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Title: Pearls & Parasites
Author: Shipley, Arthur Everett
Language: English
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PEARLS AND PARASITES
PEARLS & PARASITES
BY ARTHUR E. SHIPLEY
OF CHRIST’S COLLEGE, CAMBRIDGE; M.A., HON. D.SC., F.R.S.
WITH ILLUSTRATIONS
LONDON
JOHN MURRAY, ALBEMARLE STREET, W.
1908
TO MY SISTER
E. D. H.
PREFACE
Most of the following essays have appeared in the pages of the
_Quarterly Review_, and I am greatly indebted to the editor and to the
proprietor of that periodical for permission to reprint them. The
article on ‘The Infinite Torment of Flies’ is an address I delivered
before the British Association at Pretoria in 1905, and the eighth essay
appeared in _Science Progress_.
As far as possible I have tried to avoid the use of long words, and thus
escape the censure of recent critics in the _Times_; but I fear I have
not altogether succeeded, and my excuse must be that with new
discoveries new conceptions arise, and these conceptions require new
names, or we cannot talk or write about them with any precision.
The essay dealing with zebras and hybrids was the first to be written,
and appeared before the rediscovery of Mendel’s remarkable work, and
must be regarded as a pre-Mendelian contribution to a subject which has
recently, in connexion with the Deceased Wife’s Sister Bill, again
aroused attention. Had it been written later the language and the
attitude taken would have been modified by recent research.
In the inquiry into the aims and finance of Cambridge University--the
only essay which does not deal with questions of economic zoology--I
have had the great advantage of the collaboration of Mr. H. A. Roberts,
the Secretary of the Cambridge University Association. But for his help
I fear I should have lost my way in the intricate mazes of the
University accounts.
For the care he has taken in making the Index, I owe thanks to Mr. G. W.
Webb, of the University Library.
A. E. S.
CHRIST’S COLLEGE,
CAMBRIDGE.
_March 10, 1908._
CONTENTS
PAGE
PEARLS AND PARASITES 1
THE DEPTHS OF THE SEA 16
BRITISH SEA-FISHERIES 42
ZEBRAS, HORSES, AND HYBRIDS 73
PASTEUR 101
MALARIA 129
‘INFINITE TORMENT OF FLIES’ 155
THE DANGER OF FLIES 174
CAMBRIDGE 183
INDEX 217
LIST OF ILLUSTRATIONS
FACING PAGE
MATOPO 84
TUNDRA (AN ICELAND PONY), HER FOAL, CIRCUS GIRL (BORN
1898), AND HER HYBRID-FOAL, SIR JOHN (BY MATOPO),
WHEN A MONTH OLD (BORN 1899) 86
ROMULUS 92
MATOPO 92
ROMULUS 96
FIG. 1.--THE PARASITE OF TERTIAN FEVER, HÆMAMŒBA VIVAX
(ROSS). HIGHLY MAGNIFIED 136
FIG. 2.--VARIOUS STAGES WHICH THE PARASITE OF THE ÆSTIVO-AUTUMNAL
FEVER, HÆMOMENAS PRÆCOX(ROSS), PASSES THROUGH IN THE BODY OF
THE MOSQUITO ANOPHELES. MAGNIFIED 2,000 TIMES. AFTER ROSS
AND FIELDING-OULD 136
FIG. 3.--FORMATION OF THE BLASTS OF HÆMOMENAS PRÆCOX
(ROSS) WITHIN THE BODY OF THE MOSQUITO ANOPHELES.
MAGNIFIED 2,000 TIMES. AFTER ROSS AND FIELDING-OULD
144
_ANOPHELES MACULIPENNIS._ MALE, IN CHARACTERISTIC
ATTITUDE 146
_ANOPHELES MACULIPENNIS._ FEMALE 146
BIBLIOGRAPHY
‘Report to the Government of Ceylon on the Pearl-Oyster Fisheries of the
Gulf of Manaar.’ By W. A. Herdman, F.R.S. Parts I. and II. Published by
the Royal Society. London, 1904.
‘On the Origin of Pearls.’ By H. Lyster Jameson. Proceedings of the
Zoological Society of London, 1902.
‘Aus den Tiefen des Weltmeeres.’ By C. Chun. Jena: Gustav Fischer, 1900.
‘Tierleben der Tiefsee.’ By O. Seeliger. Leipzig: Wilhelm Engelmann,
1901.
‘Report of the Scientific Results of the Voyage of H.M.S. _Challenger_.’
Edited by the late Sir C. Wyville Thomson and John Murray. A Summary of
the Scientific Results. Published by Order of Her Majesty’s Government,
1885.
‘La Vie au Fond des Mers.’ By H. Filhol. Paris: G. Masson, 1885.
‘The Fauna of the Deep Sea.’ By Sydney J. Hickson. London: Kegan Paul,
Trench, Trübner and Co., 1894.
‘British Fisheries: their Administration and their Problems.’ By James
Johnstone. London: Williams and Norgate, 1905.
‘An Examination of the Present State of the Grimsby Trawl Fishery, with
Especial Reference to the Destruction of Immature Fish.’ By E. W. L.
Holt. _Journal of the Marine Biological Association_, vol. iii.
Plymouth, 1895.
_Journals of the Marine Biological Association of the United Kingdom_,
vols. i.-vii. Plymouth.
‘Conseil Permanent International pour l’Exploration de la Mer. Rapports
et Procès Verbaux,’ vol. iii. Copenhagen.
‘Fishery Board for Scotland. Report on the Fishery and Hydrographical
Investigations in the North Sea and Adjacent Waters, 1902-1903.’ [Cd.
2612.] London, 1905.
‘Marine Biological Association. First Report on the Fishery and
Hydrographical Investigations in the North Sea and Adjacent Waters
(Southern Area), 1902-1903.’ [Cd. 2670.] London, 1905.
‘Annual Reports of the Inspectors of Sea-Fisheries for England and
Wales.’ London, 1886-1905.
‘The Penycuik Experiments.’ By J. C. Ewart. London and Edinburgh: A. and
C. Black, 1899.
‘Experimental Investigations on Telegony.’ A paper read before the Royal
Society, London, June 1, 1899. By Professor J. C. Ewart.
‘La Vie de Pasteur.’ Par René Vallery-Radot. Paris: Hachette, 1900.
‘Pasteur.’ By Percy Frankland and Mrs. Percy Frankland. (Century Science
Series.) London: Cassell, 1898.
‘The Soluble Ferments and Fermentation.’ By J. Reynolds Green.
(Cambridge Natural Science Manuals.) Cambridge University Press, 1899.
‘Micro-organisms and Fermentation.’ By Alfred Jörgensen. Translated by
A. K. Miller and A. E. Lennholm. Third edition. London: Macmillan, 1900.
‘Lectures on the Malarial Fevers.’ By William Sydney Thayer, M.D.
London: Henry Kimpton, 1899.
‘On the Rôle of Insects, Arachnids, and Myriapods as Carriers in the
Spread of Bacterial and Parasitic Diseases of Man and Animals. A
Critical and Historical Study.’ By George H. F. Nuttall, M.D., Ph.D.
‘Johns Hopkins Hospital Reports,’ vol. viii.
‘Instructions for the Prevention of Malarial Fever.’ Liverpool School of
Tropical Medicine. Memoir I. Liverpool: University Press, 1899.
‘Report of the Malaria Expedition of the Liverpool School of Tropical
Medicine and Medical Parasitology.’ By Ronald Ross, D.P.H., M.R.C.S.; H.
E. Annett, M.D., D.P.H.; and E. E. Austen. Liverpool School of Tropical
Medicine. Memoir II. Liverpool: University Press, 1900.
‘A System of Medicine, by many Writers.’ Edited by Thomas Clifford
Allbutt, M.A., M.D., LL.D., vol. ii., 1897; vol. iii., 1897. London:
Macmillan and Co.
‘A Handbook of the Gnats and Mosquitoes.’ By Major George M. Giles,
I.M.S., M.B., F.R.C.S. London: John Bale, Sons, and Danielsson, Limited,
1900.
‘Reports to the Malaria Committee, Royal Society, 1899 and 1900.’ By
various authors. London: Harrison and Sons, 1900.
Proceedings of the Boston Society of Natural History, vol. xvi., 1874.
U.S.A. Department of Agriculture, Division of Entomology, Bulletin 4,
new series.
‘Manchester Memoirs,’ vol. li., 1906, p. 1; _Quarterly Journal of
Microscopical Science_, vol. li., 1907, p. 395.
‘Endowments of the University of Cambridge.’ Edited by John Willis
Clark, M.A., Registrar of the University of Cambridge. Cambridge:
University Press, 1904.
‘Report of a Meeting held at Devonshire House on January 31, 1899, to
inaugurate the Cambridge University Association.’ Cambridge: University
Press, 1899.
‘Statements of the Needs of the University.’ Cambridge: University
Press, 1904.
‘University Accounts for the Year ended December 31, 1904.’ _Cambridge
University Reporter_, March 17, 1905.
‘Abstracts of the Accounts of the Colleges.’ _Cambridge University
Reporter_, February 10, 1905.
PEARLS AND PARASITES
_Know you, perchance, how that poor formless wretch--_
_The Oyster--gems his shallow moon-lit chalice?_
SIR EDWIN ARNOLD.
Certain Eastern peoples believe that pearls are due to raindrops falling
into the oyster-shells which conveniently gape to receive them.
‘Precious the tear as that rain from the sky
Which turns into pearls as it falls on the sea,’
as the poet Moore writes. This belief is of ancient origin, and is
probably derived from classical sources, since Pliny tells us that the
view prevalent in his time was that pearls arise from certain secretions
formed by the oyster around drops of rain which have somehow effected an
entrance into the mantle cavity of the mollusc. Probably this theory of
the origin of pearls has ceased to be held for many centuries except in
the East, where tradition has always received more credit than
experiment. In the West it has long been known that pearls are formed as
a pathological secretion of the mineral arragonite, combined with a
certain amount of organic material, formed by the oyster or other
mollusc around some foreign body, whose presence forms the irritant
which stimulates the secretion. This secretion is of the same chemical
and mineralogical nature as the mother-of-pearl which gives the inside
of the shell of so many molluscs a beautiful iridescent sheen.
An oyster-shell consists of three layers, the outermost termed the
_periostracum_, the middle the _prismatic layer_, and the innermost the
_nacreous layer_. Everywhere the shell is lined by the mantle,
consisting of a right and left fold or flap of the skin, which is in
contact with the nacreous layer all over the inside of the shell. The
edge of the mantle is thickened and forms a ridge or margin; and it is
this edge which secretes the two outer layers. This permits the shell to
grow at its edge whilst the rest of the mantle secretes all over its
surface the nacreous or pearly layer. The relative thickness of these
three layers varies very greatly. In the fresh-water mussel (_Unio_) the
nacreous layer is many times thicker than the two outer layers put
together; and such nacreous shells are usually associated with molluscs
which are known to represent very ancient or ancestral species. It is
also the layer which disappears most readily as the specimens become
fossilized; and in fossil Mollusca it is often represented by mere
casts, which fill the position it once occupied.
The fact that the nacre is deposited by the whole surface of the mantle
has been appreciated by the Chinese. By inserting little flattened
leaden images of Buddha between the mantle and the shell, and leaving
the oyster at rest for some time, the image becomes coated with
mother-of-pearl and incorporated in the substance of the shell; and in
this way certain little joss figures are produced. This industry is said
to support a large population in some coast districts of Siam.
The nacre, then, is produced by the outermost layer of the mantle or
fleshy flap that lines the shell--the external epithelium; and, if a
foreign body gets between this epithelium and the shell, the mantle
will, in order to protect itself, secrete a pearly coat around it. But
valuable pearls are not those which are partially or wholly fused with
the shell, but those which lie deep in the tissues of the body; and they
are probably formed in the following manner: The intrusive, irritant
body forms a pit in the outer surface of the mantle; this pit deepens,
and at first remains connected with the outside by a pore; ultimately
the pore closes, and the bottom of the pit becomes separated as a small
sac free from all connexion with the outside. The sac now sinks into the
tissues of the oyster, enclosing in it the foreign body. It will be
noticed that the inside of the sac is lined by and is derived from the
same tissue or epithelium as covers the outside of the mantle. Now this
epithelium continues to do what it has always been in the habit of
doing; that is, it secretes a nacreous substance all round the intrusive
particle. Layer after layer of this nacre is deposited, and thus a pearl
is formed. At first the layers will conform roughly to the outline of
the embedded body, but later layers will smooth over any irregularities
of the nucleus around which they are deposited, and a spheroidal or
spherical pearl is produced. If the irregularities are too pronounced,
an irregular pearl is formed; and such pearls, on merely æsthetic
grounds, command a lower price.
It is thus clear that pearls are formed around intrusive foreign bodies;
and until comparatively recently these bodies were thought to be
inorganic particles, such as grains of sand. Recent research has,
however, shown that this is seldom the case, and that as a rule the
nucleus, which must be present if a pearl is to be formed, is the larva
of some highly-organized parasite whose life-history is certainly
complicated but as yet is not completely known. The knowledge, however,
which we already possess enables us to do much to ensure steady success
in a very speculative industry; and with complete knowledge there is no
reason why pearl fisheries should not be under as good control as oyster
fisheries now are.
It was about fifty years ago (1857-1859) that the problem of the Ceylon
pearl-oyster fishery was first attacked in a thoroughly scientific
spirit by a certain Dr. Kelaart. His reports to the Government of the
island contain the following suggestive sentences:
‘I shall merely mention here that M. Humbert, a Swiss zoologist,
has, by his own observations at the last pearl fishery,
corroborated all I have stated about the ovaria or genital glands
and their contents; and that he has discovered, in addition to the
Filaria and Circaria (_sic_), three other parasitical worms
infesting the viscera and other parts of the pearl-oyster. We both
agree that these worms play an important part in the formation of
pearls; and it may be found possible to infect oysters in other
beds with these worms, and thus increase the quantity of these
gems. The nucleus of an American pearl drawn by Möbius is nearly of
the same form as the Circaria found in the pearl-oysters of Ceylon.
It will be curious to ascertain if the oysters in the Tinnevelly
banks have the same species of worms as those found in the oysters
on the banks off Arripo.’
Unfortunately Dr. Kelaart died shortly after making this report, leaving
his investigations incomplete.
Some seven years before, in 1852, Filippi had shown that the pearls in
our fresh-water mussel (_Anodonta_) were formed by the larvæ of a fluke
(a trematode), to which he gave the name of _Distomum duplicatum_. Many
students of elementary biology, as they painfully try to unravel the
mystery of molluscan morphology, must have come across small pearls in
the tissues of the fresh-water mussels (_Unio_ or _Anodonta_); but these
are said to have less lustre and to be more opaque than the sea pearl;
so the pearl fisheries of the Welsh and Scotch rivers are falling into
disuse. Our ancestors, however, thought otherwise. Less than fifty years
ago the Scotch fisheries brought in some £12,000 a year; and a writer of
the early part of the eighteenth century describes Scotch pearls as
‘finer, more hard and transparent than any Oriental.’ British pearls
were highly thought of by the Romans. Pliny and Tacitus mention them;
and Julius Caæsar is said to have dedicated a breastplate ornamented
with British pearls to Venus Genitrix. Fresh-water pearls are still
‘fished’ with profit in Central Europe; but the Governments of Bavaria,
Saxony, and Bohemia watch over the industry and only grant a licence to
fish any stretch of water about once in twelve years--a restriction
which, had it been imposed on our fisheries, might have saved a
vanishing industry.
In 1871 Garner showed that the pearls in the edible mussel (_Mytilus
edulis_), which is largely used for bait upon our coasts, were formed
round the larvæ of a fluke, a remote ally of the liver-fluke that causes
such loss to our sheep-breeders. This origin of pearls has been more
completely followed out by Mr. Lyster Jameson. Nor must we forget to
mention the researches of Giard (1897) and Dubois (1901) in the same
subject. We know the life-history of the organism forming pearls in this
edible mussel more completely than we do that of any other pearl-forming
parasite; and, before returning to the Ceylon pearls, we will briefly
consider it.
Mr. Lyster Jameson finds that the pearls of the _Mytilus_ are formed
around the cercaria or larval form of a fluke which, in its adult
stages, resides in the intestine of the scoter (_Œdemia nigra_), and
was originally described from the eider-duck (_Somateria mollissima_) in
Greenland and named _Leucithodendrium somateriæ_, after its first known
host. The cercaria larvæ of these flukes form the last stage in a
complex series of larval forms which occur in the life-history of a
trematode or fluke, and they differ from the adult in two points--their
generative organs are not fully developed, and they usually have a tail;
but this organ is wanting in our pearl-forming cercaria, called a
cercariæum by Mr. Jameson. Such a larva has only to be swallowed by a
scoter to grow up quickly into the adult trematode capable of laying
eggs. Now this bird, called by the French fishermen the ‘cane moulière,’
is the greatest enemy to the mussel-beds; it is not only common around
the French mussel-beds of Billiers (Morbihan), but occurs in numbers at
the mouth of the Barrow channel, close to our English pearl-bearing
mussel-beds. With its diving habits it destroys and eats large
quantities of the mollusc. Those cercariæ which are already entombed in
a pearl cannot, of course, grow up into adults, even if they gain
entrance to the alimentary canal of the scoter; but those that are not
ensheathed may do so. Further, the fluke may possibly live in other
hosts where no pearl is formed. At any rate, there seems no lack of
larvæ successful in their struggle to attain maturity, for it has been
calculated that the alimentary canal of an apparently healthy scoter may
harbour as many as six thousand adult flukes.
Thus there are two courses open to the cercaria when it has once found
its way into the mussel; it either forms the nucleus of a pearl and
perishes, or it is swallowed by a scoter, becomes adult, and prepares to
carry on the race. But how do the cercariæ make their way into the
mussel, and whence do they come? At present their birth, like that of
Mr. Yellowplush, is ‘wrapped up in a mistry.’ We may presume that the
eggs make their way out of the scoter into the sea-water, and that there
they hatch out a free-swimming larva, which, after the manner of
trematodes, swims about looking for a suitable host. Within this host
it would come to rest and begin budding off numerous secondary larvæ, in
which stage it may assume considerable size and becomes known as a
_sporocyst_. No one, however, has seen the eggs hatch, or the
free-swimming larva; but Mr. Jameson produces evidence to show that the
sporocyst stage occurs in two other common molluscs--viz., in a clam
(_Tapes decussatus_) and in the common cockle (_Cardium edule_). The
former mollusc abounds in the black gravelly clay which forms the bottom
of the mussel-beds at Billiers; and every specimen out of nearly two
hundred examples investigated by Mr. Jameson was found to be infested
with sporocysts containing larvæ closely resembling those which act as
pearl-nuclei in the edible mussel. Exactly similar sporocysts were found
in about fifty per cent. of the common cockles examined in the Barrow
channel, where the species _Tapes decussatus_ does not occur.
Within the sporocyst certain secondary larvæ are formed, as is habitual
with the flukes. These secondary larvæ are the cercariæ; and it is in
this stage that the animal makes its way into the pearl-mussel and
ultimately forms the nucleus of a pearl. Precisely how it leaves the
sporocyst and the first host--_i.e._, the _Tapes_ or _Cardium_--is not
known. Certain experiments made by Jameson, who placed mussels which he
thought were free from parasites in a tank with some infected _Tapes_,
are not quite conclusive, and have been ably criticized by Professor
Herdman. It is true that, when examined later, the mussels were well
infected; but it was not definitely shown that they were not infected at
the start; and further, the numbers used were too small to justify a
very positive conclusion. Still, on the whole, it may safely be said
that life-history of the organism which forms the pearls in _Mytilus
edulis_ probably involves three hosts: the scoter, which contains the
mature form; the _Tapes_ or _Cardium_, which contains the first larval
stage; and the mussel, which contains the second larval stage, which
forms the pearl.
Recently Professor Dubois has been investigating the origin of pearls in
another species of _Mytilus_ (_M. galloprovincialis_) which lives on the
French Mediterranean littoral. The nucleus of this pearl is also a
trematode, but of a species different from that which infests the edible
mussel. The interest of Professor Dubois’ work, however, lies in the
fact that he claims to have infected true Oriental pearl-oysters by
putting them to live with his Mediterranean mussels. He fetched his
oysters, termed ‘Pintadin,’ from the Gulf of Gabes in Southern Tunis,
where they are almost pearlless--one must open twelve to fifteen hundred
of these to find a single pearl--and brought them up amongst the
mussels. After some time had elapsed they became so infected that three
oysters opened consecutively yielded a couple of pearls each. These
observations, however, require confirmation, and have been adversely
criticized by Professor Giard.
To return to the Ceylon pearls. The celebrated fisheries lie to the
north-west of the island, where the shallow plateaux of the Gulf of
Manaar afford a fine breeding-place for the pearl-oyster. The
pearl-oyster is not really an oyster, but an allied mollusc known as
_Margaritifera vulgaris_. It lives on rocky bottoms known locally as
paars. The fisheries are very ancient and have been worked for at least
2,500, perhaps for 3,000 years. Pliny mentions them, but he is,
comparatively speaking, a modern. The Cingalese records go much farther
back. In 550 B.C. we find King Vijaya sending his Indian father-in-law
pearls of great price; and there are other early records. From the
eighth to the eleventh century of our era the trade seems to have been
chiefly in the hands of the Arabs and Persians; and many references to
it occur in their literature. Marco Polo (1291) mentions the pearls of
the kings of Ceylon; and in 1330 a friar, one Jordanus, describes 8,000
boats as taking part in the fishery. Two centuries later, a Venetian
trader named Cæsar Frederick, crossed from India to the west coast of
Ceylon to observe the fishery; and his description might almost serve
for the present day, so little do habits alter in the East.
The records of the Dutch and English fisheries are naturally more
complete than those of their predecessors. The last Dutch fishery was in
1768, and the first English was in 1796, before the fall of Colombo. The
fishery is not held every year, but at irregular intervals; and
sometimes these intervals have been long. For instance, the oysters
failed between 1732 and 1746, and again between 1768 and 1796, under the
Dutch régime, and from 1837 to 1854 under the English. On the other
hand, the fishing is sometimes annual; recently, it took place with
great success in 1887 and the four following years, culminating in the
record year 1891, when the Government’s share of the spoil amounted to
close upon one million rupees. After this there was a pause till 1903,
when the fishery became annual.
The Lieutenant-Governor, Sir Everard im Thurn, now Governor of Fiji, has
given a lively account of the fishing scene. He tells us that every
year, in November, a Government official visits the oyster-beds, takes
up a certain number of oysters, examines them for pearls, and submits
his results to certain Government experts. If, as they have done
recently, these experts pronounce that there will be a fishing, this
information is at once made known; and, partly by advertisement, but
probably more by passing the word from man to man, the news rapidly
spreads throughout India, up the Persian Gulf, and to Europe. In the
meantime preparations on a large scale have to be made.
‘On land, which is at the moment a desert, an elaborate set of
temporary Government buildings have to be erected for receiving and
dealing with many millions of oysters and their valuable if minute
contents. Court-houses, prisons, barracks, revenue offices,
markets, residences for the officials, streets of houses and shops
for perhaps thirty thousand inhabitants, and a water-supply for
drinking and bathing for these same people, have to be arranged
for. Lastly, but, in view of the dreadful possibility of the
outbreak of plague and cholera, not least, there are elaborate
hospitals to be provided.’
By March or April some hundreds of large fishing vessels have assembled
at Manaar; and a population which varies during the next two months
between 25,000 and 40,000 souls has gathered together.
The fishing-boats leave early in the morning for their respective
stations; and, on reaching them, the Arab and Indian divers descend,
staying under water from fifty to eighty seconds, and eagerly scooping
up the oysters and depositing them in baskets slung round their necks.
By midday the divers are worn out; and at noon a gun is fired from the
master-attendant’s vessel as a signal for return. The run home may take
some hours, according to the distance and the wind; and it is during
this time that a considerable number of pearls are said to be
abstracted. The men on the boats are occupied with the sorting of the
oysters and cleaning them of useless stones, seaweed, and other objects
which are gathered with them. The finest pearls lie just within the
shell, embedded in the edge of the mantle; and these readily slip out
and are concealed about the person of the finder. The Government does
what it can to check peculation and keep a guard on each boat; but, in
spite of all its efforts, there seems no doubt that many of the ‘finest,
roundest, and best-coloured pearls’ pass into the possession of those
who have no right to them.
On reaching the shore the oysters are carried to the Government building
or ‘Kottus,’ a vast rectangular shed, where they are divided into three
heaps; two of these fall to the Government, and the third belongs to the
divers. This latter share the divers sell as soon as they quit the
‘Kottus,’ sometimes parting with dozens to one buyer, and sometimes
selling as few as two or one. In the meantime the Government’s
two-thirds have been counted and are left for the night. At nine o’clock
in the evening these oysters are put up to auction. The Government agent
states how many oysters there are to dispose of, and then sells them in
lots of one thousand. Some rich syndicates will perhaps buy as many as
50,000 at prices which fluctuate unaccountably during the evening.
Within a short time the price will inexplicably drop from thirty-five
rupees to twenty-two rupees a thousand, and may then rise again as
suddenly and inexplicably as it sank. Early in the morning each
purchaser removes his shells to his own private shed, where for a week
they are allowed to rot in old canoes and other receptacles for water,
and are then searched for pearls. For a couple of months this great
traffic goes on, until the divers are thoroughly exhausted, and the camp
melts away.
Owing to the continuous failure of the fishery for ten years from 1891,
the Government determined to call in the aid of experts. In the spring
of 1901 Professor Herdman of Liverpool was asked by the Colonial Office,
then under the direction of Mr. Chamberlain, to visit Ceylon and to
report upon the state of the fishery. He reached Colombo early in 1902.
He was fortunate in taking out an exceptionally well qualified assistant
in Mr. J. Hornell. After a thorough examination of the fishing-grounds,
Professor Herdman reported to the Government of Ceylon as follows:
‘The oysters we met with seemed, on the whole, to be very healthy.
There is no evidence of any epidemic or of much disease of any
kind. A considerable number of parasites, both external and
internal, both protozoan and vermean, were met with; but that is
not unusual in molluscs, and we do not regard it as affecting
seriously the oyster population.
‘Many of the larger oysters were reproducing actively. We found
large quantities of minute “spat” in several places. We also found
enormous quantities of young oysters a few months old on many of
the paars. On the Periya paar the number of these probably amounted
to over a hundred thousand million.
‘A very large number of these young oysters never arrive at
maturity. There are several causes for this. They have many natural
enemies, some of which we have determined. Some are smothered in
sand. Some grounds are much more suitable than others for feeding
the young oysters, and so conducing to life and growth. Probably
the majority are killed by overcrowding.
‘They should therefore be thinned out and transplanted. This can be
easily and speedily done, on a large scale, by dredging from a
steamer at the proper time of the year, when the young oysters are
at the best age for transplanting.
‘Finally, there is no reason for any despondency in regard to the
future of the pearl-oyster fisheries if they are treated
scientifically. The adult oysters are plentiful on some of the
paars, and seem for the most part healthy and vigorous; while young
oysters in their first year, and masses of minute spat just
deposited, are very abundant in many places.’
The chief causes of the failure of the fisheries, at any rate the chief
causes which can be dealt with by man, are overcrowding and
over-fishing. It might be supposed that these factors would counteract
each other; but it must be remembered that they become effective at the
two opposite poles of the oyster’s existence, which is thought to cover
five, six, or seven years. The overcrowding takes place when the oyster
is quite young and hardly fixed on the submerged reefs, whilst the
over-fishing takes place when the animal is fully matured and perhaps
growing old. The fact that Professor Herdman and Mr. Hornell conveyed
the young oysters from Manaar in the north of the island by boat to
Colombo and then on by train to Galle in the south, and there succeeded
in rearing them, shows that there would be little difficulty in
artificially rearing oysters in convenient localities and then
transplanting them to such fishing-grounds as show danger of depletion.
With regard to over-fishing, if the grounds are under the charge of a
trained zoologist there is no reason why this should go on.
When Professor Herdman was called in to advise the Government, he saw at
once that it was the oyster that had failed in the last ten years, not
the pearls within the oysters. Microscopic examination of thin sections
made through decalcified pearls showed that they are almost in all cases
deposited around a minute larval cestode or tapeworm. These larvæ make
their way into the oyster, and the irritation they set up induces the
formation of the pearl, just as was the case with the cercaria-formed
pearls of the mussel. Where do these larvæ come from? We cannot say with
absolute certainty. Older specimens of tapeworms belonging to the new
species, _Tetrarhynchus unionifactor_, also live in the oyster; and it
may be that, were a larva to escape entombment in a pearl, it would grow
up into one of these. But even these never become mature in the oyster;
to attain sexual maturity they must be swallowed by a second host. What
is the second host of the pearl-forming cestode? This question we are
only recently able to answer, and here, again, without absolute
certainty. I have recently described the adult form of _T. unionifactor_
from a large ray, _Rhinoptera javanica_. In this fish, which feeds
largely on oysters, the cestodes exist in swarms in the stomach, and the
eggs make their way from the fish into the oysters, and there some of
them grow up, but most of them perish in their pearly casket. If, as I
believe, this is the history of the pearl-forming organism, we must
regard the _Rhinoptera_ as a friend to the industry, and not, as
hitherto, an enemy which helps to destroy the oyster-beds.
The discovery of the cestode larva as a real cause of pearl-formation
received an interesting confirmation shortly after it had made it. M. G.
Seurat, working independently at Rikitea on the island of Mangareva, in
the Gambier group, discovered a very similar larva in the local
pearl-oyster around which pearls are formed; this larva, if we may judge
from pictures, is almost certainly the same as the one from Ceylon.
Professor Giard regards it as belonging to a tapeworm of the genus
_Acrobothrium_; and, if he be right, then Professor Herdman’s larva is
an _Acrobothrium_ too. We have so little knowledge of the early forms of
cestodes that we cannot accept this attribution as final. We may,
however, hope for further information, for a French zoologist, M.
Boutan, started some little time ago for the East to work at the
problem; Mr. Hornell is still at work in Ceylon; and Mr. C. Crossland,
who has had much experience in marine work in the tropics, has been
appointed, at the request of the Soudan Government, to investigate the
pearl-oyster beds of the Red Sea. Finally Dr. Willey, of the Colombo
Museum, has recently described similar larvæ in the pearls of the
‘window-pane’ oyster, _Placuna placenta_, from the eastern shores of
Ceylon.
In 1904 it was again found possible to hold a fishery in Ceylon. It was
held at a place called Marichikaddi, also on the north-west coast. In
the course of thirty-eight days over 41,000,000 oysters were taken. The
trade was very brisk; the prices paid were unprecedented. The 1905
fishery, which began on February 18, promised to beat all records. On
February 22 the catch was nearly 4,500,000 oysters; and the Government’s
share for that day was £9,000. Since this date each year has yielded a
bountiful harvest, and in financial circles the London Syndicate, who
have obtained a ‘concession’ of the oyster-beds for twenty years from
the Ceylon Government, are understood to be ‘doing very well.’
It is perhaps too soon to attribute this success to the efforts of
Professor Herdman and Mr. Hornell, the latter of whom, we understand,
has been permanently retained as biologist to the syndicate; but we have
no doubt that, acting under their advice, the oyster-bed may be made a
steady, in place of a most intermittent, source of revenue. In this
connexion it may be mentioned that radiography is now being used, and by
its means the oysters containing large pearls can be separated from
those that do not, and the latter returned to the sea. Besides their
valuable work in solving this particular problem, Professor Herdman and
his colleague have made a rich collection of marine animals, which are
being examined by a number of specialists. The results of their labours
have appeared in a handsome series of volumes published under the
auspices of the Royal Society; and it is from the first of these that
many of the facts contained in this article are derived. The memoirs
included in the volumes contain many important additions to our
knowledge; but no result is more interesting or more economically
important than the confirmation of the fact that, as M. Dubois puts it,
‘La plus belle perle n’est donc, en définitive, que le brillant
sarcophage d’un ver.’
THE DEPTHS OF THE SEA
_Here in the womb of the world--here on the tie-ribs of earth._
RUDYARD KIPLING.
The first recorded attempt to sound the depths of the ocean was made
early in the year 1521, in the South Pacific, by Ferdinand Magellan. He
had traversed the dangerous straits destined to bear his name during the
previous November, and emerged on the 28th of that month into the open
ocean. For three months he sailed across the Pacific, and in the middle
of March, 1521, came to anchor off the islands now known as the
Philippines. Here Magellan was killed in a conflict with the natives.
The records of his wonderful feat were brought to Spain during the
following year by one of his ships, the _Victoria_; and amidst the
profound sensation caused by the news of this voyage, which has been
called ‘the greatest event in the most remarkable period of the world’s
history,’ it is probable that his modest attempt to sound the ocean
failed to attract the attention it deserved. Magellan’s sounding-lines
were at most some two hundred fathoms in length, and he failed to touch
bottom; from which he ‘somewhat naïvely concluded that he had reached
the deepest part of the ocean.’
It was more than two hundred years later that the first serious study of
the bed of the sea was undertaken by the French geographer Philippe
Buache, who first introduced the use of isobathic curves in a map which
he published in 1737. His view, that the depths of the ocean are simply
prolongations of the conditions existing in the neighbouring sea-coasts,
though too wide in its generalization, has been shown to be true as
regards the sea-bottom in the immediate vicinity of Continental coasts
and islands; and undoubtedly it helped to attract attention to the
problem of what is taking place at the bottom of the sea.
Actual experiment, however, advanced but slowly. So early as the
fifteenth century, an ingenious Cardinal, one Nicolaus Cusanus
(1401-1464), had devised an apparatus consisting of two bodies, one
heavier and one lighter than water, which were so connected that when
the heavier touched the bottom the lighter was released. By calculating
the time which the latter took in ascending, attempts were made to
arrive at the depths of the sea. A century later Puehler made similar
experiments; and after another interval of a hundred years, in 1667 we
find the Englishman Robert Hooke continuing on the same lines various
bathymetric observations; but the results thus obtained were fallacious,
and the experiments added little or nothing to our knowledge of the
nature of the bottom of the ocean. In the eighteenth century Count
Marsigli attacked many of the problems of the deep sea. He collected and
sifted information which he derived from the coral-fishers; he
investigated the deposits brought up from below, and was one of the
earliest to test the temperature of the sea at different depths. In 1749
Captain Ellis found that a thermometer, lowered on separate occasions to
depths of 650 fathoms and 891 fathoms respectively, recorded, on
reaching the surface, the same temperature--namely, 53°. His thermometer
was lowered in a bucket ingeniously devised so as to open as it
descended and close as it was drawn up. The mechanism of this instrument
was invented by the Rev. Stephen Hales, D.D., of Corpus Christi
College, Cambridge, the friend of Pope, and perpetual curate at
Teddington Church. Dr. Hales was a man of many inventions, and, amongst
others, he is said to have suggested the use of the inverted cup placed
in the centre of a fruit-pie in which the juice accumulates as the pie
cools. His device of the closed bucket with two connected valves was the
forerunner of the numerous contrivances which have since been used for
bringing up sea-water from great depths.
These were amongst the first efforts made to obtain a knowledge of
deep-sea temperatures. About the same time experiments were being made
by Bouguer and others on the transparency of sea-water. It was soon
recognized that this factor varies in different seas; and an early
estimate of the depth of average sea-water sufficient to cut off all
light placed it at 656 feet. The colour of the sea and its salinity were
also receiving attention, notably at the hands of the distinguished
chemist Robert Boyle, and of the Italian, Marsigli, mentioned above. To
the latter, and to Donati, a fellow-countryman, is due the honour of
first using the dredge for purposes of scientific inquiry. They employed
the ordinary oyster-dredge of the local fishermen to obtain animals from
the bottom.
The invention of the self-registering thermometer by Cavendish, in 1757,
provided another instrument essential to the investigation of the
condition of things at great depths; and it was used in Lord Mulgrave’s
expedition to the Arctic Sea in 1773. On this voyage attempts at
deep-sea soundings were made, and a depth of 683 fathoms was registered.
During Sir James Ross’s Antarctic Expedition (1839-1843) the temperature
of the water was constantly observed to depths of 2,000 fathoms. His
uncle, Sir John Ross, had twenty years previously, on his voyage to
Baffin’s Bay, made some classical soundings. One, two miles from the
coast, reached a depth of 2,700 feet, and brought up a collection of
gravel and two living crustaceans; another, 3,900 feet in depth, yielded
pebbles, clay, some worms, crustacea, and corallines. Two other
dredgings, one at 6,000 feet, the other at 6,300 feet, also brought up
living creatures; and thus, though the results were not at first
accepted, the existence of animal life at great depths was demonstrated.
With Sir James Ross’s expedition we may be said to have reached modern
times: his most distinguished companion, Sir Joseph Hooker, is still
living. It is impossible to do more than briefly refer to the numerous
expeditions which have taken part in deep-sea exploration during our own
times. The United States of America sent out, about the time of Ross’s
Antarctic voyage, an expedition under Captain Wilkes, with Dana on board
as naturalist. Professor Edward Forbes, who ‘did more than any of his
contemporaries to advance marine zoology,’ joined the surveying ship
_Beacon_ in 1840, and made more than one hundred dredgings in the Ægean
Sea. Lovén was working in the Scandinavian waters. Mr. H. Goodsir sailed
on the _Erebus_ with Sir John Franklin’s ill-fated Polar Expedition; and
such notes of his as were recovered bear evidence of the value of the
work he did. The Norwegians, Michael Sars and his son, G. O. Sars, had
by the year 1864 increased their list of species living at a depth of
between 200 and 300 fathoms, from nineteen to ninety-two. Much good work
was done by the United States navy and by surveying ships under the
auspices of Bache, Bailey, Maury, and de Pourtalès. The Austrian frigate
_Novara_, with a full scientific staff, circumnavigated the world in
1857-1859. In 1868 the Admiralty placed the surveying ship _Lightning_
at the disposal of Professor Wyville Thomson and Dr. W. B. Carpenter
for a six weeks’ dredging trip in the North Atlantic; and in the
following year the _Porcupine_, by permission of the Admiralty, made
three trips under the guidance of Dr. W. B. Carpenter and Mr. Gwyn
Jeffreys.
Towards the end of 1872 H.M.S. _Challenger_ left England to spend the
following three years and a half in traversing all the waters of the
globe. This was the most completely equipped expedition which has left
any land for the investigation of the sea, and its results were
correspondingly rich. They have been worked out by naturalists of all
nations, and form the most complete record of the fauna and flora, and
of the physical and chemical conditions of the deep, which has yet been
published. It is from Sir John Murray’s summary of the results of the
voyage that many of these facts are taken. Since the return of the
_Challenger_ there have been many expeditions from various lands, but
none so complete in its conception or its execution as the British
Expedition of 1872-1875. The U.S.S. _Blake_, under the direction of A.
Agassiz, has explored the Caribbean Sea; and the _Albatross_, of the
same navy, has sounded the Western Atlantic. Numerous observations made
by the German ships _Gazelle_ and _Drache_, and Plankton Expedition, the
Norwegian North Atlantic Expedition, the Italian ship _Washington_, the
French ships _Travailleur_ and _Talisman_, the Prince of Monaco’s
yachts, _Hirondelle_ and _Princesse Alice_, under his own direction, the
Austrian ‘Pola’ Expedition, the Russian investigations in the Black Sea,
and lastly, by the ships of our own navy, have, during the last
five-and-twenty years, enormously increased our knowledge of the seas
and of all that in them is. This knowledge is still being added to. At
the present time the collections of the German ship _Valdivia_ and of
the Dutch _Siboga_ Expedition are being worked out, and are impatiently
awaited by zoologists and geographers of every country. The _Discovery_
and the _Gauss_, although primarily fitted for ice-work, have added much
to what is known of the sea-bottom of the Antarctic; and amongst men of
science there is no abatement of interest and curiosity as to that
_terra incognita_.
Before we attempt to describe the conditions which prevail at great
depths of the ocean, a few words should be said as to the part played by
cable-laying in the investigation of the subaqueous crust of the earth.
This part, though undoubtedly important, is sometimes exaggerated; and
we have seen how large an array of facts has been accumulated by
expeditions made mainly in the interest of pure science. The laying of
the Atlantic cable was preceded, in 1856, by a careful survey of a
submerged plateau, extending from the British Isles to Newfoundland, by
Lieutenant Berryman of the _Arctic_. He brought back samples of the
bottom from thirty-four stations between Valentia and St. John’s. In the
following year Captain Pullen, of H.M.S. _Cyclops_, surveyed a parallel
line slightly to the north. His specimens were examined by Huxley, and
from them he derived the _Bathybius_, a primeval slime which was thought
to occur widely spread over the sea-bottom. The interest in this
‘Urschleim’ has, however, become merely historic, since John Y.
Buchanan, of the _Challenger_, showed that it is only a gelatinous form
of sulphate of lime thrown down from the sea-water by the alcohol used
in preserving the organisms found in the deep-sea deposits.
The important generalizations of Dr. Wallich, who was on board H.M.S.
_Bulldog_, which, in 1860, again traversed the Atlantic to survey a
route for the cable, largely helped to elucidate the problems of the
deep. He noticed that no _algæ_ live at a depth greater than 200
fathoms; he collected animals from great depths, and showed that they
utilize in many ways organisms which fall down from the surface of the
water; he noted that the conditions are such that, whilst dead animals
sink from the surface to the bottom, they do not rise from the bottom to
the surface; and he brought evidence forward in support of the view that
the deep-sea fauna is directly derived from shallow-water forms. In the
same year in which Wallich traversed the Atlantic, the telegraph cable
between Sardinia and Bona, on the African coast, snapped. Under the
superintendence of Fleeming Jenkin, some forty miles of the cable, part
of it from a depth of 1,200 fathoms, was recovered. Numerous animals,
sponges, corals, polyzoa, molluscs, and worms were brought to the
surface, adhering to the cable. These were examined and reported upon by
Professor Allman, and subsequently by Professor A. Milne Edwards; and,
as the former reports, we ‘must therefore regard this observation of Mr.
Fleeming Jenkin as having afforded the first absolute proof of the
existence of highly organized animals living at a depth of upwards of
1,000 fathoms.’ The investigation of the animals thus brought to the
surface revealed another fact of great interest, namely, that some of
the specimens were identical with forms hitherto known only as fossils.
It was thus demonstrated that species hitherto regarded as extinct are
still living at great depths of the ocean.
During the first half of the last century an exaggerated idea of the
depth of the sea prevailed, due in a large measure to the defective
sounding apparatus of the time. Thus Captain Durham, in 1852, recorded a
depth of 7,730 fathoms in the South Atlantic, and Lieutenant Parker
mentions one of 8,212 fathoms--depths which the _Challenger_ and the
_Gazelle_ corrected to 2,412 and 2,905 fathoms respectively. The deepest
parts of the sea, as revealed by recent research, do not lie, as many
have thought, in or near the centres of the great oceans, but in the
neighbourhood of, or at no great distance from, the mainland, or in the
vicinity of volcanic islands. One of the deepest ‘pockets’ yet found is
probably that sounded by the American expedition on board the
_Tuscarora_ (1873-1875) east of Japan, when bottom was only reached at a
depth of 4,612 fathoms. More recently, soundings of 5,035 fathoms have
been recorded in the Pacific, in the neighbourhood of the Friendly
Islands, and south of these again, one of 5,113 fathoms; but the deepest
of all lies north of the Carolines, and attains a depth of 5,287
fathoms. It thus appears that there are ‘pockets’ or pits in the sea
whose depth below the surface of the water is about equal to the height
of the highest mountains taken from the sea-level. Both are
insignificant in comparison with the mass of the globe; and it is
sometimes said that, were the seas gathered up, and the earth shrunk to
the size of an orange, the mountain ranges and abysmal depths would not
be more striking than are the small elevations and intervening
depressions on the skin of the fruit.
But it is not with these exceptional abysses that we have to do; they
are as rare and as widely scattered as great mountain-ranges on land. It
is with the deep sea, as opposed to shoal water and the surface layers,
that this article is concerned; but the depth at which the sea becomes
‘deep’ is to some extent a matter of opinion. Numerous attempts, headed
by that of Edward Forbes, have been made to divide the sea into zones or
strata; and, just as the geological strata are characterized by peculiar
species, so, in the main, the various deep-sea zones have their peculiar
fauna. These zones, however, are not universally recognized; and their
limits, like those of the zoogeographical regions on land, whilst
serving for some groups of animals, break down altogether as regards
others. There are, however, two fairly definite regions in the sea; and
the limit between them is the very one for our purpose. This limit
separates the surface waters, which are permeable by the light of the
sun and in which owing to this life-giving light, _algæ_ and vegetable
organisms can live, from the deeper waters which the sun’s rays cannot
reach, and in which no plant can live. The regions pass imperceptibly
into one another; there is no sudden transition. The conditions of life
gradually change, and the precise level at which vegetable life becomes
impossible varies with differing conditions. With strong sunlight and a
smooth sea, the rays penetrate further than if the light be weak and the
waters troubled.
Speaking generally, we may place the dividing-line between the surface
layer and the deep sea at 300 fathoms. Below this no light or heat from
the sun penetrates; and it is the absence of these factors that gives
rise to most of the peculiarities of the deep sea. It is a commonplace,
which every schoolboy now knows, that all animal life is ultimately
dependent on the food-stuffs stored up by green plants; and that the
power which such plants possess of fixing the carbonic acid of the
surrounding medium, and building it up into more complex food-stuffs,
depends upon the presence of their green colouring matter (chlorophyll),
and is exercised only in the presence of sunlight. But, as we have
pointed out, ‘the sun’s perpendicular rays’ do not ‘illumine the depths
of the sea’; they hardly penetrate 300 fathoms. This absence of sunlight
below a certain limit, and the consequent failure of vegetable life,
gave rise at one time to the belief that the abysses of the ocean were
uninhabited and uninhabitable; but, as we have already seen, this view
has long been given up.
The inhabitants of the deep sea cannot, any more than other creatures,
be self-supporting. They prey on one another, it is true; but this must
have a limit, or very soon there would be nothing left to prey upon.
Like the inhabitants of great cities, the denizens of the deep must have
an outside food-supply, and this they must ultimately derive from the
surface layer.
The careful investigation of life in the sea has shown that not only the
surface layer, but all the intermediate zones teem with life. Nowhere is
there a layer of water in which animals are not found. But, as we have
seen, the _algæ_ upon which the life of marine animals ultimately
depends, live only in the upper waters; below 100 fathoms they begin to
be rare, and below 200 fathoms they are absent. Thus it is evident that
those animals which live in the surface layers have, like an
agricultural population, their food-supply at hand, while those that
live in the depths must, like dwellers in towns, obtain it from afar.
Many of the inhabitants of what may be termed the middle regions are
active swimmers, and these undoubtedly from time to time visit the more
densely peopled upper strata. They also visit the depths and afford an
indefinite food-supply to the deep-sea dwellers.
But probably by far the larger part of the food consumed by abysmal
creatures consists of the dead bodies of animals which sink down like
manna from above. The surface layers of the ocean teem with animal and
vegetable life. Every yachtsman must at times have noticed that the sea
is thick as a _purée_ with jelly-fish, or with those little transparent,
torpedo-shaped creatures, the _Sagitta_. What he will not have noticed,
unless he be a microscopist, is that at almost all times the surface is
crowded with minute organisms, foraminifera, radiolaria, diatoms. These
exist in quite incalculable numbers, and reproduce their kind with
astounding rapidity. They are always dying, and their bodies sink
downwards like a gentle rain.[1] In such numbers do they fall, that
large areas of the ocean bed are covered with a thick deposit of their
shells. In the shallower waters the foraminifera, with their calcareous
shells, prevail, but over the deeper abysses of the ocean they take so
long in falling that the calcareous shells are dissolved in the water,
which contains a considerable proportion of carbonic acid gas, and their
place is taken by the siliceous skeletons of the radiolarians and
diatoms. Thus there is a ceaseless falling of organisms from above, and
it must be from these that the dwellers of the deep ultimately obtain
their food. As Mr. Kipling in his ‘Seven Seas,’ says of the deep-sea
cables:
‘The wrecks dissolve above us; their dust drops down from afar--
Down to the dark, to the utter dark, where the blind
white sea-snakes are.’
In trying to realize the state of things at the bottom of the deep sea,
it is of importance to recognize that there is a wonderful uniformity of
physical conditions _là-bas_. Climate plays no part in the life of the
depths; storms do not ruffle their inhabitants; these recognize no
alternation of day or night; seasons are unknown to them; they
experience no change of temperature. Although the abysmal depths of the
polar regions might be expected to be far colder than those of the
tropics, the difference only amounts to a degree or so--a difference
which would not be perceptible to us without instruments of precision.
The following data show how uniform temperature is at the bottom of the
sea.
In June, 1883, Nordenskiöld found on the eastern side of Greenland the
following temperatures: at the surface 2·2° C.; at 100 metres 5·7° C.;
at 450 m. 5·1° C. In the middle of December, 1898, the German deep-sea
expedition, while in the pack-ice of the Antarctic, recorded the
following temperatures: at the surface -1° C.; at 100 m.-1·1° C.; at 400
m. 1·6° C.; at 1,000-1,500 m. 1·6° C.; at 4,700 m.-0·5° C. These may be
compared with some records made in the Sargasso Sea by the Plankton
Expedition in the month of August, when the surface registered a
temperature of 24° C.; 195 m. one of 18·8° C.; 390 m. one of 14·9° C.;
and 2,060 m. one of 3·8° C. It is thus clear that the temperature at the
bottom of the deep sea varies but a few degrees from the freezing-point;
and, whether in the tropics or around the poles, this temperature does
not undergo anything like the variations to which the surface of the
earth is subjected.
There are, however, some exceptions to this statement. The
Mediterranean, peculiar in many respects, is also peculiar as to its
bottom temperature. In August, 1881, the temperature, as taken by the
_Washington_, was at the surface 26° C.; at 100 m. 14·5° C.; at 500 m.
14·1° C.; and from 2,500 m. to 3,550 m. 13·3° C. These observations
agree, within one-fifth of a degree, with those recorded later by Chun
in the same waters. There are also certain areas near the Sulu Islands
where, with a surface temperature of 28° C., the deep sea, from 730 m.
to 4,660 m., shows a constant temperature of 10·3° C.; and again, on the
westerly side of Sumatra, the water, from 900 m. downwards, shows a
constant temperature of 5·9° C.; whilst in the not far distant Indian
Ocean it sinks at 1,300 m. to 4° C., and at 1,700 m. to 3° C. In spite
of these exceptions, we may roughly say that all deep-sea animals live
at an even temperature, which differs by but a few degrees from the
freezing-point. Indeed, the heating effect of the sun’s rays is said not
to penetrate, as a rule, further than 90 to 100 fathoms, though in the
neighbourhood of the Sargasso Sea it undoubtedly affects somewhat deeper
layers. In the Mediterranean the heat-rays probably do not penetrate
more than 50 fathoms. Below these limits all seasonable variations
cease. Summer and autumn, spring and winter, are unknown to the dwellers
of the deep; and the burning sun of the tropical noonday, which heats
the surface water to such a degree that the change of temperature from
the lower waters to the upper proves fatal to many delicate animals when
brought up from the depths, has no effect on the great mass of water
below the 100-fathom line.
Again, in the depths the waters are still. A great calm reigns. The
storms which churn the upper waters into tumultuous fury have but a
superficial effect, and are unfelt at the depth of a few fathoms. Even
the great ocean currents, such as the Gulf Stream, are but surface
currents, and their influence is probably not perceptible below 200
fathoms. There are places, as the wear and tear of telegraphic cables
show, where deep-sea currents have much force; but these are not common.
We also know that there must be a very slow current flowing from the
poles towards the Equator. This replaces the heated surface waters of
the tropics, which are partly evaporated and partly driven by the
trade-winds towards the poles. Were there no such current, the waters
round the Equator, in spite of the low conductivity of salt water,
would, in the course of ages, be heated through. But this current is
almost imperceptible; on the whole, no shocks or storms disturb the
peace of the oceanic abyss.
An interesting result of this is that many animals, which in shallower
waters are subject to the strain and stress of tidal action or of a
constant stream, and whose outline is modified by these conditions, are
represented in the depths by perfectly symmetrical forms. For instance,
the monaxonid sponges from the deep sea have a symmetry as perfect as a
lily’s, whilst their allies from the shallower seas, subject as they are
to varying tides and currents, are of every variety of shape, and their
only common feature is that none of them are symmetrical. This radial
symmetry is especially marked in the case of sessile animals, those
whose ‘strength is to sit still,’ attached by their base to some rock or
stone, or rooted by a stalk into the mud. Such animals cannot move from
place to place, and, like an oyster, are dependent for their food on
such minute organisms as are swept towards them in the currents set by
the action of their cilia. A curious and entirely contrary effect is
produced by this stillness on certain animals, which, without being
fixed, are, to say the least, singularly inert. The sea-cucumbers or
holothurians, which can be seen lying still as sausages in any shallow
sub-tropical waters, are nevertheless rolled over from time to time, and
present now one, now another, surface to the bottom. These have retained
the five-rayed symmetry, which is so eminently characteristic of the
group Echinoderma, to which they belong. But the holothurians in the
deep sea, where nothing rolls them about, continue throughout life to
present the same surface to the bottom; and these have developed a
secondary bilateral symmetry, so that, like a worm or a lobster, they
have definite upper and lower surfaces. These bilateral holothurians
first became known by the dredgings of the _Challenger_, and formed one
of the most important additions to our knowledge of marine zoology for
which we are indebted to that expedition.
At the bottom of the sea there is no sound--
‘There is no sound, no echo of sound, in the deserts of the deep,
Or the great grey level plains of ooze where the shell-burred
cables creep.’
The world down there is cold and still and noiseless. Nevertheless, many
of the animals of the depths have organs to which by analogy an
auditory function has been assigned. But it must not be forgotten that
even in the highest land-vertebrates the ear has two functions. It is at
once the organ of hearing and of balancing. Part of the internal ear is
occupied with orientating the body. By means of it we can tell whether
we are keeping upright, going uphill or descending, turning to the right
or to the left; and it is probably this function which is the chief
business of the so-called ears of marine animals. Professor Huxley once
said that, unless one became a crayfish, one could never be sure what
the mental processes of a crayfish were. This is doubtless true; but
experiment has shown, both in crayfishes and cuttlefishes, that, if the
auditory organ be interfered with or injured, the animal loses its sense
of direction and staggers hither and thither like a drunken man. It is
obvious that animals which move about at the bottom require such
balancing organs quite as much as those which skim the surface, and it
is in no wise remarkable that such organs should be found in those
dwellers in the deep which move from place to place.
If we could descend to the depths and look about us, we should find the
bottom of the sea near the land carpeted with deposits washed down from
the shore and carried out to sea by rivers, and dotted over with the
remains of animals and plants which inhabit shoal waters. This deposit,
derived from the land, extends to a greater or less distance around our
coast-line. In places this distance is very considerable. The Congo is
said to carry its characteristic mud 600 miles out to sea, and the
Ganges and the Indus to carry theirs 1,000 miles; but sooner or later we
should pass beyond the region of coast mud and river deposit, the
seaward edge of which is the ‘mud-line’ of Sir John Murray.
When we get beyond the mud-line, say a hundred miles from the Irish or
American coast, we should find that the character of the sea-bottom has
completely changed. Here we should be on Rudyard Kipling’s ‘great grey
level plains of ooze.’ All around us would stretch a vast dreary level
of greyish-white mud, due to the tireless fall of the minute globigerina
shells mentioned above. This rain of foraminifera is ceaseless, and
serves to cover rock and stone alike. It is probably due to this chalky
deposit that so many members of the ‘Benthos’--a term used by Haeckel to
denote those marine animals which do not swim about or float, but which
live on the bottom of the ocean either fixed or creeping about--are
stalked. Many of them, whose shoal-water allies are without a pedicel,
are provided with stalks; and those whose shallow-water congeners are
stalked are, in the depths, provided with still longer stalks. Numerous
sponges--the alcyonarian _Umbellula_, the stalked ascidians, and, above
all, the stalked crinoids--exemplify this point.
Flat as the Sahara, and with the same monotony of surface, these great
plains stretch across the Atlantic, dotted here and there with a yet
uncovered stone or rock dropped by a passing iceberg. In the deeper
regions of the ocean--where, as we have already seen, occasional pits
and depressions occur, and great ridges arise to vex the souls of the
cable-layers--the globigerina ooze is replaced by the less soluble
siliceous shells of the radiolarians and diatoms. The former are largely
found in pits in the Pacific, the latter in the Southern Seas. But there
is a third deposit which occurs in the deeper parts of the ocean--the
red clay. This is often partly composed of the empty siliceous shells
just mentioned; but over considerable areas of the Pacific the number of
these shells is very small, and here it would seem that the red clay is
largely composed of the ‘horny fragments of dead surface-living
animals, of volcanic and meteoric dust, and of small pieces of
water-logged pumice-stone.’ On whichever deposit we found ourselves,
could we but see the prospect, we should be struck with the monotony of
a scene as different as can well be imagined from the variegated beauty
of a rock-pool or a coral island lagoon.
There is, however, an abundance of animal life. The dredge reveals a
surprising variety and wealth of form. Sir John Murray records ‘at
station 146 in the Southern Ocean, at a depth of 1,375 fathoms, that 200
specimens captured belonged to 59 genera and 78 species.’ He further
states that this was ‘probably the most successful haul, as regards
number, variety, novelty, size, and beauty of the specimens,’ up to the
date of the dredging; but even this was surpassed by the captures from
the depths at station 147. The Southern Ocean is particularly well
populated. The same writer says: ‘The deep-sea fauna of the Antarctic
has been shown by the _Challenger_ to be exceptionally rich, a much
larger number of species having been obtained than in any other region
visited by the expedition; and the _Valdivia’s_ dredgings, in 1898,
confirm this.’ There seems to be no record of such a wealth of species
in depths of less than 50 fathoms, and we are justified in the belief
that the great depths are extremely rich in species.
The peculiar conditions under which the Benthos live have had a marked
influence on their structure. Representatives of nearly all the great
divisions of the animal kingdom which occur in the sea are found in the
depths. Protozoa, sponges, cœlenterata, round-worms, annelids,
crustacea, polyzoa, brachiopoda, molluscs, echinoderms, ascidians,
fishes, crowd the sea-bottom. The _Valdivia_ has brought home even
deep-sea ctenophores and sagittas, forms hitherto associated only with
life at the surface. The same expedition also secured adult examples of
the wonderful free-swimming holothurian, _Pelagothuria ludwigi_, which
so curiously mimics a jelly-fish. It was taken in a closing-net at 400
to 500 fathoms near the Seychelles. Most of these animals bear their
origin stamped on their structure, so that a zoologist can readily pick
out from a miscellaneous collection of forms those which have a deep-sea
home. We have already referred to a certain ‘stalkiness,’ which lifts
the fixed animals above the slowly deepening ooze. Possibly the
long-knobbed tentacles of the deep-sea jelly-fish, _Pectis_, on the tips
of which it is thought the creature moves about, may be connected with
the same cause. The great calm of the depths and its effect upon the
symmetry of the body have also been mentioned; but greater in its effect
on the bodies of the dwellers in the ocean abysses is the absence of
sunlight.
No external rays reach the bottom of the sea, and what light there is
must be supplied by the phosphorescent organs of the animals themselves,
and must be faint and intermittent. A large percentage of animals taken
from the deep sea show phosphorescence when brought on deck; and it may
be that this emission of light is much greater at a low temperature, and
under a pressure of 1 to 2 tons on the square inch, than it is under the
ordinary atmospheric conditions of the surface. The simplest form which
these phosphorescent organs take is that of certain skin-glands which
secrete a luminous slime. Such a slime is cast off, according to Filhol,
by many of the annelids; and a similar light-giving fluid is exuded from
certain glands at the base of the antenna and elsewhere in some of the
deep-sea shrimps. But the most highly developed of the organs which
produce light are the curious eye-like lanterns which form one or more
rows along the bodies of certain fishes, notably of members of the
Stomiadæ, a family allied to the salmons. From head to tail the
miniature bull’s-eyes extend, like so many portholes lit up, with
sometimes one or two larger organs in front of the eyes, like the port
and starboard lanterns of a ship, so that when one of these fishes swims
swiftly across the dim scene it must, to quote Kipling again, recall a
liner going past ‘like a grand hotel.’ Sometimes the phosphorescent
organ is at the tip of a barbel or tentacle, and it is interesting to
note that the angler-fish of the deep sea has replaced its white lure,
conspicuous in shallow water, but invisible in the dark, by a luminous
process, the investigation of which leads many a creature into the
enormous, toothed mouth of the fish.
A peculiar organ, known by the name ‘phæodaria,’ exists in the body of
certain radiolarians found only in the deep seas. It has been suggested
that this structure gives forth light; and, if this be the case, the
floor of the ocean is strewn with minute glow-lamps, which perhaps give
forth as much light as the surface of the sea on a calm summer’s night.
There is, however, much indirect evidence that, except for these
intermittent sources, the abysses of the ocean are sunk in an
impenetrable gloom.
When physical conditions change, living organisms strive to adapt
themselves to the changed conditions. Hence, when the inhabitants of the
shallower waters made their way into the darker deeps, many of them, in
the course of generations, increased the size of their eyes until they
were out of all proportion to their other sense-organs. Others gave up
the contest on these lines, and set about replacing their visual organs
by long tactile tentacles or feelers, which are extraordinarily
sensitive to external impressions. Like the blind, they endeavour to
compensate for loss of sight by increased tactile perception; and in
these forms the eyes are either dwindling or have quite disappeared. An
instance in point is supplied by the crustacea, many of whom have not
only lost their eyes, but have also lost the stalk which bore them; but
amongst the crustacea some genera, such as _Bathynomus_, have enormous
eyes with as many as four thousand facets. It is noticeable that this
creature has its eyes directed downwards toward the ground and not
upwards, as is the case with its nearest allies. On the whole the
crustacea lose their eyes more readily, and at a less depth, than
fishes. Many of the latter--_e.g._, _Ipnops_--are blind, and in others
the eyes seem to be disappearing. Thus, amongst the deep-sea cod,
_Macrurus_, those which frequent the waters down to about 1,000 fathoms,
have unusually large eyes, whilst those which go down to the deeper
abysses have very small ones. Many of the animals which have retained
their eyes carry them at the end of processes. Chun, in his brilliant
account of the voyage of the _Valdivia_, has figured a series of fishes
whose eyes stand out from the head like a pair of binoculars; and
similar ‘telescope’ eyes, as he calls them, occur on some of the
eight-armed cuttle-fish. The larva of one of the fishes has eyes at the
end of two stalks, each of which measures quite one-fourth of the total
length of the body.
The colour of the deep-sea creatures also indicates the darkness of
their habitat. Like cave-dwelling animals, or the lilac forced in
Parisian cellars, many of them are blanched and pale; but this is by no
means always the case. There is, in fact, no characteristic hue for the
deep-sea fauna. Many of the fishes are black, and many show the most
lovely metallic sheen. Burnished silver and black give a somewhat
funereal, but very tasteful appearance to numbers of deep-sea fish.
Others are ornamented with patches of shining copper, which, with their
blue eyes, form an agreeable variety in their otherwise sombre
appearance. Many of the fishes, however, present a gayer clothing. Some
are violet, others pale rose or bright red. Others have a white almost
translucent skin, through which the blood can be seen and its course
traced even in its finer vessels. Purples and greens abound amongst the
holothurians; other echinoderms are white, yellow, pink, or red. Red is,
perhaps, the predominant colour of the crustacea, though it has been
suggested that this colour is produced during the long passage to the
surface, and that some of the bright reds which we see at the surface
are unknown in the depths. Violet and orange, green and red, are the
colours of the jelly-fishes and the corals.
It thus appears that there is a great variety and a great brilliancy
amongst many of the bottom fauna. With the exception of blue, all
colours are well represented; but the consideration of one or two facts
seems to show that colour plays little part in their lives. Apart from
the fact that to our eyes, at any rate, these gorgeous hues would be
invisible in the depths, it is difficult to imagine that each of these
gaily-coloured creatures can live amongst surroundings of its own hue.
Again, it is characteristic that the colour is uniform. There is a
marked absence of those stripes, bands, spots, or shading which play so
large a part in the protective coloration of animals exposed to light.
Although there is no protective coloration amongst the animals of the
deep sea, the luminous organs, which make, for instance, some of the
cuttlefishes as beautiful and as conspicuous as a firework, may, in some
cases, act as warning signals. Having once established a reputation for
nastiness, the more conspicuous an animal can make itself the less
likely is it to be interfered with. One peculiarity connected with
pigment, as yet inexplicable, is the fact that, in deep-sea animals,
many of the cavities of the body are lined with a dark or, more
usually, a black epithelium. The mouth, pharynx, and respiratory
channels, and even the visceral cavity, of _Bathysaurus_ and _Ipnops_,
and indeed of all really deep-sea fishes, are black. It can be of no use
to any animal to be black inside; and the only explanation hitherto
given is that the deposit of pigment is the expression of some
modification in the excretory processes of the abysmal fishes.
It was mentioned above that the absence of eyes is to some extent
compensated by the great extension of feelers and antennæ. Many of the
jelly-fishes have long free tentacles radiating in all directions; the
rays of the ophiuroids are prolonged; the arms of the cuttle-fish are
capable of enormous extension. The antennæ of the crustacea stretch
widely through the water, and, in _Aristoeopsis_, cover a radius of
about five times the body-length. In _Nematocarcinus_ the walking-legs
are elongated to almost the same extent; and this crustacean steps over
the sea-bottom with all the delicacy of Agag. The curious arachnid-like
pycnogonids have similarly elongated legs, and move about, like the
‘harvestmen’ or the ‘daddy-long-legs,’ with each foot stretched far from
the body, acting as a kind of outpost. The fishes, too, show
extraordinary outgrowths of this kind. The snout may be elongated till
the jaws have the proportions of a pair of scissor-blades, each armed
with rows of terrible teeth; or long barbels, growing out from around
the mouth, sway to and fro in the surrounding water. In other cases the
fins are drawn out into long streamers. All these eccentricities give
the deep-sea fishes a bizarre appearance; their purpose is plainly to
act as sensory outposts, warning their possessor of the presence of
enemies or of the vicinity of food.
All deep-sea animals are of necessity carnivorous, and probably many of
them suffer from an abiding hunger. Many of the fishes have enormous
jaws, the angle of the mouth being situated at least one-third of the
body-length from the anterior end. The gape is prodigious, and as the
edge of the mouth is armed with recurved teeth, food once entering has
little chance of escape. So large is the mouth that these creatures can
swallow other fish bulkier than themselves; and certain eels have been
brought to the surface which have performed this feat, the prey hanging
from beneath them in a sac formed of the distended stomach and
body-wall. It has been said of the desert fauna that ‘perhaps there
never was a life so nurtured in violence, so tutored in attack and
defence as this. The warfare is continuous from the birth to the death.’
The same words apply equally to the depths of the ocean. There, perhaps,
more than anywhere else, is true the Frenchman’s description of life as
the conjugation of the verb ‘I eat,’ with its terrible correlative, ‘I
am eaten.’
Connected with the alimentary tract, though in some fishes shut off from
it, is the air-bladder, an organ which contains air secreted from the
blood, and which, amongst other functions, serves to keep the fish the
right side up. The air can be reabsorbed, and is no doubt, to some
extent, controlled by muscular effort; but there are times when this
air-bladder is a source of danger to deep-sea fishes. When they leave
the depths for shallower water, where the pressure is diminished, the
air-bladder begins to expand; and, should this expansion pass beyond the
control of the animal, the air-bladder will act as a balloon, and the
fish will continue to rise with a rate of ascension which increases as
the pressure lessens. Eventually the fish reaches the surface in a state
of terrible distortion, with half its interior hanging out of its mouth.
Many such victims of levitation have been picked up at sea, and from
them we learnt something about deep-sea fishes before the self-closing
dredge came into use.
One peculiarity of the abysmal fauna, which, to some extent, is a
protection against the cavernous jaws mentioned above, is a certain
‘spininess’ which has developed even amongst genera that are elsewhere
smooth. Such specific names as _spinosus_, _spinifer_, _quadrispinosum_,
are very common in lists of deep-sea animals, and testify to the wide
prevalence of this form of defence. A similar spiny character is,
however, found in many polar species, even in those of comparatively
shallow water; and it may be that this feature is a product of low
temperature and not of low level. The same applies to the large size
which certain animals attain in the depths. For instance, in the Arctic
and Antarctic Seas the isopodous crustacea, which upon our coasts
scarcely surpass an inch in length, grow to nine or ten inches, with
bodies as big as moderate-sized lobsters. The gigantic hydroid polyps,
_e.g._, _Monocaulus imperator_ of the Pacific and Indian Oceans,
illustrate the same tendency; and so do the enormous single spicules,
several feet long and as thick as one’s little finger, of the sponge
_Monorhaphis_. Amongst other floating molluscs at great depths, chiefly
pteropods, the _Valdivia_ captured a gigantic _Carinaria_ over two feet
in length. Of even greater zoological interest were giant specimens of
the _Appendicularia_, which were taken at between 1,100 and 1,200
fathoms. This creature, named by Chun, _Bathochordæus charon_, reaches a
length of about five inches, and has in its tail a notochord as big as a
lamprey’s. All other genera of this group are minute, almost
microscopic.
There are two other peculiarities common amongst the deep-sea fauna
which are difficult to explain. One is a curious inability to form a
skeleton of calcareous matter. The bones of many abysmal fishes are
deficient in lime, and are fibrous or cartilaginous in composition.
Their scales, too, are thin and membranous, their skin soft and velvety.
The shells of deep-sea molluscs are as thin and translucent as
tissue-paper; and the same is true of some brachiopods. The test of the
echinoderms is often soft, and the armour of the crustacea is merely
chitinous, unhardened by deposits of lime. Calcareous sponges are
altogether unknown in the depths. This inability to form a hard
skeleton--curiously enough this does not apply to corals--is not due to
any want of calcareous salts in the bottom waters. It is known that
calcium sulphate, from which animals secrete their calcium carbonate,
exists in abundance; but those animals which dwell on the calcareous
globigerina ooze are as soft and yielding as those which have their home
on the siliceous radiolarian deposits. Animals which form a skeleton of
silex do not suffer from the same inability; in fact, the deep-sea
radiolarians often have remarkably stout skeletons, whilst the wonderful
siliceous skeletons of the hexactinellid sponges are amongst the most
beautiful objects brought up from the depths.
The second peculiarity, for which there seems no adequate reason, is the
reduction and diminution in size of the respiratory organs. Amongst the
crustacea, the ascidians, and the fishes this is especially marked. The
gill laminæ are reduced in number and in size; and the evidence all
points to the view that this simplification is not primitive but
acquired, being brought about in some way by the peculiar conditions of
life at great depths.
When the first attempts were made to explore the bed of the ocean, it
was hoped that the sea would give up many an old-world form; that
animals, known to us only as fossils, might be found lurking in the
abysmal recesses of the deep; and that many a missing link would be
brought to light. This has hardly proved to be the case. In certain
groups animals hitherto known only as extinct, such as the stalked
crinoids and certain crustacea--_e.g._, the Eryonidæ--have been shown to
be still extant. The remarkable _Cephalodiscus_ and _Rhabdopleura_, with
their remote vertebrate affinities, have been dragged from their dark
retreats. Haeckel regards certain of the deep-sea medusæ as archaic, and
perhaps the same is true of the ascidians and holothurians; but, on the
whole, the deep-sea fauna cannot be regarded as older than the other
faunas of the seas. The hopes that were cherished of finding living
ichthyosauri or plesiosauri, or the Devonian ganoid fishes, or at least
a trilobite, or some of those curious fossil echinoderms, the cystoids
and blastoids, must be given up. Certain of the larger groups peculiar
to the deep sea have probably been there since remote times; but many of
the inhabitants of the deep belong to the same families, and even to the
same genera, as their shallow-water allies, and have probably descended
in more recent times. There, in the deep dark stillness of the ocean
bed, unruffled by secular change, they have developed and are developing
new modifications and new forms, which are as characteristic of the deep
sea as an Alpine fauna is of the mountain heights.
BRITISH SEA-FISHERIES
ἂγει
...πόντου τ' εἰναλίαν ϕύσιν σπείραισι δικτυοκλώστοις,
περιϕραδἠς ἀνήρ.
SOPHOCLES: _Antigone_.
To contemplate all the legislation concerning English sea-fishing and
the administration of this vast industry during the last century is
alike to bewilder the reason and to fatigue the patience. The industry
is an enormous one, and of the utmost value to the dwellers in these
islands. At the present time there are over 27,000 vessels, manned by
more than 90,000 seamen, fishing from the ports of Great Britain. They
land over 900,000 tons of fish, worth some £10,000,000, during the year.
In addition to the fishermen who remove the fish from the sea, a
considerable population of packers, curers, coopers, hawkers, etc., is
employed. For instance, out of the 20,000 hands employed in the Shetland
herring-fishery summer of 1906, 11,000 have been at sea, and 9,120, of
whom 7,560 were women, have been employed on shore, not to mention the
large number of railway employés who are engaged in the transport of a
very perishable article. Apart from the material interests of the trade
(the capital invested in steamers, sailing-boats, and gear of all kinds
being estimated at more than £11,000,000), the fishing industry is of
great importance to the country as a training-ground for sailors and
marine engineers, and as affording a means of livelihood to a vigorous
and an independent population.
Like any other industry, and--because the life-history of the
inhabitants of the sea is still so obscure--perhaps more than any other
industry, sea-fishing is liable to arbitrary fluctuations. There was,
for instance, a partial failure in the herring-fishery in the summer of
1906 on the north and north-east of the Shetlands. The total number of
crans landed was 438,950, as against 632,000 in 1905, a record year; and
some of the Shetlanders have been hard put to it to live. Such a failure
sets thinking those whose livelihood is threatened; but fishermen,
although keen observers in what immediately concerns them, are not
widely educated men, and cannot take into account in estimating causes,
the many factors of the problems, some of which usually escape even the
most talented of marine biologists. Fishermen seek a sign, usually an
obvious one; in the present case, the bad season was attributed to the
presence of certain Norwegian whaling companies, which a few years ago
established themselves in the Shetlands and are destroying the common
rorqual, the lesser rorqual, Sibbald’s rorqual, the cachalot, the
humpbacked whale, and more rarely the Atlantic right-whale. These are
killed for their blubber; the flesh is made into sausages, largely
consumed in Central Europe; and the bones are ground up for manure.
It is, however, doubtful if whaling is in any way responsible for the
scarcity of the herrings. According to the evidence collected by Mr.
Donald Crawford’s Committee on this subject in 1904, it would appear
that practically the only point on which the fishermen were then agreed
was that the spouting of the whales was often a good guide as to the
position of the herring-shoals. But the whales do not bring the
herrings; and the fishermen are not even agreed that they serve to
concentrate them. It is probable that the general migrations and
shoaling habits of the herrings are far more dependent on the physical
character of the water--a relation which is particularly clear, as the
international investigations have already shown, in areas where sharply
contrasted ocean-currents are constantly striving for the mastery as
they are in the neighbourhood of the Shetland Isles. The hydrographical
bulletin of the International Council recorded a distinctly lower
temperature for the Atlantic current between Iceland and Scotland at the
beginning of the year 1906 than at the corresponding season of 1903,
1904, or 1905; and an unusually low temperature has been characteristic
of the Shetland waters throughout the summer of 1906. The Gulf Stream
could more justly be blamed for the comparative failure of the Shetland
fishery in 1906 than the Norwegian whalers, whose operations have
probably done no more injury to the herring-fishery than they did in
1905 or the year before. Such failures are often real disasters to a
seafaring population--a race who are, as a rule, of small versatility
and unable to turn readily to new trades. Their occurrence usually
provokes a cry for legislation.
Such an outcry is in this country usually met by the appointment of a
Commission, or of a special Parliamentary Committee. Seventeen such
inquiries into sea-fisheries have been held since Queen Victoria came to
the throne, an average of one every four years. The usual process is
gone through; a certain number of more or less influential gentlemen
(one of them perhaps an expert) are given a ‘wide reference,’ and they
proceed to take evidence. An energetic secretary, usually a young
barrister, collects facts; a great number of witnesses, like Mrs.
Wititterly, ‘express an immense variety of opinions on an immense
variety of subjects.’ These are written down and printed; and the
Commissioners, with the aid of the energetic secretary, seek to distil
wisdom out of the printed evidence of the multitude, and base on it
their recommendations. Legislation is sometimes recommended; but in the
case of the sea-fisheries of this country it has, perhaps fortunately,
seldom followed the presentation of any of these reports.
It seems, indeed, that the time is hardly yet ripe for deep-sea fishery
legislation, much as it may be needed; and the reason is that our
knowledge of the questions involved, although rapidly increasing, is
still too deficient to form a sound basis for law-making. We propose to
confine our attention mainly to the North Sea, and, from another point
of view, mainly to the English fishing authorities, as opposed to those
of Scotland and Ireland, in each of which countries the fishing industry
is controlled by a separate Board. The fundamental and central question
to be settled is whether there is a diminution in the fish generally, or
in any particular species of food-fish in the North Sea area, by far the
most productive of our fishing-grounds. If the answer is affirmative, we
may ask, What is the cause of this diminution? and, How can it be
arrested?
In 1863 Professor Huxley, Mr. (afterwards Sir) J. Caird, and Mr. G. Shaw
Lefevre were constituted a Royal Commission to inquire--(1) whether or
not the value of the fisheries was increasing, stationary, or
decreasing; (2) whether or not the existing methods of fishing did
permanent harm to the fishing-grounds; and (3) whether or not the
existing legislation was necessary. Three years later the Commission
reported; and their Report forms an important milestone on the road of
English fishery administration.
Since 1866 great progress has been made in our knowledge of the
life-history of food-fishes; yet even to-day we are hardly in a position
to answer the questions set to Professor Huxley and his colleagues. At
that time nothing was known about the eggs or spawn of the food-fishes.
Even while the Commission was sitting, in 1864, Professor G. O. Sars for
the first time discovered and described the floating ova of the cod, and
succeeded in artificially fertilizing the ova and rearing the young. The
following year he did the same with the mackerel; and Professor Malm of
Göteborg about this time obtained and fertilized the eggs of the
flounder. Since that time we have found out the eggs of all the valuable
food-fish, and artificially hatched most of them. But the facts about
the cod’s eggs appear to have been unknown to the Commission. They had
to rely upon such data as the return of fish carried by the railway
companies, the current prices of fish in the market, the return on the
capital invested, and the impressions of leading merchants and
fishermen. They had little scientific knowledge of sea-fisheries to
guide them, for the knowledge scarcely existed; and they had no
trustworthy statistics. Nevertheless, as was usually the case when
Professor Huxley was concerned, they arrived at very definite
conclusions--conclusions which subsequent writers have felt to be, for
the time when they were formulated, sound. There was no doubt that at
that date, both in Scotland and in England, the fisheries were
improving; the number and the value of the fish landed at our
fishing-ports were annually increasing; the capital invested in the
industry yielded a satisfactory return.
The Commissioners strongly opposed the bounty system, which had done so
much to build up the herring-fisheries in Scotland. They recommended the
policy of opening the ports and the territorial waters to foreign
seamen. They regarded the sea as free to all, just as the International
Congress of Lawyers in the autumn of 1906 declared the air to be. They
found no reason to believe that the supply of fish was diminishing.
They were aware of the enormous destruction, especially of immature
fish, consequent upon the methods of fishing, but regarded this
destruction as infinitesimal compared with what normally goes on in
Nature, and held that it did no permanent harm to the fisheries. They
recommended that all laws regulating fishing in the open seas should be
repealed, and, with two exceptions, that similar laws dealing with
inshore fisheries should also be repealed; and they suggested that an
Act should be passed dealing with the policing of the seas. The Sea
Fisheries Act of 1868 carried these recommendations into effect, removed
from the Statute-book over fifty Acts, some dating back for centuries,
and rendered it possible for a fisherman to earn his living ‘how, when,
and where he pleased.’
But since 1868 much has changed. Beam-trawls continued to be
increasingly used down to 1893, since which date they have been
replaced, in steam-trawlers, by the more powerful otter-trawl. There has
been an immense increase in the employment of steam-vessels. In 1883 the
number of steamers was 225, with a tonnage of 6,654 tons; in 1892 the
steamers numbered 627, with a tonnage of 28,271. During the same time
the number of first-class sailing-vessels had sunk from 8,058 to 7,319,
whilst the tonnage was practically stationary--244,097 tons in 1883, as
compared with 244,668 tons in 1892. The introduction of the use of ice,
which took place about 1850, and the invention of various methods of
renewing and aerating the water in the fish-tanks, enabled the boats to
remain much longer on the fishing-grounds, and to waste much less time
in voyaging to and from the ports where the fish is landed. Further, the
time spent on the grounds was appreciably lengthened by the employment
of ‘carriers,’ which collect the fish from the fleet of trawlers and
carry it to port. This process of ‘fleeting,’ as it is called, at first
confined to the sailing-smacks, is still used by the large Hull fleets
of steam-trawlers which provide Billingsgate and more recently, Hull,
itself with daily supplies of trawled fish fresh from the
fishing-grounds. There has also been a great growth in dock and other
accommodation.
With the tendency to use larger vessels and more complex machinery came
the tendency to form companies and syndicates. The fisherman ceased to
own his boat, and now retains at best a share in it. The increase in
size of both the vessel and the gear necessitates increased intricacy in
the operations of fishing and increased specialization on the part of
the hands. The old fishing community, whose fathers and grandfathers
have been fishers, is disappearing before the advance of modern economic
forces. The fishing-village is turning into the cheap seaside resort.
The scene of operations of the North Sea fisherman is by no means
limited to the area in the map over which the two words wander. Roughly,
for purposes of definition, we may say that a North Sea fisherman is one
who lands his fish at an eastern port. Should he do so at a southern or
western port, even though he hail from Lowestoft or Scarborough, he
temporarily ceases, for our purpose, to be a North Sea fisherman. The
North Sea codmen work along the Orkneys, the Shetland and Faröe Islands,
Rockall and Iceland. The fishing-grounds of East Coast trawlers now
range from Iceland and the White Sea to the coasts of Portugal and
Morocco. Boats have gradually made their way along the Continental
coasts on the eastern side of the North Sea, opening up, about the year
1868, the grounds to the north of the Horn reef off the Danish coast. In
this direction, as in the Icelandic grounds, the pioneers have been the
codmen and the ‘liners,’ who catch their fish on hooks attached to long
lines--sometimes seven miles in length and carrying 7,000 hooks--which
are lowered to near the bottom and attached to buoys. The ‘liners’ also
first exploited the more central portions of the North Sea, fishing the
great Fisher Bank for many years before the appearance there, about
thirty years ago, of the trawlers, who have only used it as a
winter-ground since about 1885. It was not until about 1891 that
trawlers visited the Icelandic grounds.
In spite of the increase in the area of the fishing-ground which took
place in the last century, the intensity of the fishing has more than
kept up with the new areas exploited. Professor Huxley’s Commission held
the view that not only were there as good fish in the sea as ever came
out of it, but that the fish were as many and as large as before, and
that there was no reason to suppose their number would diminish. Indeed,
when we consider that an unfertilized fish-egg is rarely found in the
sea, and that, according to Dr. Fulton, of the Fishery Board for
Scotland, the female turbot produces annually 8,600,000 eggs, the cod
4,500,000, the haddock 450,000, the plaice 300,000, the flounder
1,400,000, the sole 570,000, whilst the herring has to be content with
the comparatively meagre total of 31,000, optimism seems permissible. On
the other hand, the reflection that, if the stock of cod remains about
constant, only two out of the 8,600,000 ova attain maturity, gives some
idea of the destructive forces at work.
The eggs are expelled into water, whilst a male is ‘standing by,’
fertilized in the water, and (except in the case of the herring, whose
eggs sink) those of the chief food-fishes float to the surface, where
they pass the first stages of their development. Except, again in the
case of the herring, which has definitely localized spawning-grounds,
there has hitherto been little trustworthy evidence as to the existence
either of stereotyped spawning migrations or of very definite
breeding-grounds in the case of the chief food-fishes. The great Lofoten
cod-fishery in spring is based on such a migration, as it is at this
time of the year that the cod approach the coast in dense shoals for
spawning purposes. During the summer, after the spawning is over, the
cod disappear northwards. But with respect to the spawning habits of
fishes in the waters most frequented by British fishermen we know little
more than that the greater number of fish spawn in relatively deep water
and at some distance from land. Light will doubtless be thrown upon this
problem by the international investigations now in progress. The
brilliant discovery by the Danish investigators of immense numbers of
the fry of the common eel in the deep water of the Atlantic, west of
Ireland, and the absence of the eggs and fry from the North Sea and
Baltic, render it practically certain that the countless hordes of eels
which leave the rivers of North Western Europe in autumn migrate to the
ocean for spawning purposes; and, more remarkable still, that the
delicate young elvers which enter the same streams in autumn have
already overcome the perils of their long return migration.
Before considering the evidence for the existence of a progressive
impoverishment of the fishing-grounds, it should be recorded that the
Trawling Commission of 1885 held that the increase of trawling had led
to a scarcity of fish in the inshore waters; and that to get good
catches it was necessary to go farther to sea. Eight years later, the
Select Committee of 1893 held that ‘a considerable diminution [had]
occurred among the more valuable classes of flat-fish, especially among
soles and plaice’; and that of 1900 reported that ‘the subject of the
diminution of the fish-supply is a very pressing one, and that the
situation is going from bad to worse.’
The evidence which induced this change of view rests partly on
experiment, partly on statistics. Although the new view may be correct,
none of the older sources of evidence are altogether satisfactory. One
charge which used to be made against the trawl--that it destroyed the
fish-spawn--has been disproved. The ova of all the prime food-fish, as
we have seen, with the exception of those of the herring, float on the
surface; and the herring is a fish that shows no sign of diminishing in
number. In 1886 the Scottish Fishery Board began experiments to
determine whether the number and size of fish were diminishing on a
certain limited area or not. The Firth of Forth and St. Andrews Bay were
closed against commercial trawling, and divided into stations. Once a
month the ship employed by the Board visited each station and trawled
over a given area. The fish taken were counted and measured. For the
first few years the results indicated an increase of food-fish; but,
taking a longer period and considering the flat-fishes alone, we find
that the numbers of plaice and lemon-sole taken sank from 29,869 for the
five years 1885-1890, to 28,044 for the five years 1891-1895. On the
other hand, the dab, a comparatively worthless fish, had increased from
19,825 to 29,483.
These figures, it is true, have not been generally accepted as an exact
measure of the changes which took place during the period investigated;
but independent criticism has corroborated their general tendency. It
looks as if protection had been encouraging the wrong sort--a process
not unknown elsewhere. The explanation possibly lies in the facts
adduced by Dr. Fulton that the plaice and lemon-soles spawn only in the
deep water outside the closed areas, where they are subject to
continuous fishing, with the apparent result of a decrease in the number
of eggs and fry inshore; whilst the dabs spawn to a large extent in the
protected waters, and many of them in the offshore waters are able, in
consequence of their small size, to escape through the meshes of the
commercial trawl, even when mature.
Two further experiments, carried out in 1890 and 1901 by the Scottish
Fishery Board and the Marine Biological Association respectively, showed
for the first time that the annual harvest of a given area bears a much
larger proportion to the stock of fish than had been previously
supposed. These were experiments with marked fish, designed originally
to trace their migrations. Out of more than 1,200 plaice liberated in
the Firth of Forth and St. Andrews Bay, more than 10 per cent. were
recovered almost exclusively by hook and line. Owing to these waters
being closed against trawlers, there is reason to believe that the
number actually recaptured by trawl and line together was very much
greater. Again, out of more than 400 marked plaice liberated on the
Torbay fishing-grounds, 27 per cent. of those liberated in the bay, and
35 per cent. of those set free on the offshore grounds, were recaptured
by trawlers.
The evidence derived from statistics has hitherto been, in many
respects, unsatisfactory. In spite of the recommendations of more than
one Royal Commission, nothing was done towards a systematic collection
of fishery statistics until the late Duke of Edinburgh, at a conference
held at the Fisheries Exhibition of 1883, happened to read a paper on
some statistics collected by coastguards as to the quantity and quality
of fish landed. This paper being sent to the Board of Trade, ‘it was
decided to establish a collection of fishery statistics for England and
Wales on the same lines, and generally by the same machinery, as has
been recommended by His Royal Highness.’ Unfortunately, neither the
lines nor the machinery have proved sound. The officials have also been
hampered by want of funds. The Treasury offered £500 (afterwards
increased to £700) a year for statistical purposes--a totally inadequate
sum when distributed as wages among the 157 ‘collectors’ scattered round
our coasts. The duties of these collectors were to send monthly returns
of thirteen different kinds of ‘wet fish’ and three kinds of shellfish,
stating the quantities landed and the market value at the port. They had
no powers to demand information from anyone, or to examine books or
catches or market-and railway-returns; and they were subject to but
little if any supervision.
Not only were these statistics untrustworthy, even as a simple record of
the quantities of fish landed, but they were rendered practically
useless for exact inquiries concerning the decline of the fisheries,
through the neglect of any precautions to discriminate between the
catches in the home waters and those on distant fishing-grounds of a
totally different character. Fish from Iceland, Faröe, and the Bay of
Biscay, as these areas were successively exploited, all went to swell
the totals in the single column of ‘fish landed,’ thus rendering it
quite impossible to determine the state of the fishery on the older
fishing-grounds around our coasts. Taking the statistics as they stand,
however, we find that during 1886-1888 the average quantity of fish
annually landed on the coasts of England and Wales amounted to 6,263,000
cwt., valued at £3,805,000; during 1890-1892, 6,184,000 cwt., valued at
£4,496,000; during 1900-1902, 9,242,000 cwt., valued at £6,543,000.
The average price of fish per cwt. in these periods was consequently
12s. 2d. in 1886-1888, 14s. 6½d. in 1890-1892, and 14s. 3½d. in
1900-1902. The census returns indicate that the population of England
and Wales had risen in the meantime from about 28,000,000 in 1887 to
29,000,000 in 1891, and 32½ millions in 1901. We thus see that the
people were steadily increasing their expenditure on fish, viz., from
2s. 9d. per head in 1887 to 3s. 1d. in 1891, and to 4s. per head in
1901. The quantity consumed amounted to 25 lb. per head in 1887, 23·9
lb. in 1891, and 38·8 lb. in 1901.
To appreciate the significance of these figures it is necessary to bear
in mind that, prior to 1891, the fishing was mostly prosecuted in the
North Sea and in the immediate neighbourhood of our coasts. During this
period the price rose 20 per cent. and the supply fell--facts which
indicate with tolerable certainty that the yield of the older
fishing-grounds had reached its limits, if it was not actually
declining. But in the following decade the conditions were reversed; the
supply increased 50 per cent., and the price fell 3d. per cwt. This was
the period of rapid increase in the number of steam-trawlers, of the
exploitation of new fishing-grounds in distant waters, and of a great
expansion of the herring-fishery.
There was thus no question of a general scarcity of fish. Fishing-boats
were multiplying, and supplies increasing by leaps and bounds. Between
1891 and 1901 the average annual catch of plaice rose from 677,000 cwt.
to 959,000 cwt., that of cod from 367,000 to 748,000 cwt., and that of
herrings from 1,400,000 to 2,800,000 cwt. In the absence of specific
information as to the yield of the older fishing-grounds, Parliament and
the Government turned a deaf ear to the fishermen’s complaints.
But in 1900 it was shown to the Parliamentary Committee on the Sea
Fisheries Bill of that year that, during the past decade, characterized
(as we have seen) by a general fall in the price of fish, the price of
plaice had risen 17 per cent., and that of other valuable flat-fishes
from 3 to 6 per cent. It was also shown that, while the catching power
had multiplied three-fold in ten years, the catch of trawled fish had
only increased 30 per cent. In 1901 the inspectors of fisheries provided
a table contrasting for ten years the annual supply of trawled fish at
Grimsby, Hull, and Boston (which receive the products of the Icelandic
fisheries), with that of other East Coast ports which derive their fish
exclusively from the North Sea. In the former ports the supply had
increased from year to year, while at the other ports the supply during
the years 1895-1900 was in no year so great as in the least productive
of the years 1890-1895. The fishermen’s case was at last made out; and
in 1902 the late Government decided to participate in the investigations
recommended by the Christiania Conference in 1901 for the purpose of
formulating international measures for the improvement of the North Sea
fisheries.
It is satisfactory to turn from the past records of neglect, from the
supineness of the authorities, the imperfections of the statistics, the
inadequate pittance devoted to investigations, to the progress which has
taken place since the Government decided to devote a reasonable
proportion of public funds to the improvement of knowledge on fishery
subjects. The collection of official statistics has been reorganized on
all our coasts on a system which aims at obtaining complete accounts of
the results of each voyage of every first-class fishing-boat; the
catches of trawlers and liners are now distinguished; the quantities of
fish caught in the North Sea are distinguished from those taken beyond
that area; the quantities of large, medium, and small fish are
separately recorded in important cases; the numbers, tonnage, and
landings of different classes of fishing-vessels are separately
enumerated.
It is interesting to note the first results of the more exact system
introduced in 1903. Considering only the fish caught in the North Sea
and landed on the East Coast, we note a marked decline in the total
catch of steam-trawlers during the years 1904, 1905, and 1906, and an
increase in the catch of sailing trawlers. The former declined from 4¾
million cwt. in 1903 to 3¾ million cwt. in 1905; the latter increased
from 277,000 cwt. in 1903 to 296,000 cwt. in 1905. It is shown, however,
that these changes were accompanied by a considerable fall in the amount
of fishing by steam-trawlers and a rise in the case of the sailing
trawlers, so that inferences concerning impoverishment or the reverse
would be premature. Nevertheless a fall in the abundance of haddock may
be inferred from the fact that not only the total catch of this species,
but also the average catch of the boats fell off continuously from 8·4
cwt. per diem in 1903 to 6·1 cwt. per diem in 1905. The fall is also
seen to be mainly due to a scarcity of ‘small’ haddocks in 1904 and 1905
as compared with 1903. With the conclusions to which such data as these
are likely to lead we are not now concerned; but these examples are
sufficient to show that the official statistics are no longer a confused
mass of useless figures, but a rational and fairly accurate system
capable of analysis.
We have now to examine those experimental branches of investigation
which are equally necessary for the effective solution of fishery
problems. The chief possible causes of an impoverishment of the sea are
three in number. First, as in the central United States the accumulated
richness of a virgin soil produced at first huge crops, so, when fishing
began in the North Sea an accumulated wealth, both in the number and in
the greater size of the individual fish, was drawn upon. This
‘accumulated stock’ has been fished out.
Secondly, a given area of the sea, like a given area of land can support
but a limited quantity of produce. There is a definite amount of food
for fish in a definite volume of sea; a limit is therefore set to the
number of fish in that volume of water. Professor Hensen and Professor
Brandt, of Kiel, have shown that a square metre of the Baltic produces
an average of 150 grammes of dry organic material in the shape of
diatoms, copepods, and other floating organisms. A similar area of land
produces 180 grammes of ultimate food-substance. The productivity of the
sea is judged on this basis to be about 20 per cent. less than that of
the land. The actual amount is of less importance than the consequences
it entails. If the methods of fishing are more destructive of one
species than another, comparatively worthless species may become
dominant in areas where they were formerly scarce, and thus consume the
food which should be reserved for their betters. It is commonly reported
that the dab has tended to usurp the position formerly taken by the
plaice, not only in the Scottish firths, but on the Dogger Bank, in the
Devonshire bays, and in other localities. Dr. Garstang, of the Marine
Biological Association, tells us that small plaice transplanted to the
Dogger Bank in 1904 grew three times as much in weight as did their
fellows on the coastal banks; but in the following year they grew only
twice as much, owing to the presence of vast quantities of small
haddocks, which ate the plaice’s food and were nevertheless too small
and worthless themselves to be landed by the fishermen. Yet formerly the
Dogger teemed with large plaice and haddock. It was stated to the Royal
Commission in 1863 that the fishermen avoided the Bank as causing gluts
of fish and depreciation of price; and witnesses from Yarmouth and Hull
assured the Commission that between two and three tons of fish, chiefly
haddock and plaice, were frequently taken by smacks in a three hours’
haul. As small plaice are confined to the coastal banks, and large
plaice are now scarce, it follows that the great food-reserves on the
Dogger Bank, which seem providentially designed for the fattening of
plaice, are wasted on worthless dabs and baby haddocks. Thus may one
cause of impoverishment lead on to another. Perhaps the right remedy in
a case like this is to promote the wholesale transplantation of young
plaice, as in the case of oysters, mussels, etc. The experiments already
made by the Marine Biological Association point strongly in this
direction.
Thirdly, the excessive destruction of young fish is another, and perhaps
the greatest, cause of the impoverishment of the sea. The destruction is
enormous. In the winter of 1882-1883 it was estimated that in the Firth
of Forth, the Firth of Tay, and the Moray Firth, 143,000,000 of young
herrings and a much greater quantity of sprats were captured. These were
mostly sold as manure. Yet the herring does not decrease; it is the
flat-fish, the plaice and the sole, that suffer most. In 1896, 368 tons
of small fish were seized by the Fishmongers Company at Billingsgate; in
1897, 143 tons; and in 1898, 96 tons. These were sold as manure or
destroyed. Mr. Holt estimates that, while over 7,000,000 mature plaice
were landed in the port of Grimsby during the year April, 1893, to
March, 1894, over 9,000,000 plaice not sexually mature were brought to
port; or, taking the trade distinction between ‘small’ and ‘large’ fish,
over 6,500,000 plaice under 13 inches in length were landed, as against
9,700,000 over 13 inches. So many as 10,407 young plaice have been taken
from a single drag of a shrimp trawl. These are but a few instances out
of many, showing the great destruction which is going on among the young
of our more valuable food-fishes.
The questions they suggest are still a matter of discussion. Whether
even this destruction has an appreciable effect on the adult population
is debatable. It does not seem to have affected the herring; and we
must not forget the prodigious number of offspring given to fish. The
taking of immature fish is not in itself uneconomic, unless by that
means we so far reduce the total number that the adult stock begins to
dwindle. Sardines are more valuable than their adult form, the pilchard;
whitebait, mainly composed of young sprats, with from 1 to 20 per cent.
of young herrings, fetch more in the market than the parent form; and so
long as the adults exist in sufficient number to keep up the stock of
fry, sardine and whitebait fishing is perfectly legitimate.
But, assuming impoverishment from one or other or all of the causes
enumerated, we should ask what steps can be taken to check it,
especially as regards the more valuable flat-fish. It is at this stage
that scientific knowledge becomes particularly important. At least nine
out of every ten Acts of restrictive legislation have been shown by
experience to be futile, or to have produced results absolutely
different from those anticipated. It is equally plain that the failure
of these attempts to interfere with the natural course of events has
been largely due to inadequate knowledge of the complicated factors
which affect the growth, multiplication, and distribution of fish, and
of the influence which particular modes of fishing exert upon the
sources of supply.
Let us examine the first-mentioned cause of impoverishment, the
destruction of the ‘accumulated stock.’ This formula has been eagerly
adopted by some who hesitate to admit the existence of any form of
over-fishing. It implies that a state of equilibrium is possible between
the forces of destruction and the forces of repair; that on virgin
territory older individuals tend to accumulate beyond what is necessary
for the maintenance of the ‘current stock’; and that their removal
entails no real injury to the supply. In scientific terms this means
that the average age of mature individuals of a natural stock may be
reduced by man to a lower point which represents the economic optimum.
The Patagonian cannibals seem to have been early converts to the
soundness of this theory. The difference between the Patagonian who eats
his mother-in-law and the fisherman who destroys the overgrown plaice is
that the former’s actions are deliberate and limited, while the removal
of the accumulated stock is not so much an object of the fisherman as an
unpremeditated consequence of the intensity with which fishing
operations tend to be conducted. Does the fisherman abate his operations
when the economic optimum has been reached? Clearly not. He fishes till
it ceases to pay; and no other motive affects him. It is plainly a
question for scientific inquiry whether, in a given case, the fishery
has been prosecuted to excess, and has reduced the average age too far,
or not.
On this question the International North Sea Investigations have already
thrown valuable light, for the study of the intensity of fishing by
means of definite experiments with marked fish has formed an important
part of the programme; and the investigation of the age of plaice, cod,
and other species has been vigorously prosecuted. According to the
latest report of the Council of the Marine Biological Association, more
than 7,000 marked plaice have been set free by their staff, and 24 per
cent. altogether have been recaptured. Of the medium-sized fish which,
furnish the best test of the intensity of fishing, 30 per cent. in
twelve months have been captured in the southern part of the North Sea,
where sailing trawlers predominate, and 40 per cent. on the Dogger Bank
and adjacent grounds, where the fishing is done by steam-trawlers. It
seems, however, that some of the fish lose their labels before being
caught again. A still closer idea of the severity of the fishing may
perhaps be got from another experiment with weighted bottles, which
were specially devised by Mr. G. P. Bidder to act as indicators of
bottom currents, and were thrown overboard from the _Huxley_ in the
winter of 1904-1905, in the southward parts of the North Sea. Out of 600
bottles more than 54 per cent. were returned by trawl fishermen within
twelve months. If anything like half the adolescent stock of plaice is
taken by our trawlers every year on the deep-sea fishing-grounds, the
establishment of the fact must profoundly affect our views as to the
causes of depletion and the remedies to be applied; for the fishing in
these instances seems not to have been on the so-called ‘small-fish’
grounds or nurseries, but in areas which have always been recognized as
legitimate fields of work.
The possibility of determining the age of fish is quite a recent
discovery, and is based on the observation that the scales, vertebræ,
and especially the ‘otoliths’ or ear-stones of fish, show alternate dark
and light rings of growth, corresponding with the summer and winter
seasons of the year, exactly like the rings in the wood of trees. Many
difficult problems are likely to be cleared up by a knowledge of the age
of fish on different fishing-grounds; and, to judge from the scale on
which this investigation is being pursued, it will not be long before we
may expect something in the nature of an age-census. The Council of the
Marine Biological Association have reported no less than 12,000
age-determinations of plaice by their North Sea staff up to June last;
and the German and Dutch investigators are working on similar lines.
To conclude our argument, we should now examine the question whether it
is possible to determine to what extent and in what manner the
destruction of immature fish, which is admittedly enormous, is injurious
to the permanent supply. We have already referred to Mr. Holt’s
statistics, which showed that 40 per cent. of the plaice landed in
Grimsby in the year 1893-1894 were below 13 inches in length. In 1904,
30 per cent. of the plaice landed from the North Sea on the whole East
Coast were below 11 inches in length. German statistics show that from
1895 to 1904 there was no sensible increase in the total weight of
plaice landed in that country, but the proportion of ‘small’ fish (below
14 inches in length) steadily increased from 68 per cent. in 1895 to 87
per cent. in 1904. There can thus be little doubt that the supply is
being maintained only by drawing more and more upon the fish of smaller
size and of less value.
It seems to have been too readily assumed, however, that this increasing
destruction of small plaice is the great cause of the declining catches
of better fish. Has the cart not been put before the horse? In view of
what has been said above concerning the general severity of the fishing,
does it not look as though the capture of increasing quantities of small
plaice were a consequence, and not the cause, of the general depletion
of the grounds? The people demand plaice. The proprietor of a large
fried-fish shop in the East End was a witness before the House of Lords
Committee on the Sea-Fisheries Bill of 1904. His customers numbered from
500 to 3,000 daily; and there were 2,000 other establishments of the
same kind in London. He told the Committee: ‘Plaice is the most popular
fish in our line of business; people do not care for any other.’ Owing
to the higher price of plaice, however, he was often compelled to
substitute cheaper kinds of fish. In one month he had even made five
purchases of small turbot and brill, against only two of plaice, in
order to meet the demand. ‘You must understand,’ he added, ‘that amongst
the class of people we deal with we do not sell turbot and brill as
turbot and brill; we have to sell it as plaice. Plenty of people, if
you said you had turbots, would not have them.’ It is obvious that
fishermen would not land small plaice if large were plentiful. It was
not until the large fish became scarce that fishermen began to take the
small.
If these facts are correctly stated, the remedial treatment of the
undersized-plaice problem must be taken up from a new standpoint. We
must apparently give up the expectation that by merely stopping the
destruction of small plaice we shall replenish the sea. The fishing
seems to be too severe for that. Every autumn our trawlers fish the
waters between the Dogger and the eastern grounds, confident that they
will take a good catch of medium-sized plaice averaging 12 to 15 inches
in length. These are fish which no fisherman in these days would
despise. Though mixed with a considerable proportion of still smaller
fish, no possible size-limit will prevent him from reaping this annual
harvest. These fish, as has now been shown by the North Sea experiments,
are undertaking their first migration from the coastal grounds to the
deeper waters. However much we protect the still smaller fish inshore,
this wall of nets will be interposed every autumn between the shore and
the open sea. The greater the benefits of protection inshore, the denser
will be the barrier confronting the fish outside, and the smaller the
chances of escape.
To this must be added a new disturbing element, mentioned by Dr.
Garstang in his evidence before the House of Lords Committee in 1904. It
is generally agreed that the only possible form which protection can
take is that of a size-limit, below which it shall be illegal to land or
sell fish. In the case of steam-trawlers this limit must be high enough
to render it unprofitable for the boats to fish on grounds where the
small plaice are most abundant, since the majority of undersized fish
are too much injured in the process of capture to be capable of
survival if returned to the sea. It is otherwise with the small local
sailing-boats (whether Danish, German, or Dutch) which are accustomed to
fish on the small-fish grounds. These boats catch the fish alive and
throw the undersized fish overboard in a living condition. As they can
operate nowhere else, it may be taken for granted that the Governments
of their respective countries, however anxious they may be to improve
the fisheries, will scarcely consent to impose such a size-limit as to
render it unprofitable for their local boats to fish.
The utmost possible protection of the small plaice would consequently be
attained by determining (_a_) a high size-limit for steam-trawlers,
practically debarring them from fishing on the coastal grounds; and
(_b_) the highest size-limit for sailing-boats that would be consistent
with the profitable pursuit of their calling. The first pick of the fish
would consequently fall to the local boats; and, if protection should
result, as it is reasonable to expect, in an increase in the number of
plaice on the coastal grounds, there would be every inducement for these
local boats to multiply in number, with the laudable object of catching
as many as possible of the marketable plaice before they could migrate
to the offshore waters. In practice some fish would escape; but, in the
absence of any restriction upon the number of local boats, there seems
no reason to expect that the number of emigrant plaice would, in the
long run, be any greater than at present. Even under existing
conditions, the local fishery on the west coast of Denmark has developed
from a value of about £40,000 in 1897 to nearly £80,000 in 1904.
If, however, we are right in assuming that a given area of ground can
only produce a given weight of fish per annum, it is fairly certain
that, under protection, the increased density of the fish inshore will
result in a retardation in the average rate of growth, an example of
which we have given on a previous page. This must produce one or other
of two results: either the small fish will remain longer on the inshore
grounds before emigration, or they will emigrate offshore at a smaller
size than at present. Judging, therefore, from the evidence available,
it seems probable that legislative restrictions on the lines indicated
can do little to replenish the offshore fishing-grounds, while such
restrictions may lead to a slight, and possibly a substantial, increase
in the number of small boats fishing along the coasts affected.
While Great Britain can grudge no benefit to the fisheries of other
countries, it is the improvement of the deep-sea fisheries which is the
paramount interest of this country. Doubts, it has been said, are
resolved by action; but if we have correctly analyzed the complicated
factors which affect this problem, we have also shown how essential to
right action is the fullest possible knowledge concerning all the
factors involved. Grave as the North Sea problem undoubtedly is, it is
equally certain that the condition of the fishing industry generally was
never more prosperous than at the present time. The figures quoted in an
earlier part of this article prove this statement to be no paradox.
Interference of some kind, whether by legislation, transplantation,
artificial culture, or some combination of all these means, seems
ultimately to be inevitable. But, if we are to interfere with the
fishing industry more successfully than our predecessors, we should take
advantage of the present time of prosperity to increase our knowledge on
every side--scientific, statistical, experimental--so as to be able to
act with conviction when the whole circumstances are clearer and the
adequacy of our proposals is less open to doubt. Moreover, in view of
the growing interest of other countries, especially Germany and Holland,
in deep-sea trawling, and of the international character of the most
critical problems, there can be no two opinions as to the desirability
of continuing these investigations on some kind of international basis,
a basis which has already been productive of very promising results.
Before turning our attention to the various bodies which administer and
investigate the fisheries of England, a short consideration of what is
done in the two great countries which have scientifically developed
their fisheries may be profitable. In Germany we have the Kiel
Commission, and in the United States the Commission of Fish and
Fisheries. The Kiel Commission exists for the scientific investigation
of the German seas. It was established in 1870 at the suggestion of a
German sea-fishery society--an interesting example of the belief which
the German layman has in science. It consists of four Kiel
professors--Hensen representing physiology, Karl Brandt zoology, Reinke
botany, and Krümmel geography--and of Dr. Heincke, director of the
biological station on Heligoland. An annual grant of £7,500 is made by
the German Government for the maintenance of the laboratories at Kiel,
the cost of steamers for investigations, the cost of the handsome
reports published under the name of ‘Wissenschaftliche
Meeresuntersuchungen,’ and for salaries; of these the five members of
the Commission divide but £270 between them. The German Government has
also spent considerable sums on the biological station in Heligoland,
and make it an annual allowance of about £1,000.
The American Commission, like that of Kiel, is not an administrative
body, but concerns itself with the acquisition and application of
knowledge concerning fisheries; like it, too, it is independent of
official control. It reports directly to Congress. It was established in
1871. Its work is, however, of a more practical kind; besides general
scientific investigation, it collects fishery statistics and undertakes
commercial fishery inquiries, assists in finding markets, and generally
advises the trade and the Legislature when diplomatic action is
indicated; finally, it is by far the most energetic fish-breeding
institution in the world. Much of its work is concerned with the vast
system of inland waters--rivers and lakes--which traverse the Continent.
The work has been carried out on a scale unknown elsewhere, and Congress
has supported it with ample funds. The appropriation in 1897-1898
exceeded £97,000, of which £41,000 was spent on salaries, £16,000 on
scientific investigations and upkeep of steamers, £37,000 on
fish-culture (mostly fresh-water), and £3,000 on administration and
statistics. Besides this central body, many of the States possess fish
commissions of their own. The commissioners control numerous
laboratories and fish-hatcheries, two sea-going vessels, and many
railway-cars specially designed for the transport of fish-fry.
Space does not permit our dealing with the Scottish and Irish Fishery
Boards. The former has existed for a century, and, being independent of
departmental control, while enjoying a moderate income and the advice of
such zoologists as Goodsir, Allman, Sir John Murray, Cossar Ewart, W. C.
McIntosh--who has done more than anyone in the Empire to elucidate the
life-histories of marine fishes--and D’Arcy Thompson, together with an
able staff, the Fishery Board for Scotland has done much thorough and
useful work. The fisheries of Ireland suffered from the economic
disturbances which overtook Ireland during the nineteenth century, and
reached, perhaps, their lowest ebb in 1890. The industrial revival, with
which the name of Sir Horace Plunkett is so indissolubly connected, has
included in its scope the Irish fisheries. The fishery branch of the
Department of Agriculture and Technical Instruction receives an annual
grant of £10,000, and, under the guidance of the Rev. S. Green and Mr.
E. W. L. Holt, is already doing much to promote the fishing of the
well-stocked Irish seas.
The English official fishery staff seems to have sprung from the
requirements of the Salmon Fishery Act of 1861. To carry out the
regulations over fresh-water fisheries recommended by that Act two
inspectors were appointed, and these were at first attached to the Home
Office; a further Act in 1886 transferred these inspectors to the Board
of Trade, and extended their duties so as to include the preparation of
annual reports on sea-fisheries. In 1903 another transfer took place;
and the inspectors were transferred to the Board of Agriculture, which
then became the Board of Agriculture and Fisheries.
At present the central staff consists of an assistant secretary and two
inspectors, in addition to a body of statistical experts. Their duties
are far too numerous for so small a staff. Much of their time is taken
up with the comparatively unimportant fresh-water fisheries; and these
are the subject of a separate report. Without actually administering the
byelaws of the local committees, they exercise a certain supervision
over their actions. They have to attend numerous inquiries all over the
country, and to prepare annual reports; and they are responsible for the
collection of the statistics which have recently assumed so extensive a
development. Besides the central authorities at the Board of Agriculture
and Fisheries, there are local fisheries committees established by an
Act of 1888. These committees can be established by the county and
borough councils on application to the Board of Agriculture and
Fisheries, which defines the area over which a committee shall have
jurisdiction. One-half of such a committee is chosen by the local
councils, and one-half by the central authority. The necessary money is
raised by a local rate. A committee may draft byelaws; but these only
become operative if confirmed by the Board. These byelaws differ,
according to conditions, in different parts of England. They deal
largely with restrictions on trawling. No steam-trawler is allowed to
trawl within the three-mile limit around the coast of England; even the
sailing trawler is forbidden. The byelaws also deal with the sizes of
the meshes of nets, shrimping, crabbing, etc.
Neither the central authorities, whose chief function is to administer
the law and collect statistics, nor the local committees, whose
expenditure is limited to the ‘shell-fisheries’--and, stretch the Act to
the breaking point, you still cannot make a flat-fish into a
shellfish--have either the time or the money for scientific experiment.
This has to a large extent been left to local or private enterprise, and
is mainly confined to three centres--the Northumberland coast, the
Lancashire and western district, and the Channel and North Sea. The
first-named area has recently been supplied by a private benefactor with
funds for an efficient laboratory at Cullercoats, from which much useful
work may be expected.
It is difficult to disentangle the Lancashire and Western Sea-fishery
Committee from Liverpool University on the one hand, and from the
Liverpool Marine Biological Committee or Society on the other. The
Committee owns a handsome marine station at Port Erin, on the Isle of
Man; here and at the fish-hatchery at Peel, in Cumberland, the largest
fish-breeding experiments in England are carried out. In 1904, 5,000,000
young plaice were reared and put into the sea from Port Erin alone. The
Committee publishes annual reports and a series of ‘Memoirs.’ It is
probably to this Committee that the University owes its connexion with
the local sea-fisheries authorities. In the laboratories and museums of
the University the scientific work of the local districts is carried on
by officials paid by the Fisheries Committee; and special rooms in the
handsome new zoological department have been assigned to these two
organizations. The connecting link between the three bodies is the
professor of zoology, Dr. Herdman, who is honorary director of the
scientific work, and to whose untiring energy the University and the
district owe a large debt. With him work two trained naturalists, Dr.
Jenkins, the Superintendent of the District Committee, and Mr. James
Johnstone, whose lucid and admirable work is mentioned at the head of
this article. From it many of our figures and facts have been taken.
The third and last body occupied with original marine research is the
Marine Biological Association of the United Kingdom. It is the most
important of these institutions, and aims at a national rather than a
local activity. The fine laboratory which dominates the eastern end of
Plymouth Hoe was erected at a cost of £12,000, and opened in 1888. The
object of the Association is to ‘promote researches leading to the
improvement of zoological and botanical science, and to an increase of
our knowledge as regards the food, life-conditions, and habits of
British food-fishes and molluscs.’ Although a high average of scientific
work has been displayed in the published ‘Memoirs’ connected with the
Plymouth laboratory, great attention has also been paid to matters of
practical interest. In a list of some 350 papers published, with the aid
or under the auspices of the Association, between 1886 and 1900, nearly
one-half deal directly with economic problems. From 1892 to 1895 the
officers of the Association carried on at Grimsby extensive
investigations into the destruction of immature fish; and it is
gratifying to find that the Select Committee of 1893 extended its
recognition to the ‘facts and statistics’ submitted by the Scotch
Fishery Board and by the Association. In the summer of 1902 the
Association, at the request of the Government, undertook to carry out
the English portion of the International Investigation of the North Sea.
The scope of this inquiry is immense; and its importance to the largest
fisheries available for our fishermen is incalculable. Some idea of the
kind of work accomplished has been furnished in the preceding pages.
What now seems to be most required, in addition to the maintenance of
the work already in progress, is a closer co-operation of these various
bodies with one another and with the central authority now established
under the President of the Board of Agriculture and Fisheries. The
outlines of some such scheme seem plainly indicated by the existing
constitution of these various bodies. The Fisheries Department is
responsible for administration, statistics, and general advice to the
President of the Board on fishery matters. The Marine Biological
Association undertakes general marine investigations of a national as
distinct from a local character, as well as such local investigations
and experiments as can conveniently be carried out at its laboratories.
The Sea-fishery Committees need additional powers to enable them to
carry out local scientific investigations more fully in their respective
areas. Perhaps an annual conference between the representatives and
experts of these bodies and the officials of the Fishery Department, for
the express purpose of drawing up plans of work for the ensuing year,
would, in the first instance, be the best means of leading up to more
intimate co-operation and organization.
The Reports on the North Sea Investigation so far published deal only
with the work of the earlier years of the investigations; but already
the great prospective value of the results is fully apparent. The Marine
Biological Association has carried out the portion of the general scheme
entrusted to it with energy and success; and Englishmen have no need to
fear comparison with the work done in other countries.
ZEBRAS, HORSES, AND HYBRIDS
_This matchless horse
Is the true pearl of every caravan._
SIR F. H. DOYLE.
The views and writings of Darwin have influenced in an unexpected way
the nature of the work carried on by biological investigators during the
past fifty years. To a great extent, whilst generally holding the
doctrines he held, they have forsaken his methods of inquiry.
If animals and plants have arrived at their present state by descent
with modification from simpler forms, it ought to be possible by careful
searching to trace the line of ancestry; and it is this fascinating but
frequently futile pursuit which has dominated the minds of many of our
ablest zoologists for the last thirty years. To such an extent has this
pedigree-hunting been carried that there is scarcely a group of
invertebrates from which the vertebrates have not been theoretically
derived; and one of the ablest of our physiologists has used his great
powers in the attempt to trace the origin of the backboned animals from
a spider-like creature, and has exercised his ingenuity in a plausible
but unconvincing effort to equate the organs of a king-crab with those
of a lamprey. This appeal to comparative anatomy and the consequent
neglect of living animals and their habits are no doubt partly due to
the influence of Huxley, Darwin’s most brilliant follower and exponent.
He had the engineer’s way of looking at the world, and his influence
was paramount in many schools. The trend which biology has taken since
Darwin’s time is also partly due to a fervent belief in the
recapitulation theory, according to which an animal in developing from
the egg passes through phases which resemble certain stages in the past
history of the ancestors of the animals. For example, there is no doubt
that both birds and mammals are descended from some fish-like animal
that lived in the water and breathed by gills borne on slits in the
gullet, and every bird and mammal passes through a stage in which these
gill-slits are present, though their function is lost, and they soon
close up and disappear. In the hope, which has been but partially
realized, that a knowledge of the stages through which an animal passes
on its path from the ovum to the adult would throw light on the origin
of the race, the attention of zoologists has been largely concentrated
on details of embryology, and a mass of facts has already been
accumulated which threatens to overwhelm the worker.
The two chief factors which play a part in the origin of species are
heredity and variation, and until we know more about the laws which
govern these factors, we cannot hope to arrive at any satisfactory
criteria by which we can estimate the importance of the data accumulated
for us by comparative anatomists and embryologists. Signs are not
wanting that this view is beginning to be appreciated. The publication
of ‘Materials for the Study of Variation’ by Mr. Bateson some years ago
shows that there exists a small but active school of workers in this
field; and recent congresses on hybridization give evidence that in
America, on the Continent, and in Great Britain, one of the most
important sides of heredity is being minutely and extensively explored.
Professor Cossar Ewart’s experiments, which we shall attempt to
summarize, deal with heredity and cognate matters, and although they
are so far from complete that the results hitherto obtained cannot be
regarded as final, they mark an important stage in the history of the
subject.
Twelve years ago Professor Ewart began to collect materials for the
study of the embryology of the horse, about which, owing to the
costliness of the necessary investigations, very little is at present
known. At the same time he determined to inquire into certain theories
of heredity which have for centuries influenced the breeders of horses
and cattle, and the belief in which has played a large part in the
production of our more highly bred domestic animals. Foremost amongst
these is the view widely held amongst breeders that a sire influences
all the later progeny of a dam which has once produced a foal to him.
This belief in the ‘infection of the germ,’ or ‘throwing-back’ to a
previous sire, is probably an old one, possibly as old as the similar
faith in maternal impressions which led Jacob to placed peeled wands
before the cattle and sheep of his father-in-law Laban. The phenomenon
has recently been endowed with a new name--Telegony. Since the
publication of Lord Morton’s letter to Dr. W. H. Wollaston, President of
the Royal Society, in 1820, it has attracted the attention, not only of
practical breeders, but of theoretical men of science. The supporters of
telegony, when pressed by opponents, having almost always fallen back on
Lord Morton’s mare, it will be well to recall the chief incidents in the
history of this classic animal.
It appears that early in last century Lord Morton was desirous of
domesticating the quagga. He succeeded in obtaining a male, but, failing
to procure a female, he put him to a young chestnut mare of
seven-eighths Arab blood which had never been bred from before. The
result was the production of a female hybrid apparently intermediate in
character between the sire and the dam. A short time afterwards Lord
Morton sold his mare to Sir Gore Ouseley, who bred from her by a fine
black Arabian horse. The offspring of this union, examined by Lord
Morton, were a two-year-old filly and a year-old colt. He describes them
as having
‘the character of the Arabian breed as decidedly as can be expected
where fifteen-sixteenths of the blood are Arabian, and they are
fine specimens of that breed; but both in their colour and in the
hair of their manes they have a striking resemblance to the
quagga.’
The description of the stripes visible on their coats is careful and
circumstantial, but the evidence of the nature of the mane is less
convincing:
‘Both their manes are black; that of the filly is short, stiff, and
stands upright, and Sir Gore Ouseley’s stud-groom alleged that it
never was otherwise. That of the colt is long, but so stiff as to
arch upwards and to hang clear of the sides of the neck, in which
circumstance it resembles that of the hybrid.
This is the classical--we might almost say the test--case of telegony:
the offspring resembled not so much the sire as an earlier mate of the
dam. The facts related tended to confirm the popular view, and that view
is now widely spread. Arab breeders act on the belief, and it is so
strongly implanted in the minds of certain English breeders that they
make a point of mating their mares first with stallions having a good
pedigree, so that their subsequent progeny may benefit by his influence,
even though poorly-bred sires are subsequently resorted to.
The evidence of Lord Morton’s mare convinced Darwin of the existence of
telegony. After a careful review of the case, he says: ‘There can be no
doubt that the quagga affected the character of the offspring
subsequently got by the black Arabian horse.’ Darwin, however, latterly
came to the conclusion that telegony only occurred rarely, and some
years before his death expressed the opinion that it was ‘a very
occasional phenomenon.’ Agassiz believed in telegony. He was strongly of
opinion
‘that the act of fecundation is not an act which is limited in its
effect, but that it is an act which affects the whole system, the
sexual system especially; and in the sexual system the ovary to be
impregnated hereafter is so modified by the first act that later
impregnations do not efface that first impression.
Romanes also believed that telegony occasionally occurred. He paid a
good deal of attention to the matter, commenced experiments in the hope
of settling the question, and corresponded at length on this subject
with professional and amateur breeders and fanciers. The result of his
investigations led him to the conclusion ‘that the phenomenon is of much
less frequent occurrence than is generally supposed. Indeed, it is so
rare that I doubt whether it takes place in more than 1 or 2 per cent.
of cases.’ He adds that his professional correspondents regard this as
an absurdly low estimate. Tegetmeier and Sutherland believe that
telegony exists in dogs and other animals; and Captain Hayes, whose
opinion probably coincides with that of the majority of veterinary
surgeons, takes for granted that it occurs in horses. A controversy some
years ago in the _Contemporary Review_ shows us that Mr. Herbert Spencer
was a firm upholder of telegony, and that he had a theory of his own as
to the mode in which it is brought about.
The explanations put forward by the supporters of telegony as to the
mechanism by which it is effected differ widely. It will be well to
discuss them here. The view that telegony is due to the mental
impression of the dam, held by Sir Everard Home and many others since
his day, has nothing to support it; but the other two views, which may
be termed (1) the infection hypothesis, and (2) the saturation
hypothesis, demand more detailed treatment.
The infection hypothesis supposes that the reproductive organs of the
mother are specifically altered or infected by bearing offspring to a
previous sire. The method by which this is effected is now most commonly
thought to be by a fusion or blending of some of the unused germ-cells
of the first sire with the unripe ova in the ovary of the dam.
Physiologists, however, regard this as very unlikely. Although at the
time that the ovum of a mare is fertilized there are usually other ova
almost mature, or approaching maturity, these disappear during
gestation. Subsequent offspring arise from successive crops of ova, into
whose composition it is most improbable that the earlier spermatozoa
could enter. Further, it is known that in the Equidæ the male germinal
cells do not live long within the body of the female; they are already
disintegrating eight days after insemination, and they probably lose
their fertilizing power after three or four days, if not sooner; hence
it is not possible for them to remain in the body during the whole of a
period of gestation and to fertilize the next succeeding batch of ova.
The second theory which attempts to account for the phenomenon of
telegony is termed the saturation hypothesis. In the words of Mr. Bruce
Lowe, who has formulated the theory, we may say that, ‘briefly put, it
means that with each mating and bearing the dam absorbs some of the
nature or actual circulation of the yet unborn foal, until she
eventually becomes saturated with the sire’s nature or blood, as the
case may be.’ Although not very well expressed, it is obvious what the
author means; and if this saturation really takes place, it accounts for
a good deal more than telegony. It would affect the whole body and
nature of the dam, and not only the reproductive organs, which,
according to Romanes and others, are alone influenced. There is no doubt
that matter can and does pass from the blood of the embryo into that of
the mother--in certain classes of mammalia, at any rate. The published
Report of the Fourth International Congress of Zoology, which met in
1898 at Cambridge, contains a paper by Professor Hubrecht, of Utrecht,
in which he describes certain blood-corpuscles formed in the embryo
which undoubtedly make their way into the maternal bloodvessels and take
part in her circulation. That matter can pass from the bloodvessels of
the embryo to those of the mother is further demonstrated by the
experiments of M. Charrin, who showed that diphtheritic toxins injected
into the embryos of a rabbit caused the death of the mother within five
days, and further that a rabbit can be rendered immune by injecting
anti-diphtheritic toxins into the embryos.
There is nothing in these experiments to show that the nature of the dam
is radically altered; and in the Equidæ, in which, as we have seen, the
classical case of telegony occurred, there is a strong presumption
against any such transference of blood-corpuscles from the embryo to the
mother. Still, taking all the facts into consideration, it appears that,
if telegony exists, it is more likely to be brought about by saturation
than by the direct infection of the ovary; though, if the former method
be accepted, telegony must be confined to the mammals and the
comparatively few other animals whose young spend some time in the body
of the mother and are not hatched out from eggs which have lost their
connexion with the body of the mother at an early stage.
Before passing on to consider the views of those who hold that telegony
does not exist and to see what light the Penycuik experiments throw on
the subject, a word or two may be said about Mr. Herbert Spencer’s
theory of the mode in which telegony, in which he firmly believed, is
brought about. He suggested that some ‘germ-plasm’ passes from the
embryo into the mother and becomes a permanent part of her body, and
that this is diffused throughout her whole structure until it affects,
amongst other organs, the reproductive glands. This view, which in some
respects recalls the pangenesis of Darwin, is intermediate between the
saturation and the infection hypotheses. Professor Ewart refers to it as
‘indirect infection.’
Weismann, to whom we owe the term telegony, came to consider the facts
for and against its existence in connexion with his well-known inquiry
into the inheritance of acquired characters. If telegony be true, there
is no need to look further for a clear case of the inheritance of a
character which has been acquired during the lifetime of the parent. The
quagga-ness--if one may be permitted to use such an expression--of Lord
Morton’s mare was acquired when she was put to the quagga or shortly
afterwards, and was transmitted to her foals. A clearer case of a
character acquired during lifetime and transmitted to offspring could
not be imagined. Weismann does not absolutely deny the possibility of
the existence of telegony, but he would like more evidence. In the
_Contemporary Review_ he writes: ‘I must say that to this day, and in
spite of the additional cases brought forward by Spencer and Romanes, I
do not consider that telegony has been proved.’ And further: ‘I should
accept a case like that of Lord Morton’s mare as satisfactory evidence
if it were quite certainly beyond doubt. But that is by no means the
case, as Settegast has abundantly proved.’ He would, in fact, refer the
case to reversion, and quotes Settegast to the effect that every
horse-breeder is well aware that the cases are not rare when colts are
born with stripes which recall the markings of a quagga or zebra. We
shall return to this point later.
A considerable number of German breeders support the contention of
Weismann that telegony is as yet unproven, and it may be pointed out
that in Germany, on the whole, breeders have had a more scientific
education than in England, and that in that country science is regarded
with less aversion or contempt than is usually the case among so-called
practical men in England. Settegast has been quoted above: neither he
nor Nathusius, a leading authority on domestic cattle, has ever met with
a case of telegony, and the same is true of Professor Kühn, the late
Director of the Prussian Agricultural Station at Halle. We may mention
one more case of an experienced breeder who was equally sceptical--the
late Sir Everett Millais, who was, as is well known, an authority of
great weight in the matter of dog-breeding. He writes as follows, in a
lecture entitled ‘Two Problems of Reproduction’:
‘I may further adduce the fact that in a breeding experience of
nearly thirty years’ standing, during which I have made all sorts
of experiments with pure-bred dams and wild sires, and returned
them afterwards to pure sires of their own breeds, I have never
seen a case of telegony, nor has my breeding-stock suffered. I may
further adduce the fact that I have made over fifty experiments for
Professor Romanes to induce a case of telegony in a variety of
animals--dogs, ducks, hens, pigeons, etc.--but I have hopelessly
failed, as has every single experimenter who has tried to produce
the phenomenon.’
It is thus evident that there was a considerable body of opinion, both
practical and theoretical, for and against telegony; and that a
re-investigation of the subject was urgently needed. Such a
re-investigation has been begun by Professor Ewart at Penycuik. Since
the clearest and most definite evidence of this throwing back to a
previous sire is derived from the crossing of different species of the
Equidæ, it was desirable to repeat the experiment of Lord Morton. This
is now unfortunately impossible, because the quagga is extinct. The
zebra is, however, still with us, and the mating of a zebra stallion
with every variety of horse, pony, and ass, and subsequently putting the
dam to pure-bred sires, has been the more important part of the numerous
experiments carried on in the Midlothian village some ten miles
southwest of Edinburgh.
Before considering in detail the result of the experiments it will be
necessary to say a few words on the question of the various species of
zebra; and since, like Weismann, Professor Ewart explains certain of the
phenomena attributed to telegony by reversion, it will be as well to
inquire how far reversion is known amongst the Equidæ, and what evidence
we have that the ancestor of the horse was striped.
Matopo, the zebra stallion from which Professor Ewart had, some eight
years ago, bred eleven zebra-hybrids from mares of various breeds and
sizes, belongs to the widely distributed group of Burchell’s zebras.
Many sub-species or varieties are included in this group, which, as
regards the pattern of the stripes, passes--in certain varieties found
in Nyassaland--into the second species, the mountain zebra, once common
in South Africa. The third species is the Grévy’s zebra of Shoa and
Somaliland; it is probably this species which attracted so much
attention in the Roman amphitheatres during the third century of our
era. A pair of Somali zebras were presented to the late Queen some years
ago by the Emperor Menelik, and for a time were lodged in the Zoological
Gardens, Regent’s Park. This species measures about fifteen hands high,
is profusely striped, and stands well apart from the other two groups.
It is important to note that in Professor Ewart’s opinion it is the
most primitive of all the existing striped horses.
There is no direct evidence that the ancestors of horses were striped.
Certain observers think that some of the scratches on the life-like
etchings on bone, left us by our palæolithic cave-dwelling ancestors,
indicate such stripes; but little reliance can be placed on this. On the
other hand there is much indirect evidence. Every one who has an eye for
a horse, and who has travelled in Norway, is sure to have noticed the
stripings, often quite conspicuous, on the dun-coloured Norwegian
ponies. Colonel Poole assured Darwin that the Kathiawar horses had
frequently ‘stripes on the cheeks and sides of the nose.’ Breeders are
well aware that foals are often born with stripes, usually on the
shoulders or legs, less frequently on the face. Such stripes as a rule
disappear as the colt grows up, but can often be detected in later life
for a short time after the coat has been shed; they are sometimes only
visible in certain lights, and then produce somewhat the same impression
as a watered silk. From the facts that more or less striped horses are
found all over the Old World; that in Mexico and other parts of America
the descendants of horses which were introduced by the Spaniards and
which afterwards ran wild are frequently dun-coloured and show stripes;
that foals are frequently striped; and that mules not uncommonly have
leg and shoulder stripes, the inference is largely justified that the
ancestors of all our horses were striped.
The hypothesis of reversion has recently been called in question, and no
doubt the term has been much abused. Animals and plants have been said
to revert to some remote ancestor when they have varied in some
particular, and this variation has then been described as a primitive
character possessed by the ancestor; thus there has been much arguing
in and about a vicious circle. But the fact that a term has been
illogically applied does not destroy the existence of that which the
term signifies, and there can be no doubt that reversion exists. That it
exists in the Equidæ is shown by the following proofs: (1) The ancestors
of the horse had four premolar teeth in the upper jaw; the modern horse
has lost, or is losing, the first of these, and as a rule has only
three. When the first is present--the so-called wolf-tooth--it is small,
and soon disappears. Zebras usually retain the ancestral number. A few
years ago Professor Ewart had a Shetland pony in which the first
premolar was relatively nearly as large as it is in hipparion, one of
the supposed ancestors of the horse. (2) There is no doubt that the
horse is descended through three-toed ancestors from five-toed
ancestors. All trace of the latter condition is now lost in development,
but an embryo horse six weeks old has three toes as completely formed as
those of a rhinoceros. The outer toes then begin to dwindle, and the
newly-born foal supports itself on its central digit alone; but horses
are occasionally born with two digits, each encased in a hoof, and at
very rare intervals with three. Cæsar’s favourite horse was
polydactylous, and so was Alexander’s Bucephalus. Major Waddell, in his
book on the Himalayas, refers to a creamy fawn-coloured pony, which ‘had
a black stripe down the spine ... broad black stripes over the
shoulders, flanks, and legs, and dappled spots over the haunches.’ Many
other instances might be quoted, but enough has been said to show that
reversion is found in the Equidæ, as in other families of animals.
We now pass to the experiments made at Penycuik in crossing the zebra
Matopo with various mares of different breeds.
1. Matopo was first mated with Mulatto, one of Lord
[Illustration: MATOPO.
_To face page 84._]
Arthur Cecil’s black West Highland ponies. The result was the hybrid
Romulus, which on the whole, both in mental disposition and bodily form,
took more after his father than his mother. His striping was even more
marked than that of his sire. He had a semi-erect mane, which was shed
annually. The pattern of the markings, on both body and face, resemble
the stripes on a Somali zebra--which, as we have seen, is regarded by
Professor Ewart as the most primitive type--more than they resembled
that of any of Burchell’s zebras. The profuse striping is a point of
difference between this hybrid and Lord Morton’s. The quagga-hybrid was
less striped than many dun-coloured horses (see illustration).
The mother Mulatto was next mated with a highly-bred grey Arab horse,
Benazrek. The offspring agreed in all respects with ordinary foals; it
had, however, a certain number of indistinct stripes which could only be
detected in certain lights. The stripes were not nearly so clear as in a
foal bred by Mr. Darwin from a cross-bred bay mare and a thoroughbred
horse, and they disappeared entirely in about five months.
Mulatto has produced a third foal to Loch Corrie, a sire belonging to
the Isle of Rum group of West Highland ponies, and closely resembling
its mate. This foal was about as much striped as its immediate
predecessor. In both cases the pattern of the stripe differed not only
from that of Matopo, the previous sire, but from that of the hybrid
Romulus. These two foals seem to lend some support to telegony; but the
evidence which might be drawn from the second of them is destroyed by
the fact that the sire, Loch Corrie, has produced foals from two West
Highland mares, one brown and one black, and each of these foals has as
many and as well-marked stripes as the foal of Mulatto.
2. Four attempts were made to cross the zebra with Shetland ponies: only
one succeeded. The hybrid was a smaller edition of Romulus. The dam Nora
had been bred from before, and had produced by a black Shetland pony a
foal of a dun colour which was markedly striped. After the birth of the
hybrid she was put to a bay Welsh pony; the resulting foal had only the
faintest indication of stripes, which soon disappeared. It is a
remarkable fact that Nora’s foals were more striped before she had been
mated with the zebra than afterwards.
3. Five Iceland ponies were mated with Matopo, of whom one produced, in
1897, a dark-coloured hybrid. The dam, Tundra, was a yellow and white
skewbald, which had previously produced a light bay foal to a stallion
of its own breed. Her third foal (1898) was fathered by a bay Shetland
pony, and in coloration closely resembled its dam. There was no hint of
infection in this case. In 1899 Professor Ewart bred from this mare, by
Matopo, a zebra-hybrid of a creamy fawn colour, and so primitive in its
markings that he believes it to stand in much the same relation to
horses, zebras, and asses as the blue-rock does to the various breeds of
pigeons (see illustration).
4. Two Irish mares, both bays, produced hybrids by Matopo, and
subsequently bore pure-bred foals. One of the latter was by a
thoroughbred horse, the other by a hackney pony. The foals were without
stripes, and showed no kind of indication that their mother had ever
been mated with a zebra.
5. Although Professor Ewart experimented with seven English thoroughbred
mares and an Arab, he only succeeded in one case. The mare produced twin
hybrids, one of which, unfortunately, died immediately after birth. In
the summer of 1899 the same mare produced a foal to a thoroughbred
chestnut; ‘neither
[Illustration: TUNDRA (AN ICELAND PONY), HER FOAL, CIRCUS GIRL (BORN
1898), AND HER HYBRID-FOAL, SIR JOHN (BY MATOPO), WHEN A MONTH OLD (BORN
1899).
_To face page 86._]
in make, colour, nor action’ does it in any way resemble a zebra or a
zebra-hybrid.
6. A bay mare which had been in foal to Matopo for some months
miscarried. Here--if there is anything in the direct infection
theory--the unused germ-cells of the zebra had a better chance than
usual of reaching the ova from which future offspring are to arise, yet
neither of the two foals which this mare subsequently produced to a
thoroughbred horse ‘in any way suggests a zebra.’
The above is the record of the successful experiments which have been
tried at Penycuik, with a view of throwing light on the existence of
telegony in the Equidæ. Experiments have also been made with other
animals, such as rabbits, dogs, pigeons, fowls, and ducks. Space allows
us to quote but one. Six white doe rabbits, all of which had borne pure
white offspring to white bucks, were crossed with wild brown rabbits.
The result was forty-two young rabbits, all of a bluish-black colour,
which in a very short time turned to a brown. These, at the time of
writing, were about half grown, and Professor Ewart tells us that it was
almost impossible to distinguish them from a full-blooded wild rabbit
kept in the same enclosure. The half-breeds, however, were tamer and
slightly lighter in colour. The mother does next bred with white bucks
again, and in every case bred true. The pure white young showed no trace
of throwing back to a previous sire.
A phenomenon somewhat similar to telegony, and one which seems at
present quite unexplained, is that a hen which has been crossed with a
cock of another breed often lays eggs whose shell is no longer like that
of its own breed, but in colour, and frequently in texture, resembles
that of the breed with which it has been crossed. Mr. Bulman has
recorded a case of this in the pages of ‘Natural Science.’ Some
Orpington fowls which laid eggs of a buff tint were allowed to run
loose in a large yard with fowls of various breeds. After a few months
they were confined in separate pens again, and for several weeks
afterwards they continued to lay white eggs. There seems to be no doubt
of the existence of this curious phenomenon; it is mentioned by Gadow in
his volume on ‘Birds,’ in Bronn’s ‘Thierreich,’ by Nathusius in the
_Journal für Ornithologie_, and in Newton’s ‘Dictionary of Birds.’ When
one calls to mind that the shell is deposited by a special shell-gland
which is in no way connected with the ovary, but is a part of the quite
distinct oviduct, and that the change in the colour of the eggshell must
be caused by some change brought about in this gland by
cross-fertilization, we begin to recognize how mysterious and
inexplicable are many of the problems which affect breeding.
Throughout his account of his experiments Professor Ewart is extremely
cautious in claiming to prove anything, but we think he has justified
his claim to have shown that telegony by no means always occurs, as many
breeders believe. His experiments so far support the view of Continental
mule-breeders that telegony, if it takes place, occurs very seldom. But
the experiments are not complete, and it is much to be hoped that they
may be continued. If it should subsequently appear that out of fifty
pure-bred foals from dams which have been previously mated with the
zebra no single instance of telegony be found, the doctrine may surely
be neglected by breeders; and if in the experiments which are now being
carried out with various other mammals and birds telegony does not
occur, the doctrine may be relegated to what the Americans would term
the ‘dumping-ground’ of old superstitions. The present state of the
matter may be summed up in the Professor’s own words: ‘The experiments,
as far as they have gone, afford no evidence in support of the telegony
hypothesis.’ Nothing has occurred which is not explicable on the theory
of reversion.
Partly owing to a certain doubt or distrust which has recently been
expressed as to the existence of reversion, and no doubt partly because
it is reasonable to hold that the phenomena of telegony may all be
referred to reversion, Professor Ewart has made some direct experiments
on this subject. Darwin, Tegetmeier, and many others have made numerous
breeding experiments on pigeons, with the result that we may say that
the crossing of extreme forms usually tends to reversion in the
offspring. The ancestor of the domestic pigeon is known with tolerable
certainty to have been the blue-rock pigeon, _Columba livia_. By
crossing a male barb-fantail and a female barb-spot Darwin produced a
bird ‘which was hardly distinguishable from the wild Shetland species’
of blue-rock. In his description of this experiment, Darwin, as Weismann
points out, confines himself chiefly to the coloration: he does not
inquire how far reversion also appears in the structure of the bird.
This question has been answered by one of Professor Ewart’s many
experiments with pigeons. He crossed a white fantail cock with the
offspring of an owl and an archangel. The fantail was pure white, with
thirty feathers in its tail, and was so prepotent as to produce white
offspring when mated with blue pouters. The owl-archangel was more of an
owl than an archangel. One of the young of this complex pair had the
coloration of the Shetland rock pigeon, which has a white croup and the
wings in front of the bars a uniform blue; the other resembled the
Indian rock pigeon in having a blue croup and the front part of the
wings chequered. In this second bird there was complete reversion as to
colour, and in the first, wherever measurements were possible, there
was practically complete reversion also as to form. ‘In its
measurements it is relatively almost identical with a typical Shetland
blue-rock.’ The tail feathers are twelve in number, and show but the
faintest indications of any colour-inheritance from their immediate
parents. An additional point of interest is that in disposition this
bird seems wilder and more shy than the domesticated breeds usually are.
It is vigorous and hardy, and is much admired by the fanciers.
Another bird whose wild ancestor is known with a high degree of
certainty is the barn-door fowl. It has sprung from the jungle fowl,
_Gallus bankiva_, and less remotely from the game fowl. Hence, if fowls
of different breeds are crossed, the offspring, should reversion occur,
ought to resemble either the jungle fowl or their less remote ancestors,
the game fowl. A dark red-breasted bantam was crossed with an Indian
game Dorking; of the nine chickens which resulted, six resembled
Dorkings, and three in both form and colour resembled game birds. Two of
the three grew up, and the only visible trace of their parentage was a
double comb inherited from their cross-bred father. Here again the
reversion does not stop at the colour and form, but extends to
disposition; the birds are very shy, and fly about like wild birds. The
above are but two instances out of many which might be quoted from the
Penycuik experiments; they are, however, unusually clear cases, and
should do something to restore confidence amongst recent doubters of
reversion.
An animal is said to be prepotent when it strongly impresses its own
peculiarities of form, colour, temperament, etc., on its offspring. In
the above-mentioned experiment with pigeons the owl had been prepotent
over the archangel in the mother of the offspring which showed such
marked reversion. There is no factor in breeding of more importance
than prepotency, and none which it is more difficult to estimate. The
term is necessarily a relative one, and, further, it may affect some
characters and not others. Often it must go undetected, as in the case
of the leader of a herd of wild cattle, who may be highly prepotent, but
whose prepotency, unless he is mated with members of another herd
displaying different characters, may pass unnoticed. Breeders claim to
be able to produce cattle so prepotent that they will produce their like
however mated. A well-known dealer in highly-bred ponies used to boast
that he had a filly so prepotent that, though she were sent to the best
Clydesdale stallion in Scotland, she would throw a colt showing no
cart-horse blood. Prepotency is usually obtained by inbreeding, which up
to a certain point fixes the character of a race, and in all cases tends
to check variation and reversion--the Jews, for instance, as a race are
strongly prepotent--but there is no doubt that it may also arise as a
sport, and this is probably its more usual origin in a state of nature.
Professor Ewart, however, believes that inbreeding is much commoner
among wild animals than has usually been conceded, and he holds the
opinion that the prepotency so induced has played a considerable part in
the origin of species. This, if true, would to some extent take the
place of Romanes’ ‘physiological selection’; for Romanes also thought
that, though of great importance, variation and natural selection were
insufficient to account for the origin of species without some factor
which would help to mitigate the swamping effect of intercrossing--some
such agency as the fences of modern farms and cattle-ranches--without
which the famous cattle breeds of the world would soon disappear in a
general ‘regression towards mediocrity.’
In inbreeding the great difficulty of the breeder is to know when to
stop. Carried too far it undoubtedly leads to degeneracy. In the
‘Domesticated Animals of Great Britain,’ Lowe records the case of a
gentleman who inbred foxhounds to such an extent that ‘the race actually
became monstrous and perished.’ Hogs, if too closely inbred, grow hair
instead of bristles; their legs become short and unable to support the
body; and not only is their fertility diminished, but the mothers cannot
nourish the young. That infertility is induced by inbreeding is further
shown by some experiments of Ritzema Bos with rats. From seven rats of
one family and an unrelated male he continued inbreeding for a period of
some six years, and bred about thirty generations. The average of the
numbers in each litter fell from 7½ in 1887 to 4-7/12 in 1891 and 3⅕ in
1892. Further, the offspring of inbred parents are usually weak. Sir
Everett Millais estimated that 60 to 70 per cent. of inbred dogs
attacked by distemper were carried off.
On the other hand, inbreeding often succeeds even when carried to what
the ordinary man would consider excess. The ‘Herd-book’ contains the
following case in point. The bull Bolingbroke and the cow Phœnix were
more closely related to one another than half-brother is to half-sister.
They were mated, and produced the bull Favourite. Favourite was then
coupled with his dam, and produced the cow Young Phœnix; he was then
coupled with his daughter Young Phœnix, and the world-famed Comet was
the result. Professor Ewart tells us that if there was little crossing
in the production of Comet, there was still less in that of Clarissa,
the mother of the celebrated Restless. An instance of the faith in close
inbreeding which exists in the minds of breeders occurred in a letter
which the _Field_ published in 1898, in which the writer stated he had
heard ‘Mr. Joseph Osborne, the ablest authority living on English
[Illustration: ROMULUS.]
[Illustration: MATOPO.
_To face page 92._]
thoroughbreds, declare that you cannot now get too much of Birdcatcher.’
So far as is known, no direct investigations have been made to test how
far inbreeding may be carried in the Equidæ; but, on the other hand, the
breeding of racehorses may perhaps be looked upon as a gigantic
experiment in this direction. Our English thoroughbreds can be traced
back to a few imported sires--the Byerly Turk, imported in 1689; the
Darley Arabian, in 1710; and the Godolphin Arabian, in 1730. Since then,
by careful breeding and nutrition, they have increased on an average
some 8 or 9 inches in height. There is, however, a widely-spread
impression that at present there is a marked deterioration in the
staying power and in the general ‘fitness’ of the racer. The falling off
is further shown by a fact commented on by Sir Walter Gilbey--viz., ‘the
smallness of the percentage of even tolerably successful horses out of a
prodigious number bred at an enormous outlay.’ In support of this he
quotes a sentence from the _Times_ (December 27, 1897), referring to a
sale in which thirty-two yearlings had been sold for 51,250 guineas.
‘These thirty-two yearlings’ (said the _Times_) ‘are represented by
two winners of five races, Florio Rubattino and La Reine, who have
contributed about £2,000 to the total cost; and there is not, so
far as can be known, a single one of the thirty others with any
prospect of making a racehorse.’
If, then, it is true that the English racehorse is on the down grade,
what steps should be taken to arrest this descent? Sir Everett Millais
restored a pack of basset hounds by crossing them with a bloodhound, the
original forefather of bassets. The resulting pups were bassets in form,
but not quite bassets in colour; when, however, these cross-breeds were
mated with bassets the majority of the pups turned out to be perfect
bassets both in shape and coloration. This indicates that one way to
rejuvenate the racehorse would be to have recourse to a new importation
of the best Arab mares that the plains of Arabia can produce. Breeders
hesitate to adopt this course, because their present breed is not only
larger, but, over very short distances, fleeter than its forefathers.
The shortening of the course in recent years is probably a further sign
of the degeneracy of our present racers. Were new blood introduced, and
more three-or four-mile races instituted, we should doubtless soon have
a return to the champion form of bygone days. Another method would be to
import some of the racers of Australia or New Zealand, and cross them
with the home product. Different surroundings, food, etc., soon
influence the constitution, and this being so, it would be advisable to
select those horses of pure descent which have been longest subjected to
these altered conditions. Thus the chance of reversion occurring would
be increased.
It has been noticed more than once in the preceding pages that a young
animal showing reversion is strong and vigorous. It is the belief of
dog-breeders that those members of an inbred litter which show reversion
are the strongest and best. Similarly, experience shows that if an
inbred sire and dam produce a dun-coloured striped foal it almost always
turns out well. Reversion is accompanied by a rejuvenescence; it is as
though the young animal had appeared at an earlier period in the
life-history of the race, before the race had undergone those changes in
the way of deterioration which so often accompany inbreeding.
Wild animals are frequently thought to be prepotent over tame ones, but
of the eleven zebra-hybrids bred at Penycuik only two took markedly
after their sire, the zebra Matopo.[2] There are other experiments
recounted which tell the other way, and at present this matter remains
in a state of considerable uncertainty. Further experiment may probably
show that though in most cases the oldest type is likely to prevail, the
offspring may take after the most inbred of its parents. The matter is
not altogether as simple as the above statements would imply. For
instance, a sport is often strongly prepotent. Standfuss’s experiments
in hybridizing butterflies tend to show this, and Mr. Galton even looks
upon prepotency as a sport or an aberrant variation. These butterfly
experiments also indicate that the male is usually prepotent over the
female; but so many questions of nutrition, the maturity of the
germ-cells, etc., enter into these intricate problems that it is
exceedingly difficult to disentangle the several factors which play a
part in the constitution of every living being.
Some years ago it used to be taught that species are infertile _inter
se_; nowadays it almost seems that we are giving up the idea of species
altogether. No two naturalists take precisely the same view of what
constitutes a species, and no one has succeeded in defining shortly and
clearly what a species is. The intersterility test has broken down; the
common goose and the Chinese goose, the common duck and the pintail
duck, various species of pheasant, the ox of Europe and the American
bison or the Indian zebu, not only breed together, but yield hybrids
which are themselves fertile; and the same is true of many plants. Why
the hybrids of Equidæ should prove sterile is not clear.
This article must not close without a word or two more about the
zebra-hybrids. It is mentioned above that only two out of the eleven
which have already been born took strongly after their father. This is
no proof that the wilder animal is not prepotent. Recent experiments in
hybridizing echinoderms, star-fish, seaurchins, etc., show that the
hybrid tends to resemble that species whose germ-cells are most nearly
approaching maturity; and thus the nutrition of the germ-cell is but
another thread in that complex tangle of heredity which must not be
overlooked in attempting to estimate the part played by prepotency and
reversion.
Those who have seen the young hybrids playing about in the fields at
Penycuik must agree that they are the most charming and compactly built
little animals possible; ‘_marvellous steeds, striped as a melon is, all
black and white_,’ as the poet has it. Of Romulus, the eldest of the
herd, Professor Ewart says:
‘When a few days old [he] was the most attractive little creature I
have ever seen. He seemed to combine all the grace and beauty of an
antelope and a well-bred Arab foal.... What has struck me from the
first has been his alertness and the expedition with which he
escapes from suspicious or unfamiliar objects. When quite young, if
caught napping in the paddock, the facility with which he, as it
were, rolled on to his feet and darted off was wonderful.’
The writer can fully confirm all the praise Professor Ewart lavishes on
his pets; in truth Romulus has been well described as a ‘bonnie colt
with rare quality of bone ... and with the dainty step and dignity of
the zebra.’ Remus, the offspring of the Irish mare, was from the first
more friendly than his half-brother; he objected less to the process of
weaning, and promised to be the handsomest and fleetest of the existing
hybrids.
On the whole the hybrids are unusually hardy; at the time of writing
only two have been lost--one, a twin, which died almost as soon as it
was born, and
[Illustration: ROMULUS.
_To face page 96._]
another which lived some three months and then succumbed. It is only
fair to say that the dam of the latter, who was only three years old
when the hybrid was born, had been much weakened by attacks of the
strongylus worm, and that she was the victim of close inbreeding. Both
the zebras and the hybrids which have been under observation at Penycuik
show a remarkable capacity for recovering from wounds. Accidental
injuries heal with great rapidity. On one occasion the surviving twin
was discovered with a flap of skin some five inches long hanging down
over the front of the left fetlock. The skin was stitched into its place
again, during which operation the little hybrid fought desperately, and
cried piteously; but it soon recovered, the wound healed, and now
scarcely a scar remains. There was no lameness and no swelling either at
the fetlock or above the knee. Some time ago four hybrid colts and three
ordinary foals were attacked by that scourge of the stable, the
strongylus worm. One of the latter died and another was reduced almost
to a skeleton: the hybrids, though obviously affected, suffered much
less than the others, and soon recovered. It is further noticeable that
the hybrids suffer less from colds and other slight ailments than the
mares and horses amongst which they live. Thus it seems that Colonel
Lugard’s hope has to some extent proved true. Some years ago, when
administering British East Africa, he strongly recommended the breeding
of zebra mules from both the horse and the donkey, believing that they
would prove exceptionally hardy and possibly impervious to the tsetse
fly. So far as Professor’s Ewart’s experiments go, the first part of the
forecast has proved correct. Unfortunately, the latter half has not been
justified.
The much dreaded tsetse fly, which has interfered so seriously with the
colonization of whole tracts of South Africa, is now known not to be
the direct cause of the disease which follows its puncture, but to be
the means by which the organism which causes the disease is introduced
into the body. In this respect the tsetse fly resembles the malarial
mosquito. It is not thought that the organism--a hæmatozoon--passes
through any of the stages of its life-history within the body of the
fly, but that the proboscis of that insect merely acts like an
inoculating needle. An answer to the important question, Are
zebra-hybrids fly-proof or not? has been attempted. Professor Ewart
generously allowed an experiment to be tried on two of his hybrids,
which were inoculated with the hæmatozoon, supplied from the
Pathological Laboratory at Cambridge. The result was unfortunate, for,
although the hybrids resisted the disease far longer than a mare which
was also inoculated as a control experiment, both ultimately succumbed.
There is no doubt that it is a comparatively easy matter to breed these
hybrids, and that they are not only extremely attractive animals to the
eye, but hardy and vigorous, possessed of great staying powers, and
promising to be capable of severe work. It is recognized that one of the
gravest difficulties which the Indian Army Corps has to contend with is
the paucity of mules, both for transport and mountain-battery work; and
at the time of the South African War a Commission was busily employed
purchasing mules both in Italy and in Texas, and elsewhere. Should these
hybrids turn out as well as they at present promise, they may fill a
want which is acutely felt by those responsible for the conduct of our
frequent ‘small wars,’ and, if bred largely in East Africa, may, as
Colonel Lugard suggested, prove a source of wealth and revenue in the
future.
We have hitherto said little or nothing about the book itself with which
we have been dealing. The larger part consists of three articles
reprinted from the _Veterinarian_ and one from the _Zoologist_; but the
more recent and more important half is the General Introduction,
covering a hundred pages, in which Professor Ewart sums up the results
of his experiments. The form of the work necessarily involves a good
deal of repetition, but in so complex a subject this is on the whole
rather an advantage than otherwise. Professor Ewart’s style is clear,
and his pages abound in apposite illustrations. The book cannot fail to
attract both the man of science and the practical breeder.
From what we have said it is evident that the Penycuik experiments are
of the highest interest both practical and theoretical, and the public
spirit and self-devotion shown by the Edinburgh professor in carrying
them out cannot be too widely recognized. The expense of feeding and
housing some thirty to forty horses, asses, and zebras is very great,
and the initial expenditure in erecting stables, buying land and fencing
it, is also considerable. It is, perhaps, not too much to hope that some
public body may be willing to undertake at least a part of the burden.
The Zoological Society of London possesses, not only the necessary
establishment required, including a well-trained staff, but it also has
facilities for obtaining all kinds of animals which are far greater than
those of any private individual. We hope that the day is not far distant
when experiments of this kind will be systematically carried on under
the direction of the authorities who control the Gardens in Regent’s
Park. Probably such experiments would have better prospects of success
at a farm in the country than in London, and there is much to be said
for such an experimental farm under the management of a body like the
Zoological Society. Apart from the more strictly scientific use to which
it might be put, it would serve as a convenient sanatorium for those
animals which cannot stand the fogs and damp of London.
PASTEUR
_Je suis chimiste, je fais des expériences et je tâche de comprendre ce
qu’elles disent._--PASTEUR.
As one walks down the Rue des Tanneurs, in the small provincial town of
Dôle, where the main line from Paris to Pontarlier sends off a branch
north-east towards Besançon, a small tablet set in the _façade_ of a
humble dwelling catches the eye. It bears the following inscription in
gilt letters: ‘Ici est né Louis Pasteur le 27 décembre 1822.’
Pasteur came of the people. In the heraldic meaning of the term, he was
emphatically not ‘born.’ His forbears were shepherds, peasants, tillers
of the earth, millers, and latterly, tanners. But he came from amongst
the best peasantry in Europe, that peasantry which is still the backbone
of the great French nation. The admirable care with which records are
preserved in France has enabled Pasteur’s son-in-law and latest
biographer to trace the family name in the parish archives back to the
beginning of the seventeenth century, at which period numerous Pasteurs
were living in the villages round about the Priory of Mouthe, ‘en pleine
Franche-Comté.’
The first to emerge clearly from the confused cluster of possible
ancestors is a certain Denis Pasteur, who became miller to the Comte
d’Udressier, after whom he doubtless named his son Claude, born in 1683.
Claude in his turn became a miller, and died in the year 1746. Of his
eight children, the youngest, Claude-Étienne, was the great-grandfather
of Louis Pasteur. The inhabitants of Franche-Comté were, in large part,
serfs--‘gens de mainmorte,’ as they termed them then. Claude-Étienne,
being a serf, at the age of thirty wished to enfranchise himself; and
this he did in 1763, by the special grace of ‘Messire
Philippe-Marie-Francois, Comte d’Udressier, Seigneur d’Ecleux, Cramans,
Lemuy, et autres lieux,’ and on the payment of four _louis-d’or_. He
subsequently married and had children. His third son, Jean-Henri, who
for a time carried on his father’s trade of tanner at Besançon, seems to
have disappeared at the age of twenty-seven, leaving a small boy,
Jean-Joseph Pasteur, born in 1791, who was brought up by his grandmother
and his father’s sister.
Caught in the close meshes of Napoleon’s conscription, Jean-Joseph
served in the Spanish campaign of 1812-1813 as a private in the third
regiment of infantry, called ‘le brave parmi les braves.’ In course of
time he was promoted to be sergeant-major, and in March, 1814, received
the Cross of the Legion of Honour. Two months later the abdication had
taken place; and the regiment was at Douai, re-organizing under the name
of ‘Régiment Dauphin.’ Here was no place for Jean-Joseph, devoted to the
Imperial Eagle and unmoved by the Fleur-de-lys. He received his
discharge, and made his way across country to his father’s town,
Besançon. At Besançon he took up his father’s trade and became a tanner;
and, after one feverish flush during the Hundred Days, and one contest,
in which he came off victor, with the Royalist authorities, who would
take his sword to arm the town police, he settled down into a quiet,
law-abiding citizen, more occupied with domestic anxieties than with the
fate of empires.
Hard by the tannery ran a stream, called La Furieuse, though it rarely
justified its name. Across the stream dwelt a gardener named Roqui;
amongst the gardener’s daughters one Jeanne-Étiennette attracted the
attention of, and was attracted by, this old campaigner of twenty-five
years. The curious persistence of a family in one place, combined with
the careful preservation of parish records, enables M. Vallery-Radot to
trace the family Roqui back to the year 1555. We must content ourselves
with Jeanne-Étiennette, who in 1815 married Jean-Joseph. Shortly
afterwards the young couple moved to Dôle and set up house in the Rue
des Tanneurs.
Louis Pasteur’s father was a somewhat slow, reflective man; a little
melancholic, not communicative; a man who lived an inner life, nourished
doubtless on the memories of the part he had played on a larger stage
than a tannery affords. His mother, on the other hand, was active in
business matters, hard-working, a woman of imagination, prompt in
enthusiasm.
Before Louis Pasteur was two years old, his parents moved first to
Marnoz and then to a tannery situated at the entrance to the village of
Arbois; and it was Arbois that Pasteur regarded as his home, returning
in later life year after year for the scanty absence from his laboratory
that he annually allowed himself. Trained at the village school, he
repeated with his father every evening the task of the day. He showed
considerable talent, and his eagerness to learn was fostered by the
interest taken in him by M. Romanet, principal of the College of Arbois.
At sixteen he had exhausted the educational resources of the village;
and, after much heart-searching and anxious deliberation, it was decided
to send the young student to Paris to continue his studies at the Lycée
Saint-Louis. It was a disastrous experiment. Removed so far from all he
knew and loved, Louis suffered from an incurable home-sickness, which
affected his health. His father hearing this, came unannounced to
Paris, and with the simple words, ‘Je viens te chercher,’ took him home.
Here for a time he amused himself by sketching the portraits of
neighbours and relatives, but his desire to learn was unquenched, and
within a short time he entered as a student at the Royal College of
Franche-Comté at Besançon. This picturesque town, situated only thirty
miles from Arbois, was within easy reach of his home; and, above all, on
market days his father came thither to sell his leather.
At eighteen Pasteur received the degree of Bachelier ès Lettres, and
almost immediately was occupied in teaching others; but Paris, although
once abandoned, was again asserting its powers of attraction, and by the
autumn of 1842 he was once more following the courses at the Lycée
Saint-Louis. He also attended the brilliant lectures of Dumas at the
Sorbonne, and vividly describes the scene: ‘An audience of seven or
eight hundred listeners, the too frequent applause, everything just like
a theatre.’ At the end of his first year in Paris he achieved his great
ambition, and succeeded in entering the École Normale, and entering it
with credit.
For the last year or two Pasteur had been studying mathematics and
physics; at the École Normale he especially devoted himself to
chemistry. Under the teaching of Dumas and of Balard his enthusiasm
redoubled, and he passed his final examinations with distinction. Balard
was indeed a true friend. Shortly after the end of his career at the
École Normale, the Minister of Public Instruction nominated Pasteur to a
small post as teacher of physics at the Lycée of Tournon. But banishment
from Paris meant banishment from a laboratory. Balard intervened,
interviewed the Minister, and ended by attaching Pasteur to his staff of
assistants.
It must always be remembered that Pasteur was trained as a
chemist--_was_, in fact, a chemist. In afterlife he attacked problems
proper to the biologist, the physiologist, the physician, the
manufacturer; but he brought to bear on these problems, not the
intellect of one trained in the traditions of natural science, medicine,
or commerce, but the untrammelled intelligence of a richly-endowed mind,
‘organized common sense’ of the highest order. After the legal, there
is, perhaps, no learned profession so dominated by tradition, by what
our fathers have taught us, as the medical; and the advances in
preventive medicine which will ever be connected with Pasteur’s name owe
at least something to the fact that he was unfettered by any traditions
of professional training or etiquette. Passing from the diseases of the
lowest of the fungi to those of a caterpillar, a fowl, a sheep, until he
reached those of man himself, it must be acknowledged that he approached
the art of healing along an entirely new path.
His first researches were purely chemical--‘On the Capacity for
Saturation of Arsenious Acid,’ ‘Studies on the Arsenates of Potassium,
Soda, and Ammonia’--but he had been early attracted to the remarkable
observations of Mitscherlich and others on the optical properties of the
crystals of tartaric acid and its salts. Ordinary tartaric acid
crystals, when dissolved in water, turn the plane of polarized light to
the right; but another kind of tartaric acid, called by Gay-Lussac
racemic acid, and by Berzelius paratartaric acid--as M. Vallery-Radot
remarks, the name does not matter, and each is equally terrifying to the
lay mind--leaves it unaffected. In spite of the different actions of the
solutions of these two acids on light, Mitscherlich held their chemical
composition to be absolutely identical.
This set Pasteur thinking. He repeated the experiments. On examining
the crystals of sodium-ammonium salt of racemic acid, he noticed that
certain facets giving a degree of asymmetry were always found on the
crystals of the optically active salts and acids. On examining the
crystals of the racemic acid, he did not find, as he had expected,
perfect symmetry; but he saw that, whilst some of the crystals showed
these facets to the right, others showed them to the left. In fact,
sodium-ammonium racemate consisted of a mixture of right-handed and
left-handed crystals, which neutralized one another as regards the
polarization of light, and were thus optically inactive. With infinite
patience Pasteur picked out the right from the left handed crystals, and
investigated the action of their solutions on polarized light. As he
expected, the one sort turned the plane of polarization to the left, the
other to the right. A mixture of equal weights of the two kinds of
crystals remained optically inactive. ‘Tout est trouvé!’ he exclaimed;
and rushing from the laboratory, embraced the first man he came across.
‘C’était un peu comme Archimède,’ as his biographer gravely remarks.
His work immediately attracted attention. Biot, who had devoted a long
and strenuous life to the problems of polarization, was at first
sceptical, but, after a careful investigation, was convinced. Pasteur
began to be talked about in the circle of the Institute.
In the midst of these researches Pasteur’s mother died suddenly, and her
son, overwhelmed with grief, remained for weeks almost silent and unable
to work. Shortly after this we find the old longing revived, and Pasteur
sought at any cost some post near Arbois, somewhere not quite out of the
reach of those he loved. Besançon was refused him, but at the beginning
of 1849 he replaced M. Persoz as Professor of Chemistry at Strasbourg.
The newly-appointed Rector of the Academy of Strasbourg, M. Laurent,
had already gained the respect and the affection of the professoriate.
He and his family were the centre of the intellectual life of the town.
Within a few weeks of his arrival Pasteur addressed to the Rector a
letter, setting forth in simple detail his worldly position, and asking
the hand of his daughter Marie in marriage. The wedding took place on
May 29, 1850, and there is a tradition that Pasteur, immersed in some
chemical experiment, had to be fetched from the laboratory to take his
part in the ceremony at the church. Never was a union more happy. From
the first Madame Pasteur, animated by the spirit of the Academy of
Science, which always prints ‘Science’ with a capital letter, not only
admitted, but approved the principle that nothing should interfere with
the laboratory; whilst, on his side, Pasteur always flew to his wife to
confide in her first of all any new discovery, any new advance he had
made in his researches. During the five years passed at Strasbourg
Pasteur continued to work on the borderline between chemistry and
physics. His work on the polarization of light of the tartaric acid
crystals led him into the question of the arrangement of the atoms
within the molecule. ‘Il éclaire tout ce qu’il touche!’ exclaimed the
once sceptical but now convinced Biot; and it is hardly too much to say
that his researches were the starting-point of the new department of
physics which, under the name of stereo-chemistry, has attained vast
developments during the last quarter of the past century. These
researches were rewarded by the French Government, which in 1853
conferred on him the ribbon of the Legion of Honour, and received the
recognition of our own Royal Society, which rewarded him in 1856 the
Rumford medal.
It was whilst working at his beloved tartrates that he made an
observation which first directed his attention towards the problems of
fermentation. A German firm of manufacturing chemists, of whom there
were many in the neighbourhood of Strasbourg, noticed that impure
commercial tartrates of lime, when in contact with organic matter,
fermented if the weather were warm. Pasteur tested this, and found that,
when racemic acid is fermented under ordinary conditions, it is only the
right-handed variety that is affected; and he suggests that this is
probably the best way in which to prepare the left-handed acid.
Before dealing with Pasteur’s work on fermentation it is well to recall
how the matter stood when he began to study it. From the earliest period
fermentation had attracted the attention of mankind, but the first
record of an attempted explanation is that of Basilius Valentinus, a
Benedictine monk and alchemist, who lived at Erfurt during the latter
half of the fifteenth century. He was, perhaps, more of a pharmacologist
than a chemist, but we owe to him the introduction of hydrochloric acid,
which he made from oil of vitriol and salt. In his view alcohol existed
in the wort before fermentation began, and fermentation was a process of
purification of this alcohol, in which the yeast played the part of the
impurities. About a century later van Helmont, a well-to-do physician of
Vilvorde, near Brussels, a kind of regenerate Paracelsus, noted that
when fermentation occurs ‘gas’ is set free. It was van Helmont, indeed,
who invented the word ‘gas.’ Of the half-dozen words invented by
man--not derived, but created--‘gas’ is the one which has most surely
come to stay. Curiously enough, van Helmont’s predecessor, Paracelsus,
also invented two words which have, without the permanency of ‘gas,’
passed into current, though somewhat infrequent, use. They are ‘gnome’
and ‘sylph,’ the latter, perhaps, best known as recalling the outline of
Miss Henrietta Petowker in her palmier days. By his new term ‘gas’ van
Helmont did not mean an air or vapour, still less did he mean an
illuminant. He understood by this term carbon dioxide, and he points out
that when sugary solutions ferment, this gas is given off.
About 1700 Stahl, returning to a view put forward by Willis in 1659,
propounded the first physical view of fermentation. The ferment was to
their minds a body with a certain internal motion which it transmitted
to the fermentable matter. Stahl extended this view to the processes of
putrefaction and decay. One hundred years later Gay-Lussac taught that
the fermentation was set up by the presence of oxygen. The yeast-cells
had been seen and described by Leeuwenhoek as far back as 1675, but they
seem to have attracted little attention; and it was not until Schwann
published his researches, the earliest of which is dated 1837, and until
Cagniard de Latour, about the same date, put forward his vitalistic
theory--the theory which attributes fermentation to the action of living
organisms--that they were recognized as playing an important part in
fermentations. Even then they were not allowed to hold the field. Liebig
brought the weight of his great authority to oppose the vitalistic
theory. In his view the ferment was an unstable organic compound easily
decomposed, which in decomposing shook apart the molecules of the
fermenting material. This theory and that of Berzelius, who regarded
fermentation as a contact action due to some ‘catalytic’ force, divided
between them the allegiance of the chemical world, when, in the year
1854, Pasteur was nominated Professor and Dean of the new Faculty of
Science at Lille.
Here, in the centre of the beetroot industry, Pasteur had ample
opportunity to study the preparation of alcohol. The father of one of
his students owned a distillery, and suffered occasional loss from the
fermentations turning sour owing to the formation of lactic acid. He
was willing to place material at the disposal of the Professor; and
Pasteur made endless experiments, microscopic researches, notes, and at
length had the satisfaction of isolating the organism which produces the
lactic acid fermentation, and of proving that that, and that alone, was
capable of setting up this particular form of fermentation. Whilst in
the middle of his investigations on milk and the cause of its turning
sour, Pasteur was summoned to return to Paris, and installed as
scientific Director at his old college, the École Normale.
This was in 1857. The second Empire was at its zenith, and the
Government had little money to spend on science. Pasteur had to install
his laboratory in a garret, without even a boy to aid him. In this
garret he completed his work on alcohol fermentation, proved it to be
‘un acte corrélatif d’un phénomène vital, d’une organisation de
globules.’ During this work he noted a fact hitherto overlooked. It was
that the alcoholic fermentation is accompanied by the formation of small
quantities of glycerine and of succinic acid, which had up till that
date escaped the notice of chemists.
During the seven years which followed, Pasteur was ceaselessly engaged
in investigations on fermentation and on all those processes for which
micro-organisms are responsible. Whilst researching on the cause of
butyric acid formation, he discovered the remarkable fact that the
_Bacillus butyricus_, which causes the unpleasant flavour in rancid
butter, will not grow in the presence of free oxygen. Until this
discovery it had been accepted as an axiom that all living beings,
plants as well as animals, require free oxygen for the manifestation of
their energies. Here, however, was a bacillus which not only did without
oxygen but was injured by its presence. This observation, it is needless
to remark, excited much adverse criticism in the scientific world; but,
as usual, Pasteur was in the right. From the conditions under which they
grow he suggested the name ‘anaerobic’ for such bacteria as _B.
butyricus_; and later observers have shown that many pathogenic
micro-organisms are anaerobic. At the present day bacilli are usually
divided into two groups, those which grow in the presence of free oxygen
(aerobic), and those which will not grow in the presence of oxygen
(anaerobic).
Naturally the question of spontaneous generation occupied much of
Pasteur’s time. The view, that in certain circumstances living matter
originates from non-living, lasted from the classical times until
towards the end of the last century. The size of the animal so produced
varied, however, inversely with the growth of our era. Van Helmont in
the seventeenth century had a recipe for producing mice. Place a piece
of linen somewhat soiled in a vessel, add some grains of corn, flavour
with a piece of cheese, and in twenty-one days the mice will be there,
fully adult and of both sexes.
About the time that van Helmont died there was coming to the front in
Florence a young Italian poet, born at Arezzo--in whose cathedral he now
lies buried--who had a singular turn for investigating the secret
workings of organic nature. Francesco Redi--his name is immortalized in
the little larva Redia--was courtier, poet, doctor, above all zoologist;
and he belonged to that comparatively small section of teetotallers who
have enthusiastically sung the merits of wine.[3] By a series of
accurate experiments, such as nowadays are performed by every cook,
Redi proved conclusively that meat did not spontaneously produce flies.
Shortly afterwards Vallisnieri of Padua demonstrated that fruit did not
of itself give rise to grubs. In fact, unless an insect deposited its
egg in the fruit, there were no grubs.
The use of the microscope, however, lent a fresh vigour to the believers
in spontaneous generation; and, forced to relinquish the mouse and the
insect, they still found satisfaction in germs. In the middle of the
eighteenth century the doctrine was firmly upheld by an English priest,
one Needham, whose experiments, in spite of the keen, and as we now
know, unanswerable criticisms of the Abbé Spallanzani, were so
convincing that he was early elected a Fellow of the Royal Society. From
his time till late in the last century, the question of the spontaneous
origin of microscopic life has from time to time troubled the mind of
man. Pasteur, Tyndall, and others have at length laid that ghost. It
would take too much space to discuss all the experiments made to solve
this question. Pasteur’s work did not escape the liveliest criticism;
and eventually, in order to settle the matter, he appealed to the
Academy of Sciences to appoint a Commission to report on the experiments
of himself and his opponents. It is needless to say that when the
Committee met and inspected the experiments of Pasteur, and listened to
the excuses of his critics, they pronounced absolutely in favour of
Pasteur.
In 1862 Pasteur succeeded Senarmont as a member of the Academy of
Sciences; and, it is interesting to note, he was presented by the
mineralogical section. During this year he had interested himself in the
manufacture of vinegar, which is extensively carried on in and around
Orleans. He investigated the action of the _Mycoderma aceti_, the mould
whose activity converts alcohol into acetic acid; and he taught the
manufacturers the importance of pure cultures, showing them how, by a
careful manipulation of the temperature, and by artificially sowing the
fungus which effects the chemical change, the product they sought could
be produced in a week or ten days, instead of requiring two or three
months. This problem naturally led on to the acetous fermentation of
wine, the cause of great loss to French wine exporters. Pasteur was able
to demonstrate that the sourness of wine is caused by various foreign
organisms, each of which causes a peculiar flavour to appear in the wine
it attacks. The bouquet of wine is notoriously a delicate object, easily
disturbed; and the question arose how to check the growth of the
organisms without interfering with the bouquet. Pasteur solved it as he
solved similar problems with regard to milk. He was able to show that
after wine is properly oxygenated, if it be heated to a temperature of
some 55° to 60° C. the acid-forming micro-organisms are destroyed,
whilst the bouquet is unaffected. Perhaps one of Pasteur’s greatest
triumphs was his success in demonstrating this to a representative
assemblage of wine-tasters, notoriously a very opinionative class of
people.
Pasteur’s researches on micro-organisms further had a profound influence
on operative surgery. To the presence of bacteria is due many of the
dangers which used to follow on operations. If precautions are taken to
exclude the harmful germs much suffering and danger are avoided. It was
about this date--namely, in the spring of 1865--that Dr. (now Lord)
Lister, who nobly acknowledged the debt he owed to Pasteur, performed
his first operations under antiseptic treatment at the Glasgow
Infirmary. This date marks an epoch in the history of human suffering.
The chemist Dumas was about this time a member of the French Senate,
and in 1865 was charged with the duty of reporting on the petition of
some 3,500 ‘propriétaires des Départements séricicoles’ on an epidemic
which had for some years been destroying the silkworms of Southern
France. Dumas was a native of Alais, a town of the Département Gard,
situated in the centre of the silkworm industry, where also the
distinguished zoologist Quatrefages was born. Anything that affected
Alais affected Dumas; and the epidemic was destroying the prosperity of
his native town. The disease was indeed becoming serious. Already in
1849 the silkworms were sickening. The stage at which the symptoms
appeared varied--sometimes the eggs were sterile; at other times the
silkworms hatched out but to die. If they survived they became shiny;
black spots showed themselves; the worms moved with difficulty, refused
to eat, and perished; or, if they lived long enough to pupate, the pupa
either perished or the moth emerged in an enfeebled state and promptly
died.
Efforts had been made to improve the stock by importing eggs from Spain
and Portugal, but the Peninsula was soon affected. Eggs were then
fetched from Turkey, Greece, and the adjacent islands. These countries
too becoming infected, the French cultivators sent further afield and
brought eggs from Syria and the Caucasus. Even this resource failed
them, and in 1864 every silk-producing country in the world was
infected, with the solitary exception of Japan. The loss to commerce was
prodigious. In a normal year the value of the cocoons produced in
Southern France is, roughly speaking, about £4,000,000; in the years
1863 and 1864 it had fallen below £1,000,000.
When Dumas first asked Pasteur to investigate the disease which was
ruining large tracts of the South of France, the latter not unnaturally
hesitated. ‘Considérez, je vous prie, que je n’ai jamais touché un ver
à soie. Si j’avais une partie de vos connaissances sur le sujet, je
n’hésiterais pas,’ he wrote to his friend; but in spite of his
hesitation, he left for Alais, and at once commenced a campaign which
lasted during the summers of the next five years. Almost immediately on
his arrival he detected in the sick silkworms the corpuscles of Cornalia
and Filippi, which we now call the _Micrococcus ovatus_. These
micrococci are comparatively large and very bright; they occur in the
tissues and blood of the silkworm, and are found even in the eggs of the
moth. They cause the disease known as Pébrine. The occurrence of the
micrococci in the eggs was one of the most important new facts observed
by Pasteur. It was the first recorded instance of a parasitic organism
being conveyed from one generation to another by the egg; and, although
recently the germ of the Texas fever (allied to the malarial organism)
has been shown to pass from one brood to another through the egg of the
tick which conveys it, it is satisfactory to record that the cases in
which this occurs are restricted in number and comparatively rare. The
ease with which _Micrococcus ovatus_ could be detected suggested a
remedy. A child, when trained, can readily identify the organism.
Healthy moths produce sound eggs and healthy larvæ; diseased moths
produce diseased progeny. At the present day, throughout the silkworm
districts of the South of France, as soon as the moth has deposited her
eggs on the piece of linen provided for that purpose, she is pinned up
with the cloth; and during the ensuing autumn and winter the women and
children are occupied in microscopically examining the body of the moth,
crushed in a little water, for traces of the micrococcus. Should any be
found, the eggs on the corresponding piece of linen are at once
destroyed. Pasteur also showed that the infected stock spread the
disease by distributing the micrococci on the mulberry-leaves, whence
they enter the silkworm by the mouth; and that the sick inoculate the
healthy by crawling over them and piercing the skin with their pointed
claws. He therefore emphasized the importance of segregating the sound
caterpillars.
The above account conveys no impression of the difficulties under which
Pasteur worked. His researches were not only new to himself but to the
world. Processes which at the present day are carried out by every
medical student had to be devised for the first time. He had to combat
the criticism of scientific men, and to overcome the almost invincible
ignorance of the agriculturist, an ignorance which at one time advocated
the desperate remedy of asperging with absinthe the leaves of the
mulberry on which the silkworms fed.
Perhaps Pasteur’s greatest difficulty was the fact that the silkworms
did not suffer from Pébrine alone; and it was some time before he
recognized that he had to deal, not with one disease, but with two. The
second disease, known as the ‘Flacherie,’ is a disease of the digestive
system caused by overcrowding and insanitary conditions in the silkworm
nurseries. Like Pébrine, it is caused by a micrococcus, _Micrococcus
bombycis_. It was whilst investigating this creature that Pasteur
discovered that, although the germ itself cannot survive a lengthy
period of desiccation, it does in certain circumstances form spores
which can survive conditions fatal to the mature organism. This is the
first case recorded of a pathogenic organism producing spores, the
existence of which has explained so many problems in the spread of
disease.
During the period from 1865 to 1870 Pasteur was by no means occupied
solely by the silkworm epidemic. In many respects it was a sad epoch in
his life. Only nine days after his first arrival at Alais he was
summoned to Arbois to see his dying father, but arrived too late. In
the autumn of the same year he lost his little daughter Camille, the
second who had died. In 1868 he himself was prostrated by a stroke of
paralysis, and, although he slowly recovered, it left traces for the
remainder of his life.
Few distinguished men of science are left to pursue their investigations
undisturbed; and Pasteur was no exception. He had much to do with
promoting the publication of the works of Lavoisier, for whose
researches he had the profoundest respect. He actively intervened in the
elections of the Academy of Science, which appears to consume an
infinity of time. He made some preliminary investigations into cholera,
an outbreak of which towards the end of the year 1865 carried off 200
victims a day in Paris. He spent a week at Compiègne as the guest of
Louis Napoleon, and in a series of _séances_ explained the methods and
results of his labours. He wrote on the work of Claude Bernard; he drew
up schemes for certain reforms in the University; he gave advice on the
higher education of the country, and tried to stem the troubles of the
École Normale. In fact, he drew lavishly upon his reserve of health and
energy until the breakdown of 1868 was inevitable.
After a tedious recovery he recommenced his work. The success of his
methods had been acknowledged by the Austrian Government, who conferred
on him in 1868 the prize of 5,000 florins offered to anyone who should
succeed in discovering the best means of dealing with Pébrine. The same
year the University of Bonn conferred on him the honorary degree of
Doctor of Medicine; and in 1869 he was elected a foreign member of the
Royal Society. As was to be expected, detractors were not wanting: but
these were silenced by the campaign undertaken in 1869 by Pasteur on
foreign soil. The Master of the Imperial Household, Marshal Vaillant,
who devoted his declining years to scientific experiments, had repeated
in his apartments in the Tuileries the observations of Pasteur on the
silkworm disease, and had verified the accuracy of his conclusions. He
suggested to the Emperor that the Villa Vicentina, a property belonging
to the Prince Imperial, should be placed at Pasteur’s disposal for
further research. This villa, situated a few miles from Trieste,
belonged at one time to the Princess Élise, one of the sisters of
Napoleon I., who had lived quietly there after the fall of the First
Empire. On her death it passed to her daughter, the Princess Baciocchi,
and she in turn bequeathed it to the Prince Imperial. It had been a
great centre of the silkworm industry; but for some years no cocoons had
been produced, owing to the ravages of the disease.
By short stages, owing to his precarious health, Pasteur made his way to
Illyria, taking with him some sound silk-moth eggs, and during the
winter not only confirmed his previous researches, but re-established
the industry on such a scale that in the following spring the sale of
cocoons from this estate alone reached the figure of 26,940 francs.
During this winter he dictated to his wife the classic book in which he
recorded the results of his last five years’ work. Pasteur returned to
Paris through Munich, where he had the pleasure of meeting Liebig, one
of the most determined of his adversaries. Although he was unable to
induce the German savant to discuss scientific affairs, he always dwelt
with pleasure on the courtesy and cordiality with which he was received.
On his return the Emperor nominated him a Senator for life; but, before
the gazette appeared in which the nomination would have been recorded,
war was declared. From his birth Pasteur had been an ardent patriot, and
during the progress of the war he suffered acutely. So much did he feel
the reverses of his country, and what he regarded as the undue
harshness of the victors, that he felt constrained to return the
diploma of Doctor of Medicine which two years before he had accepted
from the University of Bonn. He did so in a letter which contained some
expressions of feeling with regard to the head of the invading army.
These had better have been omitted, but were perhaps pardonable under
the circumstances; they in no way excuse the terms of reply which Dr.
Naumann, Dean of the Faculty of Medicine at Bonn, permitted himself to
use--terms which would be discreditable in an ill-bred street _gamin_.
From 1871 to 1876, the year in which he published his ‘Études sur la
Bière,’ Pasteur was again largely occupied with the study of
fermentation. Part of his object was undoubtedly to place the French
brewers on an equality with the German; and in this he certainly had a
large measure of success. To one who knew Paris under the Second Empire
and who revisits it under the Third Republic, one of the first changes
observable in the life of the _café_ is the enormous consumption of
‘bocks.’ Pasteur’s work, however, went far beyond the establishment of a
national industry. He started investigations which have changed brewing
from an art into a science; and his most fitting memorial in this
respect is the bust which decorates the hall of the Carlsberg
Institution at Copenhagen, an institution devoted to the study of all
problems of fermentation. In his ‘Études’ Pasteur laid great stress on
the fact that every fermentation is brought about by micro-organisms,
and he dwells at length on the marked influence which certain bacteria
exercise on the nature of the fermentations, and on the character of the
beer produced. He did not, however, see, what Hansen demonstrated in
1883, that many of the commonest diseases of beer are caused by certain
species of yeast-cell differing specifically from those which cause its
normal fermentation. Indeed, he paid but small attention to species,
regarding it as waste of time, as it undoubtedly often is, to trouble
about names and synonyms.
As Professor Jörgenson and Dr. J. R. Green have shown in two
recently-published works, we have learnt much about brewing during the
last five-and-twenty years. The nucleus of the yeast-cell has been made
visible by appropriate staining; some thirty different species of
yeast-cell have been described, and their properties as ferments have
been investigated; Buchner, by grinding up the yeast-cells, has produced
an extract, called zymase, capable of converting sugar into alcohol; the
fact has been established that it is not so much bacteria as other
fungi, allied and often congeneric with the yeast-cell, which produce
disease in beer; still, allowing a full measure of credit to later
workers, we may look back to Pasteur’s researches in the early seventies
as establishing for the first time a scientific basis for brewing.
The same remarks are applicable to Pasteur’s work on the diseases due to
specific organisms in the region of preventive medicine. We have built
and are building a lordly edifice, but he drew the plan and even laid
the foundations. More than two centuries ago Robert Boyle--‘the Father
of Chemistry and Brother of the Earl of Cork’--had said that he who
could solve the nature of fermentations would be without doubt more
capable than others of explaining certain phenomena of disease. Towards
the end of his ‘Études sur la Bière,’ Pasteur wrote: ‘The ætiology of
contagious diseases is on the eve of having unexpected light shed upon
it.’ He was already thinking of his investigations into the cause and
prevention of contagious disease.
There is a certain malady known, when it attacks cattle and sheep, as
‘charbon’ or ‘sang de rate,’ and when it attacks man, as ‘woolsorter’s
disease.’ The term ‘anthrax’ covers the disease in both beast and man;
and anthrax is produced by a bacterium known as _Bacillus anthracis_,
which had been recognized and was accused of causing the disease before
Pasteur began to interest himself in such matters. It annually carried
off 20 per cent. of the sheep in the agricultural district of La Beauce,
and in Auvergne some 10 to 15 per cent. In certain localities the loss
was greater, amounting at times to an annual death-rate of 50 per cent.
The disease was by no means confined to France; it was spread over
Europe. In the government of Novgorod it was responsible for over 56,000
deaths in three years. In Egypt it was regarded as the direct descendant
of the plagues of Pharaoh. It ravaged the large sheep farms of the
Argentine Republic.
The bacillus which causes this disease, and which at times by inhalation
effects a lodgment in the bodies of those engaged in handling wool and
hides, was already known when Pasteur took up the study of pathogenic
germs. About the same time it was also attracting the attention of the
young German physician Dr. Koch, who subsequently became a severe critic
of some of Pasteur’s work; but in this article we are dealing with
Pasteur, and limitations of space compel us to leave unnoticed the
brilliant work of many investigators who have made the latter end of the
nineteenth century one of the greatest epochs in medical history.
Pasteur and his assistants made many fascinating studies on the
behaviour and life-history of the _Bacillus anthracis_. He found it very
susceptible to slight variations of temperature. The few degrees by
which the temperature of a bird’s blood exceeds that of a mammal were
sufficient to prove fatal to the bacillus; but by an ingenious
experiment he showed that if the temperature of a bird be artificially
lowered it becomes susceptible to the disease, though it readily
recovers if the artificial surroundings be removed. Pasteur further
noted that the bacillus was not equally fatal in all animals, and that
it changed its character when passed through the body of certain classes
of animals. It was, however, not in studying the _Bacillus anthracis_
that he made the far-reaching discovery of the attenuated virus. This he
first noted when at work on chicken cholera, a disease very fatal in
poultry-yards; and he made the important discovery by one of those happy
accidents which only occur to those who possess the genius for
observation. During his numerous experiments he one day chanced to
inoculate some fowls with a forgotten culture some weeks old. To his
surprise the chickens, though made ill, did not succumb; in fact, they
rapidly recovered. He immediately tried what the effect would be if
these same fowls were inoculated with fresh cultures of a kind so
powerful as to be undoubtedly fatal to a healthy bird which had never
suffered from the disease. To his delight, the inoculated fowls resisted
the poison, and proved, in fact, immune. This simple experiment is the
basis of the world-wide prophylactic measures which are now being
carried on against all forms of bacterial disease; and, although
Pasteur’s explanation of the weakening of the virus--which he attributed
to oxygenation--has been shown to be erroneous, he must still be
regarded as the originator of methods for the production of immunity by
means of artificially attenuated organisms.
If the virus of chicken-cholera can be attenuated, and when attenuated
produces immunity from later attacks, the same is probably true of other
germs which can be cultivated outside the body. Arguing in this fashion,
Pasteur returned to his study of anthrax. Here he also succeeded, and in
the spring of 1881 he demonstrated the value of his treatment. Out of a
flock of fifty sheep one-half were inoculated, the other half were not;
the whole flock was then infected with the disease. In less than a
month the uninoculated were dead of ‘charbon,’ the inoculated were
perfectly healthy. The telegram announcing the result to Pasteur,
anxiously waiting in his laboratory at Paris, ended with the words
‘Succès épatant!’
So striking a demonstration naturally had a profound effect. It inspired
confidence in the treatment. Since the date of this experiment some
millions of sheep have been inoculated against anthrax, and several
hundred thousand oxen; and it has been calculated that, within the
succeeding twelve years, seven million francs were saved by this means
alone to French agriculture. Perhaps the convincing nature of Pasteur’s
work in this connexion is best shown by the fact that the insurance
companies of France insist on inoculation before they will insure sheep
and cattle.
We have left ourselves but little space to dwell on the work which
occupied the greater part of the last twelve years of Pasteur’s life.
Already, in the midst of his work on anthrax, he was thinking of rabies;
and in 1881 he proved that it was conveyed through the saliva of the mad
dog, and that it could be communicated to rabbits. Saliva, however, was
not in every case to be depended on. In some cases it failed to convey
the disease. Experiment showed that the poison was concentrated in the
brain. To this day no one has succeeded in finding the organism--if it
be an organism--which causes rabies. Hence it cannot be cultivated on
gelatine in test-tubes, and no modified culture of bacteria can be
produced, as is now done in the case of diphtheria and other diseases.
Other means had to be devised. After countless experiments it became
evident that, if the spinal cord of a hydrophobic rabbit be kept dry at
a temperature of 25° C. for a couple of weeks, the strength of the
virus has so far vanished that, if an emulsion of the cord be injected,
it produces no rabies, but has only a slight vaccinating effect. If two
days later an emulsion of a twelve-days-old spinal cord be injected, the
vaccinating effect is stronger; but the body, already inured to slight
doses of the poison, remains unaffected. Thus, by gradually increasing
the strength of the dose, a virus may at length be injected which would
infallibly produce rabies but for the previous inoculations. When an
animal is bitten by a mad dog, the poison transmitted takes some time to
develop--some weeks at least, and often many months. If now the
artificially introduced virus ‘gets the start,’ so to speak, of the
naturally introduced poison, by the time the latter is at its height the
animal has become gradually immunified to the specific poison and
suffers little harm. The arsenic-eaters of the Tyrol afford an analogous
case. They consume amounts of arsenic which would infallibly produce
peripheral neuritis in men unaccustomed to such a diet.
It needed no small courage on Pasteur’s part to inoculate his
fellow-creatures against hydrophobia. In 1885 a boy some nine years old,
from Meissengott in Alsace, was brought by his mother to the laboratory
suffering from fourteen wounds inflicted by a mad dog. After long
consultations with his assistants and the most anxious deliberations, he
consented to the inoculation of the boy. The next fortnight was a time
of intense anxiety, but all went well. His second patient is
commemorated by the bronze statue which ornaments the front of the
Pasteur Institute in Paris. It represents the struggle between a peasant
boy, armed only with his sabot, and a mad dog; the boy was terribly
bitten, but the treatment saved his life. It is not easy to arrive at an
accurate estimate of the death-rate caused by rabies; but the most
careful and moderate estimates show that, before this treatment was in
use, some fifteen to twenty out of every hundred persons bitten by mad
dogs died a most painful and horrible death. During the fourteen years,
from 1885 to 1899, over 23,000 persons known to have been bitten by
rabid dogs have been inoculated at the Pasteur Institute; and their
average mortality has been 0·4 per cent. In 1899, the latest year for
which statistics are available, 1,614 cases were treated, with a
mortality of 0·25 per cent. Of these, 1,506 were French and 108 were
foreigners. Of the 108 foreigners, 12 came from Great Britain and 62
from British India. It is little short of a national disgrace that we
should still be dependent on French aid to succour those amongst us who
are so unfortunate as to be bitten by a mad dog; but the nation which
gave the use of anæsthetics to the world, and which first showed the
value of antiseptics, is largely dependent to-day on foreign aid in
dealing with great outbreaks of all sorts of diseases within its
borders. The German Koch and the Russian Haffkine are called in to cope
with the cholera in India; we fall back upon the Swiss Yersin and the
Japanese Kitasato to elucidate the true nature of plague, and to devise
methods for combating its ravages. When rinderpest broke out in South
Africa it was again to Koch that we turned. The unsatisfactory position
of Great Britain in these matters is to some extent due to a small but
active section of society whose affection for their lapdogs has
overpowered their sense of duty to their neighbours. It is, however, we
fear, still more due to the unintelligent treatment of men of science by
the Government of the country, and to the want of appreciation of the
value of science shown by society at large. If, to balance the list
given a few lines above, we recall the work of our countryman Major Ross
on the malarial parasite, it serves only to remind us of the
difficulties placed in the way of his research by the officials of the
service to which he belonged and the slightness of the recognition which
for many years he received from the Government.
In 1874 the French National Assembly voted Pasteur, as some recognition
of his work on seri-culture, a pension of 12,000 francs a year; nine
years later this was increased to 25,000 francs, and it was further
agreed that the pension should be continued to his wife and children. In
1881 he was nominated to represent France at the International Medical
Congress, which met that year in London. The reception accorded him
when, with his host, Sir James Paget, he mounted the platform in St.
James’s Hall, overwhelmed him. ‘C’est sans doute le prince de Galles qui
arrive,’ he remarked to his host, never dreaming that such acclamations
could be meant for him. The following year he succeeded to Littré’s
_fauteuil_ at the Academy. In 1888 the President of the Republic opened
the Pasteur Institute, which had been erected and endowed by a public
subscription from all countries and from all classes; and there in 1892
he received a distinguished collection of scientific men, who had come
from all parts of the world to congratulate him on his seventieth
birthday.
Three years later his health began rapidly to fail. Two strokes of
paralysis followed one another at a short interval, and on September 28,
1895, he died. He lies buried in the Institute he loved so well. A
nobler monument, or one more worthy of him who lies therein, has never
been erected by man. The benefits which his simple, strenuous,
hard-working, noble life conferred on humanity cannot be estimated. They
help us, however, to realize the truth of the old Arabian proverb, ‘The
ink of science is more precious than the blood of the martyrs.’
M. Vallery-Radot has given what will probably prove to be the definitive
Life of Pasteur. He has written at length, and he has written well.
That he is not a man of strict scientific training in no way detracts
from the merit of the work; rather, in many respects, this makes the
book more readable. The pupils of Pasteur, who are now carrying on his
work, have, out of the abundance of their knowledge, helped in the more
technical portions of the book; whilst M. Vallery-Radot, from his
intimacy and relationship with the subject of his biography, has been
able to supply those personal details which form so essential and so
interesting a part of every good biography.
For one who knew Pasteur only during the last decade of his life to
attempt any account of his character may savour of impertinence. Still,
it is impossible to close this article without some tribute to his
simple dignity of manner, and, above all, to his infinite kindness. No
man has done more to lessen suffering in this world, both in man and in
the lower animals, and probably but few have felt so much sympathy with
suffering in others. As a boy--and French country boys are not more
thoughtful about the suffering of animals than those of other races--he
refused to go shooting. ‘La vue d’une alouette blessée lui faisait mal.’
As an old man it was a touching sight to see him amongst the sufferers
under treatment at the Institut Pasteur, patting the little children on
the head, heartening up the timid and giving sous to the brave,
infinitely tender to the frightened mothers. ‘Men of science, my Sandra,
are always the humanest,’ as Laura said in ‘Vittoria.’ Another
dominating trait in his character was his unflinching desire for truth;
to ‘prove all things,’ and to ‘hold fast that which is good,’ was the
motto of his working life. His success was in no small measure due to
the rigorous tests he applied at all stages of his investigations; it
was also due to the untiring assiduity with which he worked, never
sparing himself, never in any way thinking of himself. But, above all,
it was due to the intense thought he bestowed upon his researches.
Concentrating his intellect upon the problem in question, he thought out
all possible solutions, and was prepared for all possible eventualities.
It was this power of thought, coupled with a matchless gift of
observation and experiment, that enabled him to leave a name which
cannot be forgotten whilst civilization endures.
MALARIA
_There in a wailful choir the small gnats mourn_
_Among the river sallows, borne aloft_
_Or sinking as the light wind lives or dies._
JOHN KEATS: ‘To Autumn.’
It has been said that one-half the mortality of the human race is due to
malaria. This may very well be an exaggeration, but there can be little
doubt that, of all the ills that flesh is heir to, malaria is the most
deadly, and exercises the most profound influence on the distribution
and activities of man. It will be seen later that the disease is most
rife where the densest populations are found, and the mortality of such
a closely crowded area as India gives some idea of the enormous loss of
life and the widespread suffering caused by this disease. In 1892, out
of a total population in India of 217,255,655, the deaths from all
causes reached the figure of 6,980,785. Of these, 4,921,583 were
ascribed to ‘fever.’ All these fevers were not, of course, malarial, but
comparison with other statistics leads to the belief that a high
percentage of them was caused by malaria. Major Ross states that in 1897
over 5,000,000 deaths in the same country were recorded as due to
‘fever,’ and that out of a total strength of 178,197 men in the British
army in India, 75,821 were treated in the hospitals for malaria. Fifty
years ago the loss from malaria amongst the European population of India
was 13 per thousand. With improved methods of living and more skilful
treatment this has been reduced to 7 per thousand; but the native, who
is slow to change his ways, and usually averse to modern methods of
treatment, still retains a very high fever death-rate--over 18 per
thousand. During the years 1887-1897 the average mortality in Italy
attributed to malaria was 15,000 a year, and 2,000,000 patients annually
suffered from ‘fever.’
Apart from the mortality due to this disease, the amount of suffering
and the decline in human power and activity which it entails deserve
careful attention. Compared with the number of patients, the number of
deaths is by no means large. In round numbers, out of every thousand
soldiers in the British army in India in 1897, 420 men were attacked by
malaria, but only one in a thousand died; even in the ‘most malarious’
districts the death-rate only amounted to 6 per thousand. In Sierra
Leone, a district much more fatal than any in India, the average
death-rate of the white troops, based on hospital records extending from
1892 to 1898, is estimated by Major L. M. Wilson at 42·9 per thousand,
whilst that of the coloured troops is 5·9 per thousand. On the other
hand, the European troops show an annual number of cases of 2,134 per
thousand, and the non-European troops one of 1,056 per thousand. These
figures probably under-estimate the amount of fever amongst the troops.
It must be remembered that many soldiers who have slight attacks of
fever do not present themselves at the hospital, whilst of those who do
a considerable number are only detained for slight treatment, and are
never entered on the hospital books, and so are not recorded on the
returns.
From the statistics quoted above, it appears that of our soldiers in
India three out of every seven suffer from an annual attack of malaria
sufficiently pronounced to be recorded on the medical books, whilst our
soldiers on the west coast of Africa have an average of at least two
attacks a year, and a considerable number of them die. There is no
reason to believe that the civil population of India or West Africa is
in any degree more exempt from the disease than the military, but the
statistics in the latter case are more readily accessible.
Malarial fever, when it does not kill, leaves great weakness behind; and
all who have watched malaria patients, or patients who are already
recovering from an attack, cannot fail to have noticed the listlessness
and want of interest in their surroundings and the lack of inclination
to work that they all show. Apart from the mortality, the disease
probably levies a heavier tribute on the capacity of the officers and
officials who administer the British Empire than does any other single
agency.
Before describing the organism which causes all this misery a word or
two must be said about the distribution of the disease. Roughly
speaking, malaria is confined to a broad irregular belt running round
the world between the 4th isothermal line north of the Equator and the
16th line south. It is, however, said to occur occasionally outside
these limits--for instance, in Southern Greenland and at Irkutsk in
Siberia; but until recently the accurate diagnosis of the disease has
been difficult, and too much reliance must not be placed on these
statements. The chief endemic foci of the disease are along the banks
and deltas of large rivers, on low coasts, and around inland lakes and
marshes. Malaria is common all round the Mediterranean region: it was
well known to, and its symptoms were clearly noted by, the early
physicians since the time of Hippocrates. They even recognized the
difference between the mild spring and summer attacks and the more
pernicious effects of the autumnal fever. In France there are several
prominent malarial districts: the valley of the Loire and its tributary
the Indre, and the valley of the Rhone; also the sea-coast stretching
from the mouth of the Loire to the Pyrenees, and again the Mediterranean
sea-board. It occurs in Switzerland, and is found in Germany along the
Baltic coasts, and on the banks of the Rhine, the Elbe, and other
rivers, and in many other parts. Scarcely a province in Holland is quite
free from it, and it is found in Belgium and around Lake Wener, in
Sweden. It extends along the Lower Danube and around the Black Sea, and
spreads across Russia, being especially prevalent along the course of
the Volga and around the Caspian. From Europe it spreads over Asia
Minor, and affects all Southern Asia as far as the East Indies, but in
Japan it is curiously rare. It is also infrequent in Australia--where it
is confined to the northern half of the continent--and in many of the
Pacific Islands; and it is unknown in the Sandwich Islands, New Zealand,
Tasmania, and Samoa. In America it is more common, and of a more severe
type an the Atlantic sea-board than on the Pacific; in the last hundred
years its northern limit is said to have retreated in the centre of the
continent, though some observers think it is creeping further north in
the Eastern States. In a mild form it is known around the Great Lakes,
and in Canada and in New England; but it reaches a high degree of
intensity in the Southern States, Mexico, Cuba, and Central America,
where it probably played a greater part in ruining the projected Panama
Canal than all the corrupt financing of the speculators in Paris. It
extends throughout the warmer parts of South America, and is known in a
virulent form all over Africa except the extreme south.
In Great Britain it used to flourish. The following extract from
Graham’s ‘Social Life of Scotland in the Eighteenth Century’ shows what
a part it played in the life of the Scottish peasant:
‘The one ailment to which they were most liable, and in which dirt
had no share, was ague. This was due to the undrained land, which
retained wet like a sponge, and was full of swamps and bogs and
morasses in which “green grew the rushes.” Terribly prevalent and
harassing this malady proved to the rural classes, for every year a
vast proportion of the people were prostrated by it, so that it was
often extremely difficult to get the necessary work of the fields
performed in many districts. In localities like the Carse of
Gowrie, which in those days abounded in morasses and deep pools,
amongst whose rushes the lapwings had their haunt, the whole
population was every year stricken more or less with the trouble,
until the days came when drainage dried the soil, and ague and
lapwings disappeared.’
In England it was once very prevalent. James I. died of ‘a tertian ague’
at Theobalds, near London, and Cromwell succumbed at Whitehall to a
‘bastard tertian ague’ in 1658, a year in which malaria was very widely
spread and very malignant; and it is only within recent memory that the
fen districts in Cambridgeshire and Lincolnshire, Romney Marsh in Kent,
and the marshy districts of Somerset, have lost their evil reputation
for ague. The older chemists in the towns in the fen districts still
recall the lucrative trade their fathers carried on in opium and
preparations of quinine with the fenmen during the first half of last
century; but with the improved drainage of the fens this has all
disappeared, and at present cases of endemic malaria appear to be
unknown in England, though sporadic cases turn up at rare intervals. It
was also very prevalent along the estuary of the Thames, both on the
Essex and Kentish marshes. Pip in ‘Great Expectations’ says to his
convict:
’“I think you have got the ague.” “I’m much of your opinion, boy,”
said he. “It’s bad about here,” I told him. “You’ve been lying out
on the meshes, and they’re dreadful aguish.”’
Ireland, which appears at first sight peculiarly adapted for the
disease, seems to have been remarkably free from it. It may be that the
strong antiseptic quality of the peaty bog-water hinders the development
of the larval mosquito.
Turning now to the cause of the disease, it is interesting to note that
the discovery of the organism which produces all this misery and death
took place just about the time when Koch was making his far-reaching
investigations into the cause of tuberculosis. In 1880 Koch was at work
on the tubercle bacillus; and in the same year a French army surgeon,
named Laveran, looking down a microscope in a remote military station in
Algiers at a preparation of blood taken from a malarious soldier,
recognized for the first time the small organism which has played a
larger part in human affairs than the greatest politician or general
that ever lived. This small organism is an animal, not a plant. It
belongs to the great group of single-celled organisms, mostly
microscopic in size, called Protozoa, and it lives as a parasite inside
the body of other animals, from which it abstracts what nutriment it
needs. Before describing its structure and life-history, a word or two
must be said about its surroundings in the body of man.
That blood consists of a fluid in which enormous numbers of cells called
blood-corpuscles float is now a matter of common knowledge. These
corpuscles are of two main kinds, the red and the white, but the red
surpass the white in number, in proportions ranging from 300 up to 700
to 1. A cubic millimetre of blood contains about 5,000,000 red
corpuscles; and since these act as the carriers of oxygen from the lungs
to the tissues all over the body, and on their return journey carry away
the carbon dioxide from the tissues to the lungs, where it is given off,
it is obvious that the presence of a parasite in the red corpuscle will
have a most serious effect upon the welfare of the body.
Before Laveran’s discovery, Lankester had described a parasitic organism
living in the blood-cells of a frog, and within the last twenty years
numerous other organisms have been discovered and described by various
investigators living in the blood-corpuscles of reptiles, birds,
monkeys, and bats. There are at least three species of Hæmatozoa, as
they are called, which live in the blood of man, and these three
correspond to the three kinds of malaria--the tertian, the quartan, and
the æstivo-autumnal, or, as it is often termed, the irregular type of
malarial fever, which occurs so frequently in the late summer and autumn
in Italy and elsewhere. The hæmatozoön causing the last-named fever has
been especially studied by the Italian observers, and it differs more
markedly from those causing the tertian and quartan fevers than the
latter do _inter se_. It is not universally conceded that the
differences between these three forms of organism are such as to
establish a difference of species, but the weight of opinion is in
favour of this view. Ross even places the parasite of the
æstivo-autumnal fever in a separate genus, and we have throughout this
article adopted his nomenclature. Zoologically he groups all the three
species infesting man in Wassielevski’s family Hæmamœbidæ, which,
besides the human parasites, includes a species found in monkeys, three
species in bats, and two in birds. The species causing tertian and
quartan fevers are grouped by Ross in the genus _Hæmamœba_, the
former being called _Hæmamœba vivax_, the latter _Hæmamœba
malariæ_. The parasite causing the æstivo-autumnal fever is called
_Hæmomenas præcox_.
With the exception of a few details the life-history of all these forms
is practically identical, although the time which is occupied by
different phases of their life-cycle varies in the different species.
The account given here applies in the main to them all.
The organism which Laveran saw living in the blood-corpuscles of his
malarious patient was a minute cell of irregular shape whose nucleus can
be demonstrated by the use of appropriate reagents. The cell constantly
but slowly changes its outline, pushing out and withdrawing blunt
rounded processes; in fact, the cell resembles the lobate forms of one
of the simplest microscopic animals we know, the Amœba (Fig. 1). The
movements and change of shape consequent on them are termed amœboid,
and the organism in this stage is known as an amœbula. These
amœbulæ whilst in the blood-cell grow rapidly, and in some way they
collect the hæmoglobin, or colouring matter of the red corpuscle, within
their own bodies, and convert it into a number of dark brown or black
pigment granules, which crowd around the nucleus of the parasite. This
pigment, the so-called malarial pigment or melanin, had been recognized
by Virchow and others about the middle of the nineteenth century as a
characteristic product in the blood of malarial patients. The amœbulæ
continue to grow rapidly, at the expense of their cell-host, until,
after a definite period, which varies from one to several days, they
become mature, and by this time they have completely filled up the red
corpuscle, whose scanty remains form a tight skin round the fully-grown
parasite (Fig. 1, 1-8). When mature, one of two things happens--either
they become (1) gametocytes, whose meaning and fate we will consider
later, or they become (2) sporocytes. In the latter case the nucleus of
the amœbula breaks up into a number of small nuclei, and each
surrounds itself by a small mass of protoplasm and forms a spore (Fig.
1, 5-8). The result of this process of division may be roughly realized
if we imagine an orange with
[Illustration: FIG. 1.--THE PARASITE OF TERTIAN FEVER, HÆMAMŒBA VIVAX
(ROSS). HIGHLY MAGNIFIED.
Nos. 1, 2, 3, 4, show the growth and the changing shape of the
parasite within the blood-corpuscle; Nos. 3, 4, etc., show the
aggregation of the pigment, melanin, in the parasite; No. 5 is a
sporocyte, which in Nos. 6, 7, and 8, shows the several stages of
sporulation; No. 9 shows the spores derived from a single
sporocyte, escaped from the blood-corpuscle and free in the
blood-plasm, ready to infect new corpuscles; No. 10 is a male
gametocyte, removed from the body of man, and either in the stomach
of _Anopheles_ or on a microscope-slide, forming there flagella or
spermatozoa, _a_, Parasite; _b_, red blood-corpuscle; _c_, spore;
_d_, granules of pigment, melanin; _e_, flagellum or spermatozoön.
(From Thayer.)
]
[Illustration:
FIG. 2.--VARIOUS STAGES WHICH THE PARASITE OF THE ÆSTIVO-AUTUMNAL
FEVER, HÆMOMENAS PRÆCOX (ROSS), PASSES THROUGH IN THE BODY OF THE
MOSQUITO ANOPHELES. MAGNIFIED 2,000 TIMES. AFTER ROSS AND
FIELDING-OULD.
No. 1, Flagella or spermatozoa from male gametocyte (see Fig. 1
above); No. 2, flagellum or spermatozoön entering and fertilizing
the female gametocyte; No. 3, the fertilized cell or zygote; Nos.
1, 2, 3, are found in the blood in the stomach of the _Anopheles_;
No. 4, the fertilized cell piercing the wall of the stomach of the
mosquito to come to rest at No. 5, between the epithelial lining of
the stomach and the muscular sheath.
_To face page 136._]
but one pip in each quarter. Then the skin of the orange will represent
what is left of the red blood-corpuscle, the flesh will represent the
divided sporocyte, each quarter will represent a spore, and the pip will
represent its nucleus.
At this stage the skin to which the red corpuscle has been reduced
breaks, and the spores fall into the liquid part of the blood (Fig. 1,
9). The pigment granules which escape at the same time also pass into
the liquid of the blood, and are eaten up and removed by those
scavengers of the vascular system, the white corpuscles. Each of the
spores, after remaining a short time in the fluid of the blood, attaches
itself to a new red corpuscle, penetrates its body, and becomes a small
amœbula, which repeats the life-history described above. In this way
a few organisms will soon produce enough spores to infect a very large
number of blood-corpuscles; as many as 60 per cent. are in some cases
infected. The severity of the attack naturally depends in a great degree
on the number of corpuscles infected. Laveran not only first recognized
and described the organism[4] we are dealing with, but he definitely
connected its presence with malaria; but it was not until some time
later, in 1885, that Golgi described the sporulation of the sporocyte
and pointed out that the moment of the escape of the spores from the red
corpuscle coincides with the paroxysm of the fever. Since all the
amœbulæ of one crop are at about the same stage of growth in any one
host, millions of spores in a well-infected patient are thrown into the
liquid of the blood at about the same time; and it is clear that this
must be accompanied by a profound disturbance of the system. This
disturbance manifests itself in a feverish attack. The period when the
spores have left the corpuscles and are free in the liquid of the blood
is also the time at which the administration of quinine is said to be
most effective. Further, it is only at this stage that the disease can
be artificially transferred from one man to another. All efforts to
transmit the gametocytes have ended in failure.
_Hæmamœba vivax_, which causes the tertian fever, passes through the
various stages of its life-history in man in forty-eight hours; hence
the febrile paroxysm occurs every second day. Malaria is usually of the
tertian type, and this is certainly the most common form in temperate
climates. Occasionally the infection has been repeated, and we may find
that there are two groups of the parasite present in the blood, which
arrive at the sporulating stage on alternate days; in this case the
febrile symptoms manifest themselves every day, and the type of malaria
is designated ‘quotidian intermittent fever.’ In this case, if a single
dose of quinine be administered at the right time, one group of
parasites is killed off and the quotidian fever is reduced to a tertian.
There may occasionally be more than two groups present, or the parasites
may for some reason have failed to arrange themselves in groups, in
which case the fever becomes irregular or continuous.
In the quartan fever the parasite _Hæmamœba malariæ_ takes
seventy-two hours to complete its cycle in man, and the paroxysms occur
every three days--that is, there are two days without febrile symptoms,
followed by a day when there is a paroxysm. This form is common in
Sicily and in certain parts of Italy--for instance, around Pavia. Just
as in the tertian fever, so in quartan there may be a second infection,
in which case paroxysms arise on two successive days, followed by a day
of intermission of the fever. If a third group be present, we have a
quotidian fever. The æstivo-autumnal fever, due to _Hæmomenas præcox_,
is noted by a marked irregularity in its clinical symptoms. It usually
sets in during August, September, or October, and is attended by much
more serious results than are the regular intermittent fevers. The
pernicious or malignant form of malaria, rarely seen in temperate
climates, but common in the tropics, is caused--in many cases, though
perhaps not in all--by the same parasite.
From what has been above described, it is evident that when once the
parasite has obtained entrance to the blood it may remain and multiply
for years. The parasite is, however, very susceptible to the poisonous
action of quinine, and this is especially the case at the time when
sporulation has just taken place and the spores are being set free in
the blood. Quinine seems to have little or no effect on the organisms
whilst they are inside the blood-corpuscle, but shortly before the
paroxysm is due it should be administered. Quinine is amongst the very
few absolutely trustworthy specifics known to medical science. It seems
to have been introduced into Europe in the year 1640 by the Countess of
Chinchon, a small town south-east of Madrid. The Countess was Vice-Queen
of Peru, and in 1638 was cured of a tertian fever by the use of Peruvian
bark. Shortly afterwards she started for Europe with a supply of the
drug, but unfortunately died on the voyage. About a hundred years later
Linnæus named the plant after this lady, but acting on erroneous
information omitted the first ‘h’ in the name, and called the plant
Cinchona. According to some authorities the word ‘quinine’ is derived
from ‘quina,’ the Spanish spelling of the Peruvian word ‘kina,’ which
signified bark.
But to come back to the parasite. It was mentioned above that the
amœbulæ become either sporocytes or gametocytes. We have followed the
fate of the former and must now turn our attention to the latter. In
the genus _Hæmamœba_ the gametocyte has a general resemblance to the
sporocyte before its nucleus divides and it begins to form spores; and
it is impossible to predict which amœbulæ will become sporocytes and
which will become gametocytes. In _Hæmomenas_, however, the gametocyte
can be recognized at an early stage. In this genus some of the
amœbulæ become globular and ultimately form spores, whilst others
become elongated and slightly curved; in fact, they assume the shape of
minute sausages. These are the gametocytes. It is on this difference in
shape that Ross has founded his new genus for the parasite of the
æstivo-autumnal fever, all the essential characters of which had,
however, been previously recognized by Italian and American observers.
So long as the gametocytes remain in the blood of the patient they
undergo no further development; on being liberated from the cell into
the fluid of the blood, they degenerate and die; but if they be removed,
even only on to a microscope-slide, they begin to develop. They escape
from the red corpuscle in which they have hitherto been confined, and
some of them--the male gametocytes--are then seen suddenly to emit long
filaments (Fig. 1, 10). These filaments can be watched under a high
power struggling violently to free themselves from the cell which has
given rise to them. Ultimately they succeed, and breaking loose, at once
dart away amongst the corpuscles and other debris on the slide. So long
ago as 1880 Laveran had seen these bodies, but until 1897 their nature
was quite misunderstood. This formation of the filaments or flagella,
sometimes called ‘flagellation,’ can only take place at comparatively
high temperatures. This has an important relation to the seasonal
variation in the prevalence of the disease.
Hitherto in this article we have only studied the malarial parasite
inside the body, with the exception that we have just seen that, should
it get out, certain cells undergo a further development and produce
mobile filaments. It occurred to many that these filaments might be
spores, which were in some way carried into the blood of man. Later
research showed that this is not their true meaning; but, acting on some
such belief, Dr. Patrick Manson propounded the hypothesis that the
spores may be conveyed to man by the intervention of some blood-sucking
insect; and the brilliant and laborious researches of Major Ross,
undertaken with the view of establishing the truth or falsehood of this
hypothesis, have within the last few years cleared up the whole question
of the transmission of the disease from one patient to another.
It is a well-established belief in many malarious countries that the
mosquito plays a part in the infection. The negroes of the Usambara
Mountains, who acquire the disease when they descend to the plains, even
use the same word to denote the disease and the mosquito. In Assam, in
Italy, and in Southern Tyrol, the belief in the mosquito origin of
malaria obtains. Experienced travellers, like Livingstone, Emin Pasha,
and General Gordon, insisted on the importance of mosquito-nets,
thinking that the netting ‘acted as a filter against the malarial
poison,’ and knowing by experience that its presence diminished the
tendency to the disease. The whole epidemiological evidence was put
together in a masterly essay on the mosquito theory, read before the
Philosophical Society of Washington in 1883, by Professor A. F. A. King.
There was thus a considerable body of opinion in favour of the
mosquito-malaria theory, when, in 1894, Manson explained his views to
Major Ross, at that time a surgeon in the Indian Medical Service.
Manson’s own epoch-making researches on _Filaria_--another human
parasite whose intermediate host is the mosquito--no doubt strengthened
his faith and helped to encourage Major Ross, who in 1895 began in
Secunderabad a series of investigations, which, after much weary work,
were crowned with brilliant success. The difficulties of the work were
very great. Hardly anything was known about the great number of gnats
and mosquitoes which are found all over India, and it was often
impossible to have them accurately determined. Then no one could predict
the appearance of the parasite within the body of the mosquito--if it
were there--or in what part of the body it should be looked for. The
mosquito had to be searched cell by cell. The difficulty of dissecting a
mosquito is great even in temperate climes, and when we recollect that
hundreds of all the available species were dissected in the most
malarious districts in India, we must recognize that it was only a faith
akin to that which moves mountains which sustained the courage and
stimulated the perseverance of the tireless worker. For nearly two years
and a half Major Ross searched in vain. No matter what species of
mosquito he worked at, the results were negative. A less determined man
would long ago have abandoned the research; Major Ross only tried new
methods. At Sigur Ghat, near Ootacamund, a peculiarly malarious
district, he noticed for the first time a mosquito with spotted wings
which laid boat-shaped eggs. Shortly afterwards he was able to feed
eight specimens of this mosquito on a patient whose blood contained the
parasites in the gametocyte stage--and it should have been mentioned
above that all mosquitoes dissected were first fed upon the blood of
malarious patients. Six of these insects were searched through and
through, organ by organ, but without result. The seventh showed certain
unusual cells in the outer surface of the stomach, which contained a few
granules of the characteristic black pigment or melanin of malarial
fever. The eighth and last specimen showed the same characteristic
cells with the same characteristic pigment; but the peculiar cells,
quite unlike anything hitherto met with in the mosquito’s body, were
larger and further developed. ‘These fortunate results practically
solved the malaria problem.’
Without following in detail the various stages of the further
investigations carried on by Major Ross, we must endeavour to give an
account of the final results obtained by him and later investigators.
Being unable to obtain material for the study of malaria in man owing to
the scare caused by the outbreak of plague amongst the natives, Ross
worked out the life-history of an allied organism which causes malaria
in birds. It is to the brilliant researches of the Italian
school--prominent among whom are Grassi, Bastianelli, and Bignami--that
we owe the first complete accounts of the life-history of the human
parasite. It has already been explained that some of the parasites do
not form spores, but persist in a more or less unchanged condition
whilst in the blood of man as gametocytes. We have also seen that when
removed from the human body some of these gametocytes throw off actively
mobile filiform bodies. In 1897 MacCallum of Baltimore showed what these
filiform bodies really are. Certain of the gametocytes do not produce
them, but lie passively still on the microscope-slide, or in the blood
within the mosquito’s stomach. These are destined to form the female
cell; the filamentous bodies which break off from the first-named
gametocyte were seen by MacCallum to fuse with them, and, in fact, to
play the part of the male cell or spermatozoön. This, in fact, happens
when a mosquito feeds on a malarious patient. The gametocytes, unchanged
in the blood of man, as soon as they reach the stomach of the insect,
swell and burst from their red corpuscle. The male gametocyte throws off
the filiform bodies, which actively swim about seeking a female
gametocyte (Fig. 2, 1). When found they fuse with it, and thus produce a
fertilized cell or zygote (Fig. 2, 3). This zygote is produced on the
microscope-slide, and in the alimentary canal of certain mosquitoes, but
so far as is known at present it undergoes further development only in
the stomach of the various species of the mosquito genus _Anopheles_. In
all other cases it dies or is digested. In _Anopheles_, however, the
zygote travels to the walls of the stomach, pierces the inner coats and
comes to rest underneath the muscular tunic which ensheaths that organ
(Fig. 2, 4 and 5).
At first the zygote is very small, about the size of a red
blood-corpuscle; but it grows, and in the course of about a week it has,
roughly speaking, increased to five hundred times its original bulk
(Fig. 3, 1 and 3). Its contents have not only increased, but have
divided into some eight or twelve cells, called meres; and each of these
meres has given off round its periphery a number of filiform cells,
called blasts (Fig. 3, 2). The structure of the mere, with its coating
of blasts, may be easily understood by a zoologist when it is mentioned
that it very closely resembles that stage in the formation of the
spermatozoa of the earth-worm just before the spermatozoa separate
themselves from the blastophor; the lay mind may gain a better idea of
its appearance by recalling the head of a mop. As the zygote, still
resting on the outside of the mosquito’s stomach, matures, the cells
which are giving rise to the blasts diminish in size and disappear,
leaving the capsule packed with thousands of minute filiform slightly
spindle-shaped blasts (Fig. 3, 3). Then the capsule bursts and the
blasts make their way into the body-cavity, or space between the stomach
and the wall of the mosquito’s body. It is not known whether they have
any movement of their
[Illustration:
FIG. 3.--FORMATION OF THE BLASTS OF HÆMOMENAS PRÆCOX (ROSS) WITHIN
THE BODY OF THE MOSQUITO ANOPHELES. MAGNIFIED 2,000 TIMES. AFTER
ROSS AND FIELDING-OULD.
No. 1, The full-grown zygote dividing up into meres; No. 2, an
isolated mere which has developed its filiform bodies or blasts;
No. 3, the zygote crammed with blasts is bursting; No. 4, the
blasts are making their way into the salivary gland of the mosquito
_a_, through it into the œsophagus _b_, and finally into the
proboscis _c_.
_To face page 144._]
own, but in some way or another they make their way into the salivary
glands of the insect and accumulate in the cells which secrete the
saliva. Thence the blasts pass into the salivary duct and down the
grooved proboscis of the insect (Fig. 3, No. 4). The next time the
mosquito has a meal off a man, some of these blasts will be washed into
the man’s blood by the saliva which causes the irritation set up by a
mosquito’s bite. It is known that when an infected insect bites a
healthy man malaria ensues; and though the blasts have not hitherto been
seen to enter the blood-corpuscles, they certainly give rise to the
disease, and it can hardly be doubted that they force their way into the
red corpuscles and form the young amœbulæ which we described at the
beginning of this article.
The appended scheme will perhaps make clear the very diverse phases of
the somewhat polymorphic organisms. Those stages which occur in the
blood of man are printed in ordinary type, but those which occur in the
mosquito are in italics:
AMŒBULÆ.
|
+----------------------+----------------------+
| | |
Sporocyte. Female Gametocyte. Male Gametocyte.
| | |
Spores | |
(in liquid of blood). | |
| _Female Gametocyte._ _Filamentous bodies_ or
Amœbulæ. | _Spermatozoa_.
| | |
Sporocyte. +----------------------+
| |
| _Zygote._
Spores |
and _da capo_. _Meres._
|
_Blasts._
|
Amœbulæ.
|
+-----------------------+----------+-----------+
| | |
Sporocyte. Female Gametocyte. Male Gametocyte.
The foregoing account of this varied and romantic life-history is no
hypothetical one. With the exception that, so far as we know, no one has
yet seen the blasts enter the corpuscles and become amœbulæ, every
stage in the story has been verified over and over again by competent
observers, and their observations are now accepted by all whose opinion
in such matters has weight. Further, the facts here recorded are not
peculiar to parasites in man. Allied forms of Protozoa attack other
vertebrates, and, in fact, the first hæmatozoön whose life-history was
thoroughly worked out by Ross was the _Hæmamœba (Proteosoma)
relicta_, which causes a malaria-like disease in birds, and is conveyed
from one bird to another by means of the common gnat, _Culex pipiens_.
Again, the parasite which causes so much loss to stock-owners, the Texas
fever organism, _Pyrosoma bigeminum_, is, thanks to the researches of
Smith and Kilborne, now known to be conveyed from one ox to another by
the cattle-tick, _Boöphilus bovis_. Thus, however strange the
life-history of the malarial parasite may seem to the unscientific, it
is very much what might have been expected by zoologists who have worked
on allied organisms, and it is vouched for in its main features by the
most expert workers in England, France, America, Italy, and Germany. The
whole literature of the subject of transmission of disease by insects
has been ably sifted and brought together by Dr. Nuttall in a monograph
whose title is mentioned in the Bibliography.
For two years and a half Major Ross dissected mosquitoes, looking for
traces of the malaria organism and finding none, but at last found what
he sought in a species of mosquito that had hitherto escaped his
attention. This means that, like most other parasites, the Hæmamœbidæ
will develop in one kind of animal and in one kind only. If taken up by
another kind they are simply digested. The mosquito with the
[Illustration: _ANOPHELES MACULIPENNIS._
MALE, IN CHARACTERISTIC ATTITUDE.]
[Illustration: _ANOPHELES MACULIPENNIS._
FEMALE.
_To face page 146._]
spotted wings and boat-shaped eggs undoubtedly belonged to the genus
appropriately named _Anopheles_; and only the species of this genus, so
far as we know, are capable of conveying the infection from man to man.
In their bodies only will the gametocytes develop. If swallowed by other
biting insects or by leeches, etc., they disintegrate, and are no more.
The word mosquito has no scientific import; derived from the Spanish or
Portuguese, it simply means ‘little fly’; it is used popularly to denote
a gnat which bites, and most gnats bite when they have a chance. The
word is sometimes extended to include certain midges. The Dipterous
family, Culicidæ, to which the gnat belongs, contains, according to
Major Giles, some 242 species, divided amongst 8 genera. The great
majority of species, some 160, however, belong to the genus _Culex_;
_Anopheles_ includes 30; whilst the remainder are divided amongst the
other 6 genera, none of which are large. The collections which have been
made at the British Museum, and which were worked out by Mr. Theobald,
contain many species of _Anopheles_ new to science; so that we have now
some half hundred species of the genus ‘which has been hopelessly
convicted of being the medium by which the malaria parasite is
transmitted from person to person.’ According to the last-named
authority, we have in England 17 species of _Culex_, and 2 of
_Anopheles_, _A. bifurcatus_ and _A. maculipennis (claviger)_, though
some authorities are inclined to add a third, _A. nigripes_. Five other
species, belonging to the smaller genera of Culicidæ, make a total of
some 24 species of gnat or mosquito found in England. _Culex pipiens_,
probably the commonest gnat the wide world over, conveys the parasite
_Proteosoma_, or, as Ross now calls it, _Hæmamœba relicta_, of the
avian malaria from bird to bird; but it will not carry the parasite of
human malaria. Indeed, 14 different species of _Culex_ have been tried
in this respect, and in each case with negative results. The same nice
adjustment of parasite to host is found in _Anopheles_. It will not
convey the bird malaria, that is to say, the gametocytes are destroyed
in its body, but it is readily infected by the human parasite, and at
the present date a considerable number of species have been successfully
tried, and this not only in Europe, but in Africa, India, and the United
States.
_Anopheles_ is obviously worth studying. It has now been found very
commonly distributed in England, _A. maculipennis_ abounding in the
eastern counties. Its boat-shaped eggs, laid, not as are those of the
genus _Culex_, in little rifts, but singly, give rise to a charming
little larvæ, whose diet of minute algæ gives a greenish tint to the
centre of the body, which elsewhere is of a brownish hue. When at rest,
these small larvæ float on the water parallel with the surface, and not
hanging down into the water as does the larval _Culex_. They have a most
beautiful arrangement of minute hairs, arranged like the ribs of an
umbrella turned inside out, along the upper surface of their backs, and
by the action of these hairs they hang on to the surface-film. Their
breathing organs open near the tail, but are not produced into the long
respiratory tube by which the _Culex_ larva can be so easily recognized.
They possess the most marvellous arrangements on the head for setting up
currents conveying food to the mouth, and, in fact, they afford one of
the most charming objects of ‘animated nature’ that one could desire to
watch. After some days, varying in number according to the temperature,
the larva turns into one of those curious active Dipterous pupæ which
are well known in the case of other gnats. Like the larva, the pupa
floats at the surface of the water. When mature its integument splits
along the back; then the perfect insect steps out, rests a moment to
dry its wings, and sails away into the air.
It is very doubtful if the male _Anopheles_, which can easily be
distinguished from the female by its bushy feathered tentacles, quite
visible to the naked eye, ever sucks blood. The habit in the female is
possibly prompted by a desire to obtain material for the growth of the
ova. Out of the numerous genus _Culex_ only four species are known in
which the male bites; and it is probable that malaria is always conveyed
from man to man by the activity of the female. It is difficult to say
how long mosquitoes live in the imago state--certainly, if fed, for many
weeks. The earlier collectors, not knowing how to feed them, used to
cork them up in glass tubes, and then, noticing in a day or two that the
poor insect had died, retired to their studies and wrote moral essays on
the brevity of life, or learned treatises on the duration of life in
relation to the methods of ovipositing. Now we feed the imagos--as a
rule, on bananas--and they live well in confinement. The fertilized
female survives the winter, hibernating in some dusky corner, and it is
probable that some of the eggs also carry the species over the cold
months from autumn to the following spring.
It should, perhaps, be mentioned that the infected mosquito does not
transmit the parasites to its offspring. This was an important point to
ascertain, because it is known that the tick which causes Texas fever
does transmit its parasite to the young ticks, and they in turn
communicate the disease to the oxen. A somewhat similar case of the
transference from parent to offspring of an organism causing disease is
that of the Pébrine, caused by a parasite which attacks silkworms, and
which is conveyed by the infected ova from one generation to another.
The above short résumé of the life-history and habits of _Anopheles_ has
been given as a prelude to the important question: What can be done to
diminish malaria? A few years ago, before we understood the cause of the
disease, much had been done to lessen it. While aiming at other objects,
we drove malaria out of England by draining. Now that we know the secret
of the disease we can direct our efforts more intelligently. There are
two points exposed to attack. The first is the sporulating organism in
the blood of man, the second is the insect. If we could eliminate the
organism from man, the mosquito would be saved much suffering, and would
be powerless to infect man; or, if we could prevent the mosquito from
access to man, either by guarding him against its bites or by killing
off the insect, the hæmotozoön would, in the course of time, gradually
die out.
Both methods should be tried. Malarious patients should, so far as
possible, be treated with quinine, and no effort should be spared to
free their system from the parasite. Special precautions, such as
hanging up mosquito curtains, etc., should be taken to prevent the
access of the mosquito to the patient; otherwise he acts as a centre of
infection. It is almost equally important to protect the healthy man
living in a malarious place. The mosquito net must be carefully made,
and let down over the bed well before sunset; its free edges should be
tucked under the mattress, and the greatest care should be taken to
prevent the ingress of a mosquito, especially when slipping within the
curtains. Punkahs should be employed as much as possible; they certainly
tend to keep the _Anopheles_ at a distance. In the summer of 1899 an
experiment was initiated by Sir Patrick Manson which must convince even
those least open to conviction that malaria is preventable if proper
precautions be taken. That the bite of an infected mosquito can convey
malaria may be taken as proved by the voluntary submission of Mr. T. P.
Manson to the experiment, as recounted in the _Times_.[5] This
gentleman allowed himself to be bitten, in this country, by insects
previously fed on malarious patients; and in due course the
disease--tertian ague--showed itself in him. To prove the other side of
the case required even more courage and endurance. During the spring of
1899, Dr. Low and Dr. Sambon, of the London School of Tropical Medicine,
with Signor Terzi, an Italian artist, and two servants, have been living
in a mosquito-proof hut, near Ostia, in the Roman Campagna, and remained
in perfect health. The spot selected for this experiment is so malarious
that the Romans regard spending a single night there as equivalent to
contracting a virulent type of malaria. Yet, when Professor Grassi and
several other experts visited the mosquito-proof hut on September 12,
1900, they found the inhabitants in perfect health--a fact which they
telegraphed, with their salutations, to Sir Patrick Manson, ‘who first
formulated the mosquito-malarial theory.’ The conditions under which Dr.
Low and Dr. Sambon and their Italian companions lived were all directed
to the avoidance of being bitten by mosquitoes. During the daytime they
were allowed out of their hut, because the chance of being bitten in
broad daylight is so small that it may be neglected; but they were
‘gated’ an hour before sunset, and were not allowed out until an hour
after sunrise. The mosquitoes were kept out of the hut by the use of
wire-gauze doors and windows. By these precautions contact between
mosquito and man has been avoided, and man has now lived for months in
one of the most malarious spots in Europe without acquiring a trace of
malaria. It is most satisfactory to record that a similar success has
attended the efforts of the Italian authorities to improve the state of
things in the great plain of Salerno. Visitors to Paestum and
Battipaglia cannot fail to have noticed how malaria has marked that
district as its own. By taking such precautions as are indicated above,
the peasants and railway signalmen have, during the last few years, for
the first time, escaped the disease; whilst for the first time newcomers
to the district have failed to contract it. The intelligent activity of
the Italian Government, and the well-known interest taken in the
question by the King and Queen of Italy, cannot fail to have a
profoundly beneficial effect upon the lives of some of the poorest and
most hard-working of European peasantry.
The problem in Africa is more complex, owing to the fact that the native
population is thoroughly permeated with the parasite. Mr. Christophers
and Dr. Stephens, in their ‘Further Reports to the Malaria Committee,’
have shown that the children of natives are in the great majority of
cases infected with malaria. In one village where the _Anopheles_ was
found in ‘considerable numbers,’ 90 per cent. of the babies suffered, 57
per cent. of the children up to eight years, 28 per cent. of the
children up to twelve years, after which age the children were ‘very
rarely infected.’ This is but one example out of many, all tending to
show that after a time a certain immunity to the disease is acquired,
and, further, that travellers should as far as possible avoid the
neighbourhood of native villages, and, above all, decline to sleep in
native huts.
The destruction of the mosquito, at any rate in neighbourhoods inhabited
by man, is a matter of difficulty, but is worth attempting. To expect to
destroy the mature insect seems a vain thing, but the larva can be more
easily dealt with. _Anopheles_--unlike the common gnat, which breeds
close to houses, in cisterns, garden fountains, old tubs, drains,
etc.--prefers rain-water puddles, natural hollows by the roadside, small
ponds, and rice-fields. We have occasionally found the larvæ of
_Anopheles_ and _Culex_ in the same water in England, but this is
probably exceptional. In England, so far as our experience goes, the
_Anopheles_ larvæ are usually met with in shallow water easily heated by
the sun’s rays; and we have always found them in association with the
common green water-weed _Spirogyra_, though they are not known to eat
this.
Attention to the standing water round houses or near towns will do much
to diminish the scourge of mosquitoes. All pots and pans containing
water should be regularly turned out once a week, and puddles should be
brushed out. The larva takes some seven days to develop, so that once a
week suffices to destroy each brood. All useless water should be drained
away and stagnant ponds filled up. The introduction of fish has markedly
diminished the number of mosquitoes around the late Mr. Hanbury’s
celebrated garden at La Mortela on the Riviera. They eagerly devour the
larvæ, and should be made use of in all large areas of water. For
smaller areas some ‘culicide’ should be tried, and more experiments in
this direction are urgently needed. One of the simplest remedies known
is kerosene oil. A piece of rag tied to a stick should be dipped into
the oil, and then applied to the surface of the water. The oil diffuses
in a fine film over the surface and clogs the breathing tubes of the
larval insect; it possibly interferes with the action of the surface
tension--at any rate, the larvæ die. Fresh tar has the same effect. This
‘painting’ of the water must be renewed once a week. Wells and cisterns
should be kept closed. A more careful selection of the site for houses,
and a more liberal use of wire-netting mosquito shutters, will do much
to minimize the risk to Europeans in malarious districts.
The various remedies suggested above have been tried with success in
different parts of the world. The writer has been assured by an old
inhabitant of Colombo that the mosquitoes have distinctly diminished in
number in parts of that town since the custom of storing water near the
houses was abandoned. During the summer of 1900 the authorities at
Sassari in Sardinia claim to have ‘practically exterminated the
mosquitoes ... by killing the larvæ in the swamps with petroleum, and
the flies with chlorine and other destructive chemicals.’[6]
The extinction of malaria in England is a kind of by-product of the
draining operations which restored to the agriculturist large tracts of
land in the fen districts and elsewhere. The breeding-places of the
mosquitoes were dried up and their numbers materially lessened; at the
same time the parasite was killed in an increasing number of patients.
Thus the mosquitoes which survived had fewer opportunities of infecting
themselves, and as time went on the parasite was ultimately eliminated.
_Anopheles_, though in diminished numbers, is still with us, and is
especially to be found in those parts of England once infested with the
malaria; but the parasite has disappeared.
‘INFINITE TORMENT OF FLIES’
_Where the water is stopped in a stagnant pond,
Danced over by the midge._
R. BROWNING: ‘By the Fireside.’
The last few years of the nineteenth and the first few years of the
present century are marked in the annals of medicine by a great increase
in our knowledge of certain parasitic diseases, and, above all, in our
knowledge of the agency by which the parasites causing the diseases are
conveyed from host to host.
Chief among these agencies in carrying the disease-causing organisms
from infected to uninfected animals are the insects, and, amongst the
insects, above all the flies. Flies--_e.g._, the common house-fly
(_Musca domestica_)--can carry about with them the bacillus of anthrax,
and, if brought into contact with a wounded surface, may thus set up an
outbreak of woolsorter’s disease. Flies, ants, and other even more
objectionable insects, are not only capable of disseminating the plague
bacillus from man to man, and from rat to man, but they themselves fall
victims to the disease, and perish in great numbers. They are active
agents in the spread of cholera, and the histories of the South African
and Cuban wars definitely show that flies play a large part in carrying
the bacilli of enteric fever from sources of infection to the food of
man, thus spreading the disease. They are also accused of conveying the
inflammatory matter of Egyptian ophthalmia, and of the ‘sore-eye,’ so
common in Florida, from one human being to another.
The diseases already mentioned are caused by bacteria. But flies also
play a part in the conveyance of a large number of organisms which are
not bacteria, but which, nevertheless, cause disease, and cause it on
the largest scale.
Of all the twenty-two orders into which the modern entomologist divides
the class Insecta, that of the Diptera, or true flies, is, perhaps, the
easiest to recognize, for it is characterized by one very obvious
feature, the presence of the fore-wings only. The hind-wings are
replaced by a pair of small-stalked, club-shaped ‘balancers,’ which are
readily visible in some kinds of fly--_e.g._, the daddy-long-legs--but
in others are by no means conspicuous. Thus it is an easy matter to
determine whether an insect be a fly or not. To determine what
particular kind of fly it be is, however, a very different affair. At
present some forty thousand species of Diptera are known, and have been
more or less completely described or figured; and Mr. D. Sharp estimates
that this number is ‘only a tithe of what are still unknown to science.’
Further, the group has been rather neglected. Flies, speaking generally,
are neither attractive in their appearance nor engaging in their habits,
and it is a cause for no astonishment that entomologists have preferred
to work at other groups.
In considering the part played by flies in disseminating diseases not
caused by bacteria, we can neglect all but a very few families, those
flies which suck blood having alone any interest in this connexion.
From the point of view of the physician, by far the most important of
these families is the Culicidæ, with over three hundred described
species and five sub-families, of which two, the Culicina and the
Anophelina, interest us in relation to disease. The gnats or
mosquitoes--the name is indifferently used, and has no scientific
application--are amongst the most graceful and most beautiful insects
that we know, but they have been judged by their works, and undoubtedly
are unpopular, and we shall see that this unpopularity is well deserved.
Gnats belong both to the genus _Culex_ and to the genus _Anopheles_. The
genus _Culex_, from which the order takes its name, includes not only
our commonest gnat, often seen in swarms on summer evenings, but some
hundred and thirty other species. Members of this genus convey from man
to man the _Filaria nocturna_, one of the causes of the widely-spread
disease filariasis, one variety of which is the elephantiasis, so common
in parts of the tropics. In patients suffering from this disease minute
embryonic round-worms swarm in the bloodvessels of the skin during the
hours of darkness. Between six and seven in the evening they begin to
appear in the superficial bloodvessels, and they increase in number till
midnight, when they may occur in such numbers that five or six hundred
may be counted in a single drop of blood. After midnight the swarms
begin to lessen, and by breakfast-time, about eight or nine in the
morning, except for a few strayed revellers, they have disappeared from
the superficial circulation, and are hidden away in the larger
bloodvessels and in the lungs.
In spite of their incredible number--some authorities place it at thirty
to forty millions in one man--these minute larval organisms, shaped
something like a needle pointed at each end, seem to cause little harm.
It might be thought that they would traverse the walls of the
bloodvessels and cause trouble in the surrounding tissues; but this is
prevented by a curious device. It is well known that, like insects,
round-worms from time to time cast their skins, and the young larvæ in
the blood cast theirs, but do not escape from the inside of this
winding-sheet; and thus, though they actively wriggle and coil and
uncoil their bodies, their progress is as small and their struggles as
little effective as are those of a man in a strait-waistcoat.
The causes of the periodicity of the appearance of these round-worms in
the superficial bloodvessels are not completely understood, but they
appear to have more relation with the usual sleeping hours of humanity
than with day and night. In individuals who sleep by day and work by
night the _Filaria nocturna_ is found in the bloodvessels of the skin
during the day. Thus, whilst between 5 p.m. and 7 or 8 a.m. the vessels
of the skin of Cox the Hatter would be well peopled by the round-worms,
they would only come to the surface in Box the Printer during the
daytime, whilst he was sleeping in the lodgings of Mrs. Bouncer.
One reason of the normal appearance of the creatures in the blood at
night is undoubtedly connected with the habits of its second host, the
gnat or mosquito. Two species are accused of carrying the _Filaria_ from
man to man--_Culex fatigans_ and _Anopheles nigerrimus_. Sucked up with
the blood, the round-worms pass into the stomach of the insect. Here
they appear to become violently excited, and rush from one end to the
other of their enveloping sheath, until they succeed in breaking through
it. When free, they pierce the walls of the stomach of the mosquito, and
come to rest in the great thoracic muscles. Here the _Filarias_ rest for
some two or three weeks, growing considerably, and developing a mouth
and alimentary canal; thence, when they are sufficiently developed, they
make their way to the proboscis of the mosquito. Here they lie in
couples, and it would be interesting to determine whether these couples
are male and female. Exactly how they effect their exit from the
mosquito and their entrance into man has not yet been accurately
observed, but presumably it is during the process of biting. Only
inside man they work their way to the lymphatics, and very soon the
female begins to pour into the lymph a stream of young embryos, which
reach the bloodvessels through the thoracic duct. It is, however, the
adults which are the source of all the trouble. They are of considerable
size, three or four inches in length, and their presence, by blocking
the channels of the lymphatics, gives rise to a wide range of disease,
of which elephantiasis is the most pronounced form. We can consider
later how the disease can be averted by keeping down the number of gnats
and by preventing their access to infected patients.
We now pass to the second of the diseases carried by gnats, that of
malaria.
The parasite which causes malaria is a much more lowly organized animal
than the _Filaria_. It is named _Hæmamœba_, and it, too, is conveyed
by an insect, and, so far as we know, by one genus of mosquito only, the
_Anopheles_. Hence, from the point of view of malaria, it is important
to know whether a district is infected with _Culex_ or _Anopheles_. The
former is rather humpbacked, and keeps its body parallel with the
surface it is biting, and its larva hangs at an angle below the surface
of the water, by means of a respiratory tube. _Anopheles_, on the other
hand, carries its body at a sharp angle with the surface upon which it
rests, and its larva lies flat below the surface-film and parallel with
it. The malarial parasite lives in the blood-cells of man, but at a
certain period it breaks up into spores, which escape into the fluid of
the blood, and it is at this moment that the sufferer feels the access
of fever. The presence and growth within the blood-cells result in the
destruction of the latter, a very serious thing to the patient if the
organisms be at all numerous. If the spores be sucked up by an
_Anopheles_, they undergo a complex change, and ultimately reproduce an
incredible number of minute spores or ‘blasts,’ each capable of
infecting man again if it can but win entrance into his body.
Under normal circumstances, for each _Filaria_ larva which enters a
mosquito, one _Filaria_ issues forth, longer, it is true, and more
highly developed, but not much changed. The malaria-parasite undergoes,
in its passage through the body of the _Anopheles_, many and varied
phases of its life-history. As the Frenchman said of the pork, which
goes into one end of the machine in the Chicago meat factories as live
pig, and comes out at the other in the form of sausages, ‘Il est
diablement changé en route.’ The mosquito is as truly a host of the
malarial parasite as man, and is as necessary for its full development
as is man. Judging by the number and extent of the lesions in the
insect’s body, it must suffer far more than man, and it is undoubtedly
killed at times, and perhaps fairly frequently, by the parasite.
Whoever has watched under a lens the process of ‘biting’ as carried on
by a mosquito, must have observed the fleshy proboscis (_labium_)
terminating in a couple of lobes. The labium is grooved like a gutter,
and in the groove lie five piercing stylets, and a second groove, or
_labrum_. It is along this labrum that the blood is sucked. Between the
paired lobes of the labium, and guided by them (as a billiard cue may be
guided by two fingers), a bundle of five extremely fine stylets sinks
slowly through the epidermis, cutting into the skin as easily as a
paper-knife into a soft cheese. Four of these stylets are toothed, but
the single median one is shaped like a two-edged sword. Along its
centre, where it is thickest, runs an extremely minute groove, only
visible under a high power of the microscope. Down this groove flows the
saliva, charged with the spores or blasts of the malaria-causing
parasite. Through this minute groove has flowed the fluid which, it is
no exaggeration to say, has changed the face of continents, and
profoundly affected the fate of nations.
It is an interesting fact that, amongst the Culicidæ, it is the female
alone that bites. The mouth-parts of the male are weaker, and seem
unable to pierce the skin. It has been suggested that a meal of blood is
necessary for the development of the eggs; but the evidence for this is
not conclusive. There must be millions and millions of mosquitoes in
sparsely inhabited or uninhabited districts, in Africa, in Finland, in
Northern Asia, and America, which never have a chance of sucking blood;
and it is impossible to believe that these millions do not lay eggs.
The female is undoubtedly greedy. If undisturbed, she simply gorges
herself until every joint of her chitinous armour is stretched to the
cracking-point. At times even, like Baron Munchausen’s horse after his
adventure with the portcullis, what she takes in at one end runs out at
the other. But she never ceases sucking. The great majority of
individuals, however, can never taste blood, and subsist mainly on
vegetable juices. In captivity they cannot last longer than five days
without food and drink; but they can be kept alive for weeks on a diet
of bananas, pineapples, and other juicy fruits.
_Anopheles_ is often conveyed great distances by the wind, or in railway
trains or ships; but of itself it does not fly far; about five or six
hundred yards--some authorities place it much lower--is its limit.
Beyond this distance they do not voluntarily stray from their
breeding-places. Both _Anopheles_ and _Culex_ lay their eggs, as is well
known, in standing water, and here three out of the four stages in their
life-history--the egg, the larva, and the pupa--are passed through. The
larva and the pupa hang on to the surface-film of the water by means of
certain suspensory hairs, and by their breathing apparatus. Anything
which prevents the breathing tubes reaching the air ensures the death of
the larva and pupa. Hence the use of paraffin on the pools or
breeding-places. It, or any other oily fluid, spreads as a thin layer
over the surface of the pools and puddles, and clogs the respiratory
pores, and the larvæ or pupæ soon die of suffocation.
In Ismailia the disease has been reduced to an amazing extent, and quite
recently remarkable results have followed the use of these preventive
measures at Port Swettenham, in the Federated Malay States. Within two
months of the opening of the port in 1902, 41 out of 49 of the
Government quarters were infected, and 118 out of 196 Government
servants were ill. Now, after filling up all pools and cleaning the
jungle, no single officer has suffered from malaria since July, 1904,
and the number of cases amongst the children fell from 34·8 to 0·77 per
cent. The only melancholy feature about this wonderful alleviation of
suffering due to the untiring efforts of the District Surgeon, Dr.
Malcolm Watson, is that his fees for attending malarial cases have
dropped to zero.
Thus a considerable degree of success has attended the efforts of the
sanitary authorities, largely at the instigation of Major Ross, all over
the world, to diminish the mosquito plague. It is, of course, equally
important to try and destroy the parasite in man by means of quinine.
This is, however, a matter of very great difficulty. In Africa and in
the East nearly all native children are infected with malaria, though
they suffer little, and gradually acquire a high degree of immunity.
Still, they are always a source of infection; and Europeans living in
malarious districts should always place their dwellings to the windward
of the native settlements. Knowing the cause, we can now guard against
malaria; mosquito-nets and wire windows and doors are a sufficient
check on the access of _Anopheles_ to man. If they could only be kept
permanently apart, we might hope for the disappearance of the parasite
from our fauna. In relieving man from the pest, all lovers of animals
will rejoice that we are also relieving the probably far more acute
sufferings of one of the most delicate and beautiful insects that we
know.
Another elegant little gnat, _Stegomyia fasciata_, closely allied to
_Culex_, with which, until recently, it was placed, is the cause of the
spread of that most fatal of epidemic diseases, the yellow fever. Like
the _Culex_, but unlike the _Anopheles_, _Stegomyia_ has a humpbacked
outline, and its larva has a long respiratory tube at an angle to its
body, from which it hangs suspended from the surface-film of its watery
home. It is a very widely distributed creature; it girdles the earth
between the Tropics, and is said to live well on shipboard. It breeds in
almost any standing fresh water, provided it be not brackish. The female
is said to be most active during the warmer hours of the day, from noon
till three or so, and in some of the West Indies it is known as the
‘day-mosquito.’
The organism which causes yellow fever has yet to be found. It seems
that it is not a bacterium, and that it lives in the blood of man. It
evidently passes through a definite series of changes in the mosquito,
for freshly infected mosquitoes do not at once convey the disease. After
biting an infected person, it takes twelve days for the unknown organism
to develop in the _Stegomyia_ before it is ready for a change of host.
The mosquitoes are then capable of inoculating man with the disease for
nearly two months. The period during which a man may infect the
mosquito, should it bite him, is far shorter, and extends only over the
first three days of the illness.
Very careful search has hitherto failed to reveal the presence of the
parasite of yellow fever. By its works alone can it be judged. It seems
that, like the germ of rinderpest and of foot-and-mouth disease, it is
ultra-microscopic, and our highest lenses fail to resolve it. From the
course of the disease and the nature of its host, it will probably prove
to be something like the organism which causes malaria. The means of
warring against _Anopheles_ and _Culex_ are equally applicable in the
case of _Stegomyia_, but, since the last-named flies by day, they are
more difficult to carry out, and more irksome to endure. By the
intelligent application of these preventive measures the Americans have
freed Havana for the first time from yellow fever, and have materially
reduced the amount of malaria, and they have been equally successful at
Panama.
King Solomon sent to Tarshish for gold and silver, ivory, and apes and
peacocks, and at the present day people mostly go to Africa for gold,
diamonds, ivory, and game. These are the baits that draw them in. Of the
great obstacles, however, which have for generations succeeded in
keeping that great continent, except at the fringes, comparatively free
from immigrants, three--and these by no means the least important--are
insignificant members of the order Diptera. We have considered the case
of _Culex_ and _Anopheles_; the third fly we have now to do with is the
tsetse fly (_Glossina_), which communicates fatal diseases to man and to
cattle and domesticated animals of all kinds.
There are at least seven species of the genus which received its name as
long ago as 1830, when Wiedemann first described it. Perhaps the best
known species is _Glossina morsitans_, which was named by Westwood.
The members of the genus _Glossina_ are unattractive insects, a little
larger than our common house-fly, with a sober brownish or
brownish-grey coloration. When at rest the two wings are completely
super-imposed, like the blades of a shut pair of scissors; and this
feature readily serves to distinguish the genus from that of all other
blood-sucking flies, and is of great use in discriminating between the
tsetse and the somewhat nearly allied _Stomoxys_ and _Hæmatopota_.
The tsetse flies rapidly and directly to the objects it seeks, and must
have a keen sense of smell or sight, or both, making straight for its
prey, and being most persistent in its attacks. The buzzing which it
produces when flying is peculiar, and easily recognized again when once
heard. After feeding, the fly emits a higher note, a fact recalling the
observation of Dr. Nuttall and the present writer on the note of
_Anopheles_, in which animal they observed that, ‘the larger the meal,
the higher the note.’ The tsetse does not settle lightly and
imperceptibly on the sufferer as the Culicidæ do, nor does it alight
slowly and circumspectly after the manner of the house-flies, but it
comes down with a bump, square on its legs. Like the mosquito, the
tsetse is greedy, and sucks voraciously. The abdomen becomes almost
spherical, and of a crimson red, and in the course of a few seconds the
fly has exchanged the meagre proportions of a Don Quixote for the ampler
circumference of a Sancho Panza. There is a good deal of discrepancy
between the reports of the various sufferers as to the pain of the bite.
No doubt different persons are very differently affected, and suffer to
very varying degrees. Unlike so many of the blood-sucking Diptera, in
which the habit is confined to the females, both sexes of _Glossina_
attack warm-blooded creatures.
The fly always seems to choose a very inaccessible portion of the body
to operate on--between the shoulders in man, or on the back and belly in
cattle and horses; even inside the nostrils in the latter, or on the
forehead in dogs. According to Lieutenant-Colonel D. Bruce, R.A.M.C., to
whom we owe so much of our knowledge of this fly and its evil work, the
female does not lay eggs, but is viviparous, and produces a large active
yellow larva, which immediately crawls away to some secluded crevice,
and straightway turns into a hard, black pupa, from which the imago
emerges in some six weeks. Thus two stages, the egg and the larva, both
peculiarly liable to destruction in the Culicidæ, are practically
skipped in the tsetse--at any rate, in some species. On the other hand,
this advantage is probably to a great extent counterbalanced by the
smallness of the number of the larvæ produced, compared with the number
of the eggs laid by the oviparous Diptera.
The genera of the Culicidæ which we have considered are found
practically all over the world, but the genus _Glossina_, except that it
just reaches Arabia, is fortunately confined to Africa. From the
admirable map of the geographical distribution of the fly compiled by
Mr. Austen we gather that its northern limit corresponds with a line
drawn from the Gambia, through Lake Chad to Somaliland, somewhere about
the 13th parallel of north latitude. Its southern limit is about on a
level with the northern limit of Zululand. The tsetse, of course, is not
found everywhere within this area, and, though it has probably escaped
observation in many districts, it seems clear that it is very
sporadically distributed. Mr. Austen further thinks that it may occur
outside the boundary above laid down, and suggests that the great
mortality amongst the horses in the Abyssinian campaign against King
Theodore may have been caused by it.
Even where the tsetse is found it is not uniformly distributed, but
occurs in certain localities only. These form the much dreaded
‘fly-belts.’ The normal prey of the fly is undoubtedly the big game of
Africa, including crocodiles, but they are not the only factor in its
distribution; the nature of the land also plays a part. There are the
usual discrepancies in the accounts of travellers, especially of African
travellers, as to the exact localities the _Glossina_ affects; but most
writers agree that the tsetse is not found in the open veld. It must
have cover. Warm, moist, steamy hollows, containing water and clothed
with forest growth, are the haunts chosen. Even within the fly-belt
there are oases, due, perhaps, to an absence of shrubs or trees, where
no flies are.
The tsetse fly belongs to the family Muscidæ, the true flies, a very
large family, which also includes our house-fly, blue-bottle fly, etc.
These flies, unlike _Anopheles_ and _Culex_, are day-flies, and begin to
disappear at or about sunset, a fact noted centuries ago by Dante:
‘Nel tempo che colui, che il mondo schiara,
La faccia sua a noi tien meno ascosa,
Come la mosca cede alla zanzara.’[7]
The practical disappearance as the temperature drops has enabled the
South African traveller to traverse the fly-belts with impunity during
the cooler hours of the night. At nightfall the tsetse seems to retire
to rest amongst the shrubs and undergrowth, but, if the weather be warm,
it may sit up late; and some experienced travellers refrain from
entering a fly-belt, especially on a summer’s night, until the
temperature has considerably fallen.
The sickness and death of the cattle bitten by the tsetse were formerly
attributed to some specific poison secreted by the fly, and injected
during the process of biting. It is now, largely owing to the researches
of Colonel Bruce, known to be due to the inoculation of the beasts with
a minute parasitic organism conveyed from host to host by the fly. The
disease is known as ‘nagana,’ and the organism that causes it is a
species of _Trypanosoma_, a flagellate Protozoon or unicellular
organism, which moves by means of the lashing of a minute, whip-like
process. Since Bruce’s researches a number of _Trypanosomas_ have been
found causing diseases in various parts of the world. Thus _T. evansii_
causes the ‘surra’ disease of cattle, horses, and camels in India. _T.
equinum_ produces the ‘mal de caderas’ of the horse-ranches of South
America, and _T. equiperdum_ is responsible for the North African
disease called by the French the ‘dourine.’ _T. theileri_ causes the
gall-sickness, and there are others. These parasites were first seen by
Gruby, who named them in 1843, in the blood of a frog; they live, not as
does the malaria parasite, in the blood-cells, but in the fluid of the
blood. The particular species of _Trypanosoma_ which causes nagana is
_Trypanosoma brucei_, and it does not attack man, and some goats and
donkeys seem also immune; but, with these exceptions, all domesticated
animals suffer, and in a great percentage of cases the disease
terminates in death. Just as the native children in Africa form the
source of the supply of the malarial parasite without appearing to
suffer much, so the big game of the country abound in _Trypanosoma_
without appearing to be any the worse. They are, in Lankester’s phrase,
‘tolerant’ of the parasite, and a harmony between them and the parasite
has been established, so that both live together without hurting one
another. Under a more natural condition of things than at present
obtains in South Africa, the big game formed the natural prey of the
tsetse; and, indeed, so dependent is the fly on the antelopes, etc.,
that, in places where the game has been exterminated, the fly has also
disappeared. It is from the big game that the disease has spread. In
their bodies the harmful effect of the parasite has through countless
generations become attenuated, but it leaps into full activity again as
soon as the _Trypanosoma_ wins its way into the body of any introduced
cattle, horse, or domesticated animal. Whether the _Trypanosoma_ does
any harm to the fly, or whether it passes through any stages of its
life-history in the body of the fly, is still a debatable point.
Possibly it does not, and the proboscis of the fly acts then simply as
an inoculating needle.
The Report of Colonel Bruce, which was issued three years ago, shows
that the sleeping-sickness which devastates Central Africa, from the
West Coast to the East, is also conveyed by a species of tsetse fly.
Writing over a hundred years ago of Sierra Leone, Winterbottom mentions
the disease. ‘The Africans,’ he says, ‘are very subject to a species of
lethargy which they are very much afraid of, as it proves fatal in every
instance.’ Early last century it was recorded in Brazil and the West
Indies; and in all probability the deaths which our slave-owning
ancestors used to attribute to a severe form of home-sickness, or even
to a broken heart, were in reality caused by sleeping-sickness. The
severity of the disease, which always terminates fatally, is shown by
the fact that in a single island--Buvuma--the population has recently
been reduced by it from 22,000 to 8,000, whilst whole districts have
been almost depopulated. In one year the deaths in the region of Busoga
reached a total of 20,000; and it is calculated that although the
disease was only noticed in Uganda for the first time in 1901, that by
the middle of 1904 100,000 people have been killed by it. The disease is
caused by the presence of a second species of _Trypanosoma_ in the blood
and in the cerebro-spinal fluid. The existence of this parasite has now
been proved in all the cases recently investigated. Apparently the
_Trypanosoma_ can live in the blood without doing much harm, and only
when it reaches the cerebro-spinal canal does it set up the
sleeping-sickness. It is also found in great numbers in the lymphatic
glands, especially those of the neck, which in patients infected by the
parasite are usually swollen and tender. From the similarity of the
parasite to that causing the cattle disease of South Africa, the idea at
once arose that the _Trypanosoma_ was conveyed from man to man by a
biting insect. Along the lake shores a species of tsetse (_Glossina
palpalis_) abounds; and it was noticed that if the fly, having fed off a
sleeping-sickness patient, bit a monkey, the monkey became infected.
Further, flies which were captured in a sleeping-sickness district were
also capable of conveying the disease to healthy monkeys. The proof that
sleeping-sickness is due to a _Trypanosoma_ known as _T. gambiense_
present in the cerebro-spinal fluid of the patient, and that it is
conveyed from man to man by _Glossina palpalis_, seems now complete.
Fortunately, like its congener, _G. palpalis_ is confined to certain
districts. The knowledge of these, and of the habits of this species of
fly, will suggest preventive measures; and the brilliant research of
Colonel Bruce and his colleagues, Captain Grieg and Dr. Nabarro, may yet
save the much-tried African continent from the most fatal of recent
diseases.
Finally, we come to a last class of disease which is of the utmost
interest to the agriculturist and settler, and yet at present is but
little understood. These diseases are caused by various species of a
Protozoon named _Piroplasma_, and the diseases may collectively be
spoken of as piroplasmosis. When they are present in cattle they are
spoken of in various parts of the world as Texas fever, tick fever,
blackwater, redwater, and many other French, German, Italian, and
Spanish names. Heartwater in sheep is a form of piroplasmosis. Horses
also suffer, and the malignant jaundice or bilious fever, which makes it
impossible to keep dogs in certain parts of this country, is also caused
by a _Piroplasma_. Finally, under the name of Rocky Mountain fever,
spotted or tick fever, the disease attacks man throughout the west half
of the United States.
The organisms which cause the disease live for the most part in the red
blood-corpuscles, but they are sometimes to be found in the plasma or
liquid of the blood. Unfortunately, we know but little about the
life-history of the _Piroplasma_, or of the various stages it passes
through, but we do know how it is transmitted from animal to animal and
from man to man.
We have seen that the carrier or ‘go-between’ in the case of the malaria
is the mosquito, and in the case of the sleeping-sickness is the tsetse
fly. The _Piroplasma_, however, is not conveyed from host to host by any
insect, but by mites or ticks, members of the large group of Acarines,
which include beside the mites the spiders, scorpions, harvestmen, and
many others.
The ticks differ from the insect bearers of disease inasmuch as the tick
that attacks an ox or a dog does not itself convey the disease, but it
lays eggs--for I regret to say here, as with the _Anopheles_, it is the
female only that bites--and from these eggs arises the generation which
is infective, and which is capable of spreading the disease. The tick
which conveys the _Piroplasma_ from dog to dog is called _Hæmophysalis
leachi_. The brilliant researches of Mr. Lounsbury have shown that even
the young are not immediately capable of giving rise to the disease. The
female tick gorges herself with blood, drops to the ground, and begins
laying eggs. From these eggs small six-legged larvæ emerge. These larvæ,
if they get a chance, attach themselves to a dog, gorge themselves, and
after a couple of days fall off. If their mother was infected they
nevertheless do not convey the parasite. After lying for a time upon the
ground the larval tick casts its skin and becomes a nymph, a stage
roughly corresponding with the chrysalis of a butterfly. This nymph, if
it has luck, again attaches itself to the dog and has a meal, but it
also fails to infect the dog. After a varying time it also drops to the
ground, undergoes a metamorphosis, and gives rise to the eight-legged
adult tick. Here at last we reach the infective stage; the adult tick is
alone capable of giving the disease to the animal upon which she feeds,
and then only when she is descended from a tick which has bitten an
infected host. Think what a life-history this parasite has! Living in
the blood-corpuscles of a dog, sucked up by an adult tick, passed
through her body until it reaches an egg, laid with that egg, being
present while the egg segments and slowly develops into the larva,
living quiescent during the larval stage and the nymph stage, surviving
the metamorphosis, and only leaping into activity when the adult stage
is reached. This most remarkable story probably indicates that the
_Piroplasma_ undergoes a series of changes comparable to those of the
malaria organism when it is inside the mosquito; what these stages are
we do not at present know, but Dr. Nuttall and Mr. Smedley at Cambridge,
and many other observers elsewhere, are at work on the problem, and soon
we shall have more light.
With regard to bovine piroplasmosis, Koch, and others have distinguished
redwater fever, which is conveyed by _Rhipicephalus annulatus_, and in
Europe probably by _Ixodes reduvius_ from the Rhodesian fever, which is
conveyed by _Rhipicephalus appendiculatus_, and I regret to say by a
species dedicated to myself, _Rhipicephalus shipleyi_.
The heartwater disease of sheep and goats is similarly conveyed by
_Amblyomma hebræum_, the Bont tick, and many farmers accuse _Ixodes
pilosus_ of causing the well-known paralysis from which sheep suffer in
the early autumn; and there are many others, diseases such as the
chicken disease of Brazil, which is so fatal to poultry yards, and which
is conveyed by the _Argas persicus_.
I will not weary you with more diseases. I think I have said enough to
show that within the last few years a flood of light has been thrown
upon diseases not only of man and his domestic animals, but upon such
insignificant creatures as the mosquito and the tick. I have tried to
show how these diseases interact, and how both hosts are absolutely
essential to the disease. We can now to a great extent control these
troubles; the old idea that there is something unhealthy in the climate
of the Tropics is giving way to the idea that the unhealthiness is due
to definite organisms conveyed into man by definite biting insects. We
have at last, I think, an explanation of why Beelzebub was called the
Lord of Flies.
THE DANGER OF FLIES
_And Moses said, Behold, I go out from thee, and I will entreat the
Lord that the swarms of flies may depart from Pharaoh, from his
servants, and from his people, to-morrow._--EXODUS.
It is one of those facts which not unfrequently occur in science that we
know less about the life-history and habits of the commonest insects
than we know about scarce and remote species. For instance, the
life-history of the common house-fly, one of the most widely distributed
insects in the world, is as yet very incompletely known.
It was Linnæus who first described this insect and named it _Musca
domestica_, and de Geer who, in the middle of the eighteenth century,
first described its transformation. In 1834 Bouché described the larva
of the insect as living in the dung of horses and fowls. In 1873 the
well-known American entomologist, A. S. Packard, reinvestigated the
question, and L. O. Howard has recently written on the subject. In our
own country C. Gordon Hewitt is publishing a monograph on the house-fly,
which will, when completed, fill a long-felt want. Packard noted that in
the August of 1873 the house-fly was particularly abundant, especially
in the neighbourhood of stables. He was able to observe the insects
laying their ova in clumps containing some 120 eggs in the crevices of
stable manure, ‘working their way down mostly out of sight.’ The eggs
hatched in about twenty-four hours, but he noticed that those hatched in
confinement required from five to ten hours longer, and that these
larvæ when hatched were smaller than those hatched out in the open. The
eggs are oval and cylindrical, one twenty-fifth to one-twentieth of an
inch long and about one-hundredth of an inch wide, and of a dull,
chalky-white colour.
The little larva has not been seen emerging from the egg-case, but
probably, as in the case of the meat- or blow-fly, _Musca vomitoria_, the
eggshell splits longitudinally and the maggot pushes its way out. The
length of the newly-hatched larva in its first stage (or instar) is
seven-hundredths of an inch, and it remains in this stage about
twenty-four hours, when it casts its skin and appears as a larger maggot
three-twentieths of an inch long. In this condition it remains from
twenty-four to thirty-six hours. After a second moult the maggot attains
the length of one-quarter of an inch, and in this stage it remains five
or six days. During its life the larva moves actively about amongst its
surroundings, eating up the decaying matter, but avoiding bits of straw
and hay. There is some evidence to believe that, if pressed for food,
larvæ may devour one another. After living altogether some five to seven
days, the larva somewhat suddenly turns into a dark brown pupa or
chrysalis. The transition takes place very rapidly--in the course of a
few minutes--and the pupa remains enclosed in the last larval skin.
After another period of five to seven days in normal circumstances the
insect hatches out, at first running around with soft and baggy wings,
which, however, soon stretch out, harden, and dry. It is worthy of note
that whereas Howard found the complete metamorphosis to take ten days,
and Packard from ten to fourteen days, in the cooler climate of
Manchester Hewitt finds it takes from twenty to thirty days. The last
named gives some interesting particulars as to the effect of the weather
upon the rate of development. It is believed that many flies pass the
winter in the pupa state; the adult fly also survives the cold weather
hidden away in cracks and crevices, from which it may from time to time
emerge when the sun shines warmly.
When the larvæ are reared in too dry manure, they attain only one-half
their usual size. Too direct warmth and the absence of moisture and
available semi-liquid food also tend to dwarf them.
A word may be said about the distribution of the insect. It is
practically cosmopolitan. As Mr. Austen records:
‘The British Museum collection, though very far from complete,
includes specimens from the following localities: Cyprus;
North-West Provinces, India; Wellesley Province, Straits
Settlements; Hong Kong; Japan; Old Calabar; Southern Nigeria; Suez;
Somaliland; British East Africa; Nyassaland; Lake Tanganyika;
Transvaal; Natal; Sokotra; Madagascar; St. Helena; Madeira; Nova
Scotia; Colorado; Mexico; St. Lucia; the West Indies; Pará, Brazil;
Monte Video, Uruguay; Argentine Republic; Valparaiso, Chili;
Queensland; New Zealand.’
It is carried all over the world in ships and trains, and seems to be
equally at home in the high latitudes of Finmark or in the humid heat of
Equatorial Brazil.
The diseases which flies convey from man to man--which rendered them by
no means the least formidable of the plagues of Egypt, and fully
justified Beelzebub’s title of the ‘Lord of Flies’--are for the most
part conveyed mechanically. The proboscis acts as an inoculatory needle.
No part of the life-history of the disease-causing organism must
necessarily be carried on in the body of the fly; it is conveyed
mechanically and without change from an infected to a healthy subject.
The mouth parts can pick up the anthrax bacillus, and if the fly then
alight upon a wounded surface it will set up woolsorter’s disease. It,
together with the flea, is accused of transmitting the plague bacillus,
not only from man to man, but from rat to man. Flies are active agents
in disseminating cholera; and anyone who has watched them clustering
around the inflamed eyes of the children in Egypt, or in Florida, will
not readily acquit them of being the active agents in the spread of
inflammatory ophthalmia or of ‘sore eye.’
It is worthy of note that after exhaustive experiments on the tsetse fly
(_Glossina palpalis_), which conveys that most fatal of diseases,
sleeping-sickness, Professor Minchin and his colleagues, Mr. Gray and
Mr. Tulloch, have come to the conclusion that the Protozoon
(_Trypanosoma gambiense_) which causes the disease does not--as might be
expected--pass through certain stages of its life-history in the fly,
but is mechanically conveyed upon the biting mouth parts of the insect.
The deadly parasite is, indeed, so easily cleaned off these appendages
that a single bite is sufficient to wipe them off. A tsetse fly which
has bitten an infected person will set up the disease in the next person
(or monkey) it bites; but the insertion of the proboscis, quick and
instantaneous as it is, serves to clean it--to wipe off adhering
trypanosomes, and if it now bite a second person (or monkey), it fails
to convey the disease. This is a most important discovery, and contrary
to what we should have expected; but our knowledge of the history of the
genus _Trypanosoma_ is still too small to justify generalization,
difficult as it is to avoid it. The diseases which in our country are
disseminated by flies are all bacterial and all mechanically conveyed.
In passing, it is worth recording that, contrary to the usual statement
that tsetse flies are confined to the continent of Africa, Captain R. M.
Carter[8] has recently brought some back from the Tabau River and from
other localities in South Arabia. Mr. Newstead has recognized the
specimens as belonging to the species _Glossina tachinoides_. It
evidently does not live on big game here, since, except the gazelle,
game is absent. The Bedouins say that it bites donkeys, horses, dogs,
and man, but not camels or sheep. It is at times so troublesome as to
force the natives to shift their camps.
The common house-fly has been known for some time to be an active agent
in the dissemination of bacterial diseases. In intestinal
disorders--such as cholera and enteric fevers, which are caused by
micro-organisms, the flies convey the bacteria from the dejecta of the
sick to the food of the healthy. In the recent war in South Africa they
are described in the standing camps as dividing their activities
‘between the latrines and the men’s mess-tins and jam rations.’[9] In
the Spanish-American War in Cuba, and in the South African War, and in
several recent outbreaks of enteric fever in the British army in India,
flies have been proved to be the carriers of the _Bacillus typhosus_.
Dr. Veeder[10] writes:
‘In a very few minutes they may load themselves with dejections
from a typhoid or dysenteric patient, not yet sick enough to be in
hospital or under observation, and carry the poison so taken up
into the very midst of the food and water ready for use at the next
meal. There is no long roundabout process involved. It is very
plain and direct; yet when thousands of lives are at stake in this
way the danger passes unnoticed.’
Similar records come from the Boer camp at Diyatalawa in Ceylon. The
bacilli are conveyed direct, just as they might be by an inoculating
needle. They do not pass into the body of the fly, neither do they
undergo any part of their life-history in its tissue.
Dr. Sandilands[11] has recently investigated outbreaks of epidemic
diarrhœa. He points out that the prevalence of diarrhœa follows
the earth’s temperature, and does not follow the temperature of the
atmosphere. It is a well-known fact that this illness is more prevalent
in the houses of the poor than in the mansions of the rich. As Dr.
Newsholme, late Medical Officer of Health for Brighton, said:
‘The sugar used in sweetening milk is often black with flies which
have come from neighbouring dust-bins or manure heaps; often from
the liquid stools of diarrhœa patients in the neighbouring
houses. Flies have to be picked out of the half-emptied can of
condensed milk before it can be used for the next meal. When we
remember the personal uncleanliness of some mothers, and that they
often prepare their infants’ food with unwashed hands, the
inoculation of this food with virulent colon bacilli of human
origin ceases to be a matter of surprise.’
Compared with cow’s milk, which nourishes a very numerous progeny of
bacteria, the bacterial content of Nestlé’s milk is very low, according
to Dr. Sandilands. In certain seasons the cow’s milk is exposed to
temperatures which favour an enormous multiplication of bacteria, and
yet it is not then a frequent source of diarrhœa--in fact, mere
numbers have little or no influence on the incidence of the illness. The
greater number of cases are due to infection conveyed from some patient
in the near neighbourhood and conveyed mechanically by flies.
The great attraction of the sweetened condensed milk for flies to some
extent explains the greater prevalence of infantile diarrhœa among
children fed on this preparation.
As was stated above, one of the most remarkable features in the
prevalence of infantile diarrhœa is that it follows the rise and fall
of the earth’s temperature, and not that of the air. In the same way the
number of house-flies does not reach its maximum with the first burst of
hot weather. The prevalence of these insects follows rather than
coincides with periods of great heat. The flies, in fact, lag behind the
air temperature and persist for a time after the hot weather has ceased.
In other words, the meteorological conditions associated with an
increase or a diminution of the prevalence of diarrhœa exercise a
similar influence on the prevalence of flies.
The transference of the _Filaria bancrofti_, whose presence in the human
body in the adult stage is associated with various diseases of the
lymphatics, the most pronounced of which is the terrible elephantiasis,
is due to more than one species of gnat or mosquito. It is true that no
one has ever seen the actual transference of the _Filaria_ from the
biting organs of the _Culex_, _Anopheles_, _Panoplites_, or _Stegomyia_
into the human body, but the circumstantial evidence is so strong that
on it any jury would convict. Noè and Grassi have demonstrated a similar
mode of infection for the _Filaria immitis_, which exists in the adult
stage in such incredible numbers in the cavity of the right side of the
heart of dogs, especially in tropical and in sub-tropical countries,
that it is difficult to see how the circulation can be maintained at
all. It is therefore interesting to note that the proboscis of our
common house-fly frequently harbours a larval nematode which has been
described by Carter[12] under the name of _Habronema muscæ_; and again
(if it be the same species) by Generali[13] under the name _Nematodum
sp._ (?), and again by Piana,[14] who is inclined to think it is the
larval form of _Dispharagus nasutus_ (Rud.). What the further history of
this parasite is we do not conclusively know, but, judging by
analogy--and in the case of the grosser parasites it is not always wise
to do that--the nematode probably develops in some higher animal which
eats the fly. Piana brings forward a good deal of evidence that this is
the domestic fowl.
Another parasite which attacks flies is the fungus or mould _Empusa
muscæ_, whose growth is fatal to the insect. The hyphæ penetrate into
the body, and as they grow weaken the fly until it is unable to lift a
leg, but remains glued by its viscid feet to the object upon which it
rests. The fungus spreads and radiates out in all directions, covering
the fly as with a velvety pile, and giving off countless minute spores,
which are blown away, to alight, if they are lucky, on a further victim.
I think enough has been said to prove that flies are a very real danger
to our community. I have refrained from giving the appalling statistics
of our infant mortality, partly because of the difficulty of
discriminating between the claims of the flies and those of other
agencies which affect the lives of our babies--_e.g._, the insurance
companies which do a large trade in insuring infants. Legislation has
not attempted to control the latter. Sanitation might do much to destroy
the former. In well-administered towns slaughterhouses no longer ‘fill
our butchers’ shops with large blue flies’; they have been replaced by
abattoirs, under proper inspection. Stables should also be segregated or
controlled. The practice of backing the mansions of Berkeley Square by
stable yards should either be given up, or the manure-heaps in which the
flies breed should be under cover so close as to prevent the access of
the fly. A layer of lime spread over the manure effectively prevents
the fly laying. Creolin, in its cheap commercial form, is also
recommended, sprayed over the manure-heaps every two or three days. It
not only deters flies from ovipositing, but should they succeed in doing
so it kills the resulting larvæ.[15]
Ross has shown us how to clear Ismailia of malaria; the Americans have
rid Havana, for the first time in a century, of yellow fever; the same
could be done with flies, if only the people liked to have it so. The
motorcar, with all its destruction of nervous tissue, its prevention of
sleep, its danger to life and to limb, has one great merit--it affords
no nidus for flies.
CAMBRIDGE
‘_Our dear Cambridge._’
COWLEY:
‘On the Death of Mr. William Hervey.’
The grant of a charter to the Victoria University in 1880 marked the
beginning of a new era in English education. Not to speak of Scotland
and Wales, there are in England to-day six Universities which bring the
new learning and the old to the very doors of the vast populations which
surround their seats. Birmingham claims the Midlands; Manchester,
Liverpool, Leeds, and Sheffield instruct the manufacturing and
commercial centres of the North; while the University of London, full of
new aspirations, does its best for the huge and somewhat apathetic
population of the capital. The calculated prodigality of the State
endowments of Germany, the individual generosity of the citizens of the
United States, the vigour of the young Universities of Canada, have
smitten the national conscience, if not with shame, at least with fear.
But, while so powerful a lever as the dread of industrial decay may have
been necessary to overcome the intellectual inertia of the country, the
consequent impetus given to the study of science and (it may be hoped)
of letters is not dying away, but rather taking permanent shape; and it
is now impossible to say, as was said in 1903 by one of the members of
the Mosely Educational Commission, that ‘in this country ... we seem to
be doing nothing for its own sake, and least of all in education.’
The new edition of the ‘Endowments of the University of Cambridge’
suggests other, though kindred, reflections. The book has for its basis
a series of documents, beginning with the year 1293, and ending with the
year 1904. The learned Registrary has prefaced the account of each
bequest with an explanation, and, by his discriminating comment, has
invested his material with something of that charm which characterizes
all his work. In one aspect his book serves, and is intended to serve,
as a history of the progress of education in Cambridge; and the large
amount of new matter which has been incorporated since the previous
edition of the ‘Endowments’ in 1876 is, in this aspect, highly
satisfactory. Yet, though it is a mistake to suppose that the flow of
benefactions to the ancient Universities has entirely ceased, the fact
remains that Cambridge has twice appealed--once in 1898, and once again
in the spring of 1904--for help, without which she cannot meet her
national responsibilities. Oxford has at last been constrained to
confess that she is in a similar, if not yet so dire, a strait; and it
is easy to understand the effort which it has cost her, as well as her
sister University, to sue _in formâ pauperis_.
In truth, the neglect, almost absolute, of Oxford and Cambridge, while
the new Universities are finding generous benefactors, either leads to
the conclusion that the old Universities are condemned and found
wanting, or has its origin in a profound misconception of their efforts
and resources. It may be urged that neither alternative is true; that
the needs of the new Universities are more urgent, and that the needs of
Oxford and Cambridge will in turn receive attention. But a delay of a
few years may in these days involve damage which will not be repaired
for more than one generation. Of Cambridge, at any rate, it is asserted
that she is at the end of her means, that in the last forty years she
has, in her efforts at development, strained her resources to the
utmost, and that without assistance, which, to be effectual, must be
both prompt and generous, no further advance is possible. Science has
emptied the University chest, yet, as the late master of Trinity Hall
said, ‘Science is still hungry and aggressive.’ As the result of her
straitened resources Cambridge can no longer satisfy the just demands
either of science or of letters. When we compare this state of things
with that in Germany, where the University of Berlin enjoys a State
endowment of £170,000 per annum, or in the United States, whose
Universities have received from private benefactors alone £42,000,000
sterling in the last thirty years, apart from large funds provided by
the State, we are forced to recognize that much yet remains to be done
in England.
It is not difficult to suggest some reasons for the comparative neglect
of the older Universities in the matter of benefactions. In the first
place, neither of them can appeal to local patriotism; and an appeal on
the wider ground of national efficiency is not so easily nor so
effectively pushed home. Next, it is hard to imagine that a University
whose colleges enjoy a corporate income of something like £300,000 a
year can be in serious want of funds. Moreover, if this deficiency
really exists, it is generally regarded as the result of the squandering
of revenue on an extravagant system of ‘prize fellowships’--that is,
fellowships given as the reward merely for a high place in examination,
and held by barristers, doctors, and civil servants, professors and
lecturers in other Universities, and even successful men of
business--persons who do not contribute in any way to the efficiency of
the University as a teaching or as an investigating body.
* * * * *
We propose briefly to examine the University balance-sheet, the college
system, and the question of the fellowships, and to endeavour to give
the candid inquirer some ground for a judgment on the claims of
Cambridge. But we must first discuss what is perhaps the most serious
obstacle to the satisfaction of her needs. This obstacle is the belief,
apparently ineradicable, that the older Universities teach and care for
nothing but the ancient languages, theology, and mathematics. For the
persistence of this belief the daily press and public speakers are in a
great measure to blame. Scarcely a week passes without an allusion which
betrays, if not a culpable levity, a most unfortunate ignorance.
Cambridge men have listened with amazement to the covert attacks on
Cambridge science, and have wondered how long it may be before Cambridge
letters are also disparaged. Of late, too, another note has been heard;
and, notwithstanding the just aspiration of the new Universities to a
many-sided activity, alike in the literary and scientific fields, an
attempt, which must be stigmatized as ungenerous and illiberal, has been
made in the press and on the public platform to limit the functions of
the ancient Universities, and to drive them back into the grooves of the
thirties and forties, from which Cambridge, to say nothing of Oxford,
has so completely escaped. Whatever the reason may be, it is at least
certain that Cambridge is frequently written and spoken of as if she
were still the Cambridge of 1850.
It has been suggested, even in responsible journals, that Oxford and
Cambridge would do well to keep to the older lines of education, and to
leave newer studies to their younger rivals. The obsession of men’s
minds by an ideal which passed away half a century ago can alone account
for the impression that the policy of restriction to the ancient
learning is in any way possible, or has been possible for these fifty
years. Those who know Cambridge may well be astonished that responsible
persons should gravely speak of the University of Newton and Charles
Darwin, of Maxwell and Rayleigh, as still shrouded in medieval shadow.
It cannot be too often repeated that since the Commission of 1850, or
rather since the promulgation of the new statutes in 1856, the
University has advanced without pause to claim as her own the whole
field of modern knowledge; and that it is the rapidity of her advance
which has depleted her treasury. The state of things before 1850 need
here be referred to only for purposes of contrast. The only avenue to an
honours degree was then the Mathematical Tripos, or, for students of
classics, the Mathematical combined with the Classical Tripos. Science
formed no part of the regular course of instruction. Adam Sedgwick
himself, pre-eminent geologist as he afterwards became, knew nothing of
geology when admitted to his professorship. When he was appointed to his
chair, classics, mathematics, and, in a less degree, theology and law,
were well endowed; but effective provision for modern studies or for
science there was none. In 1851 was founded the Disney professorship of
archæology, and the creation of this chair may fairly be considered to
be the first step towards the recognition of the sciences of ethnology
and anthropology. The imperial value of ethnological and anthropological
research is incontestable, and to this research no more important
contribution has been made than by the bands of Cambridge travellers and
students.
Mention has been made in the first place of the studies more closely
related to the ‘humanities,’ because it does not seem generally to be
realized how thoroughly even the ancient learning is to-day imbued by
the scientific spirit. But, so early as the year 1851,[16] new avenues
to an honours degree were opened by way of the Moral Sciences Tripos
(embracing at present psychology, logic and methodology, political
economy, ethics, metaphysical and moral philosophy and psychophysics),
and the Natural Sciences Tripos (embracing chemistry, physics,
mineralogy, geology, botany, zoology, human anatomy, and physiology). In
1857 the Sadlerian professorship of pure mathematics was founded by the
consolidation of an old endowment; and Cayley was the first occupant of
the chair. In 1863 the block of buildings known as ‘The Museums’ was
commenced, with a view to providing accommodation for the professors of
the natural sciences; additions were made to the original buildings in
1877, 1880, 1882, 1884, and 1890, as new branches of science became
important. In 1858 the ‘Civil Law Classes’ were replaced by the Law
Tripos; the professor of civil law and the Downing professor of the laws
of England were given a colleague by the creation of the Whewell
professorship of international law in 1867; and the Law School has since
1904 possessed a worthy habitation, built partly at the expense of the
University, partly by the help of eminent Cambridge lawyers, and
completed by the generous donation of the law library by Miss Squire. In
1866 the professorship of zoology was founded.
The School of Medicine has grown continuously; and its progress is
associated with the great names, to mention no others, of Sir George
Humphry, Sir George Paget, and Sir Michael Foster. In 1883 were founded
the professorships of surgery, physiology, and pathology. The diploma of
public health was instituted in 1875, and the diploma in tropical
medicine--the first of its kind in the kingdom--in 1904. The latter
diploma is destined to a brilliant future in Cambridge; and the
University, together with the schools of tropical medicine in London and
Liverpool, is doing much to raise the scientific standard of research
in a study so vitally important to the teeming populations of our
tropical possessions. The students attending the School of Medicine in
Cambridge number nearly four hundred, despite the high standard of the
attainments necessary for qualification. In 1904 important new
buildings, with provision for bacteriology, pathology, and public
health, were opened by the King.
The year 1869 was marked by the foundation of the Slade professorship of
fine art, and the professorship of Latin. The endowment of the latter
chair is but £300 a year, half provided by the University and half by
the friends of the late Dr. Kennedy, the famous headmaster of Shrewsbury
School. That the University should have had to wait till 1869 for the
foundation of a chair of Latin, and that the parsimonious contribution
of £150 a year was all that could be spared towards the stipend of the
professor, scarcely lends colour to the prevailing belief that the
University, kindly and naturally as she may be disposed towards the old
learning, squanders on the teaching of ancient languages resources which
ought to be otherwise employed. In 1875 the Historical Tripos was
founded; and the School of History, starting under the influence of
Seeley, has become one of the most popular avenues to an honours degree.
A professorship of ancient history was founded in 1898.
The Historical Tripos already provided in some measure for the study of
political science and political economy as component parts of a liberal
education. But latterly the need for a more thorough study of economic
conditions has been felt to be imperative for those who look forward to
a career in the higher branches of business or in public life; while, as
regards the professional economist, it has been realized that his work
as a student must be carried much farther than has hitherto been
customary, if he is to attack with success those problems which bring
his science close to reality and to the needs of the practical man. A
Tripos in Economics has therefore been established, the first
examination for which was held in 1905. The advanced portion of it
includes such subjects as modern methods of production, transport and
marketing, trusts, the recent development of joint-stock companies,
railway and shipping organization and rates, banking systems, stock
exchanges, investment markets, international aspects of credit and
currency, tariffs and bounties; and it is expected that, as in the
second parts of most other triposes, a mass of new work, the result of
current research, not yet available in text-books, will be placed before
the students.
The Medieval and Modern Languages Tripos dates from 1886. It provides
for the study of English, French, German, Spanish, Italian, and Russian.
A colloquial test has recently been added. The Semitic Languages Tripos
was established in 1878; the Indian Languages Tripos was founded in
1879, and merged in the Oriental Languages Tripos in 1895. The
University founded a professorship of Sanskrit in 1867; and a chair of
Chinese has existed since 1888. The University possesses the finest
Chinese library in the world outside of China, the gift of Sir Thomas
Wade. Provision is made for the teaching of Arabic, Persian, Turkish,
Hausa, Burmese, and the Indian vernaculars of Bengali, Hindustani,
Marathi, and Tamil. The teaching of living Oriental languages for the
benefit of practical students is carefully co-ordinated under a recently
appointed director of studies; and not only are the most necessary
languages taught in their living forms by competent scholars, but these
latter are assisted by a staff of carefully selected native
_répétiteurs_. Towards the expenses of this work the University
contributes about £2,800 a year. A professorship of Anglo-Saxon was
founded in 1878.
In 1871 the chair of experimental physics was founded, a chair held in
succession by Clerk Maxwell, Lord Rayleigh, and J. J. Thomson; and in
1874 the famous Cavendish laboratory, the munificent gift of its late
chancellor to the University, was opened. The laboratory was designed by
Maxwell; and the chancellor himself, soon after its completion, provided
all the instruments which were immediately required. In 1894 the area of
the laboratory was increased, the cost being defrayed, in part, by a sum
of £2,000 saved by Professor Thomson out of fees received from students;
but the constant pressure on the available space by research students
coming from all quarters of the globe rendered further extension
urgently necessary, an extension which Lord Rayleigh’s generous gift of
the Nobel Prize has now enabled the University to undertake. Astronomy
has a traditional home in Cambridge; and the observatory, which in 1706
found a strange temporary site over the gateway of Trinity College,
began to be built on its present site in 1822. The observatory, which
takes its regular share of the work mapped out for the observatories of
Europe, has received important additions in the shape of both building
and equipment in recent years.
In 1875 the professorship of mechanism and applied science was
established; and in 1878 the first engineering workshops were built in
the University, and fitted with machine tools and other necessary
equipment. In 1894 the new engineering laboratories were opened during
the tenure of the professorship by Dr. Ewing, now director of naval
education. In 1894, also, the first examination for the Mechanical
Sciences Tripos, which gives a degree in honours to students of
engineering, was held. In 1899 the generosity of Mrs. Hopkinson and her
family made possible the addition of a much needed new wing to the
laboratory. The buildings of the department now contain lecture-room
accommodation which seats about 360 students simultaneously, a
drawing-office for a class of ninety, two rooms for elementary heat and
mechanics, a boiler-room, an engine-room with ten heat-engines of
different types, arranged so that the measurement of all quantities
concerned may be systematically made by the students, a large room for
dealing with strength of materials and with hydraulics, a dynamo-room
fitted with various kinds of dynamos, a motor-room fitted with motors of
all the usual types, and several other rooms for special purposes. The
greater part of the staff have had practical engineering experience of
some kind; and it is usual during the long vacation for one or two
members of the staff, as well as a number of the students, to go into a
drawing-office or into works in order to keep in touch with practice.
The school numbers at present more than 250 students, and supplies young
engineers with a scientific training to various public services, as well
as to mechanical and electrical firms.
The University chemical laboratory was built in 1887; and, while
planning it, the professor of chemistry spent some months in visiting
the newest laboratories on the Continent and in America. The importance
of botany has of late years so greatly increased that its study is
represented in Cambridge by a professor, a reader, and two University
lecturers, besides demonstrators, assistant demonstrators, and
attendants. In 1904 botany was housed in a separate building of its own,
the finest devoted to that science in the United Kingdom, and one of the
finest in Europe. The physiology of plants, bacteriological research,
and the cultivation of hybrids and seedlings, are completely provided
for. The extensive botanic garden belonging to the Senate is at the
disposal of the staff and the students, the more distinguished of whom,
after completing their degree course in Cambridge, start on a course of
research in this country or abroad. The importance of the department as
touching agriculture on its scientific side can hardly be overestimated.
The professorship of agriculture was founded in 1899, and endowed for a
term of years by the munificence of the Worshipful Company of Drapers, a
body which, with commendable breadth of view, recognizes alike the
importance of applied scientific instruction for the artisan and of
scientific investigation in all forms of the national activity. The
department of agriculture is conducted on the most practical and
progressive lines. It provides instruction in the principles of
agriculture for the sons of landowners, farmers, and others. It conducts
experiments on crops and live stock, making every effort to secure the
intelligent co-operation of farmers. The University experimental farm,
for the use of which the department is indebted to the generosity of a
member of Clare College, has an area of 140 acres. The County Councils
of Cambridgeshire and nine neighbouring counties co-operate in the work
and assist it by subsidies. The field experiments of the department
extend over ten counties. Parties of farmers visit the experimental
plots every season in order to see the results of the experiments and to
discuss them with members of the staff; and reports which summarize
these results are widely distributed in the districts concerned. Of the
suitability of Cambridge as a site for a school of agriculture, and of
the importance of the work undertaken by the school, it may be well to
leave the late professor to speak for himself.
‘I have but recently become a member of the University, and, like a
good many others, I at one time doubted the possibility of founding
a thoroughly satisfactory school of agriculture in one of the old
English Universities. But I no longer doubt; and as one who, before
coming to Cambridge, was a teacher or student in five British
Universities, I will venture to say that nowhere else do such
opportunities exist. Apart altogether from the exceptional
facilities for the study of science possessed by the University,
and apart, too, from the exceptional practical skill of the farmers
in the surrounding counties, the old University appears to me to be
more disposed to extend a helping hand to agriculture than many of
her younger sisters; and nowhere has a more friendly reception been
given than at Cambridge to the new organization fostered by the
activity of the Board of Agriculture....
‘American experience leaves no room for doubt that modern
scientific methods are capable of greatly increasing the prosperity
of agriculture, and that the farmer has no better ally than the
laboratory worker. But, if we wish to make these benefits ours, we
must cease to be satisfied with imported information; ... we must
aim at securing for agriculture the services of British
specialists, men who will give their whole time to the study of one
subject under the conditions which prevail in our own country. To
the extent of our resources this has been the policy of our
agricultural department in Cambridge.
‘We are in the centre of the finest land in England; we already
have an organization by which we reach the farmer; we know his
wants; and the University has supplied us with well-qualified
teachers of applied science. If we were in possession of suitable
laboratories, properly equipped for research, we should find
competent investigators and willing assistants among the younger
members of the University who are always ready to engage in
original work, either with the view of gaining knowledge or in
order to qualify themselves for appointments.’
In considering the development of all these departments, and the
foundation of the chairs and other teaching posts made necessary by
them, it must be remembered that the professorships already existing
before 1850 included, among others, those of chemistry, anatomy,
botany, geology, mineralogy, medicine, physic, political economy, moral
philosophy, modern history, Arabic, and music; that these chairs had,
before the Commission of 1850, no very important duties attached to
them; and that in the last fifty years each has been adapted to its
place in the University system, and each has in turn become a new centre
of activity round which, to use a convenient term unfamiliar in
Cambridge, a ‘faculty’ has crystallized. To many important developments
it has been possible to allude only in the most cursory manner. The
merest mention must suffice for the diploma in geography; the diploma in
mining engineering, with its provision for practical experience in mines
in this country or abroad; the diploma in forestry, which is a logical
outcome of the development of the botanical and agricultural schools;
the provision for military studies, and the Day Training College for
teachers. The latter has both a primary and a secondary department, and
the certificate given by the University in the theory, history, and
practice of education, and for practical efficiency, attracts teachers
in great numbers from all parts of the country.
* * * * *
Development so wide and so rapid as that which we have sketched has been
of necessity costly. The expenditure since 1862 on buildings devoted to
science alone must have considerably exceeded £300,000, the greater part
having taken place in the latter years of the period; and it must be
remembered that the University has had also to equip and maintain the
observatory, the cost of which is not included in the amount just
mentioned, and to spend large sums on the University library. Except in
one or two cases, in which a special benefaction fund had been
appropriated to adornment by the desire of the benefactor, these
buildings have been erected with the strictest regard to economy. The
amount expended cannot be said to be an inordinate sum for a modern
University to have spent on scientific buildings and equipment. Yet even
this expenditure would have been impossible without external help.
The cost of the maintenance of the buildings erected and of the very
inadequately paid staffs, now presses on the limits of the available
income; and it is contended that but little more can be attempted for
many years, if ever, without external aid. We will proceed, then, to a
rough analysis of the resources of the University and colleges, and of
the allotment of these resources. Before doing so, however, it may be
well to state that the colleges provide adequately, but not
extravagantly, for the teaching of classics and mathematics, for
elementary teaching in many other subjects, and for individual
assistance to the student and supervision of his work in the subjects
taught in the University. The collegiate system also ensures a close
contact and intercourse between teacher and student not otherwise or
elsewhere attainable. The University, in its teaching aspect, may be
regarded as an organization for providing instruction in all those
branches of knowledge the teaching of which cannot be economically
undertaken by the colleges. Thus, for the teaching of science, and for
the provision of costly laboratories, the University is responsible; and
the higher and more specialized teaching in most other departments is
also provided by the University. The ancient endowments are, in the
main, college endowments; but the history of the development of modern
subjects is also the history of the development of the University; and
it is the University rather than the colleges which is at present in
need of substantial financial help. But to suppose that the colleges do
not heartily co-operate in the University teaching would be erroneous;
at the present time one college may be better organized than another
for this particular purpose, but the colleges may safely be trusted soon
to come into line.
The corporate income of the seventeen colleges is, roughly, £310,000 per
annum. This, with a sum of about £52,000 (called the Tuition Fund),
received annually from the lecture and laboratory fees of the 3,200
students, and £30,000 received annually by the University for degree and
other fees, constitutes the whole available income for college as well
as University purposes, if we except certain Trust Funds for the
endowment of some professorships, and those funds of the nature of
charities of which the colleges are merely administrators.
The corporate income of the colleges consists of (1) endowments, usually
in the form of estates, which bring in £220,000 a year; (2) fees, rent
of rooms, profits on kitchens, and so forth, which bring in £90,000. But
the colleges are great landowners and have the outgoings of landowners.
Though the expenses of the estate management are only about 7 per cent.
of the revenues arising from the estates, yet £130,000 a year are spent
on management, repairs, and improvements on the estates, rates and
taxes,[17] interest on loans, and the maintenance of the costly college
buildings in Cambridge. Many of the latter are national monuments of
surpassing interest, the proper care of which is a duty to the nation.
When allowance has been made for the inevitable expenditure under these
heads, there is left only £180,000 for all other purposes. The
fellowships and the stipends of the heads of houses absorb £78,000; and
the contributions of the colleges towards scholarships, as determined in
the main by statute, and as distinct from any separate endowment,
account for £32,000.
An analysis of the distribution of the fellowship money may
conveniently be deferred for the moment; but it may be stated that the
sum spent on scholarships finds, inside the University at least, many
critics. The expenditure on scholarships is undoubtedly, however, in the
main, a fulfilment of the intentions of their founders, and, if we may
judge by the recent expenditure of County Councils, is in accordance
with public feeling. After deduction of fellowships and scholarships,
there is left of the corporate income a sum of £70,000. Of this sum,
£32,000,[18] or nearly one-half, is paid as a direct contribution to the
University; but, as will be seen immediately, the colleges contribute to
the University in many other ways. Of the £38,000 remaining, £4,000 goes
to supplement the Tuition Fund of £52,000 received from the students as
fees; the sum of £56,000 so obtained is applied to the provision of
college and University lecturers. A large proportion of these fees is
paid to the scientific departments of the University; and of the fees so
paid the greater part is assigned as a contribution to the maintenance
of the several departments, and not, directly at least, to the payment
of lecturers.
Deducting the sum of £4,000, contributed by the colleges to the Tuition
Fund, we have left over of the corporate income a sum of £34,000, or
about £2,000 per college, available for the payment of college officers
and servants, the expenses of the college libraries, printing, and other
expenses. If, then, it can be shown that the £78,000 spent on the
fellowships is not extravagantly allotted--and of this more below--it is
clear that the colleges can contribute but little more than they do at
present to the University teaching.
An idea of the serious effect of the fall of agricultural rent on the
college incomes may be gathered from the fact that one of the larger
colleges has in the last thirty years suffered a loss of revenue
amounting to £10,000 a year.
We now turn to the question of the fellowships. The sum of £78,000 was
in 1904 divided among seventeen heads of houses and about 315 ordinary
fellows. Of this sum the heads of houses received among them, as far as
can be ascertained, the not excessive amount of £15,000, very unequally
divided. The average stipend of a fellow is thus about £200 per annum.
When the last Commission sat, the maximum stipend of a fellow was fixed
at £250; and it was thought that this sum would usually be reached. But,
except in the case of one or two colleges, which are the fortunate
possessors of town property, the maximum is now never reached; and in
certain cases the value of a fellowship has fallen to less than £100 per
annum. Of the 315 fellows, some 245 were in 1904 resident and some 70
non-resident. Of the residents, about 225 were holding some University
or college office, educational or administrative. Of the non-residents,
and of the residents who were holding no office, the greater number had
earned their fellowships by holding some qualifying position, such as a
lectureship for a given number of years, usually twenty. Among the
non-residents, in addition to fellows who hold their fellowships as a
pension, were to be found students who are prosecuting research away
from Cambridge; such students are, as a rule, liable to be summoned to
reside, as college exigencies may demand. Several other non-residents
are fellows who have but recently received appointments away from
Cambridge; their fellowships will, under the new statutes, lapse in a
year or two.
The analysis shows that the number of ‘prize fellowships’ is small; and
it is believed that they are steadily vanishing. To assist the reader in
obtaining a general idea of what is done with the fellowships, the
combined result in the case of two colleges is here given. The two
colleges in question have been chosen because the writers happen to be
in a position to account for the occupant of every fellowship in each
college. As will be seen, the two colleges render most valuable
assistance to the University; and they have practically rid themselves
of the burden of prize fellowships imposed on them by the Commission of
1856. The two colleges dispose, according to the University calendar of
1905-6, of forty fellowships between them. Of these, five are pension
fellowships; five are held by professors in the University, as part of
their stipend; twelve are held by University lecturers, demonstrators,
or other University officers; eleven are held by college officers or
lecturers; five are held by research students in Cambridge; two junior
fellowships are held by non-residents. One of the latter was recently
appointed to a professorship in another University, and his fellowship
has just lapsed; the other holds a prize fellowship. It is unlikely
that, when his fellowship lapses, another prize fellow will be elected
in his place. There are in residence at each of the two colleges a
number of University lecturers and officers, and of college lecturers,
for whom no fellowship can be found. Speaking generally of the
fellowships allotted to college teaching, it may be said that, with the
help of a portion of the Tuition Fund, they enable the colleges to
provide the college lecturers with stipends on which an unmarried man,
occupying rooms in college, may comfortably live. When we turn to the
University lectureships, there is often another tale to tell.
The University income, which has to bear almost the whole cost of modern
developments, is made up of the following items: matriculation, degree,
examination, and other fees, £30,000; direct contributions from
colleges, £32,000; income from endowments, £2,000--£64,000 in all.
In 1904 the University, in the course of its ordinary work, expended
£65,300, distributed roughly as follows:
£
Officers, secretaries, and servants 4,100
Maintenance of business offices, registry,
senate house, and schools 1,300
Rates and taxes 3,400
Obligatory payments from income 1,300
Stipends of professors 12,400
Stipends of readers, University lecturers,
demonstrators, and other teachers 9,100
Maintenance and subordinate staff of scientific
departments (including the botanic garden
and observatory) 9,600
University library, staff, and upkeep 6,300
Examiners’ fees, etc. 5,900
Debt on buildings, sites, sinking fund, and
interest on building loans 8,500
Printing and stationery 2,600
Pension funds (professors, £200; servants, £150) 350
Miscellaneous expenses 450
-------
£65,300
There are forty-four professors, very few of them receive £800 or more a
year (including fellowships), while the lowest limit of a professor’s
stipend, unless he holds a fellowship, is about £90 a year. The average
annual income of a professor is not more than £550, and of the yearly
revenue of £24,000 required to produce this average, £7,000 are paid in
the shape of fellowships by the colleges, and about £4,600 from the
income of special trust funds and other benefactions, one payment of
£800 a year being for a term of years only. One or two professors at
most receive a proportion of the fees paid for lectures and
laboratories in their respective departments. There are twelve
University readers (or sub-professors). The new statutes contemplated
for a reader the salary of £400 a year, but, owing to the inadequacy of
the University income, none receives more than £300, and in several
cases only £100 is paid. There are fifty-three University lecturers
whose stipends range from £200 a year to £50, and it is melancholy to
note how many of these receive the lower sum, without any assistance
from endowments, such as fellowships or the like. There are thirteen
University teachers, almost all of them appointed by the Board for
Indian Civil Service studies, and occupied, in the main, in teaching
eastern dialects; and there are forty-four demonstrators, curators, and
superintendents of museums, whose stipends range from £200 a year to
nothing at all.
The incomes of some of these gentlemen are supplemented by fellowships,
of others by a share of lecture fees; a few, too, may hold two such
offices as curator and lecturer simultaneously. But, when the addition
from all sources (about £8,000 from fees or special funds, and £13,000
from fellowships) has been made to the annual sum (£9,100) which the
University has to give, we arrive at a total of about £30,000, giving
the surprisingly low average income of £250 a year for any University
teacher other than a professor. A few of the older teachers may hold
some college office which adds a little to their income, but these are
rare exceptions. There are no resources from which these incomes may be
increased according to the service of the holder, and there is
practically no provision for pension, except in the case of those
teachers (less than one-half of the whole number) who hold fellowships,
and may expect, after many years of service, to earn the right to retain
them permanently.
In these circumstances it is not surprising that the University finds a
difficulty in retaining many of its abler teachers. At the beginning of
1904 it was estimated that over two hundred professors and lecturers at
other Universities (as distinct from University colleges) in the United
Kingdom had been educated at Cambridge, and, though that is by no means
a matter for regret, yet it is not too much to say that, in supplying
this demand for teachers, the University has done a great national work
for which she is poorly requited by her difficulty in retaining a
sufficient staff for herself. Fortunately, when all other funds are
exhausted, the fund of patriotism remains inexhaustible. It is not known
how many fellows, possessed of some private means, and attached to the
University through sheer love of their work, return their stipends to
their colleges to be employed for the general good; such men are always
anxious that their names should be concealed, but the present writers
know of three in the restricted circle of their immediate personal
friends. The special correspondent of the _Times_ writes, on the
occasion of the royal visit in 1904:
‘I may be permitted to say, as the result of my personal inquiries,
that the amount of work done either gratuitously or for very
inadequate remuneration by professors, readers, lecturers,
demonstrators, and other teachers in many departments of study and
instruction, really constitutes a very substantial endowment,
freely contributed by men who have no worldly goods to give, but
who give lavishly of their time, their energy, their intellectual
capacity, their acquired knowledge, and their disinterested
devotion to the advancement of learning. If this asset were
evaluated in pounds, shillings, and pence, the University
balance-sheet would wear a very different aspect.’
On a consideration of the analysis just made, and of the additional
facts that the Reserve Fund set aside by the University for building and
equipment during the years of her development is now exhausted, and
that her borrowing powers have been seriously reduced, it would appear
that further progress is almost entirely dependent on an increase of
endowment.
A few years ago certain of the University authorities, foreseeing the
approach of a financial crisis, put away their pride, and, with the
countenance of the chancellor, boldly begged for help. Their appeal
resulted in the collection of about £100,000, which has been expended on
the erection and equipment of various buildings devoted to science, such
as the museum of geology and the botany school, the University itself
contributing a large proportion of the expense incurred. In the list of
contributors occur the names of no fewer than 500 Cambridge men, past
and present, out of a total of 620 names. This number is a sufficient
retort to the suggestion which has been made that Cambridge does not
help herself. It must be remembered, too, that a sum of about £14,000 a
year is contributed by members of the Senate to the funds of the
University and of the colleges for the privilege of continued
membership, and that these fees are often paid out of very slender
incomes on grounds which are, as a rule, purely patriotic.
* * * * *
In enumerating the needs of the various departments it is fitting that
the older studies and their modern developments should be first passed
in review, for, though in certain respects these studies are well
equipped, and though the provision of what is necessary would not be so
costly as in the case of science, yet, in the deficiency of income
available for development, there is real danger that the humanities may
be starved.
Theology is well endowed by the piety of former generations. Yet the
present Bishop of Winchester, when Hulsean Professor of Divinity,
pleaded for an increased stipend for the professors which would permit
them to save enough to retire upon; and, in view of the small sum, £200
a year, which the University is able to pay to its pension fund, such an
increase cannot be said to be unreasonable. In law, a new post for the
teaching of jurisprudence, or of jurisprudence combined with Roman law,
is the chief requirement. The teaching of Latin and Greek is largely and
effectively supplemented by the provision made by the colleges, but the
demand for a professorship instead of a readership in classical
archæology cannot be called extravagant, while it is little short of
scandalous that the University possesses no professor, and can make no
permanent provision for the study of ancient philosophy.
The teaching of Oriental languages is perhaps more dependent than that
of any other subject on the self-sacrificing generosity of the staff.
Though but a nominal stipend and a nominal duty attach to his chair, the
Lord Almoner’s professor of Arabic voluntarily undertakes a large share
of the teaching. The payment of the Talmudic reader, depending mainly on
the generosity of a private person, is guaranteed only during the tenure
of the present reader. The cost of the colloquial teaching of spoken
Arabic, Turkish, and Persian by native instructors is guaranteed, and
sometimes in part provided, by the Sir Thomas Adams professor of Arabic.
The professor of Chinese has the inadequate stipend of £200; and the
professorship terminates with the tenure of the present holder. Apart
from the necessity of providing teaching for practical students, the
proper care of the Chinese library alone renders the permanence of the
professorship a necessity. There is no professorship or readership of
Japanese. The stipend of the present lecturer in Persian is inadequate.
Egyptology is not provided for, although there is a fine collection of
mortuary objects in the Fitzwilliam Museum; and Assyriology, although
the professor of Assyriology at King’s College, London, lives in
Cambridge, is wholly unrepresented. No provision is made for the
teaching of the Iranian dialects. Altogether some £2,000 a year could
well be spent in Oriental languages alone.
There is no chair of English literature in the University. The
professorship of Anglo-Saxon is a recent endowment. By the exertions of
the occupant of that chair a sum of £2,100 has been collected, which
yields an endowment of £60 a year for an English lectureship. To this
small stipend the University adds £50 a year. It is not surprising that
the distinguished student who has so long occupied the post should at
last have been attracted to London by a higher stipend.
French and German are represented by two readers, who in the last twenty
years have taken a large share in the development of a sound and growing
school. In the provision for the teaching of modern languages, Cambridge
ought not to be behind the northern Universities; and it is most
desirable that professorships should be established in at least French
and German. The University is indebted to a private fund for a small
endowment for the lectureship in Russian and other Sclavonic tongues.
This lectureship should be made permanent; and lectureships should be
established in Spanish and Italian.
As in the case of classics and mathematics, the University teaching in
history is largely supplemented by the colleges; but the Regius
professor pleads for an additional reader and two lecturers. A central
building with professors’ rooms and lecture-rooms and accommodation for
the professorial library is urgently required.
The newly-established school of economics and politics is in urgent
need of three or four lectureships, to which definite duties in research
should be attached, in order to extend the present range of economic
study, and to bring it close to the great problems of modern industry.
While in the Universities of Edinburgh, London, Manchester, Leeds, North
and South Wales, and Montreal, political economy is taught by economists
trained at Cambridge, their _alma mater_ is starved of the means
necessary to produce their successors.
The anthropological collections are, for want of space, in a chaotic
state. The University is fortunate in possessing many ardent workers;
and its collections are most valuable. The existing museum of archæology
and ethnology is, however, quite inadequate for their display, or even
for their storage; and a disused warehouse has been hired at Newnham to
accommodate the further collections which generous donors continue to
present. To such an extent has it been necessary to carry the economy
practised in this department that the shelves of the warehouse have been
made from old boxes. A site for a new museum has been provided by the
University, and plans have been prepared; but without the help of
extraneous benefactions it is impossible to build at present. An
adequate building would cost perhaps £25,000. The removal of the museum
to a new site would set free space greatly needed for other purposes.
The Disney professor of archæology and the curator of the archæological
museum plead also for the foundation of a chair, or at least a
readership, for the comparative study of religions; and, in view of the
relations of the Empire to every kind of cult, it is scarcely creditable
that neither of the older Universities makes any provision for this
study.
The present staff consists of the Disney professor of archæology, and a
lecturer on ethnology with a salary of £50 a year. The only
accommodation for the latter is a room in the basement of the medical
school, where he takes classes in practical work. Physical anthropology
is associated more directly with the department of human anatomy, and is
represented by another lecturer at £50 a year. The collection of skulls
brought together by Professor Macalister affords unrivalled material for
demonstrations; and, as two recent volumes from the pen of Dr. Duckworth
show, good use is made of the material. The University has recently
recognized the importance of anthropology by adopting a scheme for
granting degrees for research in this subject.
The growing importance of the architect’s profession, and the widespread
recognition of the fact that the young architect must have a preliminary
scientific training, point to the desirability of establishing a school
of architecture at Cambridge, resting on the one hand on the engineering
school, and on the other on the Slade professorship of fine arts, and
the school of archæology. The school might be organized on lines similar
to those of the medical school; and the young architect would pass his
early years of professional study on thoroughly practical lines, in the
midst of admirable examples of almost all the different styles.
In 1877 Cambridge led the way in that difficult science called sometimes
physiological psychology, sometimes experimental psychology, and
sometimes psychophysics. In that year the present professor of mental
philosophy and logic, and Dr. Venn, made a vigorous effort to establish
a psychophysical laboratory. They unfortunately failed; had they
succeeded, Cambridge would have possessed the first laboratory of this
kind in the world. In 1878 Wundt opened his laboratory at Leipzig; and
there are now some seven psychophysical laboratories in Germany, two in
Russia, ten in the United States, one in Copenhagen, one in Paris, one
in Geneva, and one in Canada. It is not that psychophysics is not
studied in Cambridge, for Dr. Rivers, the lecturer on the subject, and
Dr. Myers, have formed a school there which is second to none in Great
Britain; this school has recently supplied a reader to Oxford. But the
work is done under most discouraging circumstances. The laboratory is at
present established in a dilapidated cottage in Mill Lane and in an
adjacent disused granary. Further and better provision for this growing
subject is urgent; and the present lectureship should be converted into
a readership. The interest which is taken in the subjects under the
control of the Board of Moral Science is shown by the successful
launching of the _Journal of Psychology_, the first number of which was
published by the University Press in 1904. Lecture-rooms and a
departmental library are wanted; and the establishment of a readership
in pedagogy should not be long delayed.
In mathematics two new professorships are needed, one in pure
mathematics and one in applied mathematics; two of the present lecturers
should be made readers; and the salaries of all the lecturers should be
raised to £100 a year. One pressing need is that for two lecture-rooms,
with an adjacent library and a museum of mathematical models. Cambridge
is perhaps the most renowned mathematical school in the world; yet its
provision for the accommodation of the staff is far behind that of the
chief American Universities. A munificent benefactor has recently left a
sum of £5,000 for repairs, etc., to the Newall telescope; but there is
no stipend forthcoming for Mr. Newall, who for sixteen years has
discharged the duties of observer without remuneration. The Lowndean and
Plumian professors pay the salary of a demonstrator.
The Cavendish laboratory, owing to the position it has for years taken
in the promotion of physical research, is overcrowded with students and
researchers. Lord Rayleigh has most generously given to the University
the Nobel prize gained by him in 1904. Of this benefaction, £5,000 have
been assigned as a contribution towards the desired new wing; but money
will be required for maintenance; and the professor estimates that a sum
of £7,500 is now wanted for instruments, machinery, and laboratory
fittings. The professor of chemistry asks for more apparatus and higher
stipends for his teachers. He draws attention to the need for a
metallurgical laboratory, the provision of which, in view of the recent
establishment of a diploma in mining engineering, is urgent. Mineralogy
asks only for a trained attendant and £35 a year; but for meteorology
there is no real provision.
The Sedgwick museum, in which the department of geology is now housed,
has involved much expense in furnishing. Although the existing furniture
was all retained, there is still a demand for more cabinets; and
Professor Hughes would like to spend £2,800 on these alone, while a
large sum should be set apart for maintenance, wages, and the increase
of stipends. The demands of botany are not yet completely satisfied. A
readership to deal with the newly recognized study of scientific
forestry has recently been created.
In zoology, if we leave out of account the need for higher stipends for
teachers and higher wages for attendants, which runs like a thread
through all the departments, there are two chief requirements. The first
is for a new or, at any rate, a greatly enlarged museum. It is doubtful
if the existing site is large enough to allow an adequate increase to
the present structure; and to build a new building on another site would
probably cost £30,000; nevertheless, with the ever-increasing
collections housed in rooms already overstocked, this expenditure must
soon be faced.
A branch of experimental science dealing with the study of variation and
heredity in plants and animals has recently arisen, and has already
attained very considerable proportions in Cambridge. It seems, indeed,
that we are entering on a period when such studies will absorb the
energies of most of the younger biological students. Under Mr. Bateson
some twelve researchers are already at work following out Mendel’s law
in many varieties of plant and animal. The extreme importance of these
studies, which, if they prove a key to heredity, will place in man’s
hands an instrument as powerful as Watt’s application of steam, is shown
by the fact that Mr. Biffen has already discovered that susceptibility
to rust in wheat is Mendelian, and is thus a property which may be
eliminated by breeding. For all these studies land is required, as well
as a greenhouse, outbuildings, and a trained gardener. None of these is
as yet attainable.
The recent discoveries of the protozoic origin of malaria,
sleeping-sickness, and other human and many other animal diseases, has
directed attention both to the protozoa, with their complicated
life-histories, and to the insects which convey them from one creature
to another. Both protozoa and insects are highly specialized groups of
animals. The establishment, by the aid of the Quick bequest, of a chair
of protozoology will do something to meet the necessities of the case,
so far as the protozoa are concerned; but some provision for the study
of the insects is still needed.
A chair of physiological chemistry is urgently wanted. The pressing
problems of the day in physiology require a chemical solution.
Remarkable strides have already been made in this subject; the
interaction of the various tissues of the body by means of the blood,
the functions of the ductless glands, the problems of immunity, are all
being worked out upon a chemical basis. In this country there are but
two professors of physiological chemistry, whereas in Germany there are
eleven, in Austria eight, in France six. That Great Britain is
lamentably behind in this branch of learning is even more markedly shown
when we consider the output of original memoirs. In 1903 over 3,000
papers, written by some 2,500 workers, were published; to this total the
United Kingdom contributed no more than seventy. Cambridge has produced
many brilliant physiologists; but the school cannot afford the outlay
for even a necessary piece of apparatus costing £10; and the
demonstrators pay, out of their pittances, part of the wages of their
attendants.
The new medical schools, opened by the King in March, 1904, are but a
portion of the original plan; and, until the remaining laboratories can
be erected (at a probable cost of about £12,000), the various
departments must necessarily be cramped. Many more teachers in special
subjects are wanted, and the need of a professorship, or at least a
readership, in hygiene is pressing. A new lecture-room is wanted in the
department of human anatomy, which at present shares a room with
physiology. A considerable sum is also needed for instruments, fittings,
attendants, and libraries.
The school of engineering needs provision in metallurgy, mining
subjects, and naval architecture; of the latter, in the greatest
shipbuilding country of the world, but two chairs--one at Glasgow, and
one at Newcastle-on-Tyne--exist. New workshops and engine-rooms are also
greatly needed. The present workshops date from 1878, and are far too
small for the demands on them. The provision of a sum of money which
can be expended by the professor on the encouragement of research is
much needed.
The department of agriculture is fairly well staffed, but at present is
obliged to carry on its indoor work in four rooms in the basement of the
chemical laboratory. The amount of research carried on by the staff has
fully justified them in establishing the _Journal of Agricultural
Science_, which appeared for the first time in 1904. This is the only
periodical in the country devoted entirely to scientific agriculture. A
laboratory for agriculture is a most pressing necessity; a site is
available, but at present there is not sufficient money for the
building, which, including provision for maintenance, would cost
£20,000. The Drapers’ Company has generously promised a conditional
£5,000 towards this sum, and some £12,000 has been collected from other
sources.
Besides numerous smaller needs, there are two of primary importance
which have not yet been mentioned. The first is that for the provision
of examination rooms. The University examinations are at present held in
the Guildhall, the Corn Exchange, and other hired rooms, often badly
lighted, badly heated, and badly ventilated, and in no case well adapted
to the purpose of conducting examinations. The hiring and arranging of
the rooms costs the University at least £450 a year.
The other great need is some adequate provision for that priceless
national treasure, the University library. Mr. J. W. Clark has himself
inaugurated an appeal on its behalf. The list of donors which he is
already able to print is headed by His Majesty the King; and a sum of
over £18,000 has already been collected. This sum includes a donation of
£5,000 from the Goldsmiths’ Company, and £2,700 assigned by Lord
Rayleigh from the Nobel prize; to the remainder, resident masters of
arts have largely contributed. When it has been shown by their
contributions how keenly the residents feel on the subject of the
library, it is hoped that some generous measure of help may be
forthcoming from hands more able to give it. The library is the
mainspring of University activity; and its well-being and good
organization are important to all departments alike. Every member of the
Senate, and every other person entitled to use the library, have access
to the shelves; and no serious student, whether a member of the
University or not, is refused.
But, in its restricted area, the library cannot expand further; and the
result is congestion and inevitable disorder. The furniture and fitting
up of the rooms recently rendered available for the library will cost
some £15,000. Towards this expenditure the Financial Board has been able
to grant only £5,000, spread over three years. The cost of furnishing a
reading and reference-room is estimated at from £800 to £1,000. Further,
an increase of the staff is urgently needed. The library grows at the
rate of about 11,000 books per annum; and there are considerable arrears
of cataloguing to be overtaken. The magnificent gift of Lord Acton’s
library, for which the University is indebted to Mr. Carnegie and Mr.
John Morley, has involved considerable outlay. The number of volumes
presented is about 59,000; the binding, cataloguing, printing of titles,
and the provision of bookcases will cost about £8,000, to which the
University has contributed £6,900. Gifts such as these are of priceless
value to Cambridge; but they entail heavy expenditure. Additional
assistants, moreover, are needed to look after them; and every new room
added to the library increases the cost of maintenance. Altogether, it
is estimated that a sum of £21,200 is required for present use; and that
£3,800 a year is required for additions to the staff, the purchase and
binding of books, and for the additional expense entailed by the Acton
library. This annual income, if capitalized, represents a sum of
£126,700.
* * * * *
Modern education is a costly thing; and when, in 1904, the heads of
departments in the University made an estimate of the outlay necessary
to place their several provinces in a state of efficiency, their
deliberate and responsible calculations showed that a sum of £270,000
was required for building and equipment, and an additional annual income
of £38,000 for the increase of salaries on the very moderate scale
suggested, and for maintenance; in all, say a capital sum of a million
and a half. Even this estimate takes no account of the desirability of
providing pensions for professors who have reached the age of seventy.
As the published list of benefactions shows, Cambridge has reason to be
grateful to her recent benefactors. But to raise an endowment comparable
to that of £1,400,000 which the Johns Hopkins University received from
private munificence seems in this country to be hardly within the bounds
of possibility.
Had an appeal such as that issued by Cambridge been made in the United
States, there is little doubt that it would have met with a prompt
response. There is in Montreal a University, officered largely by
Cambridge men, and equipped with a princely magnificence of which
Cambridge dares not even dream. Dr. Ewing’s comment is pertinent. ‘It is
good,’ said he, ‘to see the colonial daughter sitting down to so lavish
a table; but is it well that the _alma mater_ at home should be left
looking wistfully at the crumbs?’ Nearer home, Mr. Carnegie has shown
what a large-minded liberality can do for the Scottish Universities. A
great benefactor who would free the University of Cambridge from a
sordid struggle, in which every pound spent on development has to be
laboriously begged, would earn an enduring fame in the annals of British
education. It has been the earnest desire of the authors of this paper
to show that the University is not unworthy of such generosity; that she
has displayed great courage and great self-denial in facing modern
conditions; and that her reputed wealth is a fiction, while her poverty
is a grim fact.
INDEX
Acarines, 171
Acids, butyric, Formation of, 110
glycerine and succinic, Formation of, 110
lactic, Fermentation of, 110
tartaric, 105
_Acrobothrium_, 14
Acton, Lord, Library of, 214
Africa: Native children infected with malaria, 162
Native population permeated with the malarial parasite, 152
West Coast of, Average of two malarial attacks a year amongst
British soldiers on the, 131
Agassiz, A., 20, 77
Alcohol, Fermentation of, 110
Alexander’s Bucephalus, 84
Algæ, 24, 25
Absence of, below 200 fathoms, 21
Allman, Professor, 22, 67
_Amblyomma hebræum_ conveys the heartwater disease in sheep, 172, 173
America, Distribution of malaria in, 132
Gifts of the Universities of, 185
_Anodonta_, 4
_Anopheles_, 144, 145
_bifurcatus_, 147
does not fly far by itself, 161
Eggs of, 148
Larvæ of, 148
Life-history of, 148, 149
_maculipennis (claviger)_, 147, 148
Male, 149
_nigerrimus_, 158
_nigripes_, 147
Position of, 159
Pupæ of, 148
Anthrax, 120, 121
produced by _Bacillus anthracis_, 121
_Appendicularia_, 39
Arbois, 103, 106
_Argas persicus_ conveys the chicken disease of Brazil, 173
_Aristoeopsis_, Antennæ of, 37
Arnold, Sir Edwin, 1
Arragonite, 1
Arripo, 4
Arsenic-eaters of the Tyrol, 124
Austen, Map of the geographical distribution of the tsetse fly by, 166
Mortality amongst the horses in the Abyssinian campaign
caused by the tsetse fly, 166
On the distribution of the fly, 176
Australia, Distribution of malaria in, 132
Baciocchi, Princess, 118
_Bacillus anthracis_, Behaviour and life-history of, 121
susceptible to variations of temperature, 121
_butyricus_, 110
_typhosus_, 178
Bacilli, Aerobic, 111
Anaerobic, 111
Bache, 19
Bailey, 19
Balard, 104
Barrow Channel, Mussel-beds of 6, 7
Bastianelli, 143
Bateson, W., Materials for the study of variation, 74
Researches on Mendel’s law, 211
_Bathochordæus charon_, named by Chun, 39
_Bathybius_, 21
_Bathynomus_, Eyes of the, 35
_Bathysaurus_, Blackness of the mouth of, 37
Battipaglia, malarious district of, 151, 152
Beelzebub called Lord of Flies, 173
Benazrek mated with Mulatto, 85
Benthos often stalked, 31, 32
Berlin, University of, State endowments of the, 185
Bernard, Claude, 117
Berryman, Lieutenant, 21
Berzelius, 109
Besançon, 102, 106
Royal College of Franche-Comté, 104
Bidder, G. P., Experiments with weighted bottles on the
intensity of fishing, 61
Biffen, Mr., Discovery that susceptibility to rust in
wheat is Mendelian, 211
Bignami, 143
Billiers, Mussel-beds of, 6
Biot, 106, 107
Blackwater fever, 170
Bos, Ritzema, Experiments of in-breeding with rats, 92
Bouché, Description of the larva of the house-fly, 174
Bouguer, 18
Boutan, 14
Boyle, Robert, 18, 120
Brandt, Professor, 57, 66
British sea-fisheries. _See_ Sea-Fisheries, British
Bronn, 88
Bruce, Colonel D.: Female tsetse fly does not lay eggs, 166
Buache, Philippe, 16
Buchanan, John Y., of the _Challenger_, 21
Buddha, Mother-of-pearl images of, 2
Bulman, 87
Buvma, Sleeping-sickness in, 169
Burchell’s zebras, 82
Stripes of, 82, 85
Busoga, Sleeping-sickness in, 169
Butterflies, Hybridizing, 95
Byerly Turk, 93
Cable, Recovery of the, by Fleeming Jenkin, 22
Cable-laying: Survey by Lieutenant Berryman, of the _Arctic_, 21
by Captain Pullen, of the _Cyclops_, 21
by Dr. Wallich, in the _Bulldog_, 21
Cæsar, Julius, and British pearls, 5
Favourite horse was polydactylous, 84
Caird, Sir J., 45
Cambridge, 183
Agriculture, Department of, conducted on the most practical
and progressive lines, 193
Experimental farm, upheld by County Councils of
Cambridgeshire and nine neighbouring counties, 193
_Journal of Agricultural Science_, established
in 1904, 213
Need of Laboratory for, 213
Professorship of, founded in 1899, 193
Anglo-Saxon, Professorship of, 206
Appeal of authorities of, 184, 204
Archæology, Disney professorship of, founded 1851, 187
Architecture, school of, Desirability of establishing, a, 208
Botanic garden, 193
Botany housed in a separate building in 1904, 192
Cavendish laboratory, opened in 1874, 191, 210
Chemical laboratory, built in 1887, 192
Chemistry, physiological, Chair of, needed, 211
Chinese, Chair of, 190
Chinese library, Proper care of, renders the permanency
of the professorship a necessity, 205
Gift of Sir Thomas Wade, 190
Colleges, Analysis of the resources of, 196
Collegiate system, 196
Corporate income of the seventeen, 197
Day training, 195
Fall of agricultural rent on incomes of, 198
Fellows, Average stipend of, 199
Fellowships and stipends of the heads of houses, 197
Fellowships, Number of prize, is small, 199
Expenses of estate management of the, 197
Income of, £300,000 a year, 185
Scholarships, 198
Tuition Fund, 197
Commission of, 1850, 187
Diplomas in forestry, 195
in geography, 195
in mining engineering, 195
Downing Professor of the Laws of England, 188
Economics, school of, Need of lectureships in the, 206, 207
Tripos in, founded, 190
Endowments of the University of, 184
Engineering laboratories opened during the tenure of the
professorship by Dr. Ewing in 1894, 191
New wing added in 1899 through the generosity of Mrs. Hopkinson, 192
Ethnology and anthropology, Recognition of, 187
Examinations, Inadequate rooms for, 213
Expenditure for the maintenance of buildings and staffs, 196
in 1904, 201
on buildings devoted to science since 1862, 195
French and German professorships, Need of, 206
Historical Tripos founded in 1875, 189
History, Ancient, Professorship of, founded in 1898, 189
Income, University, 200, 201
of lecturers, 202
of professors, 201
of readers, 202
of teachers, 202
Indian Languages Tripos, founded in 1879, 190
Latin, Professorship of, 189
Law School, 188
Law Tripos replaces the ‘Civil Law Classes’ in 1858, 188
Library, J. W. Clark’s appeal on behalf of the, 213
Lord Acton’s, 214
Library, Needs of, Donation of the Goldsmiths’ Company for the, 213
Mathematics, Newall telescope, 209
Mechanical Sciences Tripos, First examination for the, held in 1894, 191
Mechanism and applied science, Professorship of, established in 1875, 191
Medicine, School of, 188, 189
Tropical, Diploma of, instituted in 1904, 188
Medieval and Modern Languages Tripos, founded in 1886, 190
Metallurgical laboratory, Need of a, 210
Military studies, Provision for, 195
Moral Science Tripos, New avenues to an honours degree
opened in 1851 by the, 187, 188
Museums for natural sciences commenced in 1863, 188
Additions to, made in 1877, 1880, 1882, 1884, 1890, 188
Natural Sciences Tripos, 188
Needs of the various departments, 204
Nobel Prize, Gift of the, by Lord Rayleigh, 191
Observatory, building commenced in 1822, 191
Oriental Languages Tripos, founded in 1895, 190
Pathology, Professorship of, founded in 1883, 188
Physics, Chair of experimental, founded in 1871, 191
Held in succession by Clerk Maxwell, Lord Rayleigh, and J. J. Thomson, 191
Physiology, Professorship of, founded in 1883, 188
Professors and lecturers of other Universities educated at, 203
Proto-zoology, Establishment of a chair of, by the aid
of the Quick bequest, 211
_Psychology, Journal of_, first published, in 1904, 209
Psychology, Physiological, in 1877, 208
Psycho-physical Laboratory, Efforts made in 1877 to establish a, 208
Psychophysics, Study of, 209
Public Health, Diploma of, instituted in 1875, 188
Sadlerian professorship of pure mathematics, founded in, 1857, 188
Sanskrit, Professorship of, founded in 1867, 190
Sedgwick Museum, 210
Semitic Languages Tripos, founded in 1878, 190
Slade professorship of fine art, founded in 1869, 189
Surgery, Professorship of, founded in 1883, 188
Whewell professorship of international law created in 1867, 188
Zoology, Professorship of, founded in 1866, 188
Cambridgeshire, County Councils of, and nine neighbouring
counties, assist in upholding the agricultural
experimental farm, 193
‘Cane moulière,’ 6
_Cardium edule_, 7
_Carinaria_ captured by the _Valdivia_, 39
Carnegie, A., and Morley, John, Gift of Lord Acton’s
library to Cambridge University, 214
Carpenter, W. B., 20
Carter, R. M., House-fly harbours a larval nematode,
named _Habronema muscæ_ by, 181
Tsetse flies not confined to Africa, but also found in South Arabia, 178
Cavendish, 18
Cecil, Lord Arthur, 85
_Cephalodiscus_, 41
Cercaria as nuclei of pearls, 4, 5
Cercariæum, 6
‘Charbon’ or ‘sang de rate,’ Disease of, in cattle, 120
Charrin, M., Suggested explanations of telegony, 79
Chicken, Disease of, Brazil, conveyed by the _Argas persicus_, 173
Cholera, 122
Chinchon, Countess of, Quinine introduced into Europe in 1640 by the, 139
Cured of tertian fever by Peruvian bark, 139
Cholera, Investigations into, 117
Christophers, S. R., Children of African natives infected with malaria, 152
Chun, Eyes of fishes, in his account of the voyage of the _Valdivia_, 35
‘Circaria.’ _See_ Cercaria
Clark, J. W., Appeal on behalf of the Cambridge University Library, 213
Cocoons, Value of, 114
Cod, Fertilization of the floating ova of the, 46
Colombo, 11, 13
_Columba livia_, 89
Cornalia and Filippi, Corpuscles of, 115
Crawford’s, Donald, Committee on the scarcity of herrings, 1904, 43
Cromwell, O., Death of, from a ‘bastard tertian ague,’ 133
Crossland, C., 14
Ctenophores, Deep-sea, 32
_Culex_, Position of, 159
Culicidæ, 156
Anophelina, 156
Culicina, Sub-families of, 156
Female alone that bites, 161
Cusanus, Nicolaus, 17
Dana, 19
Dante, A., on flies, 167
Darley, Arabian, 93
Darwin, 76, 187
Breeding experiments with pigeons, 89
on pangenesis, 80
on stripes of a foal bred by, 85
Day-mosquito, 163
De Geer: First description of the transformation of the house-fly, 174
De Pourtalès, 19
Diarrhœa, Epidemic, 179
Infantile, 180
Diatoms, 31
Diptera, Characteristics of, 156
Species of, Forty thousand estimated as only a tithe by D. Sharp, 156
_Dispharagus nasutus_ (Rud.), 181
_Distomum duplicatum_, 4
Dôle, 101, 103
Donati, 18
Dourine disease caused by _T. equiperdum_, 168
Drapers’ Company, Promised donation of the, for
establishing an agricultural laboratory, 213
Dubois, 15
on pearls, 5, 8
Dumas, Lectures of, 104
Report on the epidemic of the destruction of silkworms, 113, 114
Durham, Captain, 22
Edwards, A. Milne, 22
Eider-duck, 5
Ellis, Captain, 17
Emin Pasha on the importance of mosquito-nets, 141
_Empusa muscæ_, 181
England, Malaria in, 133
Equidæ, 82
Reversion hypothesis in the, 84
Eryonidæ, 41
Europe, Distribution of malaria in, 131, 132, 133, 134
Ewart, Cossar, 67
Experiments in heredity, 74
Fen districts, Malaria in the, 133
Fermentation, Acetous, of wine, 113
Alcoholic, 110
First physical view of, 109
Lactic acid, 110
Presence of oxygen, 109
Processes of putrefaction and decay, 109
regarded as a contact action, 109
Studies on, 119
Vitalistic theory, 109
Opposition against the, 109
Yeast-cells, 109
Fever in India, 129
Redwater, conveyed by _Rhipicephalus annulatus_, 172
conveyed by _Ixodes reduvius_ in Europe, 172
Rhodesian, conveyed by _Rhipicephalus appendiculatus_, 172
conveyed by _Rhipicephalus shipleyi_, 172
Rocky Mountain, 171
Spotted, 171
Texas, 170
Tick, 170
Yellow, Cause of the spread of, 163
Organism not known which causes, 163
_Filaria_, 141
Elephantiasis, 159
_bancrofti_, 180
_immitis_, existing in the heart of dogs, 180
_nocturna_, 157
Round-worms in the disease of, 157
Filariasis, Disease of, 157
Elephantiasis, a variety of, 157
Filhol, on luminous slime, 33
Filippi, on origin of pearls, 4
Flacherie disease in silkworms, 116
Flies. _See_ also under Anopheles, Culicidæ, Diptera, Filaria
Beelzebub called Lord of, 173
Blue-bottle fly, 167
Danger of, 174
Destruction of, creolin deters flies from ovipositing, 182
‘Fly-belts,’ 166
House-fly, 167
Agent in the dissemination of cholera and enteric fevers, 178
Distribution of the, 176
First described and named _Musca domestica_ by Linnæus, 174
Larva of, described by Bouché, 174
of the, turning into a dark brown pupa or chrysalis, 175
Larvæ of, Food of the, 175
Life-history of, 175
Transformation of, described by de Geer, 174
Meat, or blow-fly, _Musca vomitoria_, Maggot in the Larva of, 175
Parasites of, 181
_Dispharagus nasutus_ (Rud.), 181
_Empusca muscæ_, 181
_Habronema muscæ_, 181
_Nematodum sp._ (?), 181
Tsetse fly conveys sleeping-sickness, 169
Female does not lay eggs, 166
Larva of, 166
Pupa of, 166
Geographical distribution of the, 166
(_Glossina_), 164
Habits of, 165
Mortality amongst the horses in the Abyssinian
Campaign perhaps caused by the, 166
Prey of the, is the big game of Africa, including crocodiles, 167
and bacilli, 179
Epidemic diarrhœa caused by, 179
Infantile diarrhœa caused by, 180
and disease: Agencies for carrying disease-causing organisms, 155
Agencies for transmitting the plague bacillus, 155, 177
Agencies for carrying Egyptian ophthalmia, and the
‘sore-eye’ so common in Florida, 155, 156, 177
Agencies for carrying the bacilli of enteric fever, 155
Agencies for carrying the _Bacillus typhosus_, 178
Agencies for disseminating cholera, 177
Cause of woolsorter’s disease, 155, 177
_Musca domestica_ carry the bacillus of anthrax, 155, 177
Flounder, Fertilization of the eggs of the, 46
Foraminifera, 31
Forbes, Edward, 19, 23
Foster, Sir Michael, 188
Fowl, Wild ancestor of the Barn-door, 90
Frederick, Cæsar, 9
Fulton, Dr., Diminution of plaice and lemon-soles due to
their spawning only in deep water, 51
Increase of dabs due to their spawning in protected waters, 51, 52
Gabes, Gulf of, 8
Gadow, H., 88
Galle, 13
Gall-sickness caused by _T. theileri_, 168
_Gallus bankiva_, 90
Galton, F., on prepotency as a sport, 95
Gambier group, 14
Garner, 5
Garstang, W., Transplantation of small plaice, 57
Evidence before the House of Lords Committee in 1904, 63
Gas, Invention of the word, 108
Gay-Lussac on racemic acid, 105
Generali: House-fly harbours a larval nematode called _Nematodum sp._ (?), 181
Generation, Spontaneous, 111, 112
Giard on pearls, 5, 8, 14
Globigerina, 31
_Glossina morsitans_, named by Westwood, 164
_palpalis_, conveyer of sleeping-sickness, 170
_tachinoides_, 178
Gnome, Invention of the word, 108
Godolphin, Arabian, 93
Goldsmiths’ Company, Donation of the, for Cambridge University Library, 213
Golgi, 137
Goodsir, H., 19, 67
Gordon, General, on the Importance of mosquito-nets, 141
Graham, Extract on the social life of Scotland, 132, 133
Grassi, 143, 151
Green, Rev. S., 68
Grévy’s zebra, 82
Gruby, Trypanosoma parasites first seen by, 168
Gulf Stream, 44
_Habronema muscæ_, 181
Haeckel, on ‘Benthos,’ 31
on Deep-sea medusæ as archaic, 41
_Hæmamœba malariæ_, 135
_præcox_, 135
_vivax_, 135
_Hæmatopota_, 165
Hæmatozoa, Three species of, which correspond to three kinds of Malaria, 135
_Hæmophysalis leachi_ conveys the _Piroplasma_, 171
life-history of, 171, 172
Haffkine, 125
Hales, Rev. Stephen, 18
Hansen on the Common diseases of beer caused by certain
species of yeast-cell, 119
Hayes, Captain, 77
Heartwater disease in sheep conveyed by _Amblyomma hebræum_, 171, 172, 173
Helmont, van, Gas set free when fermentation occurs, 108
Inventor of the word ‘gas,’ 108
receipt for producing mice, 111
Hensen, Professor, 57, 66
Herdman, W. A., 7, 11, 13, 15, 70
Heredity a factor in the origin of species, 74
Experiments by C. Ewart, 74
Hewitt, C. Gordon, on the house-fly, 174, 176
Hippocrates, 131
Holt, E. W. L., on Fishery statistics, 58, 62, 68
Home, Sir Everard, 77
Hooke, Robert, 17
Hooker, Sir Joseph, 19
Hopkinson, Mrs., adds new wing to engineering laboratory, Cambridge, 192
Hornell, J., 11, 13, 14, 15
Horses, 73
Bucephalus, 84
Polydactylous, 84
Striped ancestors of, 83
Kathiawar horses, 83
Norwegian ponies, 83
in Mexico, 83
Howard, L. O., on the House-fly, 174, 176
Hubrecht, Professor, Suggested explanations of telegony, 79
Humbert, 4
Humphry, Sir George, 188
Huxley, Professor, 21, 30, 45
Hybrids, 73, 95
Female production of, 75
Hardiness of, 96
Healthiness of, 97
Romulus, 85, 96
Unhealthiness of, caused by strongylus worm, 97
caused by tsetse fly, 97
Zebra, 96
Hydrophobia, First inoculation against, 124
Inbreeding, 91
Effects of, 92
Experiments, 92
in racehorses, 93
India, British Army in, Death-rate from malaria of the, 129, 130
Inoculation, Success of, 123
Saving of cattle due to, 123
_Ipnops_, Blindness of, 35
Intercrossing, Swamping effect of, 91
Ireland free from malaria, 134
Ismailia, Malaria reduced at, 162
Isobathic curves, 17
Italy, Average mortality in, from malaria, 130
_Ixodes pilosus_, cause of paralysis in sheep during the early autumn, 173
_reduvius_ conveys redwater fever in Europe, 172
James I., Death of, by a ‘tertian ague,’ 133
Jameson, Lyster, on formation of pearls, 5, 7
Jeffreys, Gwyn, 20
Jelly-fish, Tentacles of, 37
Jenkin, Fleeming, 22
Jenkins, Dr., 70
Johnstone, James, 70
Jordanus, 9
Kathiawar horses, 83
Kelaart, 4
Kennedy, Dr., 189
King, Professor A. F. A., Essay on the mosquito theory, 141
Kipling, Rudyard, 16, 26, 31, 34
Kitasato, 125
Koch, 125
‘Kottus,’ 11
Krümmel, 66
Kühn, Professor, Telegony not proved, 81
Lankester, Sir E. Ray, Description of a parasitic organism, 135
Latour, Cagniard de, 109
Laveran, Discovery of Protozoa organism in malaria, 134, 137
Lavoisier, 117
Leeuwenhoek, 109
Lefevre, G. Shaw, 45
_Leucithodendrium somateriæ_, 5
Liebig, 109, 118
Lille, Faculty of Science at, 109
Linnæus, on Peruvian bark, 139
House-fly named _Musca domestica_ by, 174
Lister, Lord, First operations under antiseptic treatment, 113
Livingstone, Importance of mosquito-nets, 141
Loch Corrie mated with Mulatto, 85
London School of Tropical Medicine, 151
London, Zoological Society of, 99
Longfellow, 111
Lounsbury, C. P., Life-history of _Hæmophysalis leachi_, 171
Lovén, 19
Low, Dr., and Sambon, Dr., Experiment against the bites of the mosquito, 151
Lowe, Bruce, Effects of inbreeding foxhounds, 92
On the saturation hypothesis, 78
Lugard, Colonel, 97
MacCallum on Malaria parasite, 143
McIntosh, W. C., 67
Mackerel, Fertilization of the floating ova of the, 46
_Macrurus_, Eyes of the, 35
Magellan, Ferdinand, 16
Malaria, 129
Æstivo-autumnal, 135, 138, 139
Africa, Children of natives infected with, 152, 162
Amœbula, 136
carried by gnats, 159
Cause of, 134
Death of James I. from, 133
Oliver Cromwell from, 133
Death-rate, Average, of white troops in Sierra Leone from, 130
Average, of coloured troops in Sierra Leone from, 130
Average, in Italy from, 130
of the British Army in India from, 130
Discovery of Protozoa organism in, 134
Distribution of, in America, 132
in Australia, 132
in Europe, 131, 132, 133, 134
Endemic foci of the disease, 131
Gametocytes, 136
_Hæmamœba_, 135, 138, 140
_vivax_, 135, 138
_Hæmomenas_, 140
_præcox_, 135, 139
in England, 133
in Fen Districts, 133
in the British Army in India, 129
Ireland free from, 134
Loss of the European population of India from, 129
Malarial pigment or melanin, 136
Mosquito origin of, 141
Quartan, 135, 138
Quinine, Use of, in, 139, 150
‘Quotidian intermittent fever,’ 138
Sporocytes, 136
Tertian, 135, 138
Malarial parasite, Destruction of, by quinine, 162
Life-history of the, 145
Major Ross’s work on the, 125
Natives in Africa permeated with the, 152
‘Mal de caderas,’ caused by _T. equinum_, 168
Malm, Professor, of Göteborg, Fertilization of the eggs of the flounder, 46
Manaar, Gulf of, 8, 10, 13
Mangareva, 14
Manson, Sir Patrick, Researches on _Filaria_, 141
T. P., Experiment on, to prove that an infected
mosquito can convey malaria, 150, 151
Marco Polo, 9
_Margaritifera vulgaris_, 8
Marichikaddi, 14
Marsigli, Count, 17, 18
Matopo, 82, 84, 86, 95
Maury, 19
Maxwell, 187
Mediterranean Sea, Temperature of the, 27
Mexico, Striped horses of, 83
_Micrococcus bombycis_, 116
_ovatus_, Examination of the moth for traces of, 115
Millais, Sir Everett, Telegony not proved, 81
Mitscherlich, Observations on the optical properties of tartaric acid, 105
Möbius on pearl formation, 4
Mollusca, Fossil, 2
Monaco, Prince of, 20
_Monocaulus imperator_, Size of, 39
_Monorhaphis_, 39
Moore, Thomas, 1
Morley, John. _See_ Carnegie, A.
Morton, Lord, Letter to Dr. W. H. Wollaston, 75
Lord Morton’s Mare, 75, 80
Mosely Educational Commission, 183
Mosquitoes, _Anopheles_. _See_ under _Anopheles_
Blasts, 144
_Boöphilus bovis_, 146
_Culex_, 147
_fatigans_, 158
_pipiens_, 146, 147
Culicidæ, 147
‘Day-mosquito,’ 163
Derivation of the word ‘mosquito,’ 147
Destruction of, 152, 153, 154
by paraffin, 162
Fish used in the, 153
Kerosene oil used in the, 153
at Sassari, 154
Growth of the zygote in, 144
Lesions in the bodies of, 160
Meres, 144
Mosquito-nets, Importance of, 141
Origin of malaria in, 141
Process of ‘biting’ by, 160
Production of the zygote in, 144
Proof of mosquito theory, 151
Suffering of, 150
Mother-of-pearl, Formation of, 1, 2
Mulatto mated with Benazrek, 85
Loch Corrie, 85
Matopo, 84
Mulgrave, Lord, 18
Murray, Sir John, 20, 30, 32, 67
_Musca domestica_, or house-fly, described and named by Linnæus, 174, 175
Muscidæ, 167
_Mycoderma aceti_, 112
Myers, Dr. _See_ Rivers, Dr.
_Mytilus_, 5
_edulis_, 5, 7
_galloprovincialis_, 8
Nacreous layer, 2
‘Nagana’ disease caused by _Trypanosoma brucei_, 168
Nathusius, 88
Telegony not proved, 81
Needham, 112
_Nematocarcinus_, Walking-legs of, 37
_Nematodum sp._ ? 181
Newall Telescope, 209
Newsholme, Dr., 179
Newstead on _Glossina tachinoides_, 178
Newton, 88, 187
Noè and Grassi, Mode of infection for the _Filaria immitis_, 180
Nora, 86
Nordenskiöld, 26
Norwegian Ponies, 83
Whaling Companies, Establishment of, in the Shetlands, 43
_Œdemia nigra_, 5
Osborne, Joseph, 92
Ouseley, Sir Gore, 76
Oysters, Artificial rearing of, 13
Sale of, 11
Paars, 8
Packard, A. S., Metamorphosis of the house-fly, 176
Reinvestigations on the house-fly, 174
Paestum, Malarious district, 151
Paget, Sir George, 188
_Panoplites_, 180
Parasite, Malarial, Major Ross’s work on the, 125
Paris, École Normale, 104, 110, 117
Lycée Saint-Louis, 103, 104
Parker, Lieutenant, 22
Pasteur, Claude, 101
Claude-Étienne, 102
Denis, 101
Jean-Henri, 102
Jean-Joseph, 102
Character of, 103
Marriage to Jeanne-Étiennette Roqui, 103
Jeanne-Étiennette, Character of, 103
Louis, 101
Administrative work, 117
Appointed Professor and Dean of the Faculty of Science at Lille, 109
Professor of Chemistry at Strasbourg, 106
Scientific Director at the École Normale, 110
Awarded the ribbon of the Legion of Honour, 107
the Rumford Medal by the Royal Society, 107
Death, September 28, 1895, 126
Discovery of the attenuated virus, 122
Education at the École Normale, Paris, 104
at the Lycée Saint-Louis, Paris, 103, 104
at the Royal College of Franche-Comté at Besançon, 104
under Dumas and Balard, 104
Elected a foreign member of the Royal Society, 117
Member of the Academy of Sciences, 112
‘Études sur la Bière,’ 119
Fermentation, Work on, 108, 119
Investigations into cholera, 117
into the cause and prevention of contagious disease, 120
into the manufacture of vinegar, 112
Life of, by M. Vallery-Radot, 126, 127, 128
Marriage with Marie Laurent, 107
Nominated a Senator, 118
Originator of methods for the production of immunity, 122
Pasteur Institute, Opening of the, 126
Pedigree, 101, 102, 103
Promoting the publication of Lavoisier’s works, 117
Receives a pension of 12,000 francs a year, 126
increased to 25,000 francs a year, 126
the degree of Bachelier ès Lettres, 104
Researches, Chemical, 105, 106, 107
Strokes of paralysis, 126
Studies on the behaviour and life-history of _Bacillus anthracis_, 121
Succession to Lìttré’s _fauteuil_ at the Academy, 126
Teacher of physics at the Lyceé of Tournon, 104
Work on rabies, 123
Pearl Fisheries, Bavarian, 5
Bohemian, 5
British, 5
Ceylon, 4, 8, 9
Chief causes of the failure of the, 12
Failure of oysters, 9
Report on the, 12
Cingalese records of, 8
Dutch, 9
English, 9
Recent, 14
Saxony, 5
Scotch, 5
Syndicate, 15
Trade in the hands of the Arabs and Persians, 8, 9
Welsh, 5
Fishery, Mode of, 10
oyster, Filaria in, 4
oyster-beds of the Red Sea, 14
Pearls, Finest, 10
Formation of, 3
by larval cestodes, 13
by tapeworms, 13
in mussels, 7
Origin of, 1
of Oriental, 13
Sale of, 11
Pébrine disease, 115, 116, 117, 149
_Pectis_, Stalks and tentacles of the, 33
_Pelagothuria ludwigi_, 33
Penycuik, Experiments on telegony at, 79, 84
Periostracum, 2
Periya paar, 12
Peruvian bark, Use of, 139
‘Phæodaria’ existing in radiolarians, 34
Philippine Islands, 16
Piana, House-fly harbours a larval nematode, _Dispharagus nasutus_ (Rud.), 181
Pigeons, Breeding experiments with, 89
‘Pintadin,’ 8
_Piroplasma_, 170
conveyed by _Hæmophysalis leachi_, 171
Malignant jaundice or bilious fever in dogs caused by a, 171
Piroplasmosis spoken of as Texas fever, tick fever,
blackwater, redwater, etc., when present in cattle, 170
Piroplasmosis, Heartwater in sheep a form of, 171
Under the name of Rocky Mountain fever, spotted or
tick fever, the disease attacks man, 171
Plankton Expedition, 27
Pliny, 1
on British pearls, 5
on Ceylon pearls, 8
Plunkett, Sir Horace, 67
Polarization, 106
Poole, Colonel, Stripes of Kathiawar horses, 83
Port Swettenham, Malaria reduced at, 162
Prepotency, Importance of, in breeding, 91
Obtained by inbreeding, 91
Sport often prepotent, 95
Prismatic layer, 2
Protozoa, Discovery of, in Malaria, 134
Puehler, 17
Pullen, Captain, 21
Pycnogonids, Legs of the, 37
Quagga, Domestication of the, 75, 82
Quinine, Introduction of, into Europe, 139
Use of, in Malaria, 139, 150, 162
Rabbits, Breeding experiments with, 87
Rabies, 123, 124, 125
Attenuated virus of, 123, 124
First inoculation against, 124
Racehorses, Breeding of, 93
Byerly Turk, 93
Darley Arabian, 93
Deterioration in the staying power of, 93
Godolphin Arabian, 93
Radiolarians, 31
‘Phæodaria’ existing in, 34
Skeletons of, 40
Rayleigh, Lord, 187
Gift of the Nobel Prize, 191
Recapitulation theory, 74
Red clay, 31
Redia larva, 111
Redi, Francesco, 111
Redwater fever, 170, 172
Reinke, 66
Remus, 96
_Rhabdopleura_, 41
_Rhinoptera javanica_, 13, 14
_Rhipicephalus annulatus_ conveys Redwater fever, 172
_appendiculatus_ conveys Rhodesian fever, 172
_shipleyi_ conveys Rhodesian fever, 172
Rikitea, 14
Rivers, Dr., and Myers, Dr., Formation of a school for psychophysics, 209
Romanes, on ‘Physiological selection,’ 91
on ‘Regression towards mediocrity,’ 91
on the Swamping effect of inter-crossing, 91
Suggested explanations of telegony, 79
Romulus, 96
Production of, 85
Ross, Sir James, 18
Sir John, 18, 19
Major R., on _Hæmamœba (Proteosoma), relicta_ worked out by, 146
on Number of deaths due to ‘fever’ in India, 129
Researches, 142, 143
Work on the malarial parasite, 125, 141
_Sagitta_, 25, 32
Sambon, Dr. _See_ Low, Dr.
Sandilands, Dr., Investigations on epidemic diarrhœa, 179
Sargasso Sea, Temperature of the, 27
Sars, Professor G. O., Fertilization of the floating ova of the cod, 46
Fertilization of the floating ova of the mackerel, 46
Michael, 19
Sassari, Extermination of mosquitoes by the use of petroleum, 154
Schwann, 109
Scoter, 6
Sea, Atlantic current, Temperature of the, 44
Colour of the, 18
Deep, Explorations, A. Agassiz’s voyage in the _Blake_, 20
_Albatross’s_ voyage, 20
Bache’s, 19
Bailey’s, 19
Captain Wilkes and Dana’s Expedition, 19
De Pourtalès, 19
Discovery of extinct species, 22
Dr. W. B. Carpenter’s and G. Jeffrey’s voyage in the _Porcupine_, 20
Expedition in the _Discovery_, 21
in the _Drache_, 20
in the _Gauss_, 21
in the _Gazelle_, 20
in the _Travailleur_, 20
in the _Talisman_, 20
in the _Valdivia_, 20
in the _Washington_, 20
Lord Mulgrave’s Expedition to the Arctic Sea, 18
Lovén’s, 19
Maury’s, 19
Michael and G. O. Sars’s, 19
Prince of Monaco’s expedition in the _Hirondelle_ and _Princess Alice_, 20
Plankton Expedition, 20
‘Pola’ Expedition, 20
Professor E. Forbes’s voyage in the _Beacon_, 19
Professor W. Thomson’s and Dr. W. B. Carpenter’s
voyage in the _Lightning_, 19, 20
Russian investigations in the Black Sea, 20
_Siboga_ Expedition, 20
Sir James Ross and Sir Joseph Hooker’s Antarctic Expedition, 18, 19
Sir John Franklin’s expedition with H. Goodsir in the _Erebus_, 19
Sir John Murray’s voyage in the _Challenger_, 20
Sir John Ross’s voyage to Baffin’s Bay, 18, 19
Soundings, History of, 17, 18, 19
Voyage of the _Novara_, 19
Depths of the, 16
Absence of storms in the, 28
Absence of stripes, bands, spots, or shading in animals from the, 36
Absence of sunlight in, 24
Abundance of animal life in the, 32
Air-bladder of animals from the, 38
_Algæ_ living in the, 24, 25
Bones of many abysmal fishes deficient in lime, 39, 40
Cavities of the bodies of animals lined with a black epithelium, 36, 37
_Challenger_ dredgings in the, 29
Colour of creatures from the, 35
Currents in the, 28
Diatoms in the, 25, 26
Distribution of animal life in the, 25
Division into zones by E. Forbes, 23
Effect of the absence of sunlight on the animals in the, 33
Enormous jaws of animals from the, 38
Eyes in the animals from the, 35
Fauna of the Antarctic shown by the _Challenger_ and
the _Valdivia_ to be exceptionally rich, 32
Feelers and antennæ of the animals from the, 37
Foraminifera in the, 26
Formation of a skeleton of silex by animals from the, 40
of the, Holothurians in the, 29
Inability of the deep-sea fauna to form a skeleton of
calcareous matter, 39, 40
Inhabitants of the, 24
in the Carolines, 23
in the Friendly Islands, 23
Jelly-fish in the, 25
Large size of Polar animals from the, 39
Mudline of Sir J. Murray, 30
Old-world forms from the, 40, 41
Phosphorescence of animals from the, 33
Radiolarians in the, 26
Records of Captain Durham in the South Atlantic, 22
of the _Challenger_ and _Gazelle_, 22
of the _Tuscarora_ East of Japan, 23
Reduction and diminution in size of the respiratory
organs in animals from the, 40
Replacement of visual organs by tentacles or feelers
by the inhabitants of the, 34
_Sagitta_ in the, 25
Salinity of the, 17
Scenery of the, 31
Spines of animals from the, 39
Sponges in the, 28
Stillness in the, 28, 29
Symmetry of animals in the, 29
Temperature of the, 17, 18, 26, 27
in the Mediterranean Sea made by the _Washington_, 27
in the Sargasso Sea made by the ‘Plankton’ Expedition, 27
near the Sulu Islands, 27
on the westerly side of Sumatra, 27
Transparency of sea-water, 18
Uniformity of physical conditions in the, 26
Fisheries Act, 1868, 47
America, American Commission, 66
Fish-breeding institution, 67
Beam-trawls used in steam-trawlers until 1893, 47
Board of Agriculture and Fisheries, Central Staff, 68
Bounty system, Objections to the, 46
British, Extent of, 43
Statistics of, 42
Value of the industry to the inhabitants, 42
Bye-laws, 69
Carriers, Employment of, 47
Causes of impoverishment, 56
‘Accumulated stock’ has been fished out, 56, 59
consumption of the plaice’s food by small haddocks, 57
Dab has usurped the position of the plaice on the Dogger Bank, 57
destruction of young fish, 58, 59
limited area for fish in a limited volume of water, 57
Christiania Conference, 1901, 55
Commissions of, 45
Dabs, Increase of, due to their spawning in protected waters, 51, 52
Denmark, Development of the local fishery on the west coast of Denmark, 64
Determination of the age of fish, 61
Diminution of fish recorded by the Trawling Commission of 1885, 50
of fish-supply being caused by the trawl disproved, 51
Distinction between ‘small’ and ‘large’ fish, 58
Dogger Bank, 57, 60
Eggs, Number of, in various fish, 49
English fishing authorities, 45
Experimental Investigations, 56
Experiments with marked fish, 52, 60, 61
with marked plaice, 60
Firth of Forth and St. Andrews Bay, Closure of, 51
Fish-breeding experiments, 69
Fishmongers’ Company, Seizure of small fish, 58
Fleeting, Process of, 48
Free Trade in, 47
Germany, Kiel Commission, 66
Haddock, Diminution of the, 56
Heligoland, Biological Station, 66
Herrings, Scarcity of, doubtful if due to whaling, 43
Spawning-grounds of the, 49
Ice, Introduction of the use of, 47
Increase in the employment of steam vessels, 47
Inquiries, Seventeen, within the last seventy years into, 44
Inspectors attached to the Home Office, 1861, 68
transferred to the Board of Trade, 1886, 68
transferred to the Board of Agriculture, 1903, 68
Intensity in the conduction of fishing, 60
in the conduction of fishing shown by experiment
with weighted bottles, 61
International character of problems, 65, 66
Lancashire and Western Sea-Fishery Committee, 69
Local Committees, 68
Marine Biological Association, 70, 71, 72
Marine Biological Association Memoirs, 70
Marine Biological Association, Transplantation experiments of the, 58
Methods of renewing and aerating the water in fish-tanks, 47
Migration of the common eel in the Atlantic, 50
of the Lofoten cod-fishery, 50
North Sea, 45
Area of the, 48, 49
International investigations of the, 60, 71
International measures for the improvement of the, 1902, 55
‘Liners’ used for catching fish in the, 49
Otter-trawl used since 1893, 47
Parliamentary Committee on the Sea-Fisheries Bill, 1900, 54
Peel, Fish-hatchery, 69
Plaice, Average annual catch of, 54
Demand of, in the fried-fish shops in the East End of London, 62
Diminution of, and lemon-soles due to their spawning
only in deep water outside the closed areas, 51
Diminution of soles and plaice recorded by the Select
Committee of 1893, 50
Rise in the price of, 54
Small, increase of, transplanted to the Dogger Bank, 57
Plaice, small, Protection of, 64
Port Erin, Marine Station at, 69
Price of fish, 53, 54
Productivity of the sea, 57
Relation of the ova to the trawl, 51
Royal Commission of, 1863, 45, 57
Royal Commission Report, 1866, 45
Salmon Fishery Act of 1861, 68
Sardines more valuable than their adult form, the pilchard, 59
Scottish and Irish Fishery Boards, 67
Select Committee of 1893, 71
‘Shell-Fisheries,’ 69
Soles, Diminution of, and plaice recorded by the Select
Committee of 1893, 50
Statistics, 52, 53, 54, 55
Suggested remedies, 65
Undersized fish, 63
United States, Commission of Fish and Fisheries. _See_
Sea-Fisheries, America, American Commission.
Whitebait fetch more in the market than the parent form, 59
Sedgwick, Adam, 187
Seeley, Professor, 189
Settegast, Telegony not proved, 80
Seurat, G., 14
Seychelles, 33
Sharp, D., Diptera, 156
Siam, Mother-of-pearl in ages made by the coast population of, 2
Sierra Leone, Average death-rate of coloured troops from malaria, 130
Average death-rate of white troops from malaria, 130
Silkworms, Cocoons, Value of, 114
Disease, Detection of the corpuscles of Cornalia and Filippi in, 115
‘Flacherie,’ 116
Parasitic organisms being conveyed from one generation to
another by the egg, 115
Pébrine, 115, 116
Sleeping-sickness conveyed by _Glossina palpalis_, 170
Conveyed by the tsetse fly, 169
Due to _Trypanosoma gambiense_, 170
in Busoga, 169
in Buvuma, 169
in Uganda, 169
Somali zebra, Stripes of a, 82, 85
_Somateria mollissima_, 5
Species, Constitution of, 95
Intersterility test, 95
Origin of, Heredity and variation chief factors in the, 74
Spencer, Herbert, Supporter of telegony, 77
Suggested explanations of telegony, 80
Sponges, 28
Spores, Production of, by a pathogenic organism, 116
_Sporocyst_, 7
Squire, Miss, Donation of, to Law School in Cambridge, 188
Stahl, 109
Standfuss’s experiments in hybridizing butterflies, 95
_Stegomyia_, 180
_fasciata_, Cause of the spread of yellow fever, 163
Larva of, 163
Stephens, J. W. W., Children of African natives infected with malaria, 152
Stereo-chemistry, 107
Stomiadæ, Light produced by eye-like lanterns of the, 33, 34
_Stomoxys_, 165
Strasbourg, 106
Strongylus worm, 97
Surgery, Operative, 113
‘Surra’ disease caused by _T. evansii_, 168
Sutherland, 77
Sylph, Invention of the word, 108
Tacitus on British pearls, 5
_Tapes decussatus_, 7
Tartaric acid, Observations on the optical properties of, 105
Tegetmeier, 77
Breeding experiments with pigeons, 89
Telegony, 75
Explanations of, by Herbert Spencer, 80
by infection hypothesis, 78
by M. Charrin, 79
by the pangenesis of Darwin, 80
by the Penycuik experiments, 79
by Professor Hubrecht, 79
by reversion hypothesis, 80, 83, 84
by Romanes, 79
by saturation hypothesis, 78
Opponents of Kühn, 81
Nathusius, 81
Settegast, 81
Sir Everett Millais, 81
Weismann, 81
Supporters of: Agassiz, 77
Captain Hayes, 77
Herbert Spencer, 77
Romanes, 77
Sir Everard Home, 77
Sutherland, 77
Tegetmeier, 77
Weismann’s inheritance of acquired characters in, 83
Terzi, Signor, Experiment against the bites of the mosquito, 151
_Tetrarhynchus unionifactor_, 13
Texas fever, Cause of, 149
Germ of, 115
Theobald, 147
Thompson, D’Arcy, 67
Thomson, Wyville, 20
Thurn, Sir Everard im, 9
Ticks convey piroplasma, 171
Tinnevelly pearl banks, 4
Tournon, Lycée of, 104
_Trypanosoma brucei_ causes the ‘nagana’ disease, 168
_equinum_ causes the ‘mal de caderas’ disease, 168
_equiperdum_ causes the ‘dourine’ disease, 168
_evansii_ causes the ‘surra’ disease, 168
_gambiense_ causes sleeping-sickness, 170, 177
_theileri_ causes ‘gall-sickness,’ 168
Tsetse fly, 97. _See_ also under _Glossina_ and Flies
Tundra, 86
Tyndall, 112
Tyrol, Arsenic-eaters of the, 124
Uganda, Sleeping-sickness in, 169
_Unio_, 2, 4
Universities, New, in England, 183
Valentinus, Basilius, Explanation of fermentation, 108
Vallery-Radot, M., ‘Life of Pasteur,’ 126, 127
Vallisnieri, 112
Variation a factor in the origin of species, 74
‘Materials for the study of,’ 74
Veeder, Dr., Flies the carriers of the _Bacillus typhosus_, 178
Venn, Dr., Effort to establish a psychophysical laboratory
in the University of Cambridge, 208
Venus Genitrix, 5
Vijaya, King, 8
Vinegar, Manufacture of, 112
Virchow, Malarial pigment or melanin, 136
Virus, Attenuated, Discovery of the, 122
Waddell, Major, 84
Wade, Sir Thomas, Chinese library presented to Cambridge University by, 190
Wallich, Dr., 21
Watson, Dr. Malcolm, Reduction of malaria at Port Swettenham, 162
Weismann, Inheritance of acquired characters in telegony, 80
Westwood, _Glossina morsitans_ named by, 164
Wiedemann, First description of the tsetse fly, 164
Wilkes, Captain, 19
Willis, 109
Wilson, Major L. M., 130
Wine, Acetous fermentation of, 113
Bouquet of, 113
Winterbottom, 169
Wollaston, Dr. W. H., 75
Woolsorter’s disease, 177
in man, 120, 177
Wundt opened the first psychophysical laboratory at Leipzig in 1878, 208
Yeast-cell, Nucleus of the, 120
Thirty different species of, 120
Yellow fever. _See_ Fever
Yersin, 125
Zebras, Attempts to cross, with Shetland ponies, 86
Burchell’s, 82
Stripes of, 85
Experiments with, 82
Grévy’s, 82
Mountain, 82
Somali, 82
Stripes of, 85
Striped ancestors of horses, 83
Zebra-hybrids, 96
Zoological Society of London. _See_ London
Zygote, Blasts, 144
Growth of the, 144
Meres, 144
Production of the, 144
Zymase, 120
BILLING AND SONS, LTD., PRINTERS, GUILDFORD.
FOOTNOTES:
[1] Owing to the comparative absence of bacteria in deep-sea water
their bodies undergo little decay.
[2] The illustration shows the difference between the facial marks of
the zebra and those of the hybrid. The latter, in this respect, bears
much the same relation to the former as a blue-rock pigeon does to a
fancy type.
[3] A volume of Redi’s poems, entitled ‘Bacco in Toscano,’ was
published in 1804. Longfellow says of him:
‘Even Redi, when he chanted
Bacchus in the Tuscan valleys,
Never drank the wine he vaunted
In his dithyrambic sallies.’
[4] It had been seen before by Virchow and others, who, however, did
not recognize its importance.
[5] The _Times_, September 21, 1900, and medical papers.
[6] _Vide_ p. 162.
[7] ‘Inferno,’ xxvi. 26-28.
[8] _Brit. Med. Journ._, No. 2,394, November 17, 1906, p. 1393.
[9] Austen, _Journal of the Royal Army Medical Corps_, vol. ii., 1904,
pp. 651-667.
[10] _Medical Record_, vol. liv., 1898, pp. 429, 430.
[11] _Journal of Hygiene_, vol. vi., 1906, pp. 77-92.
[12] _Ann. Nat. Hist._, ser. 3, vii., p. 29.
[13] _Atti Soc. Modena_, ser. 3, ii., _Radiconte_, p. 88.
[14] _Atti Mus. Milano_, xxxvi., 1896, p. 239.
[15] Theobald, ‘Second Report on Economic Entomology,’ British Museum
(Natural History), London, 1904, p. 125.
[16] The dates given for the triposes are those of the first public
examinations held.
[17] Rates, taxes, and tithe _alone_ swallow up £45,000.
[18] Including about £10,000 capitation tax.
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