English. For
a good account of the phenomena seen in the coastal region of the west
coast, see Drygalski, "Gronland-Expedition," a large monograph published
by the Gesellschaft fur physischen Erdkunde, Berlin, 1897.]
[Footnote 24: The argument is here considerably understated. The
southern point of Greenland, Cape Farewell, is in the same latitude
as the Shetland Islands and Christiania, and only one degree north of
Stockholm; Disko is in about the same latitude as the North Cape. Hence
the inhabited portion of Greenland is in the same latitude as Norway
and Sweden, both fertile and well-populated countries. Even in Central
Norway, in the Gudbrandsdal and Romsdal, thick forests grow up to a
height of at least 3000 feet above sea-level, a much greater elevation
than trees now attain in the British Isles. This latter fact is probably
to be attributed to the protective effect of thick snow lying throughout
the winter.]
[Footnote 25: For a summary of the most recent views as to the
classification and succession of the glacial deposits of the British
Isles, see Lake an Rastall, "Textbook of Geology," London, 1910, pages
466 to 473. Reference may also be made to Jukes-Browne, "The Building of
the British Isles," London, 1912, pages 430 to 440.]
[Footnote 26: Glacier-lakes are fairly common among the fjords of the
west coast of Greenland, and illustrate very well what must have
been the state of affairs in Glen Roy at the time of formation of the
Parallel Roads.]
[Footnote 27: The high-level shell-bearing deposits of Moel Tryfan,
Gloppa, near Oswestry, and Macclesfield, have given rise to much
controversy between the supporters of submergence and of land-ice. At
Moel Tryfan certain sands and gravels, with erratics, at a height of
about 1350 feet, contain abundant marine shells, generally much broken.
The northern or seaward face of the hill is much plastered with drift,
but none is to be found on the landward side, and it is suggested that
the shell-bearing material is the ground-moraine of a great ice-sheet
that came in from the Irish Sea, and was forced up on to the Welsh
coast, just reaching the watershed, but failing to overtop it. With
regard to the explanation by submergence, the great objection is the
absence of marine drift on the landward side, which is very difficult to
explain if the whole had been submerged sufficiently to allow of normal
marine deposits at such a great height. The shell beds of Macclesfield
and Gloppa are at a less elevation but of essentially similar character.
The shell-bearing deposits of Moel Tryfan were examined by a committee
of the British Association. (See "Report of the British Association"
Dover, 1899, pages 414 to 423.) At the end of this report is an
extensive bibliography.]
[Footnote 28: During the last forty years the deep-sea dredging
expeditions of H. M.S. Challenger and others have shown the abundance
and variety of animal life at great depths, especially in the Arctic and
Antarctic seas. For a recent summary, see Murray and Hjort, "The Depths
of the Ocean," London, 1912.]
[Footnote 29: It is now generally admitted that these shell-beds in
Wexford are of Pliocene age, and they therefore have no bearing on the
subject under discussion.]
[Footnote 30: The boulder deposit at Selsey has been described by Mr.
Clement Reid ("Quarterly Journal of the Geological Society," volume 48,
1892, page 355). Immediately above the Tertiary beds is a hard greenish
clay, full of derived Tertiary fossils and Pleistocene shells with large
flints and erratic blocks, some of the latter weighing several tons.
They include granite, greenstone, schist, slate, quartzite, and
sandstone, and most of them must have been transported for a long
distance. Above them are black muds with marine shells, then a shingle
beach, and above all the Coombe Rock. (See next note.)]
[Footnote 31: The Brighton elephant-bed and its equivalent, the Coombe
Rock, are fully described by Clement Reid ("On the Origin of Dry Chalk
Valleys and the Coombe Rock," "Quarterly Journal of the Geological
Society," volume 43, 1887, page 364). The Coombe Rock is a mass of
unstratified flints and Chalk debris filling the lower parts of the
dry valleys (Coombes) of the South Downs and gradually passing into
the brick-earth (loam) of the coastal plain. It is clearly a torrential
accumulation, and is supposed to have been formed while the Chalk was
frozen, thus preventing percolation of water and causing the surface
water to run off as strong streams. This must have occurred during some
part of the glacial period, which would naturally be a period of heavy
precipitation. Of very similar origin is the "Head" of Cornwall, a
surface deposit often rich in tinstone and other minerals of economic
value. The Coombe Rock has recently been correlated with deposits of
Mousterian Age.]
[Footnote 32: The former extension of the Alpine glaciers and the
deposits formed by them have been exhaustively investigated by Penck
and Bruckner ("Die Alpen im Eiszeitalter," 3 volumes, Leipzig, 1901 to
1909). In this monumental work the authors claim to have established the
occurrence of four periods of advance of the ice, to which they give the
names of Gunz, Mindel, Riss, and Wurm glaciations, with corresponding
interglacial genial episodes, when the climate was possibly even
somewhat warmer than now. Their conclusions and the data on which they
are established are summarised by Sollas (" Ancient Hunters," London,
1911, especially pages 18 to 28). For a general account of the glaciers
of the Alps and their accompanying phenomena, see Bonney, "The Building
of the Alps," London, 1912, pages 103 to 151.]
[Footnote 33: At the time of the maximum advance of the ice, during the
Riss period of Penck and Bruckner, the terminal moraine of the great
glacier of the Rhone extended as far as the city of Lyon, and towards
the north-east it became continuous with the similar moraine of the
Rhine glacier.]
[Footnote 34: For the successive phases of advance and retreat of the
Alpine glaciers, see the works quoted in Note 32.]
[Footnote 35: The Loess of Central Europe includes deposits of two
different ages. According to Penck the "Older Loess" was formed in the
period of warm and dry climate that intervened between the third and
fourth glacial episodes, while the "Younger Loess" is post-glacial.
Both divisions are for the most part aeolian deposits, formed by the
redistribution of fine glacial mud originally laid down in water and
carried by the wind often to considerable heights. A part, however, of
the so-called Loess of northern France, e.g. in the valley of the
Somme, is rain-wash, similar in character to the brick-earth of parts
of south-eastern England. The Older Loess contains Acheulean implements,
while the Younger Loess is of Aurignacian Age.
The greatest development of the Loess is in Central Asia and in China.
(See Richthofen, "China," Berlin, 1877.) In China the Loess reaches
a thickness of several thousand feet, and whole mountain-ranges are
sometimes almost completely buried in it. In the deserts of Central Asia
the formation of the Loess is still in progress. A very similar deposit,
called adobe, is also found in certain parts of the Mississippi valley.
The Loess is a fine calcareous silt or clay of a yellowish colour, quite
soft and crumbling between the fingers. However, it resists denudation
in a remarkable manner, and in China it often stands up in vertical
walls hundreds of feet in height. This property is probably assisted by
the presence of numerous fine tubes arranged vertically and lined with
calcium carbonate; these are supposed to have been formed in the first
place by fibrous rootlets.]
[Footnote 36: Although highly probable, it cannot yet be regarded as
conclusively demonstrated that the Pleistocene glaciations of Europe and
of North America were exactly contemporaneous. The ice--sheets in each
case radiated from independent centres which were not in the extreme
north of either continent, and were not in any way connected with a
general polar ice-cap. The European centre was over the Baltic region or
the south of Scandinavia, and the American centre in the neighbourhood
of Hudson's Bay. The southern margin of the American ice-sheet extended
about as far south as latitude 38 degrees north in the area lying south
of the Great Lakes, whereas the North European ice barely passed the
limit of 50 degrees north in Central Europe. This greater southward
extension in America was doubtless correlated with the same causes
as now produce the low winter temperatures of the eastern states,
especially the cold Newfoundland current. The literature of North
American glacial geology has now attained colossal dimensions, and it is
impossible to give here even a short abstract of the main conclusions.
For a general summary reference may be made to Chamberlin and Salisbury,
"Geology," volume 3; "Earth History," London and New York, 1905; or the
same authors' "Geology, Shorter Course," London and New York, 1909.]
[Footnote 37: During the last fifty years scarcely any geological
subject has given rise to a greater amount of speculation than the cause
of the Ice Age, and the solution of the problem is still apparently far
off. The theories put forward may for convenience be divided into three
groups, namely astronomical, geographical, and meteorological.
As examples of astronomical explanation, we may take the well-known
theory of Adhemar and Crohl, which is founded on changes in the
ellipticity of the earth's orbit. This is expounded and amplified by Sir
Robert Ball in his "Cause of an Ice Age." The weak point of this theory,
which is mathematically unassailable, is that it proves too much,
and postulates a constant succession of glacial periods throughout
earth-history, and for this there is no evidence. The geographical
explanations are chiefly founded on supposed changes in the distribution
of sea and land, with consequent diversion of cold and warm currents.
Another suggestion is that the glaciated areas had undergone elevation
into mountain regions, but this is in conflict with evidence for
submergence beneath the sea in certain cases. Meteorological hypotheses,
such as that of Harmer, founded on a different arrangement of air
pressures and wind-directions, seem to offer the most promising field
for exploration and future work, but it is clear that much still remains
to be explained.]
[Footnote 38: The reptile-bearing Elgin Sandstones are of Triassic Age,
and they contain a most remarkable assemblage of strange and eccentric
forms, especially Anomodont reptiles resembling those found in the
Karroo formation of South Africa.]
[Footnote 39: The meaning of this statement is not very clear. The
Conifers are not dicotyledons: their seeds contain numerous cotyledons,
up to twenty in number, and the whole plant, and especially the
reproductive system, belongs to a lower stage of development. The
argument here employed is therefore fallacious, and in point of fact the
different groups actually appeared in the order postulated by the
theory of evolution, namely: (1) Gymnosperms, (2) Monocotyledons,
(3) Dicotyledons. See Arber, "The Origin of Gymnosperms," "Science
Progress," volume 1, 1906, pages 222 to 237.]
[Footnote 40: The part of the manuscript read to Dr. Hooker in 1844
was undoubtedly the "Essay of 1844," forming the second part of the
"Foundations of the Origin of Species," a volume published by Sir
Francis Darwin on the occasion of the Darwin Centenary at Cambridge in
1909. (See also Darwin's "Life and Letters," volume 2 pages 16 to 18.)]
[Footnote 41: This projected larger work, which is often referred to in
the "Origin of Species," was never published as such, but Darwin's views
on various aspects of evolution were set forth in several later books,
such as "The Variation of Animals and Plants under Domestication," "The
Descent of Man," "Various Contrivances by which Orchids are Fertilised
by Insects," "Movements and Habits of Climbing Plants," "Insectivorous
Plants," and others.]
[Footnote 42: With this section compare the famous chapter with the same
title in the "Origin of Species."]
[Footnote 43: No attempt has been made to annotate this chapter, owing
to the impossibility of doing so within reasonable compass. Many of
the theories here quoted, and the conclusions drawn from them, have
not stood the test of time, and recent philological and ethnographical
research have clearly shown the danger of attempting to infer
the relationships of different peoples from their languages. The
modifications undergone by the languages themselves are also subject
to influences of such complex character, so largely artificial in their
origin, that any attempt to compare them with natural evolution in the
organic world must lead to false analogies. The chapter must be regarded
as an interesting exposition of one phase of Mid-Victorian scientific
thought, but having little real bearing on the subjects discussed in the
rest of the book.]
[Footnote 44: That the prophecy here given was justified is shown by
the discovery in Java in 1891, of the skull and parts of the skeleton
of Pithecanthropus erectus, a form which, according to the best
authorities, must be regarded as in many ways intermediate between
man and the apes, though perhaps with more human than ape-like
characteristics. For an account of the circumstances of its discovery
and a general description of the remains, see Sollas, "Ancient Hunters,"
London, 1911, pages 30 to 39 (with many references). Within the last
year or two interest in the ancestry of man has been greatly increased,
especially by the Piltdown discovery (see Note 11). This has led to
a revision of the whole subject, and the views formerly held have
undergone a certain amount of modification. It now seems certain that
the different types of culture as represented by the succession of
stages given in Note 12 do not correspond to a continuous development of
one single race of mankind. There is, undoubtedly, a great break between
the Mousterian and Aurignacian. Mousterian or Neanderthal man appears to
have become extinct, possibly having been exterminated by a migration of
the more highly developed Aurignacian race, which may be regarded as the
ancestor of modern man in Europe. It appears, therefore, that the really
important line of division comes, not as was formerly thought between
Palaeolithic and Neolithic, but in the middle of the Palaeolithic
between Mousterian and Aurignacian. Hence it appears that our
classification will in the near future have to undergo revision, since
the stages of culture from Aurignacian to Azilian show a much closer
affinity to the Neolithic than they do to the earlier Palaeolithic. At
the present time scarcely sufficient data are available to determine the
relationship of Pithecanthropus and Eoanthropus to the later types of
man. For an excellent summary of the most recent views see Thacker, "The
Significance of the Piltdown Discovery," "Science Progress," volume 8,
1913, page 275.]
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