Venoms - Venomous Animals and Antivenomous Serum-therapeutics

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Title: Venoms - Venomous Animals and Antivenomous Serum-therapeutics
Author: Calmette, A.
Language: English
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VENOMS

VENOMOUS ANIMALS
AND ANTIVENOMOUS
SERUM-THERAPEUTICS

A. CALMETTE, M.D.

Corresponding Member of the French Institute and of the Academy
of Medicine, Director of the Pasteur Institute, Lille

TRANSLATED BY ERNEST E. AUSTEN, F.Z.S.

NEW YORK
WILLIAM WOOD AND COMPANY
MDCCCCVIII

PREFACE TO ENGLISH EDITION.

Mr. E. E. Austen, of the British Museum, has been good enough to
undertake the translation of my book on “Venoms.” For the presentation
of my work to the scientific public in an English dress I could not
have hoped to find a more faithful interpreter. To him I express my
liveliest gratitude for the trouble that he has so kindly taken, and
I thank Messrs. John Bale, Sons and Danielsson for the care they have
bestowed upon the preparation of this edition.

A. CALMETTE, M.D.

_Institut Pasteur de Lille,
June 17, 1908._

INTRODUCTION TO FRENCH EDITION.

In the month of October, 1891, during the rains, a village in the
vicinity of Bac-Lieu, in Lower Cochin-China, was invaded by a swarm of
poisonous snakes belonging to the species known as _Naja tripudians_,
or Cobra-di-Capello. These creatures, which were forced by the deluge
to enter the native huts, bit four persons, who succumbed in a few
hours. An Annamese, a professional snake-charmer in the district,
succeeded in catching nineteen of these cobras and shutting them up
alive in a barrel. M. Séville, the administrator of the district,
thereupon conceived the idea of forwarding the snakes to the newly
established Pasteur Institute at Saigon, to which I had been appointed
as director.

At this period our knowledge of the physiological action of venoms was
extremely limited. A few of their properties alone had been brought
to light by the works of Weir Mitchell and Reichard in America, of
Wall and Armstrong in India and England, of A. Gautier and Kaufmann in
France, and especially by Sir Joseph Fayrer’s splendidly illustrated
volume (“The Thanatophidia of India”), published in London in 1872.

An excellent opportunity was thus afforded to me of taking up a study
which appeared to possess considerable interest on the morrow of the
discoveries of E. Roux and Behring, with reference to the toxins of
diphtheria and tetanus, and I could not allow the chance to escape.
For the last fifteen years I have been occupied continuously with
this subject, and I have published, or caused to be published by my
students, in French, English, or German scientific journals, a fairly
large number of memoirs either on venoms and the divers venomous
animals, or on antivenomous serum-therapeutics. The collation of these
papers is now becoming a matter of some difficulty, and it appeared to
me that the time had arrived for the production of a monograph, which
may, I hope, be of some service to all who are engaged in biological
research.

* * * * *

_Antivenomous serum-therapy_, which my studies, supplemented by those
of Phisalix and Bertrand, Fraser, George Lamb, F. Tidswell, McFarland,
and Vital Brazil, have enabled me to establish upon scientific bases,
has now entered into current medical practice. In each of the countries
in which venomous bites represent an important cause of mortality in
the case of human beings and domestic animals, special laboratories
have been officially organised for the preparation of antivenomous
serum. All that remains to be done is to teach its use to those who are
ignorant of it, especially to the indigenous inhabitants of tropical
countries, where snakes are more especially formidable and deadly.
This book will not reach such people as these, but the medical men,
naturalists, travellers, and explorers to whom it is addressed will
know how to popularise and apply the information that it will give
them.

I firmly believe also that physiologists will read the book with
profit. Its perusal will perhaps suggest to them the task of
investigating a host of questions, which are still obscure, relating
to toxins, their mode of action upon the different organisms, and
their relations to the antitoxins. There is no doubt that in the study
of venoms a multitude of workers will, for a long time to come, find
material for the exercise of their powers of research.

* * * * *

At the moment of completing this work I would like to be allowed to
cast a backward glance upon the stage that it marks in my scientific
career, and to express my heartfelt gratitude to my very dear master
and friend, Dr. Émile Roux, to whom I owe the extreme gratification
of having been able to dedicate my life to the study of experimental
science, and of having caused to germinate, grow, and ripen a few of
the ever fertile seeds that he sows broadcast around him.

* * * * *

I am especially grateful to those of my pupils, C. Guérin, A. Deléarde,
F. Noc, L. Massol, Bernard, and A. Briot, who have helped me in my
work, while showering upon me the marks of their confidence, esteem,
and attachment; to my former chiefs, colleagues, and friends of the
Colonial Medical Staff, Drs. G. Treille, Kermorgant, Paul Gouzien,
Pineau, Camail, Angier, Lépinay, Lecorre, Gries, Lhomme, and Mirville;
and to my numerous foreign or French correspondents, George Lamb,
Semple, C. J. Martin, Vital Brazil, Arnold, de Castro, Simon Flexner,
Noguchi, P. Kyes, Morgenroth, J. Claine, Piotbey, and R. P. Travers,
several of whom have come to work in my laboratory, or have obligingly
procured for me venoms and venomous animals.

I have experienced at the hands of a large number of our ministers,
consuls, or consular agents abroad the most cordial reception on
repeatedly addressing myself to them in order to obtain the papers or
information of which I was in need. It is only right for me to thank
them for it, and to acknowledge the trouble that M. Masson has most
kindly taken in publishing this book.

A. CALMETTE.

_Institut Pasteur de Lille,
March 10, 1907._

TABLE OF CONTENTS.

PART I.

Page

CHAP. I.--I. General notes on poisonous animals 1

II. General classification of poisonous snakes. Their
anatomo-physiological characters 3

CHAP. II.--Habits of poisonous snakes. Their capture 17

CHAP. III.--Description of the principal species of poisonous
snakes. Their geographical distribution 22

A. _Europe_ 22

B. _Asia, Dutch Indies and Philippine Islands_ 30

C. _Africa_ 57

D. _Australia and adjacent large islands_ 81

E. _America_ 100

F. _Hydrophiidæ_ (_sea-snakes_) 131

G. _Geographical distribution of the principal genera
of poisonous snakes in the five divisions of the
world_ 142

PART II.

CHAP. IV.--Secretion and collection of venom in snakes 147

CHAP. V.--Chemical study of snake-venoms 159

CHAP. VI.--Physiological action of snake-venoms 168

A. Physiology of poisoning in man and in animals bitten
by the different species of poisonous snakes
(_Colubridæ_, _Viperidæ_, _Hydrophiidæ_) 168

B. Physiology of experimental poisoning 170

C. Determination of the lethal doses of venom for
different species of animals 173

D. Effects of venom in non-lethal doses 177

CHAP. VII.--Physiology of poisoning (_continued_). Effects
of the various venoms on the different tissues
of the organism 179

(1) Action upon the liver 182

(2) Action upon the kidney 183

(3) Action upon the spleen, heart and lungs 183

(4) Action upon the striated muscles 184

(5) Action upon the nervous centres 185

CHAP. VIII.--Physiology of poisoning (_continued_). Action of
venoms on the blood 188

A. Effects of venom on the coagulation of the blood 188

I. Coagulant venoms 190

II. Anticoagulant venoms 192

III. Mechanism of the anticoagulant action of
venoms on the blood 195

B. Effects of venom on the red corpuscles and on the
serum 196

(1) Hæmolysis 196

(2) Precipitins of venoms 202

(3) Agglutinins of venoms 202

C. Effects of venom upon the white corpuscles: Leucolysin 203

CHAP. IX.--Physiology of poisoning (_continued_). Proteolytic,
cytolytic, bacteriolytic, and various diastasic
actions of venoms: diastasic and cellular actions
on venoms 204

A. Proteolytic action 204

B. Cytolytic action 206

C. Bacteriolytic action 206

D. Various diastasic actions of venoms 212

E. Action of various diastases upon venoms 214

CHAP. X.--Toxicity of the blood of venomous snakes 217

CHAP. XI.--Natural immunity of certain animals with respect
to snake-venoms 222

CHAP. XII.--Snake-charmers 228

PART III.

ANTIVENOMOUS SERUM-THERAPEUTICS.

CHAP. XIII.--Vaccination against snake-venom--Preparation of
antivenomous serum--Its preventive properties
as regards intoxication by venom 241

Specificity and polyvalence of antivenomous serums 248

CHAP. XIV.--Neutralisation of venom by antitoxin 253

CHAP. XV.--Treatment of poisonous snake-bites in man and
animals. Objects of the treatment. Technique of
antivenomous serum-therapy 259

PART IV.

VENOMS IN THE ANIMAL SERIES.

CHAP. XVI.--Venoms in the animal series.

1.--Invertebrates 269

A. _Cœlenterates_ 269

B. _Echinoderms_ 273

C. _Arthropods_: (_a_) _Araneids_ 274

(_b_) _Scorpions_ 276

(_c_) _Myriopods_ 280

(_d_) _Insects_ 281

D. _Molluscs_ 286

CHAP. XVII.--Venoms in the animal series (_continued_).

2.--Venomous fishes 288

A. _Teleostei. Acanthopterygii_: 1. _Triglidæ_ 290

-- -- 2. _Trachinidæ_ 297

-- -- 3. _Gobiidæ_ 300

-- -- 4. _Teuthididæ_ 301

-- -- 5. _Batrachiidæ_ 302

-- -- 6. _Pediculati_ 303

B. _Teleostei. Plectognathi_: 305

C. _Teleostei. Physostomi_: 307

-- -- 1. _Siluridæ_ 308

-- -- 2. _Murænidæ_ 309

CHAP. XVIII.--Venoms in the animal series (_continued_).

3.--Batrachians; Lizards; Mammals 312

A. Batrachians 312

B. Lizards 321

C. Mammals (_Ornithorhynchus_) 323

PART V.

DOCUMENTS.

I.--_A few notes and observations relating to bites of
poisonous snakes treated by antivenomous serum-
therapeutics_ 326

II.--_A few notes and observations relating to domestic
animals bitten by poisonous snakes and treated
with serum_ 356

III.--_Note on the collection of cobra-venom and the treatment
of poisonous bites in the French Settlements in India
(by Dr. Paul Gouzien)_ 359

LIST OF ILLUSTRATIONS.
PAGE

Fig. 1.--A. Skull of one of the non-poisonous _Colubridæ_
(_Ptyas mucosus_) 7
B. Skull of one of the poisonous _Colubridæ_
(_Naja tripudians_) 7
C. Skull of one of the poisonous _Colubridæ_
(_Bungarus fasciatus_) 7
D. Skull of one of the _Viperidæ_ (_Vipera russellii_) 7
E. Skull of one of the _Viperidæ Crotalinæ_ (_Crotalus
durissus_) 7
F. Skull of one of the _Colubridæ Hydrophiinæ_
(_Hydrophis pelamis_) 7

Fig. 2.--A. Maxillary bone and fangs of one of the _Viperidæ_
(_Vipera russellii_) 8
B. Maxillary bone and fangs of one of the _Colubridæ_
(_Naja tripudians_) 8
C. Maxillary bone and fangs of one of the _Colubridæ_
(_Bungarus fasciatus_) 8
D. Maxillary bone and teeth of one of the non-poisonous
_Colubridæ_ (_Ptyas mucosus_) 8

Fig. 3.--A. Fang of one of the _Viperidæ_ (_Vipera russellii_) 8
D. Transverse section of the fang 8

Fig. 4.--B. Fang of one of the _Colubridæ_ (_Naja tripudians_) 9
E. Transverse section 9

Fig. 5.--C. Fang of one of the _Hydrophiinæ_
(_Hydrophis pelamis_) 9
F. Transverse section 9

Fig. 6.--Three transverse sections of a poison-fang of one of
the _Colubridæ_ 9

Fig. 7.--Marks produced on the skin by the bites of different
species of snakes 10

Fig. 8.--Poison-gland and fangs of a venomous snake (_Naja
tripudians_) 11

Fig. 9.--Muscular apparatus and poison-gland of _Vipera
russellii_ 12

Fig. 10.--Muscular apparatus and poison-gland of _Vipera
russellii_ 12

Fig. 11.--Muscular apparatus and poison-gland of _Naja
tripudians_ 13

Fig. 12.--Muscular apparatus and poison-gland of _Naja
tripudians_ 13

Fig. 13.--Arrangement of the scales of the head in one of the
non-poisonous _Colubridæ_ (_Ptyas mucosus_) 14

Fig. 14.--Arrangement of the scales of the head in one of the
poisonous _Colubridæ_ (_Naja tripudians_) 15

Fig. 15.--Feeding a poisonous snake (first stage) 18

Fig. 16.--Feeding a poisonous snake (second stage) 18

Fig. 17.--Capture of a _Naja tripudians_ (first stage) 19

Fig. 18.--Capture of a _Naja tripudians_ (second stage) 20

Fig. 19.--Hindu carrying two captured Cobras in “chatties” 21

Fig. 20.--Maxillary bone, mandible, and head of _Cœlopeltis
monspessulana_ 23

Fig. 21.--(1) _Vipera berus_; (2) _Vipera aspis_; (3) _Vipera
ammodytes_; (4) _Vipera ammodytes_ 25

Fig. 22.--_Vipera aspis_, from the Forest of Fontainebleau 28

Fig. 23.--Skull of _Bungarus_ 31

Fig. 24.--_Bungarus fasciatus_ (India) 32

Fig. 25.--Skull of _Naja tripudians_ 34

Fig. 26.--_Naja tripudians_ (Cobra-di-Capello) on the defensive,
preparing to strike 35

Fig. 27.--_Naja tripudians_ (Cobra-di-Capello) 36

Fig. 28.--_Vipera russellii_ (Daboia) 45

Fig. 29.--_Pseudocerastes persicus_ 47

Fig. 30.--_Echis carinatus_ (India) 48

Fig. 31.--_Ancistrodon hypnale_ (Carawalla, of Ceylon) 50

Fig. 32.--_Lachesis okinavensis_ 52

Fig. 33.--_Lachesis flavomaculatus_ 55

Fig. 34.--Skull of _Dendraspis viridis_ 65

Fig. 35.--Skull of _Causus rhombeatus_ 68

Fig. 36.--Skull of _Bitis arietans_ (Puff Adder) 70

Fig. 37.--_Bitis arietans_ (Puff Adder) 71

Fig. 38.--_Bitis cornuta_ 73

Fig. 39.--_Bitis rasicornis_ 74

Fig. 40.--_Cerastes cornutus_ 75

Fig. 41.--_Echis coloratus_ 77

Fig. 42.--Skull of _Atractaspis aterrima_ 79

Fig. 43.--Skull of _Glyphodon tristis_ (Australian Colubrine) 83

Fig. 44.--_Pseudelaps krefftii_ 85

Fig. 45.--_Pseudelaps harriettæ_ 85

Fig. 46.--_Pseudelaps diadema_ 85

Fig. 47.--_Diemenia psammophis_ 86

Fig. 48.--_Diemenia olivacea_ 86

Fig. 49.--_Diemenia textilis_ 86

Fig. 50.--_Diemenia nuchalis_ 87

Fig. 51.--_Pseudechis porphyriacus_ (Black Snake) 87

Fig. 52.--_Denisonia superba_ (Copperhead) 89

Fig. 53.--_Denisonia coronoides_ 89

Fig. 54.--_Denisonia ramsayi_ 90

Fig. 55.--_Denisonia signata_ 90

Fig. 56.--_Denisonia maculata_ 91

Fig. 57.--_Denisonia gouldii_ 91

Fig. 58.--_Hoplocephalus bitorquatus_ 94

Fig. 59.--_Notechis scutatus_ (Tiger Snake) 95

Fig. 60.--Skull of _Acanthophis antarcticus_ (Death Adder) 96

Fig. 61.--_Acanthophis antarcticus_ 97

Fig. 62.--_Rhynchelaps australis_ 98

Fig. 63.--Skull of _Furina occipitalis_ 99

Fig. 64.--_Furina occipitalis_ 99

Fig. 65.--Skull of _Elaps marcgravii_ 101

Fig. 66.--_Elaps fulvius_ (Harlequin Snake) 105

Fig. 67.--Head and Skull of _Crotalus horridus_ (Horrid
Rattle-snake) 109

Fig. 68.--_Ancistrodon piscivorus_ (Water Viper) 110

Fig. 69.--_Lachesis lanceolatus_ (Fer-de-Lance) 112

Fig. 70.--_Lachesis neuwiedii_ (Urutù) 116

Fig. 71.--_Sistrurus catenatus_ (Prairie Rattle-snake) 121

Fig. 72.--A. Horny appendage (rattle) of a _Crotalus horridus_ 122
B. Horny appendage, longitudinal section 122
C. Separated segments of the appendage 122

Fig. 73.--_Crotalus terrificus_ (Dog-faced Rattle-snake) 123

Fig. 74.--_Crotalus scutulatus_ (Texas Rattle-snake) 126

Fig. 75.--_Crotalus confluentus_ (Pacific Rattle-snake) 128

Fig. 76.--_Crotalus cerastes_ (Horned Rattle-snake) 130

Fig. 77.--Skull of _Hydrus platurus_ 132

Fig. 78.--_Hydrus platurus_ 133

Fig. 79.--_Hydrophis coronatus_ 134

Fig. 80.--_Hydrophis elegans_ 135

Fig. 81.--Skull of _Distira_ 137

Fig. 82.--_Enhydrina valakadien_ (_E. bengalensis_) 138

Fig. 83.--Skull of _Platurus colubrinus_ 139

Fig. 84.--_Platurus laticaudatus_ (_P. fischeri_) 140

Fig. 85.--Collecting venom from a _Lachesis_ at the
Serotherapeutic Institute of São Paulo (Brazil) 154

Fig. 86.--Chloroforming a Cobra in order to collect venom at
Pondicherry (first stage) 155

Fig. 87.--Chloroforming a Cobra in order to collect venom at
Pondicherry (second stage) 157

Fig. 88.--Collecting Cobra-venom at Pondicherry (third stage) 158

Fig. 89.--Mongoose seized by a Cobra 225

Fig. 90.--Indian Snake-charmer at Colombo (Ceylon) 230

Fig. 91.--Indian Snake-charmer at Colombo (Ceylon) 231

Fig. 92.--Musical instrument used by Indian snake-charmers to
charm Cobras 232

Fig. 93.--Vaccinating a horse against venom at the Pasteur
Institute, Lille 244

Fig. 94.--Aseptically bleeding a horse, vaccinated against
venom, in order to obtain antivenomous serum, at
the Pasteur Institute, Lille 245

Fig. 95.--Technique of injecting antivenomous serum beneath
the skin of the abdomen 264

Fig. 96.--_Lactrodectus mactans_ 275

Fig. 97.--_Scorpio occitanus_ 277

Fig. 98.--_Scolopendra morsitans_ 280

Fig. 99.--Poison-apparatus of the bee 281

Fig. 100.--Interior of the gorget of the Bee 282

Fig. 101.--_Synanceia brachio_ var. _Verrucosa_ 291

Fig. 102.--_Cottus scorpius_ (Sea Scorpion, or Father Lasher) 292

Fig. 103.--_Scorpæna grandicornis_ 293

Fig. 104.--_Scorpæna diabolus_ 294

Fig. 105.--_Pterois artemata_ 295

Fig. 106.--_Pelor filamentosum_ 296

Fig. 107.--_Trachinus vipera_ (Lesser Weever) 297

Fig. 108.--Operculum and opercular spine of the Lesser Weever 298

Fig. 109.--_Callionymus lyra_ (Dragonet) 300

Fig. 110.--_Batrachus grunniens_ 302

Fig. 111.--_Thalassophryne reticulata_ 302

Fig. 112.--_Lophius setigerus_ 303

Fig. 113.--_Serranus ouatabili_ 304

Fig. 114.--_Holacanthus imperator_ 305

Fig. 115.--_Tetrodon stellatus_ 306

Fig. 116.--_Tetrodon rubripes_ 306

Fig. 117.--_Chilomycterus orbicularis_ 307

Fig. 118.--_Chilomycterus tigrinus_ 307

Fig. 119.--_Silurus glanis_ 308

Fig. 120.--_Muræna moringa_ 310

Fig. 121.--_Salamandra maculosa_ (Spotted Salamander) 314

Fig. 122.--_Triton marmoratus_ (Marbled Newt) 314

Fig. 123.--_Cryptobranchus japonicus_ (Great Japanese
Salamander) 315

Fig. 124.--_Heloderma horridum_ 322

Fig. 125.--_Ornithorhynchus paradoxus_ (Duck-billed Platypus) 324

VENOMS.

PART I.

CHAPTER I.

_GENERAL NOTES ON POISONOUS ANIMALS--POISONOUS SNAKES: GENERAL
CLASSIFICATION AND ANATOMO-PHYSIOLOGICAL CHARACTERS._

I.--GENERAL NOTES ON POISONOUS ANIMALS.

A large number of animals possess special glandular organs capable of
secreting toxic substances called _venoms_.

Sometimes these substances are simply discharged into the surrounding
medium, and serve to keep off enemies (_toad_, _salamander_); sometimes
they mingle with the fluids and digestive juices, and then play an
important part in the nourishment of the animal that produces them
(_snakes_); in other cases, again, they are capable of being inoculated
by means of _stings_ or _teeth_ specially adapted for this purpose,
and then they serve at once as a means of attack or defence, and as a
digestive ferment (_snakes_, _spiders_, _scorpions_, _bees_).

An animal is said to be _venomous_ when it possesses the power of
_inoculating_ its venom.

Venomous species are met with in almost all the lower zoological
groups, in the _Protozoa_, _Cœlenterates_, _Arthropods_, _Molluscs_,
and in a large number of _Vertebrates_ (fishes, amphibians, and
reptiles).

The _reptiles_ are best endowed in this respect, and it is in this
class of creatures that we meet with the species most dangerous to
man and to mammals in general. The study of their venom, too, is of
considerable interest, since it should lead to the quest of means of
protection sufficiently efficacious to preserve us from their attacks.

* * * * *

Venomous reptiles are not always easy to distinguish from those devoid
of any inoculatory apparatus. For this reason both classes alike have
at all times inspired mankind with a lively dread, which is displayed
among the various races in legends and religious beliefs.

In ancient days the cult of the snake occupied a prominent place. In
_Genesis_ the serpent is the incarnation of the Evil One, tempting and
deceitful. In Greece it was the symbol of wisdom and prudence. In Egypt
it was associated with the Sacred Scarabæus and the flowers of the
lotus to represent Immortality!

At Rome epidemics ceased when the snake sacred to Æsculapius was
brought from Epidaurus.

According to Kraff, the Gallas of Central Africa consider the snake as
the ancestor of the human race, and hold it in great respect.

In India the cult of the Seven-headed _Naja_, or serpent-god, was
formerly almost as flourishing as that of Buddha. It is still regarded
as a crime to kill a Cobra when it enters a hut; prayers are addressed
and food is offered to it. Its presence is an omen of happiness and
prosperity; it is believed that its death would bring down the most
terrible calamities on whomsoever should have brought it about, and on
his family.

Nevertheless, in the Indian Peninsula alone, the Cobra, the Krait, and
a few other extremely poisonous species of snakes cause every year an
average of _25,000_ deaths. The number of fatalities from the same
cause is likewise considerable in Burma, Indo-China, the Dutch Indies,
Australia, Africa, the West Indies and Tropical America generally.

The temperate regions of the globe are less severely affected; North
America the Rattle-snake and the Moccasin are especially deadly.

In France the Common Viper abounds in Jura, Isère, Ardèche, Auvergne,
Vendée, and the Forest of Fontainebleau. _Three hundred thousand_ have
been killed in twenty-seven years in the Department of Haute-Saône
alone. Every year this snake causes the death of some sixty persons.
Cow-herds, shepherds, and sportsmen fear it greatly, since it is very
dangerous to cattle, sheep, and dogs.

II.--GENERAL CLASSIFICATION OF POISONOUS SNAKES. THEIR
ANATOMO-PHYSIOLOGICAL CHARACTERS.

Poisonous snakes are divided by naturalists into two great Families,
the COLUBRIDÆ and VIPERIDÆ, distinguished from each
other by certain anatomical characters, and especially by the dentition.

The COLUBRIDÆ resemble harmless snakes, which renders them all
the more dangerous.

They are divided into two groups: OPISTHOGLYPHA (ὄπισθεν,
behind; γλυφὴ, a groove) and PROTEROGLYPHA (πρότερον, before;
γλυφὴ, a groove).

The OPISTHOGLYPHA have the upper jaws furnished in front with
smooth or non-grooved teeth, but _behind_ with one or several rows of
long, canaliculate teeth.

This group includes three _Sub-families_:--

A. The _Homalopsinæ_, having valved nostrils, placed above the snout.

B. The _Dipsadomorphinæ_, in which the nostrils are lateral in
position, and the dentition is highly developed.

C. The _Elachistodontinæ_, which have but rudimentary teeth only on
the posterior portion of the maxillary, on the palatine and on the
pterygoid bones.

Almost all the snakes belonging to these three sub-families are
poisonous, but only slightly so. They are not dangerous to man. Their
venom merely serves to paralyse their prey before deglutition takes
place; it does not afford them an effective means of defence or attack.

All the _Homalopsinæ_ are aquatic; they bring forth their young in
the water, and are met with commonly in the Indian Ocean, starting
from Bombay, and especially in the Bay of Bengal, on the shores of
Indo-China and Southern China, from Singapore to Formosa, in the
Dutch Indies, in Borneo, the Philippines, New Guinea and the Papuan
Archipelago, and as far as the north of Australia.

The _Dipsadomorphinæ_ comprise a large number of highly cosmopolitan
genera and species, found in all the regions of the earth except the
northerly portions of the Northern Hemisphere. None of these reptiles
is capable of causing serious casualties among human beings, owing
to the peculiarly defective arrangement of their poison-apparatus.
I therefore do not think it worth while to linger here over their
description.

The _Elachistodontinæ_ are of even less importance; at the present time
only two species are known, both of small size and confined to Bengal.

* * * * *

The PROTEROGLYPHA group of the _Colubridæ_ is of much greater
interest to us, since all the snakes belonging to it are armed with
powerful fangs, in front of the upper maxillaries. These fangs, which
are provided with a channel in the shape of a deep groove, communicate
at the base with the efferent duct of poison glands, which are often of
very large size.

The group is composed of two _Sub-families_:--

A. The _Hydrophiinæ_ (sea-snakes), provided with a flattened
_oar-shaped_ tail. The body is more or less laterally compressed; the
eyes are usually small, with circular pupils; the scales of the nose
have two notches on the upper labial border.

The normal habitat of all the members of this sub-family is the sea,
near the shore, with the exception of the genus _Distira_, which is
met with in the fresh water of a lake in the Island of Luzon, in the
Philippines. They are frequently found in very large numbers in the
Indian seas and throughout the tropical zone of the Pacific Ocean, from
the Persian Gulf to the west coast of the American Continent, but they
are entirely absent from the West Coast of Africa.

B. The _Elapinæ_ (land-snakes), with a cylindrical tail, and covered
with smooth or carinate scales. These serpents are frequently adorned
with brilliant colours. Some of them (belonging to the genus _Naja_)
have the faculty of expanding the neck in the shape of a parachute, by
spreading out the first pairs of ribs when they are alarmed or excited:
the breadth of the neck then greatly exceeds that of the head. They are
distributed throughout Africa, Asia, and North and South America, and
are also found in Australia, where almost all the snakes that are known
belong to this sub-family.

* * * * *

The Family VIPERIDÆ is characterised by a triangular head,
which is widened posteriorly, and by the general aspect of the body,
which is usually thick-set and terminated by a short tail. The bones
of the face are movable. The præfrontal bone is not in contact with
the nasal; the maxillary is greatly shortened and may be articulated
perpendicularly to the ectopterygoid; it bears a pair of large
poison-fangs, one on each side, and these are always accompanied by
several teeth to replace them, folded back in the gum; these latter
teeth come in succession to take the place of the principal tooth, when
this is broken or falls out of itself when the snake sheds its skin.

The poison-fangs are not _grooved_, as in the _Proteroglyphous
Colubridæ_; they are pierced by a perfectly formed canal, the upper
end of which inosculates with the efferent duct of the corresponding
poison-gland, while its lower extremity opens to the exterior a little
above and in front of the tip. The latter is always very sharp.

The palate and lower jaw are furnished with small hooked teeth, which
are solid and non-venomous.

With the exception of the species of _Atractaspis_, these snakes
are all ovoviviparous. The majority are terrestrial; a few lead a
semi-aquatic existence, while others are arboreal.

Their distribution includes Europe, Asia, Africa (with the exception
of Madagascar), and North and South America. They do not exist in
Australia.

They are divided into two _Sub-families_:--

A. The _Viperinæ_, in which the head, which is very broad and covered
with little plates and scales, has no pit between the nose and the eyes;

B. The _Crotalinæ_ (κρὁταλον, a rattle), in which the head is
incompletely covered with scales, and exhibits a deep pit on each side,
between the eye and the nostril.

* * * * *

Among snakes, the characters that serve as a basis for the
determination of genera and species are the general shape of the body,
especially that of the head, the arrangement of the cephalic scales,
the cranial skeleton, and the dentition.

* * * * *

_Cranial Skeleton._--The cranium is composed of a certain number of
bones, the homologues of which are found in the mammalian skeleton; but
the bones are complex, and subject to modifications according to the
structure and habitat of each species.

The special arrangement of the bones of the face is above all
characteristic of the poisonous snakes. Those forming the upper jaw,
the palate and the mandibles or “inter-maxillaries” are movable upon
each other and on the cranium. The upper and lower maxillaries are
united by an extensile ligament and articulated with the tympanic
bone, which permits the mouth to be opened very widely when the animal
swallows its prey.

* * * * *

_Dentition._--The _non-poisonous_ snakes have two rows of teeth in
the upper jaw--one external, the _maxillary_, usually composed of
from 35-40 small, backwardly curved teeth; the other internal, the
_palatine_, which only numbers from 20-22 teeth, having the same
curvature (fig. 1, A).

[Illustration: FIG. 1.--A, Cranial skeleton of one of
the non-poisonous _Colubridæ_ (_Ptyas mucosus_); B, cranial
skeleton of one of the poisonous _Colubridæ_ (_Naja tripudians_);
C, cranial skeleton of one of the poisonous _Colubridæ_
(_Bungarus fasciatus_); D, cranial skeleton of one of the
_Viperidæ_ (_Vipera russellii_); E, cranial skeleton of one
of the _Viperidæ Crotalinæ_ (_Crotalus durissus_); F, cranial
skeleton of one of the _Colubridæ Hydrophiinæ_ (_Hydrophis pelamis_).]

In the _poisonous_ snakes the maxillary bones are shorter, and the
_outer_ row is represented by a single long and tubular or grooved
tooth (the fang), fused with the maxillary bone, which is itself
movable (fig. 1, B, C, D, E,
F).

[Illustration: FIG. 2.--A, Maxillary bone and fangs
of one of the _Viperidæ_ (_Vipera russellii_); B, maxillary
bone and fangs of one of the _Colubridæ_ (_Naja tripudians_);
C, maxillary bone and fangs of one of the _Colubridæ_
(_Bungarus fasciatus_); D, maxillary bone and teeth of one
of the non-poisonous _Colubridæ_ (_Ptyas mucosus_). (After Sir Joseph
Fayrer.)]

Certain species (_Dipsas_) have maxillary teeth which increase in size
from front to rear; the longest teeth are _grooved_ and serve for the
better retention of prey, and also to impregnate it with saliva; but
they are not in communication with the poison-glands.

The _poison-fangs_ are normally covered with a fold or capsule of
mucous membrane, in which they are sheathed. This fold conceals a whole
series of _reserve_ teeth in different degrees of development, which
eventually become attached to the extremity of the maxillary when the
principal tooth falls out or is broken (fig. 2).

[Illustration: FIG. 3.--A, Fang of one of the
_Viperidæ_ (_Vipera russellii_); D, transverse section of the
fang.]

_Poison Apparatus._--The grooved or furrowed teeth in the
_Proteroglypha_ and the canaliculate teeth in the _Solenoglypha_ are
arranged, not for the purpose of seizing prey, but in order to deal it
a mortal blow by injecting the venom into its flesh.

In the normal position they lie almost horizontally, and exhibit no
mobility of their own. But, when the animal prepares to bite, their
erection is effected by the snake throwing its jaw back; and this
movement, which is always very sudden, enables it at the same time to
compress its poison-glands, by the aid of special constrictor muscles.

On examining the various species of poisonous snakes, we observe very
sharply marked differences in the arrangement and dimensions of the
teeth. Thus, in the VIPERIDÆ they are long, extraordinarily
sharp, and capable of producing deep wounds (fig. 2, A, and
fig. 3). They are traversed by an almost completely closed canal, from
the base, which communicates with the poison-duct, to the neighbourhood
of the point, where it opens very obliquely on the convex surface (fig.
3, A and D).

[Illustration: FIG. 4.--B, Fang of one of the
_Colubridæ_ (_Naja tripudians_); E, transverse section.]

[Illustration: FIG. 5.--C, Fang of one of the
_Hydrophiinæ_ (_Hydrophis pelamis_); F, transverse section.]

[Illustration: FIG. 6.--Three transverse sections of a
poison-fang of one of the _Colubridæ_, through A A, B
B, C C; P P, pulp cavity; V V V,
poison-canal (groove). (After C. J. Martin.)]

* * * * *

In the _Elapinæ_ sub-family of the _Colubridæ_, and especially in
the _Hydrophiinæ_, the teeth are much shorter and simply grooved or
canaliculate; that is to say, the canal communicates with the exterior
throughout its extent by a narrow slit, which traverses the entire
convex surface of the tooth (figs. 4, 5, and 6).

It does not follow from this that the bites of these reptiles are less
dangerous; the contrary, indeed, is the case, for their venom is
infinitely more active.

These differences, as well as the particular mode of arrangement of the
other little non-poisonous teeth in both jaws, enable us in many cases
to recognise, by the mere appearance of the bite, the species of snake
by which the bite has been inflicted.

[Illustration: FIG. 7.--MARKS PRODUCED ON THE SKIN BY THE
BITES OF DIFFERENT SPECIES OF SNAKES.

I. _Non-venomous Colubrine._--The bite is marked only by the imprint of
from 35-40 small palatine or pterygoid teeth, and 20-22 upper maxillary
teeth (on the outside of the foregoing) on each side.

II. _Venomous Colubrine_ (_Naja tripudians_,
PROTEROGLYPHA).--The bite exhibits 25 or 26 punctures from
the pterygoid or palatine teeth, and, on each side, one or two, rarely
three, circular wounds produced by the principal poison-fangs and by
the reserve teeth.

III. _Viperidæ_ (SOLENOGLYPHA).--The sole indication of the
bite consists of 8 or 10 punctures from the palatine or pterygoid
teeth, and one little round wound, on each side, produced by the
poison-fangs.

(After Sir Joseph Fayrer.)]

Fig. 7, above, shows how it is possible to distinguish the marks left
by a _non-venomous_ reptile, and by one of the _Proteroglypha_ or
_Solenoglypha_ respectively.

_Poison-glands._--The poison-glands occupy an extensive inter-muscular
space behind the eyes, on each side of the upper jaw. They are oval in
shape, and may, in _Naja tripudians_ for example, attain the size of a
large almond (fig. 8).

Their structure is the same as that of the salivary glands of the
larger animals. The poison that they secrete accumulates in their
_acini_ and in the efferent duct that opens at the base of the
corresponding fang.

Each gland is surrounded by a capsule, to which are partly attached
the fibres of the masseter muscle, which violently compresses it and
drives the poison, just as the piston of a syringe would do, into the
canaliculi or groove of the fang.

[Illustration: FIG. 8.--POISON-GLAND AND FANGS OF A
VENOMOUS SNAKE (_Naja tripudians_, _Colubridæ_). (Natural size.)

L, Lobe of the gland; D, poison-duct; F,
fang attached to the maxillary bone; G G, gland; M,
capsule of mucous membrane surrounding the fangs; R, reserve
fangs; A A, muscular fascia covering the gland.

(After Sir Joseph Fayrer.)]

In a few venomous snakes the gland is developed to such an extent that
it extends as far as the first ribs.

The species, on the contrary, that have the poison-teeth placed in
the hinder part of the mouth (_Opisthoglypha_) have glands but little
developed.

* * * * *

_Muscular Apparatus of the Head._--Figs. 9 and 10, 11 and 12 show the
arrangement of the principal muscles that work the jaws and glandular
organs in _Vipera russellii_ and _Naja tripudians_, which respectively
represent the most formidable types of _Viperidæ_ and venomous
_Colubridæ_.

It is not necessary to give a detailed description of each of these
muscles. Let it suffice to point out that all contribute in giving
the greatest elasticity to the jaws, and at the same time strength
sufficient to retain the prey and to cause it to pass from front to
rear towards the œsophagus, by a series of alternate antero-posterior
movements and analogous lateral ones. By means of these movements,
which are participated in by the upper and lower maxillary bones, the
palatines, mandibles or inter-maxillaries, and the pterygoids, the
animal in a manner _draws itself_ over its prey _like a glove_, since
the arrangement of its dentition does not admit of _mastication_.

[Illustration: A A, Fascia covering the anterior and posterior
temporal muscles; B, small gland; C, tendinous
insertion of the fascia; D, poison-duct; E,
poison-fang; F, reserve fangs; G, mandible;
H, ectopterygoid muscle; J, poison-gland covered
by the masseter; K, masseter inserted in the mandible;
L, insertion of the temporal muscle; M, digastric
muscle.

A A, Ectopterygoid muscle; B, præ-spheno-pterygoid
muscle; C, intermandibular muscle; D,
præ-spheno-palatine muscle; E præ-spheno-vomerine muscle;
F, capsule of mucous membrane surrounding the fangs;
G, long muscle of the neck.

FIGS. 9 AND 10.--MUSCULAR APPARATUS AND POISON-GLAND
OF _Vipera russellii_ (_Viperidæ_). (After Sir Joseph Fayrer.)]

[Illustration: A, Tracheo·mastoid muscle; B B,
digastric muscle; C C, posterior temporal muscle; D
D, anterior temporal muscle; E E, masseter; F,
poison-gland, covered by the masseter and fascia; G,
poison-duct; H, maxillary bone; I, neuro-mandibular
muscle; J, costo-mandibular muscle.

A, Entopterygoid muscle; B, poison-gland; C,
poison-duct; D, poison-fangs; E, præ-spheno-palatine
muscle; F, præ-spheno-vomerine muscle; G, capsule of
mucous membrane surrounding the fangs; H, præ-spheno-pterygoid
muscle (which erects the fangs); J, inter-mandibular muscle;
K, ectopterygoid muscle; L, long muscle of the neck
(_longus colli_).

FIGS. 11 AND 12.--MUSCULAR APPARATUS AND POISON-GLAND
OF _Naja tripudians_ (_Colubridæ_). (After Sir Joseph Fayrer.)]

[Illustration: FIG. 13.--ARRANGEMENT OF THE SCALES OF THE
HEAD IN ONE OF THE NON-POISONOUS _Colubridæ_ (_Ptyas mucosus_).
(After Sir Joseph Fayrer.)

A, Rostral scale; B, anterior frontals; B^1,
posterior frontals; C, vertical; D, occipitals;
E, supra-ciliaries; F, temporals; L,
M, nasals; N, loreals, or frenals; O,
anterior oculars, or præ-orbitals; P, posterior oculars, or
post-orbitals; Q, supralabials; G, median infralabial; H H,
lateral infralabials; I K, mentals.]

The enormous extensile power of the mouth and œsophagus thus enables
snakes to swallow animals, the size of which is several times in excess
of their own diameter.

Deglutition is slow and painful, but the gastric and intestinal juices
are so speedy in action, that the digestion of the most resistant
substances rapidly takes place. The very bones are dissolved, and the
fæces, which are voided some days later, contain only a few osseous
remains and a felt-like material composed of hair or feathers.

_Scales._--The skin of snakes, which is very elastic and extensile, is
covered with scales, small on the back, and in great transverse plates
on the entire ventral surface.

[Illustration: FIG. 14.--ARRANGEMENT OF THE SCALES OF
THE HEAD IN ONE OF THE POISONOUS _Colubridæ_ (_Naja tripudians_,
OR _Cobra-di-Capello_). (After Sir Joseph Fayrer.)]

The shape and dimensions of the scales of the head are highly
characteristic in each species. It is therefore necessary to know their
names and the arrangement that they exhibit: these details are shown
with sufficient clearness in figs. 13 and 14.

_Coloration._--The colouring exhibited by the scales of snakes is
governed generally by the biological laws of _mimicry_. It is therefore
not a character of specific value, and may be modified several times
in the course of the existence of the same reptile, according to the
surroundings in which it is obliged to live.

“Nature,” write Dumeril and Bibron, “seems to have caused the tints
and colours of snakes to vary in accordance with their habits and
modes of life. Generally speaking, the colours are greyish or dull in
species that are wont to live among sand, or which bury themselves in
loose earth, as also in those that lie in wait on the trunks or large
boughs of trees; while these hues are of a bluish-green, resembling the
tint of the leaves and young shoots of plants, in snakes that climb
among bushes or balance themselves at the end of branches. It would
be difficult to describe all the modifications revealed by a general
study of the colours of their skins. Let us imagine all the effects
of the decomposition of light, commencing with white and the purest
black, and passing on to blue, yellow, and red; associating and mixing
them together, and toning them down so as to produce all shades, such
as those of green, of violet, with dull or brilliant tints more or
less pronounced, and of iridescent or metallic reflections modified by
spots, streaks, and straight, oblique, undulating, or transverse lines.
Such is the range of colours to be found in the skin of snakes.”

This skin is covered by a thick epidermis, which is periodically
detached in its entirety, most frequently in a single piece. Before
effecting its _moult_, the reptile remains in a state of complete
repose for several weeks, as if asleep, and does not eat. Its scales
grow darker and its skin becomes wrinkled. Then one day its epidermis
tears at the angle of the lips. The animal thereupon wakes up, rubs
itself among stones or branches, divests itself entirely of its
covering as though it were emerging from a sheath, and proceeds
forthwith in quest of food.

The _moult_ is repeated in this way three or four times every year.

CHAPTER II.

_HABITS OF POISONOUS SNAKES. THEIR CAPTURE._

All poisonous snakes are _carnivorous_. They feed on small mammals
(rats, mice), birds, batrachians, other reptiles or fish, which they
kill by poisoning them by means of their fangs.

They almost always wait until their prey is dead before swallowing it.

Some of them are very fond of eggs, which they well know how to find in
the nests of birds, and swallow whole.

When a poisonous snake wishes to seize its prey, or strike an enemy,
it raises its head, and depresses the lower and elevates the upper jaw
in such a way that the _fangs_ are directed straight forward. Then,
with the quickness of a spring when it is released, the reptile makes a
sudden dart and strikes its victim. After inflicting the wound it draws
back, doubles up its neck and head, and remains prepared to strike
again.

So rapid is the action of the venom, that the wounded animal falls to
the ground almost immediately; it is forthwith stricken with paralysis,
and dies in a few moments. In most cases the snake holds it in its
mouth until death ensues; the reptile then sets to work to swallow its
victim, an operation which is always slow and painful.

In captivity poisonous snakes almost always refuse to take any food
whatever. If it be desired to keep them for a long time, it is often
necessary to resort to artificial feeding. For this purpose the snake
is seized by the head by means of a strong pair of long forceps; it is
then grasped by the neck with the left hand without squeezing too
hard (fig. 15), taking care at the same time not to give the body a
chance of coiling itself round anything. Next, one or more lumps of
beef or horse-flesh are introduced into the jaws, and gently forced
down deep into the œsophagus by means of a glass rod, which is polished
in order not to injure the mucous membrane. The œsophagus is then
gently massaged in a downward direction, in order to cause the bolus of
food to descend into the stomach (fig. 16). This operation is repeated
every fortnight.

[Illustration: FIG. 15.--FEEDING A POISONOUS SNAKE, FIRST
STAGE.]

[Illustration: FIG. 16.--FEEDING A POISONOUS SNAKE, SECOND
STAGE.]

[Illustration: FIG. 17.--CATCHING A
_Cobra-di-Capello_ (_Naja tripudians_), FIRST STAGE. (At the
French Settlement of Pondicherry, in India.)]

In this way, at my laboratory, I have been able to preserve, in perfect
condition for more than two years, Indian _Cobras_ and _Fers-de-lance_
from Martinique, taking care to keep them in a hothouse, at a
temperature of about 82° to 86° F.

It is also very important to place inside the cases a vessel full of
water, which should be frequently changed, for almost all snakes drink
often and like to bathe for whole days at a time.

[Illustration: FIG. 18.--CATCHING A
_Cobra-di-Capello_ (_Naja tripudians_), SECOND STAGE. (At the
French Settlement of Pondicherry, in India.)]

Within their reach should be placed in addition branches and rockwork,
against which they rub at the _moulting_ times, in order periodically
to rid themselves of their scarf-skin.

While moulting, snakes must neither be touched nor fed, since to force
them to take food at such a time would be fatal.

_Snake-catching._--The capture of poisonous snakes, in order to keep
them alive, can only be performed without danger by skilful persons,
who are possessed of much coolness.

The best way of securing them is suddenly to pin the neck to the ground
by means of a stick held horizontally, or a small two-pronged fork of
wood or metal (fig. 17).

The stick is rolled along until close to the occiput (fig. 18). The
animal can then be seized with the hand immediately behind the head, in
such a way that it is impossible for it to turn and bite. It is then
put into a wire cage, provided with a small movable trapdoor, with the
fastening on the outside.

In this way poisonous snakes can be sent to a distance, and left
without food for one or even two months, provided that they be kept in
a place which is somewhat moist and sufficiently warm.

Fig. 19 shows how captured cobras are carried in India, in the environs
of Pondicherry. They are enclosed in earthern _chatties_, or in baskets
of plaited bamboo, which are provided with covers, and are very
convenient for carrying snakes short distances.

[Illustration: FIG. 19.--HINDU CARRYING TWO CAPTURED
COBRAS IN “CHATTIES.”]

CHAPTER III.

_DESCRIPTION OF THE PRINCIPAL SPECIES OF POISONOUS SNAKES.
THEIR GEOGRAPHICAL DISTRIBUTION._

Poisonous snakes are especially common in the tropical zones of the
Old and New Worlds. The species found in Europe are but of small size
and not very formidable. In hot countries, on the other hand, they
attain large dimensions, their venom is much more active, and, although
they hardly ever attack man, and in most cases avoid him, they cause a
considerable number of fatal accidents.

It is sometimes a rather difficult matter to recognise from the mere
appearance of a snake whether it is poisonous or not. Naturalists
themselves are occasionally deceived. It is therefore useful to
learn to distinguish the most dangerous species by their external
characters, and to know in what countries there is a risk of their
being encountered.

_A.--EUROPE._

Of the continents of the Old World, the poorest in poisonous snakes
is Europe. The only species found there are a CŒLOPELTIS
(belonging to the Sub-family _Dipsadomorphinæ_ of the _Opisthoglypha_),
and certain VIPERINÆ, which rarely exceed 75 centimetres in
length.

CŒLOPELTIS, the cranial skeleton and head of which are
represented in fig. 20, is characterised by a narrow, concave frontal
shield, projecting supraciliaries, short snout, large eyes, with round
pupils, two poison-fangs at the back of the upper maxillaries, and a
cylindrical body. The scales of the back are finely grooved, and in the
adult slightly concave.

FIG. 20.--MAXILLARY, MANDIBLE, AND HEAD OF
_Cœlopeltis monspessulana_.

The coloration, olivaceous-brown, or deep red on the back, becomes on
the ventral surface pale yellow with brown streaks, and from five to
seven longitudinal series of small spots, which are blackish and edged
with yellow on the sides.

The mean total length is 1,800 millimetres. The tail is somewhat
tapering, and about 350 millimetres long.

The only European species is _Cœlopeltis monspessulana_, which is met
with pretty commonly in France, in the neighbourhood of Montpellier,
and Nice, near Valencia in Spain, and in Dalmatia. It is likewise found
throughout North Africa, and in Asia Minor.

A second species, _Cœlopeltis moilensis_, occurs in Southern Tunis,
Egypt, and Arabia.

The European VIPERINÆ belong exclusively to the Genus
VIPERA, the principal zoological characters of which are as
follows:--

Head distinct from the neck, covered with small scales, with or without
frontal and parietal shields; eyes small, with vertically elongate
pupils, separated from the labials by scales; nostrils lateral. Body
cylindrical. Scales keel-shaped, with an apical pit, in from 19-31
rows; ventral scales rounded. Tail short; subcaudal scales in two rows.

The Genus _Vipera_ is represented in Europe by several species, which
are likewise found in Western Asia and North Africa.

These species are:--

_V. ursinii_, _V. berus_, _V. aspis_, _V. latastii_, and _V.
ammodytes_. [1]

Vipera ursinii.

Snout obtuse, soft on its upper surface, with the frontal and parietal
shields distinct, the former about one and a half times as long as
broad, and almost always longer than the parietals. A single series of
scales between the eyes and the free margin of the lips.

Temporal shields smooth. Body scales in from 19 to 21 rows, strongly
keeled on the back, less strongly on the sides.

Colour yellowish or pale brown above, grey or dark brown on the sides,
sometimes uniform brown; spots more or less regular on the vertebral
column, oval, elliptic or rhomboidal, dark brown or flecked with white,
sometimes forming an undulous or zigzag band; two or three longitudinal
series of dark brown or black spots on the sides; small dark dots
running obliquely from the eye to the angle of the mouth; nose and lips
white, and one or two dark angular streaks on the head; chin and throat
yellowish; belly black, with transverse series of white or grey dots.
No sexual differences in coloration.

Total length from 420-500 millimetres; tail 50-55.

_Habitat_: South-east France (Basses-Alpes); Italy (Abruzzi); Istria;
Mountains of Bosnia; Plains of Lower Austria; Hungary (environs of
Buda-Pesth).

Vipera berus (_Common Viper_, or _Adder_).

Snout rounded, short and truncate; pupil vertically elongate; vertical
diameter of the eyes equal to or greater than the distance separating
them from the mouth; frontal and parietal shields distinct, the former
as long as broad, usually shorter than the space separating it from the
rostral shield; 6-13 scales round the eyes; one or rarely two series of
scales between the eyes and the lips; nasal shield single, separated
from the rostral by a naso-rostral shield; temporal scales smooth. Body
scales in 21 rows (exceptionally 19 or 23), strongly keeled; 132-150
ventral shields; 38-36 subcaudals.

[Illustration: FIG. 21.--(_1_) _Vipera berus_; (_2_) _Vipera
aspis_; (_3_, _4_) _Vipera ammodytes_.

(Natural size.)]

Colour very variable, grey, yellowish, olive, brown, or red above,
generally with an undulating or zigzag band along the vertebral column,
and a series of lateral spots. A black spot shaped like a =V=, an
=X=, or a circumflex accent, on the head. The tip of the tail is
yellow or reddish. Some specimens are entirely black.

Total length from 350 to 700 millimetres; tail 75 to 90.

_Habitat_: Northern Europe, and especially the mountains of Central
Europe; irregularly distributed in Southern Europe; Northern Spain and
Portugal, Northern Italy, Bosnia, Caucasus.

* * * * *

This viper, which is very common in France, ranges as far as the
Scandinavian Peninsula to about the 65th parallel of North Latitude. It
is sometimes met with among the mountains at an altitude of about 6,500
feet (2,000 metres). It is found on heaths, in grass-lands, vineyards,
and forests. Certain parts of the sandy moors of North Germany are
literally infested with it. It abounds in the Jura, Isère, Ardèche,
Auvergne, Brittany, Vendée, and the Forest of Fontainebleau.

It seeks its prey by night, and feeds on voles, small birds, frogs,
lizards, and small fish. During the summer it shows a preference for
moist places, often even remaining in the water, in which it swims with
ease.

Light and fire attract it. It does not climb trees, but is frequently
found coiled up on boughs of dead wood scattered on the ground.

When on the defensive, and preparing to bite, it throws its head back,
and makes a sudden dart of from a foot to sixteen inches. If irritated
it makes a sort of hissing noise.

To pass the winter it retires into the crevices of rocks or into old
tree-trunks, where it entwines itself closely with a number of its
congeners. In this way ten or fifteen vipers are frequently found
together in the same hole.

In April, the whole company awakes, and copulation then takes place.
The eggs are laid in August and September, and the young immediately
crawl out of the shell, already prepared to bite, and capable
of finding their own food. Their length at birth amounts to 230
millimetres.

The two glands of an adult adder contain about 10 centigrammes of
poison. This small quantity is sometimes sufficient to cause death; out
of 610 persons bitten, Rollinger returns 59 deaths, or about 10 per
cent.

In the departments of Vendée and Loire-Inférieure alone, Viaud Grand
Marais has noted during a period of six years 321 cases of bites from
adders, 62 of which were followed by death. In Auvergne, Dr. Fredet[2]
(of Royat) returns 14 cases, which caused 6 deaths.

Vipera aspis (_Asp_, or _Red Viper_).

(Fig. 21, _2_, and fig. 22.)

Snout slightly turned up, soft and squarely truncate; vertical diameter
of the eyes equal to the space separating them from the mouth; upper
surface of the head usually covered with small, imbricate, smooth or
feebly keeled scales, in 4-7 series, between the supraocular shields,
which are prominent. The frontal and parietal shields are usually
wanting; sometimes they are distinct, but small and irregular; the
former are separated from the supraoculars by two series of scales;
8-13 scales round the eyes; two (rarely three) series of scales between
the eyes and the labials; nasal shield single, separated from the
rostral by a naso-rostral shield. Body scales in 21-23 rows, strongly
keeled; 134-158 ventrals; 32-49 subcaudals.

Coloration very variable, grey, yellowish, brown, or red above, with a
zigzag band as in _V. berus_. Usually a black =U=-shaped mark on
the hinder part of the head, with a longitudinal black streak behind
the eyes; upper lip white, or yellowish. Ventral surface yellow, white,
grey, or black, with lighter or darker markings.

Total length, 620-675 millimetres; tail 75-95.

_Habitat_: France (especially Vendée, the Forest of Fontainebleau, and
the South), Pyrenees, Alsace-Lorraine, the Black Forest, Switzerland,
Italy and Sicily, and the Tyrol.

This viper especially frequents dry, rocky, and arid hillsides, which
are exposed to the sun. Like the adder, it hibernates in tree-trunks
and old walls. It lays from 6 to 15 eggs, from which the living young
immediately issue, provided with poison. It feeds upon small rodents,
worms, insects, and young birds. Raptorial birds, storks, and hedgehogs
pursue it and devour it in large numbers.

[Illustration: FIG. 22.--_Vipera aspis._ (Natural size.) (From
the Forest of Fontainebleau.)]

Vipera latastii.

Intermediate between _V. aspis_ and _V. ammodytes_. Snout less turned
up into a corneous appendage than in the latter. Head covered with
small, smooth, or feebly keeled, subimbricate scales, among which
an enlarged frontal shield may sometimes be distinguished; 5-7
longitudinal series of scales between the supraocular shields; 9-13
scales round the eyes; 2 or 3 series between the eyes and the labials;
nasal shield entire, separated from the rostral by a naso-rostral. Body
scales in 21 rows, strongly keeled; 125-147 ventrals; 32-43 subcaudals.

Coloration grey or brown above, with a longitudinal zigzag band,
usually spotted with white; head with or without spots on the vertex;
black streak behind the eyes; ventral surface grey, spotted with black
and white; tip of the tail usually yellow or with yellow spots.

Total length, 550-610 millimetres; tail 80-85.

_Habitat_: Spain and Portugal.

Vipera ammodytes.

(Fig. 21, _3_ and _4_).

Snout terminated in front by a horny appendage covered with 10-20
small scales; vertical diameter of the eyes less than the distance
separating them from the mouth; upper surface of the head covered
with small, smooth, or feebly keeled scales, among which an enlarged
frontal and a pair of parietal shields are sometimes distinguishable;
5-7 longitudinal series of scales between the supraoculars; 10-13
scales round the eyes; two series between the eyes and the labials;
nasal shield entire, separated from the rostral by a naso-rostral.
Body scales in 21-23 rows, strongly keeled; 133-162 ventrals; 24-38
subcaudals.

Coloration grey, brown, or reddish above, with a zigzag dorsal band,
usually spotted with white; black streak behind the eyes; belly grey or
violaceous; end of the tail yellow, orange, or coral-red.

Total length, 550-640 millimetres; tail 70-80.

_Habitat_: Southern Tyrol, Carinthia, Styria, Hungary, Danubian
principalities and kingdoms, Turkey. Does not pass beyond the 48th
parallel of North Latitude.

This viper loves very sunny places, and hillsides planted with vines.
It rarely hibernates.

In districts in which it is plentiful, it is only necessary to light a
fire at night in order to attract this species in swarms; this is the
best method of taking it.

Its food consists of small rodents, lizards, and birds.

_B.--ASIA, DUTCH INDIES, AND PHILIPPINE ISLANDS._

The species of snakes most dangerous to man are found in the
warmer regions of Asia. India especially is infested by the famous
Cobra-di-Capello (_Naja tripudians_), which possesses the highly
remarkable faculty of dilating its neck in the form of a hood when
irritated, and whose sculptured image appears on almost all the Hindu
monuments.

We shall describe in a separate section (see below, F.) the
HYDROPHIINÆ, or _Sea-snakes_, a large number of species of
which frequent the shores of the Indian Ocean, the Strait of Malacca,
the China Sea, the Moluccas, Celebes, and North Australia. In the case
of certain species the area of distribution includes the whole of
the tropical and sub-tropical zones of the Pacific Ocean, as far as
the West Coast of America. It is therefore preferable to group them
together for the purpose of comprehensive study.

Besides the above, the continent of Asia harbours a multitude of
poisonous snakes belonging to the two Families COLUBRIDÆ and
VIPERIDÆ.

The genera and species belonging to these are so diverse, that we must
confine ourselves to mentioning the essential characters of those that
present most interest.

I.--FAMILY COLUBRIDÆ.

{ (a) _Bungarus_.
{ (b) _Naja_.
Subfamily ELAPINÆ: Genera { (c) _Hemibungarus_.
{ (d) _Callophis_.
{ (e) _Doliophis_.

(a) Bungarus.

Head hardly distinct from the neck; eyes small, with round or
vertically elliptic pupils; nostril between two nasal shields. Two
large poison-fangs followed by one or two small, slightly grooved
teeth (fig. 23). Scales smooth, oblique, in 13-17 rows, enlarged and
hexagonal in shape on the vertebral column; ventral scales round. Tail
relatively short; subcaudal scales in one or two rows.

Two very dangerous snakes found in India and Indo-China belong to this
genus, _B. fasciatus_ and _B. candidus_ (var. _cæruleus_). Both are
fairly common. In Ceylon _B. ceylonicus_ is met with, and in South
China _B. candidus_ (var. _multicinctus_). The length of these snakes
is from 1,000-1,500 millimetres. The back is compressed in the shape of
a keel. The neck is not dilatable.

[Illustration: FIG. 23.--SKULL OF _Bungarus_. (After
G. A. Boulenger, _op. cit._)]

1. _B. fasciatus_ (_Banded Krait_).

Colour bright yellow, ringed with black, with a black band commencing
between the eyes, and broadening behind upon the nape and neck (fig.
24).

Especially abundant on the Coromandel Coast, in Bengal, and in Burma.
In the North-west Provinces of India it is known as the _Koclia-Krait_.
Its bite is very serious, but does not cause nearly so many fatalities
as that of the _Cobra_, since its fangs are smaller.

Dogs bitten by _B. fasciatus_ die in from four to five hours.

[Illustration: FIG. 24.--_Bungarus fasciatus_ (India). (After
Sir Joseph Fayrer.)]

2. _B. candidus._

Blackish-brown or bluish, with narrow transverse white streaks, or
small white spots, or alternate rings of yellow and dark brown; belly
white. Smaller than the foregoing, scarcely exceeding 1,000 millimetres
in length. It is known as the “Krait” in India, where, after the
Cobra, the variety _cæruleus_ causes most deaths among human beings.
It is found in jungles and rice-fields, and commonly secretes itself
in old trees and old walls. It frequently penetrates into houses,
verandahs, bathrooms, and even beds. Sir Joseph Fayrer relates the
story of a lady, who, when travelling in a palanquin, found on arriving
at her destination a “Krait” coiled up in her luggage, the snake having
thus made the journey with her throughout a whole night.

The Krait may easily be confused with _Lycodon aulicus_, a harmless
snake which closely resembles it, though it can at once be
distinguished by examining its mouth.

(b) Naja.

(Fig. 25.)

Head scarcely distinct from the neck; eyes with round pupils; nostril
between two nasal shields and an internasal. A pair of solid grooved
poison-fangs. Body elongate, cylindrical, terminated by a conical and
pointed tail. Scales smooth, disposed obliquely, in 15-25 rows. Ventral
scales round.

_N. tripudians_ (_Cobra-di-Capello_). (Fig. 26.)

Head small, covered with large shields, a frontal as long as broad, a
supraocular, a præocular, 3 postoculars, 2 + 3 or 3 + 3 temporals, 7
upper labials, 4 lower labials. Neck dilatable by the separation of
the first cervical ribs; 21-35 scales round the neck, 17-25 round the
middle of the body; 163-205 ventrals; 42-75 subcaudals.

Total length, 1,500-1,900 millimetres; tail 230.

Coloration very variable, usually cinereous grey or almost black
with a bluish sheen; belly lighter, sometimes tinted with red. The
head is frequently tinged with golden-yellow; it is spotted with
yellowish-white above, and is pure white underneath.

This species is distributed throughout the whole of Southern Asia, from
the south of the Caspian Sea to South China and the Malay Archipelago.

[Illustration: FIG. 25.--Skull of _Naja tripudians_. (After G.
A. Boulenger, _op. cit._)]

Several varieties occur, and of these the principal are:--

(1) Var. _Typica_ (fig. 27), with a black-and-white spectacle-shaped
mark on the middle of the dorsal surface of the most dilatable portion
of the neck, and one or more dark transverse bands on the ventral
surface, behind the head.

_Habitat_: India, Ceylon.

(2) Var. _Cæca_.--Colour, pale brown or uniform dark grey, without mark
on the neck, and with one or more dark transverse bands on the anterior
part of the belly.

_Habitat_: Transcaspian region, India, Java.

[Illustration: FIG. 26.--_Naja tripudians_
(_Cobra-di-Capello_) ON THE DEFENSIVE, PREPARING TO STRIKE.]

(3) Var. _Fasciata_.--Colour, brown, olive, or black, with more or less
distinct light transverse bands. White spot edged with black in the
shape of a ring or of a U on the neck, behind; a black spot on each
side in front.

_Habitat_: India, Indo-China and South China, Hainan, Cambodia, Siam,
Malay Peninsula.

(4) Var. _Sputatrix_.--Black or dark brown, with yellow or
orange-coloured spots on the sides of the head and neck. The young have
a pale spot in the shape of a U or an O on the middle of the dorsal
surface of the neck, and the throat is whitish.

_Habitat_: Chusan Islands and South China, Burma, Malay Peninsula,
Sumatra, Java.

(5) Var. _Leucodira_.--Brown or black, without mark on the neck. Throat
yellowish-white, followed by a black transverse band.

_Habitat_: Sumatra, Malay Peninsula.

(6) Var. _Miolepis_.--Brown or black; sides of the head and throat
yellowish, no mark on the neck. Young with white rings completely
encircling the body and tail.

_Habitat_: Sarawak, Labuan, Borneo.

[Illustration: FIG. 27.--_Naja tripudians_
(_Cobra-di-Capello_). (After Sir Joseph Fayrer.)]

_Naja samarensis._

Internasal shields shorter than the præfrontals, and in contact with
the præoculars; 1-3 large occipital shields behind the parietals; 1
præocular and 3 postoculars; 2 + 2 or 2 + 3 temporals; 7 supralabials,
4 infralabials; 21-23 scales across the neck, 17-19 across the middle
of the body; 159-175 ventrals; 45-50 subcaudals.

Coloration black or sometimes yellowish above; pale brown or yellowish
on the belly; neck black.

Total length, 1,000 millimetres; tail 160.

_Habitat_: Philippine Islands.

_Naja bungarus_ (_Ophiophagus_ or _Hamadryas elaps_).

(King Cobra or Hamadryad.)

A pair of large occipital shields; 1 præocular; 3 postoculars; 2 + 2
temporals; 7 supralabials, 4 infralabials; 19-21 scales across the
neck, 15 across the middle of the body; 215-262 ventral scales, 80-117
subcaudals. Neck dilatable.

Coloration very variable, yellowish, brown, olive, or black, with or
without dark transverse bands.

Total length, 3,900 millimetres; tail 630.

_Habitat_: India, Burma, Indo-China, Siam, Southern China, Malay
Peninsula and Archipelago.

* * * * *

The species of _Naja_ are oviparous, and usually lay some twenty eggs,
elliptical in shape and as large as those of a pigeon, with a soft
shell.

These snakes do not fear the proximity of man, and feed upon rats,
mice, and birds; they seek their prey chiefly in the evening, after
sunset.

They swim extremely well, and frequent the neighbourhood of
water-courses.

Indian legends relate that Brahma, having descended on earth and fallen
asleep one day at high noon, a _Naja_ placed itself in front of him
and, dilating its broad neck, procured for him kindly shade. In order
to repay it for the service rendered, Brahma gave _Naja_ the marks
that it bears on its neck, intended to frighten the kites and other
birds of prey, which are implacable enemies of this snake.

When a native of the Malabar Coast finds a _Naja_ in his dwelling, he
begs it in a friendly way to depart; if the request be without avail,
he offers it food in order to attract it outside; if the snake still
does not move, the Hindu goes in search of the pious servitors of
one of his divinities, who, procuring an offering, address the most
touching supplications to it (_Brehm_).

The mortality due to the bite of this snake, which is by far the most
common in India, is considerable. In the course of a period of eight
years, from 1880 to 1887, it amounted on the average to 19,880 human
beings and 2,100 head of cattle every year.

In 1889, 22,480 persons and 3,793 head of cattle perished from
snake-bite. Since then, the annual tale of fatalities always fluctuates
between 16,000 and 22,000, in spite of the rewards for the destruction
of snakes which the Indian Government has been obliged to institute,
which represent an expenditure of about £10,000 per annum.

For every 100 persons bitten, it is estimated that on an average from
25 to 30 die, and in most cases death supervenes in from two to twelve
hours after the bite.

_Naja bungarus_, or the Hamadryad, is the largest and most formidable
of poisonous snakes. It is very vigorous and very aggressive, but is
more rarely met with than _Naja tripudians_. It loves the vicinity of
rivers and streams, lives in forests and jungles, and climbs trees with
facility. It feeds upon other snakes (whence its name _Ophiophagus_),
and also on birds, fish, and small mammals.

Hindu snake-charmers assert that it is very difficult to capture, and
dangerous owing to its strength; they handle it only after having
extracted its poison-fangs.

A very intelligent Hindu told Torrens how he had seen the way in which
the Hamadryad procures the snakes that form its favourite food. The
Hindu in question happened to be on the flat roof of his house, when
a young Hamadryad appeared quite close to him. The snake raised its
head, expanded its neck, and emitted a shrill hissing noise. Thereupon
a dozen snakes came crawling up from all directions and assembled round
the Hamadryad, when the latter made a dart at one of them and hastened
to devour it (_Fayrer_).

The Hamadryad is dreaded with good reason, for not only is it
aggressive, and hurls itself boldly upon its adversary, but it also
pursues him, a trait exhibited by no other poisonous snake.

Cantor relates that in Assam an officer met with several young
Hamadryads which were being watched over by their mother. The latter
turned towards its enemy, who took to his heels with all speed, pursued
by the terrible reptile. The course taken led to a river, which the
fugitive did not hesitate to swim in order to gain the opposite bank,
hoping thus to make good his escape; all, however, to no purpose.
The snake still pursued him, and the officer saved himself only by a
stratagem. He dashed his turban on the ground; the snake threw itself
upon it and savagely bit it several times, thus giving the officer time
to reach a place of safety.

Cantor’s experiments show that the venom of the Hamadryad is extremely
rapid in its action. A dog usually dies a quarter of an hour after
being bitten, and Nicholson states that he has seen an elephant bitten
by a snake of this species die in three hours.

This genus includes several species of snakes of somewhat small
size, rarely exceeding 700 millimetres in length, with an elongate,
cylindrical body; the head is scarcely distinct from the neck, the
pupil round, and the tail short, while the nostril is situate between
two nasal shields. The temporal shields are arranged in a single row.
The poison-glands sometimes extend into the abdominal cavity. Scales
in 13 or 15 rows; 190-260 ventrals, 12-44 subcaudals in 2 rows.

Four species belonging to this genus are known:--

(1) _H. calligaster._--2 + 3 temporal scales, 6 supralabials.

Colour purple, with black transverse bands separated by narrow white
bars; belly and end of tail red; snout yellow, with a black band on the
upper lip below the eyes.

Total length, 520 millimetres; tail 30.

_Habitat_: Philippine Islands.

(2) _H. collaris._--No anterior temporal scales.

Colour black on the back, with black and red bands on the belly; a
yellow collar on the occiput.

Total length, 430 millimetres; tail 15.

_Habitat_: Philippine Islands.

(3) _H. nigrescens._--Scales in 13 rows. A single temporal scale;
218-251 ventrals; 33-44 subcaudals.

Belly uniformly red; upper lip yellow in front of and behind the eyes.

Total length, 1,100 millimetres; tail 115.

_Habitat_: Hills of Western India, from Bombay to Travancore.

(4) _H. japonicus._--Scales in 13 rows; 190-216 ventrals; 28-29
subcaudals; temporals 1 + 1.

Colour red on the back, with 1-5 black bands crossed by other black
bands edged with yellow. Snout and sides of head black. Belly yellow,
with large black spots alternating with black transverse bands.

Total length, 520 millimetres; tail 40.

_Habitat_: Loo Choo Islands.

(d) =Callophis.=

This genus is characterised by the maxillary bones extending forwards
beyond the palatines, with a pair of large poison-fangs, but without
other teeth. Head and eyes small, pupils round; nostril between two
nasal shields. Body cylindrical, greatly elongate. Scales smooth, in 13
rows; ventrals rounded; subcaudals in 2 rows.

Five species are known:--

(1) _C. gracilis._--Red or pale brown, with three longitudinal black
lines passing through brown, or black spots; the lateral spots
alternating with the vertebræ. Black and yellow bands under the tail
and on the belly.

Total length, 740 millimetres; tail 35.

_Habitat_: Malay Peninsula, Sumatra.

(2) _C. trimaculatus._--Head and nape black, with a yellow spot on each
side of the occiput; belly uniform red; tail with two black rings.

Total length, 335 millimetres; tail 21.

_Habitat_: India and Burma.

(3) _C. maculiceps._--Head and nape black, with one or two yellow bands
on each side. Belly red, two black rings on the tail. Diameter of the
eyes equal to two-thirds of the space separating them from the mouth.

Total length, 485 millimetres; tail 30.

_Habitat_: Burma, Indo-China, Malay Peninsula.

(4) _C. macclellandii._--Head and neck black, with a yellow transverse
band behind the eyes. The space separating the eyes equal to that
separating them from the mouth. Colour reddish-brown on the back, with
regular and equi-distant black streaks; belly yellow, with black bands
or quadrangular spots. The head exhibits two black transverse bands
separated by a yellow band.

Total length, 620 millimetres; tail 55.

_Habitat_: Nepal, Sikkim, Assam, Burma, Southern China.

(5) _C. bibronii._--Met with by Beddome in the forests of Malabar, at
an altitude of 3,280 feet. Back purplish-brown, with a pearly lustre,
and about forty irregular black transverse bands, extending to the tip
of the tail. Head black in front, cherry-red on the occiput.

Total length, 640 millimetres; tail 50.

_Habitat_: Malabar.

* * * * *

All the snakes belonging to the genus _Callophis_ are remarkable
for their bright and varied colours, whence the generic name, which
signifies “_beautiful snakes_.”

They feed exclusively on other snakes belonging to the Family
_Calamaridæ_; consequently they are not found in regions where
_Calamaridæ_ do not occur, as, for instance, in Ceylon.

They are essentially terrestrial, and live in old tree-trunks, or
clefts in rocks. They are sluggish, slow-moving, and chiefly nocturnal.

As a rule they do not seek either to defend themselves or to bite;
consequently fatal accidents caused by them are scarcely known in the
case of human beings. Their venom, however, is very toxic to animals.

(e) =Doliophis.=

This genus exhibits the same characters as _Callophis_, except that the
poison-glands, instead of being confined to the temporal region, extend
a very long way on each side of the body, to about one-third of its
length, gradually growing thicker and terminating at the base of the
heart.

It includes four species:--

(1) _D. bivirgatus._--Colour reddish-purple or black on the back, red
on the head, tail, and belly.

Total length, 1,610 millimetres; tail 190.

_Habitat_: Burma, Indo-China, Malay Peninsula, Sumatra, Java, and
Borneo.

(2) _D. intestinalis._--Brown or black on the back, with darker or
lighter longitudinal streaks; tail red beneath; belly red, crossed with
black streaks.

Total length, 580 millimetres; tail 45.

_Habitat_: Burma, Malay Peninsula, Sumatra, Java, Borneo, Celebes.

(3) _D. bilineatus._--Black on the back, with two white streaks along
the whole length of the body. Snout white; belly striped with black and
white bands. Tail orange, with two or three black rings or spots.

Total length, 710 millimetres; tail 45.

_Habitat_: Philippine Islands.

(4) _D. philippinus._--Back with dark brown cross-bands, merging into
black transverse ventral streaks, which are separated by yellow or red
interspaces. Head brown, with small yellow spots.

Total length, 430 millimetres; tail 35.

_Habitat_: Philippine Islands.

II.--FAMILY VIPERIDÆ.

The Family VIPERIDÆ is represented in Asia by a considerable
number of snakes belonging to the two Subfamilies VIPERINÆ and
CROTALINÆ.

The Asiatic VIPERINÆ belong to the genera:--

(a) _Vipera._
(b) _Pseudocerastes._
(c) _Cerastes._
(d) _Echis._

The CROTALINÆ consist of only two genera:--

(e) _Ancistrodon._
(f) _Lachesis._

1.--VIPERINÆ.

(a) =Vipera.=

We shall not recapitulate here the characters of the Genus _Vipera_,
which we described in dealing with the vipers of Europe. The genus is
represented by several species, the geographical range of which is
chiefly confined to Eastern and Central Asia.

* * * * *

(1) _Vipera renardi._--Resembles _V. berus_, but the snout is pointed
and soft, with a turned-up tip; a single series of scales between the
eyes and the lips; nostril pierced in the lower half of a single nasal
shield; 8-9 supralabial shields; 4 infralabials. Body scales in 21
rows; 130-150 ventrals; 24-37 subcaudals.

Coloration the same as in the European _V. ursinii_, but the snout and
lips are spotted with black or brown.

Total length, 395-620 millimetres; tail 40-75.

_Habitat:_ Central Asia, Turkestan.

* * * * *

(2) _V. raddii._--Snout rounded; supraocular shields erectile; eyes
surrounded by a complete circle of 14-17 scales; 9-10 supralabials;
body scales in 23 rows; 150-180 ventrals; 23-32 subcaudals.

Coloration pale brown or grey on the back, with a dorsal series of
small reddish spots arranged in alternating pairs. A black mark like
a circumflex accent on the occiput, and a black band behind the eyes.
Belly yellow, speckled with black and white.

Total length, 740 millimetres; tail 50.

_Habitat_: Armenia.

* * * * *

(3) _V. lebetina._--Snout rounded and obtuse, with a well-marked
prominence; 7-12 longitudinal series of scales between the eyes;
supraocular shields well developed or narrow, or broken up into several
small portions; 12-18 scales round the eyes; 9-12 supralabials; 4-5
infralabials; body scales in 23-27 rows; 147-180 ventrals; 29-51
subcaudals.

Coloration variable, grey or pale brown on the back, with a series of
large dark spots. Large brown mark like a circumflex accent on the
crown of the head and another on the occiput. Belly whitish, speckled
with grey-brown; end of tail yellow.

Total length, 960 millimetres; tail 120. The female may attain the
length of 1,350 millimetres.

_Habitat_: Cyprus, Galilee, Syria, Asia Minor, Transcaspia, Persia,
Mesopotamia, Afghanistan, Baluchistan, Cashmir.

* * * * *

(4) _V. russellii_ (Daboia, or Russell’s Viper). (Fig. 28.)--This
viper, which may attain a length of as much as 2,000 millimetres, is
magnificently coloured. Its dorsal surface is brownish-yellow, marked
with large oval spots of blackish-brown, edged with yellow or white.
The belly is covered with transverse bands, with beautiful triangular
black spots, bordered with white. The head, which is long, ends in
front in a thick, rounded snout; it is covered above with small keeled
scales. The nostril, which is large and laterally placed, is surrounded
by three shields and soft smooth skin.

[Illustration: FIG. 28.--_Vipera russellii_ (Syn. _Vipera
elegans_. Daboia, or Russell’s Viper). India.

(After Sir Joseph Fayrer.)]

The species is found throughout India, from Bombay to Bengal, in
Ceylon, Burma, and Siam. It is particularly common in Burma, around
Rangoon. For walking in the jungle and rice-fields, the natives of this
region encase their feet and legs in a special kind of jack-boots made
of coarse jute-cloth, in order to protect themselves from the bites of
this snake, which cause a large number of fatal accidents.

The Daboia ascends the Himalayas to an altitude of 5,250 feet. It lives
in thickets, under stones, and in the clefts of rocks. When disturbed
it makes a terrible hissing, but bites only when attacked or irritated.

It feeds upon small vertebrates, such as mice, rats, birds, and frogs,
and often enters houses in pursuit of rats.

“Schrott had the opportunity of observing a Daboia on the defensive. A
lady carrying a child on her arm was returning home towards evening;
she had almost reached her house when a bulldog accompanying her
began to bark furiously. Although the lady saw nothing, she was,
nevertheless, frightened and called for help. Schrott, who was not
far away, ran to the spot, and saw a Daboia lying across the path by
which the lady had to proceed. The reptile had its neck thrown back and
its head in a horizontal position; its bright eyes followed all the
movements of the dog, to whose barks it replied by shrill hisses. It
was only waiting for an opportunity to strike. Schrott called off the
dog, and the snake at once disappeared among the high grass close by.
Next day it was killed at the same spot” (_Brehm_).

The venom of this viper is terribly potent. According to Russell, a
large dog exhibited symptoms of poisoning five minutes after being
bitten. At the end of a quarter of an hour it lay down, uttering
heartrending cries, began to breathe with difficulty and noisily, was
seized with spasms of the jaws and cramps, and died in frightful agony
less than half an hour after the wound was inflicted. Fowls in most
cases die in less than two minutes. A horse succumbed in half an hour,
and another in eleven hours.

It appears that in India many cattle are killed by Daboias while
grazing (_Fayrer_).

(b) =Pseudocerastes.=

(Fig. 29.)

This genus is represented by a single species (_Pseudocerastes
persicus_), which appears to be exclusively confined to Persia.

The head is very distinct from the neck, and covered with small
imbricate scales; the eyes, which are small, have vertical pupils;
they are separated from the lips by small scales. The nostrils are
directed upwards and outwards. The snout is very short and rounded.
The cylindrical body has 23-25 rows of scales; 151-156 ventrals; 43-49
subcaudals.

[Illustration: FIG. 29.--_Pseudocerastes persicus._ (After
Duméril and Bibron.)]

The coloration is gray or brown, with four series of large black spots,
and the head exhibits two longitudinal black streaks behind the eyes.
The belly is whitish, dotted with black.

Total length, 890 millimetres; tail 110.

The vipers belonging to this genus are much more common in North
Africa, and we shall therefore study them in conjunction with the
African snakes. _Cerastes cornutus_ alone, the special habitat of which
is Egypt, is sometimes met with in Arabia and on the eastern bank of
the Suez Canal.

(d) =Echis.=

_Echis carinatus_ (the Phoorsa). (Fig. 30).--This viper is
characterised by the subcaudal shields being arranged in a single row.
It is savage and very aggressive, being always ready to attack. Its
length does not exceed 600 millimetres at the most. The colour of the
body is grey, more or less dark and adorned with streaks, spots, and
dots of blackish-brown. The back displays yellowish-white wavy lines,
forming X-shaped markings. The upper side of the head exhibits a yellow
spot surrounded by brown, and other small black spots, the whole
arrangement forming a fairly good representation of a cross.

[Illustration: FIG. 30.--_Echis carinatus._ India. (After Sir
Joseph Fayrer.)]

This species is found in India, Persia, Baluchistan, Arabia, and
Palestine; while, as we shall see, it also occurs in Africa. It is
fairly common in the environs of Aden.

In moving over the ground a peculiar sound is produced by the friction
of its scales. It is capable of springing with great agility a fairly
long distance on to its prey. When it believes itself in danger it
coils up, doubling its body twice in the shape of a crescent, in the
middle of which it places its head, ready to strike. Its venom is very
rapid in taking effect.

2.--CROTALINÆ.

(e) =Ancistrodon.=

The snakes belonging to this genus of _Crotalinæ_ are found in Central
and Eastern Asia, but three important species occur in the New World,
in the United States and Central America. The head is covered with
nine large symmetrical shields, but the internasals and præfrontals
are sometimes broken up into scales. The body is cylindrical; the tail
rather short; the subcaudal scales are arranged in one or two rows.

* * * * *

_A. acutus._--The snout of this snake is prolonged into an appendage
directed forwards. The head-shields are finely granulate. Body scales
arranged in 21 rows; 162-166 ventrals; 58-60 subcaudals.

Coloration brown on the back, with blackish-brown X-shaped spots; head
dark brown, yellow on the cheeks, with a black band running from the
eye to the angle of the jaw; belly yellowish, spotted with brown, with
a series of large black transverse blotches.

Total length, 1,500 millimetres; tail 200.

_Habitat_: Upper Yang-tse, China.

_A. halys._--Snout prolonged into an upturned appendage, blunt at the
tip; 7-8 supralabial scales, the third of which forms part of the
margin of the eye; body scales in 23 rows; 149-174 ventrals; 31-44
subcaudals.

Coloration yellowish, grey, red, or pale brown above, with darker spots
or cross-bars. A black spot on the snout; two black spots on the
vertex; a dark, light-edged band on the temple; belly whitish, more or
less speckled with grey or brown.

Total length, 490 millimetres; tail 65.

_Habitat_: From the borders of the Caspian Sea and the Ural River to
the Upper Yenisei; Turkestan.

_A. intermedius._--Resembles the foregoing very closely, but the snout
is not turned up at the end.

Total length, 750 millimetres; tail 85.

_Habitat_: Central Asia, Eastern Siberia, Mongolia, and Japan.

* * * * *

_A. blomhoffii._--Similar to _A. halys_, but the snout is not turned up
at the end, and the body scales are in 21 rows; 137-166 ventral scales;
29-55 subcaudals.

Coloration very variable; grey, brown, or red above, with large
black-edged spots arranged in pairs; black, light-edged band on the
temple; upper lip uniformly yellow or red; belly yellow or reddish,
more or less spotted with black, or almost entirely black.

Total length, 720 millimetres; tail 100.

_Habitat_: Eastern Siberia, Mongolia, China, Japan, Siam.

* * * * *

_A. himalayanus._--Snout scarcely turned up, with a hard tip; 5-7
supralabial shields. Body scales in 21 (rarely 23) rows; 144-166
ventrals; subcaudals in 35-51 pairs.

[Illustration: FIG. 31.--_Ancistrodon hypnale._

(The _Carawalla_ of Ceylon.)

(After Sir Joseph Fayrer.)]

Coloration brown, with black spots or transverse bands; black,
light-edged band from the eye to the angle of the mouth; belly dark
brown, or more or less whitish.

Total length, 590 millimetres; tail 90.

_Habitat_: Himalayas (5,000 to 10,000 feet), especially in the
North-west; Khasi Hills.

This snake feeds chiefly on mice.

* * * * *

_A. rhodostoma._--Snout pointed, somewhat turned up at the tip: 7-9
supralabial shields; body scales in 21 rows; 138-157 ventrals; 34-54
subcaudal pairs.

Coloration reddish, grey, or pale brown above, with large angular, dark
brown, black-edged spots arranged in pairs or alternating. Vertebral
line almost black; lips yellow, speckled with brown; brown, black-edged
band, running from the eye to the angle of the mouth. Belly yellowish,
spotted with greyish-brown.

Total length, 810 millimetres; tail 90.

_Habitat_: Java.

* * * * *

_A. hypnale_ (fig. 31).--Snout more or less turned up, with a hard,
pointed end; 7-8 supralabial shields; body scales in 17 rows; 125-155
ventrals; 28-45 subcaudal pairs.

Coloration very variable; brown, yellowish, or greyish above, sometimes
with dark brown spots or transverse bands. Cheeks brown, with a
longitudinal, white, black-edged streak on each side of the neck. Belly
more or less speckled with dark brown.

Total length, 480 millimetres; tail 65.

_Habitat_: Ceylon, and Western Ghats of India as far north as Bombay.

In Ceylon this snake is known as the _Carawalla_. It is much dreaded,
but its bite is not rapidly fatal.

(f) =Lachesis.=

This genus has many representatives in Asia and the New World. The
American species are for the most part of larger size and more
formidable.

They are characterised by a triangular head, covered with small scales
or small shields, and by a cylindrical or compressed body. The Asiatic
species have the subcaudal scales in two rows and the tail short, and
often prehensile, which enables them to climb trees or bushes, where
they lie in wait for their prey.

Their classification is based upon the following characters:--

A. First infralabial scale in contact with its fellow.

I. Scales in 21-25 (rarely 27) rows; 129-158 ventrals; 21-57
subcaudals; 5-9 series of scales between the supraocular shields; tail
_non-prehensile_.

[Illustration: FIG. 32.--_Lachesis okinavensis._ (After G. A.
Boulenger, _op. cit._)]

(1) _L. monticola._--Supraocular shields large, separated by 5-8
scales; snout obtuse.

Colour brown or yellowish above, brown or pale yellow on the sides,
with a brown temporal streak. Belly white, spotted with brown.

Total length, 740 millimetres; tail 115.

_Habitat_: Tibet, Himalayas (2,000 to 8,000 feet), Hills of Assam,
Burma, Malay Peninsula, Singapore, Sumatra.

(2) _L. okinavensis_ (fig. 32).--Supraocular shields large, separated
by a transverse series of 6-9 scales; end of snout pointed and turned
up.

Colour brown above, with dark transverse bands and a light temporal
streak. Belly brown, spotted with black, especially on the sides.

Total length, 350 millimetres; tail 60.

_Habitat_: Okinawa, Loo Choo Islands.

(3) _L. strigatus._--Supraocular shields small, sometimes broken up,
separated by 8-11 convex scales in juxtaposition.

Colour brown above, with black spots often forming a median zigzag
band; temporal band black; belly whitish, spotted with grey or black;
end of tail yellow or reddish.

Total length, 480 millimetres; tail 55.

_Habitat_: Hills near Bombay, Deccan, Anamallays and Nilgherries.

* * * * *

II. Scales in 27-37 rows; 174-231 ventrals; 54-90 subcaudals; tail
_non-prehensile_.

(4) _L. flavoviridis._--Scales in 33-37 rows; 222-231 ventrals; 75-90
subcaudals; 8-9 supralabials.

Coloration pale brown or greenish-yellow above, marbled with black;
longitudinal black streaks symmetrically disposed on the head; belly
yellow or greenish, with darker spots.

Total length, 1,215 millimetres; tail 220.

_Habitat_: Loo Choo Islands.

This snake is not infrequently termed by naturalists _Trimeresurus
riukianus_.

(5) _L. cantoris._--Scales in 27-31 rows; 174-184 ventrals; 55-76
subcaudals; 13 supralabials.

Coloration pale brown or dull green, with small black spots; a whitish
streak along the sides of the body; belly white or greenish.

Total length, 1,020 millimetres; tail 140.

_Habitat_: Andaman and Nicobar Islands.

III. Scales in 21-27 rows; 160-218 ventrals; 54-92 subcaudals; tail
_not or scarcely prehensile_.

(6) _L. jerdonii._--7-9 scales in a line between the supraocular
shields; scales in 21 or 23 rows; 164-188 ventrals; 54-67 subcaudals.

Coloration greenish-yellow or olive above, mixed with black, a dorsal
series of reddish-brown transverse rhomboidal spots; upper lip yellow,
with one or two black spots; belly yellow, more or less marbled with
black.

Total length, 930 millimetres; tail 145.

_Habitat_: Assam, Tibet, Upper Yang-tse.

(7) _L. mucrosquamatus._--10-15 scales in a line between the
supraocular shields; scales in 25-27 rows; 183-218 ventrals; 72-92
subcaudals. Colour brownish-grey above, with a series of large black
median spots and smaller ones on the sides; a black streak from the eye
to the angle of the mouth; belly brownish, spotted with white.

Total length, 1,050 millimetres; tail 210.

_Habitat_: Formosa, Assam.

(8) _L. luteus._--12 or 13 scales in a line between the supraocular
shields; scales in 23-25 rows; 182-186 ventrals; 72-74 subcaudals;
supraocular shields large.

Colour yellow above, with a series of dark rhomboidal spots, and a
dorsal, black-spotted zigzag band; a black streak on each side of the
head behind the eyes; belly yellowish, spotted with grey.

Total length, 945 millimetres; tail 164.

_Habitat_: Loo Choo Islands.

(9) _L. purpureomaculatus._--12-15 scales in a line between the
supraocular shields; scales in 25-27 rows; ventrals 160-182; subcaudals
55-76; supraocular shield very narrow, sometimes broken up.

Coloration purplish-black above, sometimes variegated with pale green;
flanks pale green; belly olive or greenish-white, uniform or spotted
with black. Some specimens are entirely green.

Total length, 980 millimetres; tail 150.

_Habitat_: Himalayas, Bengal, Assam, Burma, Malay Peninsula, Andaman
and Nicobar Islands, Pulo-Pinang, Sumatra.

IV. Scales in 21 rows (rarely 19 or 23); 7-13 series of scales between
the supraoculars; tail _more or less prehensile_.

(10) _L. gramineus_ (Syn. _Trimeresurus gramineus_. The Green Pit
Viper).--145-175 ventral scales; 53-75 subcaudals; snout slightly
projecting; supraocular shield narrow.

Colour bright green, rarely olive or yellowish, with or without darker
transverse bands; end of tail yellow or red; belly green, yellow, or
white.

Total length, 870 millimetres; tail 150.

_Habitat_: South-eastern Asia, Darjeeling, Himalayas, Ganges Delta,
Siam, Southern China, Hong Kong, Formosa, Java, Sumatra, Timor.

[Illustration: FIG. 33.--_Lachesis flavomaculatus._ (After G.
A. Boulenger, _op. cit._)]

(11) _L. flavomaculatus_ (fig. 33).--170-187 ventral scales; 53-73
subcaudals; snout projecting, obliquely truncate; supraocular shield
narrow.

Colour bright green or olive, sometimes barred with reddish-brown;
belly green, olive, or greenish-yellow; end of tail sometimes red.

Total length, 1,060 millimetres; tail 160.

_Habitat_: Philippine Islands.

(12) _L. sumatranus._--180-191 ventral scales; 58-82 subcaudals;
supraocular shield large.

Coloration bright green, with or without black transverse bands;
yellowish band on each side; belly yellow or green, with or without
black speckles; end of tail red.

Total length, 1,100 millimetres; tail 180.

_Habitat_: Singapore, Sumatra, Borneo, Palawan.

(13) _L. anamallensis._--138-158 ventral scales; 44-58 subcaudals.

Colour green, olive, yellowish, or reddish-brown; a black temporal
band; belly pale green, olive, or yellow; tail usually black and yellow.

Total length, 730 millimetres; tail 110.

_Habitat_: Anamallay and Nilgherry Hills, South India.

(14) _L. trigonocephalus._--Scales in 17-19 rows, 145-170 ventrals;
53-67 subcaudals.

Coloration green, with or without black transverse bands or spots; a
black temporal streak; belly green or yellow; end of tail usually black.

Total length, 790 millimetres; tail 130.

_Habitat_: Ceylon.

(15) _L. macrolepis._--Scales in 13-15 rows; 134-143 ventrals; 48-56
subcaudals.

Colour bright green or olive; belly pale green.

Total length, 680 millimetres; tail 120.

_Habitat_: Southern India.

B. First lower labial shield divided; the portion separated off forms
a pair of small supplementary dental shields; 144-176 ventral scales;
38-57 subcaudals; tail _prehensile_.

(16) _L. puniceus._--Scales in 21-23 rows; 12-14 series of scales
between the supraocular shields.

Colour grey, brown, or red; belly spotted with brown; end of tail red.

Total length, 640 millimetres; tail 90.

_Habitat_: Sumatra, Java, Borneo, Natuna Islands.

(17) _L. borneensis._--Scales in 19-21 rows; 10-11 series of scales
between the supraocular shields; 152-168 ventrals; 43-65 subcaudals.

Total length, 770 millimetres; tail 105.

_Habitat_: Borneo, Sumatra.

C. (18) _L. wagleri._--Scales in 19-27 rows, 127-154 ventrals; 45-55
subcaudals; tail _prehensile_.

Colour green, with darker or lighter markings, black and yellow, or
nearly entirely black.

Total length, 980 millimetres; tail 150.

_Habitat_: Malay Peninsula and Archipelago.

_C.--AFRICA._

In Africa, poisonous snakes abound throughout the whole of the tropical
and sub-tropical zones. The fatal accidents to human beings caused by
them in this continent are fewer than in India, since the population of
Africa is less dense, but several species occur, the venom of which is
especially dangerous to life.

These species belong in nearly equal numbers to the Families
COLUBRIDÆ and VIPERIDÆ.

I.--COLUBRIDÆ.

The poisonous COLUBRIDÆ of Africa are all included in the
Subfamily _Elapinæ_, of which the following are the eight principal
genera:--

(a) _Boulengerina._
(b) _Elapechis._
(c) _Naja._
(d) _Sepedon._
(e) _Aspidelaps._
(f) _Walterinnesia._
(g) _Homorelaps._
(h) _Dendraspis._

(a) =Boulengerina.=

A small snake 240 millimetres in length, the principal characters of
which are as follows:--

Maxillary bones equal to the palatines in length, with a pair of
relatively large poison-fangs, followed by three or four small teeth.

Head hardly distinct from the neck. Eye small, with round pupil;
nostril between two nasal shields. Body cylindrical; scales smooth, in
21 rows; ventrals rounded. Tail moderate; subcaudal scales in 2 rows.

The only known species, _B. stormsi_, is brown, with black transverse
bars on the neck; tail black; belly white in front, brown behind, with
a black border to the scales.

It is found in the region of Lake Tanganyika.

(b) =Elapechis.=

This genus is characterised by the size of the maxillary bones, which
is equal to that of the palatines; a pair of large poison-fangs
followed by two to four small teeth; head not distinct from the
neck; eye small with round pupil; nostril between two nasal shields.
Body cylindrical; scales oblique, smooth, in 13 or 15 rows; ventrals
rounded. Tail very short, subcaudal shields in 2 rows.

Six species are known:--

(1) _E. guentheri._--Scales in 13 rows. Snout short, rounded;
first lower labial shield in contact with its neighbour behind the
symphysis. Internasal shorter than the præfrontals; length of frontal
three-fourths of that of the parietals.

Coloration whitish or grey above, with black, white-edged cross-bands.
Belly dirty white, brownish, or grey.

Total length, 520 millimetres; tail 50.

_Habitat_: Gaboon, Congo, Angola, Central Africa.

(2) _E. niger._--Snout and arrangement of scales as before. Internasal
shields three-fourths of the length of the præfrontals; frontal
two-thirds of the length of the parietals.

Colour, black all over.

Total length, 420 millimetres; tail 30.

_Habitat_: Zanzibar.

(3) _E. hessii._--Snout as in foregoing. Symphysial shield of the lower
lip in contact with the anterior chin-shields.

Colour grey, with black cross-bars; a series of black spots on the
sides, between the bars; large black blotch on nape; belly white.

Total length, 160 millimetres; tail 12.

_Habitat_: Congo.

(4) _E. decosteri._--Snout obtusely pointed.

Colour, dark grey, each scale edged with black; belly white.

Total length, 380 millimetres; tail 38.

_Habitat_: Delagoa Bay.

(5) _E. sundevallii._--Snout obtusely pointed.

Colour reddish-brown, with yellow transverse bands, the scales in which
are edged with reddish-brown; upper lip and belly yellow.

Total length, 510 millimetres; tail 43.

_Habitat_: Caffraria.

(6) _E. boulengeri._--Scales in 15 rows.

Colour black on the back, with narrow white transverse bands;
head white, with a black streak along the parietal suture; belly
blackish-grey.

Total length, 170 millimetres; tail 14.

_Habitat_: Zambesi.

(For the characters of this genus, see Asia, p. 33.)

Six species of _Naja_ are found in Africa:--

(1) _N. haje_ or _haie_.--Scales in 21-23 rows on the neck, which is
dilatable, although slightly less so than that of _N. tripudians_, the
Cobra-di-Capello of India.

Six or seven large supralabial shields, sixth or seventh in contact
with the lower postocular. Eyes separated from the labial shields by
the suboculars. 191-214 ventral scales; 53-64 subcaudals.

Colour yellowish, olive, or uniform black; belly yellowish; black or
brown band on the neck; head sometimes blackish.

Total length, 1,180 millimetres; tail 290.

_Habitat_: Borders of the Sahara, Egypt, Southern Palestine, East
Africa as far south as Mozambique.

* * * * *

_Naja haje_ (the Egyptian Cobra) is common throughout the Nile Basin,
the Sudan and Central Africa. Livingstone mentions it several times.
In Egypt it is met with in the vicinity of ruined monuments, under the
large blocks of stone or among brushwood.

The Egyptians are greatly in dread of it, and hunt it down as often
as possible. When pursued, _N. haje_ turns bravely and faces its
adversary, raising itself upon its tail, puffing out its neck and
hissing fiercely. If too hard pressed it strikes at its enemy.

“A friend of mine,” writes Anderson, “had great difficulty in escaping
from one of these snakes. While botanising one day a _Naja_ passed
quite close to him. My friend darted backwards with all speed, but the
_Naja_ pursued and was about to attack him, when he stumbled against
an ant-hill and fell flat on his back. This, no doubt, frightened the
snake, which disappeared in a twinkling.”

Another case of the same kind is narrated by Waller, who writes: “A
young girl met with her death in a truly dramatic fashion. She was
walking behind some porters on a narrow path, when suddenly an Aspic
came out of a thick bush, attacked and bit her in the thigh; in spite
of all efforts to save her the unfortunate girl died in less than ten
minutes.” This instance, which is absolutely authentic, proves the
truth of the statements made by various travellers. Natives assert
that a full-grown _Naja_ invariably pursues either a man or an animal,
however large, when either passes within its range (Brehm).

Snake-charmers, of whom there are many in Egypt, always employ _Naja
haje_ for their performances. They know how to capture it, and tear out
its fangs by making it bite a bundle of rags.

This species rarely lives more than six or eight months in captivity,
and is quite untamable. It is fond of bathing, and remains in the water
for hours together.

“The Ancient Egyptians,” write Duméril and Bibron,[3] “are known to
have worshipped the _Naja_, which they regarded as the protector of
their crops. They allowed it to live and multiply among the cultivated
lands, which they apparently entrusted to the care of their tutelary
guardian, recognising that this snake freed them from the ravages
of the rats, the immense number of which otherwise caused terrible
destruction and even actual famine. It was, therefore, from motives of
gratitude that the Egyptian Cobra was venerated in this way; that its
image was hung up in the temples; that its skin was embalmed; and that
its effigy, so easy to recognise and to reproduce roughly, was graven
or sculptured on the stones of their monuments. This is the explanation
of the fact that paintings representing _N. haje_ are frequently
reproduced in hieroglyphics and on Egyptian sarcophagi.”

The _Naja_ was the tutelary deity of the temples, whose duty was to
prevent the profane from entering. Thus, in one of the crypts of
Denderah we find represented _Serpent-genie_, figures with a head like
that of a _Naja_ supported by the body of a man, with the hands armed
with enormous cutlasses (Mariette, _Dendérah_, p. 91, 1875).

* * * * *

(2) _N. flava._--Same arrangement of scales. Neck dilatable. 200-227
ventrals; 50-67 subcaudals.

Colour very variable, yellowish, reddish, brown, or black, uniform or
with light spots; sometimes a black transverse band on the neck.

Total length, 1,470 millimetres; tail 230.

_Habitat_: South Africa.

(3) _N. melanoleuca._--Coloration very variable. Sides of the head
yellow or whitish; labial shields tinged with black on the posterior
edge.

Total length, 2,400 millimetres; tail 400.

_Habitat_: Tropical Africa.

(4) _N. nigricollis._--Third supralabial shield the deepest, sixth and
seventh not in contact with the postoculars; 183-228 ventral scales;
55-68 subcaudals.

Coloration very variable; lower surface of the neck with a black
transverse bar.

Total length, 2,000 millimetres; tail 300.

_Habitat_: From Senegambia and Upper Egypt to Angola and the Transvaal.

(5) _N. anchietæ._--Scales in 17 rows on the neck and on the body;
181-192 ventrals; 52-62 subcaudals.

Colour blackish or brown above; end of snout and cheeks yellow; belly
yellow or pale brown, with or without black cross-bar under the neck.

Total length, 1,800 millimetres; tail 340.

_Habitat_: Angola and Ovamboland.

(6) _N. goldii._--Eyes large, two-thirds the length of the snout
in adults. Scales in 15 rows on the neck and on the body; 194--195
ventrals; 88 subcaudals.

Colour black, uniform, or with transverse series of small whitish
spots; cheeks and end of snout white, with a black border at the margin
of the shields; belly white in front, black behind; subcaudal scales
black.

Total length, 1,750 millimetres.

_Habitat_: Lower Niger.

(d) =Sepedon.=

Maxillary bones projecting considerably beyond the palatines, with a
pair of large poison-fangs; no other maxillary teeth. Head not distinct
from neck; eyes of moderate size, with round pupils; nostril between
two nasal shields and an internasal. Body cylindrical; scales oblique,
keeled, in 19 rows; ventrals rounded. Tail moderate; subcaudal scales
in 2 rows.

_S. hæmachates_ (The Spitting Snake, or Ring Hals Slang).--This snake,
which is about 700 millimetres in length, is of a bluish-brown colour,
with numerous narrow, undulating and denticulate cross-bands of yellow
or yellowish-white. The throat is black or dark red; the belly grey.

It is met with throughout West, East, and South Africa, as far as the
Cape of Good Hope, where it is very common. It lives among bushes in
sandy places, where the ground is full of the holes of rats, moles,
and small rodents, upon which it feeds. It is very active and exhibits
great ferocity.

Natives at the Cape declare that this snake is able to project its
venom to a distance of more than a yard, especially if the wind is
blowing in the same direction, and that, if the poison happens to enter
the eye, the inflammation that results therefrom often leads to loss of
sight (Smith).

As to this, a very definite statement is given by Bavay,[4] on the
authority of Le Naour:--

“While hunting in Dahomey,” wrote Le Naour to Bavay, “I thrice met with
the snake called the _Spitter_. On two occasions my dog was struck
in both eyes by the liquid projected by the reptile. Immediately
(less than two minutes afterwards), symptoms of conjunctivitis
manifested themselves, with considerable swelling of the pupils; the
conjunctivitis seemed as though it were going to be very serious, and
yielded only after twelve days’ treatment with boracic lotion, aided
by a few cauterisations with sulphate of copper.

“During my sojourn at Porto-Novo, a store-keeper at the Dogba trading
station was a victim of the _Spitter_. While working at his store
he received in his eye a jet of liquid, which produced violent
conjunctivitis.”

(e) =Aspidelaps.=

Maxillary bones extending forwards beyond the palatines, as in
_Sepedon_, with a pair of large poison-fangs; no other maxillary teeth.
Head slightly distinct from the neck. Eyes of moderate size, with round
or vertically elliptic pupils. Rostral shield very large, detached on
the sides. Body cylindrical; scales oblique, smooth or keeled, in 19-23
rows; ventrals rounded. Tail short, obtuse; subcaudal scales in 2 rows.

(1) _A. lubricus._--146-167 ventral scales; 20-28 subcaudals.

Colour orange or red, with black rings; a black bar below the eyes;
upper surface of head sometimes entirely black.

Total length, 590 millimetres; tail 55.

_Habitat_: Cape Colony and Namaqualand.

(2) _A. scutatus_ (Fula-fula of Mozambique).--115-135 ventrals; 24-38
subcaudals.

Colour pale grey, with black spots or cross-bars, and a black mark
shaped like a circumflex accent on the head. A black collar encircling
the neck, and a black vertical streak below the eye. Belly whitish.

The total length may be as much as 520 millimetres.

_Habitat_: Natal, Delagoa Bay, Mozambique.

(f) =Walterinnesia.=

Maxillary bones prolonged forwards beyond the palatines, with a pair of
large poison-fangs; no other maxillary teeth. Head distinct from the
neck; eyes rather small, with round pupils; nostril between two or
three nasal shields and the internasal. Body cylindrical; scales smooth
or feebly keeled, in 23 rows; ventrals rounded. Tail rather short;
subcaudal scales for the most part in 2 rows.

_W. ægyptia._--Colour blackish-brown on the back, paler on the belly.

Total length, 1,170 millimetres; tail 170.

_Habitat_: Egypt.

[Illustration: FIG. 34.--SKULL OF _Dendraspis
viridis_ (Poisonous West African Colubrine). (After G. A. Boulenger,
_op. cit._)]

(g) =Dendraspis.=

(Fig. 34.)

Maxillary bone curved upwards, bearing a pair of powerful poison-fangs,
not fissured, and not followed by other teeth; a long tooth at
the end of each ramus of the mandible. Head narrow, elongate; eye
moderate, with round pupil; nostril between two shields. Body slightly
compressed; scales smooth, narrow, very oblique, in 13-23 rows;
ventrals rounded. Tail long; subcaudals in 2 rows.

(1) _D. viridis._--211-225 ventral scales; 107-119 subcaudals.

Colour uniform olive-green. Shields on the head edged with black; lips
yellow; belly and tail yellow, with scales and shields bordered with
black.

Total length, 1,830 millimetres; tail 460.

_Habitat_: West Africa, from the Senegal to the Niger; St. Thome Island.

(2) _D. jamesonii._--Coloration as before. Scales in 15-19 rows (19-21
on the neck); 210-235 ventrals; 99-121 subcaudals. Tail sometimes black.

Total length, 2,100 millimetres; tail 560.

_Habitat_: West Africa, from the Niger to Angola; Central Africa.

(3) _D. angusticeps_ (The Mamba).--202-270 ventral scales; 99-121
subcaudals.

Colour green, olive, or blackish, uniform; belly yellowish or pale
green; caudal scales and shields not bordered with black.

Total length, 2,000 millimetres; tail 430.

_Habitat_: West Africa, south of the Congo; Central Africa, East
Africa, Transvaal, Natal.

(4) _D. antinorii._--Scales in 21-23 rows; 248 ventrals; 117
subcaudals. Colour olive on the back, yellowish on the belly.

Total length, 2,690 millimetres; tail 545.

_Habitat_: Abyssinia.

II.--VIPERIDÆ.

The African _Viperidæ_ all belong to the Subfamily _Viperinæ_, of which
the following are the seven principal genera:--

(a) _Causus_.
(b) _Vipera_.
(c) _Bitis._
(d) _Cerastes._
(e) _Echis._
(f) _Atheris._
(g) _Atractaspis._

(a) =Causus.=

(Fig. 35.)

Head distinct from the neck, covered with symmetrical shields; nostril
between two nasal shields, and the internasal; eyes moderate, with
round pupils, separated from the lips by subocular shields. Body
cylindrical; scales smooth or keeled, oblique on the sides, in 15-22
rows; ventral scales rounded. Tail short; subcaudals in 2 rows or
single.

Four species:--

(1) _C. rhombeatus._--Snout obtuse, moderately prominent. Scales in
17-21 rows; 120-155 ventrals; 15-29 subcaudals.

Colour olive or pale brown, usually with a series of V-shaped brown
spots bordered with white, and a large spot in the form of a circumflex
accent at the back of the head; lips bordered with black; belly
yellowish or grey.

Total length, 700 millimetres; tail 75.

_Habitat_: Tropical and South Africa, from the Gambia to the Cape.

(2) _C. resimus._--Snout prominent, more or less turned up; scales in
19-22 rows; 134-152 ventrals; 17-25 subcaudals.

Colour greyish-olive on the back; uniform white on the belly.

Total length, 470 millimetres; tail 40.

_Habitat_: Central and East Africa, Angola.

(3) _C. defilipii._--Snout prominent, more or less turned up. Scales in
17 rows; 113-125 ventrals; 10-18 subcaudals.

Colour grey or pale brown above, with a series of large rhomboidal or
V-shaped blackish-brown spots; a large A-shaped dark brown mark on the
occiput; an oblique dark streak behind the eye; supralabial shields
edged with black; belly yellowish.

Total length, 400 millimetres; tail 22.

_Habitat_: Central and East Africa, Transvaal.

[Illustration: FIG. 35.--SKULL OF _Causus
rhombeatus._ (After G. A. Boulenger, _op. cit_.)]

(4) _C. lichtensteinii._--Snout obtuse; scales in 15 rows; 142-144
ventrals; subcaudals 15-21, single.

Colour greyish, with rather indistinct darker chevron-shaped
cross-bands.

Total length, 413 millimetres; tail 35.

_Habitat_: West Africa (Gold Coast), Congo.

(b) =Vipera.=

(For the characters of this genus, see p. 23,--Europe.)

In North Africa are found _Vipera latastii_, _V. ammodytes_, and
especially _V. lebetina_, the range of which extends from Morocco to
Northern India. _Vipera superciliaris_, which occurs on the coast of
Mozambique, has the snout rounded, and the head covered with small,
imbricate, keeled scales, with a large supraocular shield; nostril very
large, between two nasal shields; scales on the body strongly keeled,
in 27 rows; 142 ventrals; 40 subcaudals.

The colour is pale reddish-brown or orange, with blackish transverse
bars broken by a longitudinal yellow band on each side; the belly is
white, spotted with black.

Total length, 570 millimetres; tail 77.

(Fig. 36.)

The _Viperidæ_ belonging to this genus have the head very distinct from
the neck, covered with small imbricate scales; the eyes rather small,
with vertical pupils, separated from the lips by small scales; the
nostrils directed upwards and outwards, usually pierced in a single
nasal shield, with a rather deep pit above, closed by a valvular
supranasal. The postfrontal bones are very large, in contact with
the ectopterygoids. Scales keeled, with apical pits, in 22-41 rows;
ventrals rounded. Tail very short; subcaudal scales in 2 rows.

(1) _B. arietans_ (the Puff Adder; fig. 37).--This viper has the
nostrils on the upper surface of the snout, and two series of scales
between the supranasal shields; 12-16 supralabials; 3-5 lower labials.
The scales on the body are in 29-41 rows, and strongly keeled; ventrals
131-145; subcaudals 16-34.

The body is thick, the head large and triangular, and the tail very
short. The colour is dirty yellow or orange, with large, transverse
or oblique, chevron-shaped black bands; an oblique black band extends
behind the eye. The belly is dirty yellow, uniform, or marked with
small black spots.

Total length, 1,350 millimetres, sometimes more; tail 160.

[Illustration: FIG. 36.--SKULL of _Bitis arietans_
(the Puff Adder). (After G. A. Boulenger, _op. cit._)]

_Habitat_: This snake is met with throughout Africa, from Southern
Morocco, Kordofan, and Somaliland, to the Cape of Good Hope, and also
in Southern Arabia. It is especially common near the Niger and on the
Congo.

When irritated, it puffs itself out to such an extent that its body
becomes twice the ordinary size. It then doubles back its head and
neck in the shape of an S, and emits a loud and prolonged hiss. Before
biting, it first strikes a blow with its head as with a battering-ram,
thus justifying its French name, _vipère heurtante_ (Striking Viper).

[Illustration: FIG. 37.--_Bitis arietans_ (the Puff Adder).
(After Duméril and Bibron.)]

The natives of South Africa assert that this Viper is able to spring
high enough to strike a rider on horseback. It feeds upon rats and
mice, in search of which it often approaches habitations.

The Hottentots hunt it in order to obtain its venom; they pound its
head between stones, and mix the pulp with the juice of certain plants
for the purpose of poisoning their arrows.

It lives for a fairly long time in captivity. At the Pasteur Institute
at Lille I have succeeded in keeping one of these snakes for two years,
feeding it by forcing milk and eggs down its throat.

(2) _B. peringueyi._--Nostrils opening upwards and outwards. Head
covered with small, strongly keeled scales, which are smallest on the
vertex; 11 scales round the eye; 3 series of scales between the eye and
the lip; 11-14 supralabials. Scales on the body in 25-27 rows, strongly
keeled; 130-132 ventrals; 19-28 subcaudals.

Colour greyish-olive, with 3 longitudinal series of grey or blackish
spots; head sometimes with a trident-shaped dark mark, followed by a
cross; under surface whitish, with small dark spots.

Total length, 325 millimetres; tail 26.

_Habitat_: Angola and Damaraland.

(3) _B. atropos._--Nostrils opening upwards and outwards, 13-16 scales
round the eye; 2-5 series of scales between the supranasals; 10-12
supralabials; 3-4 infralabials. Scales on the body in 29-31 rows, all
strongly keeled; 124-145 ventrals; 18-29 subcaudals.

Colour brown or grey-brown, with 4 longitudinal series of dark spots,
edged with black and white; two large black marks on the head; belly
grey or brown, with darker spots.

Total length, 350 millimetres; tail 25.

_Habitat_: Cape of Good Hope.

(4) _B. inornata._--Eyes smaller than in _B. atropos_, and separated
from the lips by 4 series of scales; supraorbital region raised, but
without erect horn-like scales; 15-17 scales across the head; 13-14
supralabials; 3 lower labials. Scales on the body in 27-29 rows, all
keeled; 126-140 ventrals; 19-26 subcaudals.

Total length, 350 millimetres; tail 30.

_Habitat_: Cape of Good Hope.

(5) _B. cornuta_ (fig. 38).--Nostrils opening upwards and outwards.
Head covered with small, imbricate, strongly keeled scales; 2-5 raised
scales, like horns, above each eye; 12-14 scales round the eye; 12-15
supralabials; 2-3 infralabials. Scales on the body keeled, in 25-29
rows; 120-152 ventrals; 18-36 subcaudals.

Colour grey or reddish-brown, with black spots, edged with white and
arranged in 3 or 4 longitudinal series; a dark, oblique streak from the
eye to the mouth; belly yellow or brown, uniform or spotted.

Total length, 510 millimetres; tail 35.

[Illustration: FIG. 38.--_Bitis cornuta._ (After Duméril and
Bibron.)]

_Habitat_: Cape Colony, Namaqualand, Damaraland.

(6) _B. caudalis._--Nostrils opening upwards and outwards. 12-16 scales
from one eye to the other across the head; above each eye a single,
erect, horn-like scale; 10-16 scales round the eye; 10-13 supralabials;
2-3 infralabials. Scales on the body in 22-29 rows, strongly keeled;
112-153 ventrals; 18-33 subcaudals.

Colour reddish or sandy-grey, with 2 series of brown spots with light
centres, and frequently a vertebral series of narrow spots; belly dull
yellow, uniform, or with small black spots on the sides.

Total length, 360 millimetres; tail 25.

_Habitat_: South-west Africa, from Angola to Namaqualand.

(7) _B. gabonica_ (Gaboon Viper, or River Jack Viper).--Nostrils
directed upwards and outwards. Head covered with small, moderately
keeled scales, smallest on the vertex, 13-16 from eye to eye; 15-19
scales round the eye; a pair of erectile, triangular, nasal “horns,”
consisting of sometimes tricuspid shields, between the supranasals;
13-16 supralabials; 4-5 infralabials. Scales on the body in 33-41
rows, strongly keeled; lateral scales slightly oblique; 125-140
ventrals; 17-33 subcaudals.

This viper, which often attains a length of 1,200 millimetres, is
brown, with a vertebral series of quadrangular, yellowish, or light
brown spots connected by black markings; the belly is dull yellow, with
small brown or blackish spots.

_Habitat_: Tropical Africa (West Africa, from Liberia to Damaraland;
Zanzibar, Mozambique).

This species, which is nocturnal, is often met with on the Gaboon, and
in the forests near the banks of the Ogowai. Its head is enormous,
triangular in shape, and wider above; it has a bulky body, and a very
short tail, terminating abruptly in a point.

The Gaboon Viper is a savage snake, with very active venom, and its
poison-glands are of the size of large almonds. It lives in virgin
forests, among dead wood and rocks. I have several times met with it in
manioc plantations on the edge of the woods. In broad daylight it is
sluggish, moves somewhat slowly, and never attacks man. It bites only
when surprised.

[Illustration: FIG. 39.--_Bitis nasicornis._ (After Duméril
and Bibron.)]

(8) _B. nasicornis_ (fig. 39).--Nostrils opening upwards and outwards.
Head covered with small strongly keeled scales, smaller on the vertex,
14-16 from one eye to the other; 2 or 3 pairs of compressed, erectile,
horn-like shields between the supranasals, usually separated in the
middle by 1 or 2 series of small scales; 15-18 supralabials; 4-6
infralabials. Scales on the body in 35-41 rows, strongly keeled;
124-140 ventrals; 16-32 subcaudals.

Colour purple or reddish-brown above, with pale olive or dark brown
spots; a vertebral series of brown, black-edged spots, which assume a
rhomboidal form; sides of head dark brown, with a triangular light mark
in front of the eye, and an oblique light streak from behind the eye to
the mouth; belly pale olive, spotted with black or yellow.

Total length, 1,250 millimetres; tail 125.

_Habitat_: West Africa, from Liberia to the Gaboon.

(d) =Cerastes.=

Head very distinct from the neck, covered with small juxtaposed or
slightly imbricate scales; eyes small, with vertical pupils, separated
from the lips by small scales; nostrils opening upwards and outwards.
Body cylindrical; scales keeled, with apical pits, in 23-35 rows. Tail
short; subcaudals in 2 rows.

(1) _C. cornutus_ (fig. 40).--Snout very short and broad; two erectile
horns above the eyes, which are separated by 15-21 scales and
surrounded by 14-18; 4-5 series of scales between the eyes and the
lips; 12-15 supralabials; 3 infralabials; scales on the body in 27-35
rows; 130-165 ventrals; 25-42 subcaudals.

[Illustration: FIG. 40.--_Cerastes cornutus._ (After Duméril
and Bibron.)]

Colour yellowish-brown or grey, with or without brown spots, forming
4-6 regular series, the two middle ones sometimes forming cross-bars;
an oblique dark streak behind the eye; belly white; end of tail
sometimes black.

Total length, 720 millimetres; tail 90.

_Habitat_: Northern border of the Sahara, Egypt, Nubia, Arabia, and
Southern Palestine.

(2) _C. vipera._--Snout very short and broad; head covered with small,
tubercularly keeled scales, to the number of 9-13 from eye to eye;
no “horns”; 9-14 scales round the eye; nostril between two small
shields, separated from their neighbours by 5-6 series of scales; 10-12
supralabials; 3 infralabials. Scales on the body in 23-27 rows; 102-122
ventrals, rather strongly keeled at the sides; 18-26 subcaudals. Colour
dull yellow, pale brown or reddish, with or without black spots; end of
tail often black above; ventral surface white.

Total length, 340 millimetres; tail 30.

_Habitat_: Northern border of the Sahara, from Algeria to Egypt.

The snakes belonging to this genus live constantly hidden in the
sand, lying in wait for small birds, which alight beside them without
suspicion, mistaking their horns for insects or larvæ; they also feed
upon mice. Their poison-fangs are of relatively large size.

These small and exceedingly active vipers, whose colour harmonises
marvellously with their surroundings, are very dangerous to the Arabs
and blacks, who walk barefooted; they frequently cause fatal accidents.

They are able to exist for a very long time without drinking. They
are attracted by the fires which are lighted at night round caravan
encampments.

(e) =Echis.=

(See Asia, p. 48.)

(1) _E. carinatus_ (Efa, Viper of the Pyramids).--The same as met with
in Persia, Arabia, and India. Very common in the environs of Cairo, and
throughout Egypt and Abyssinia. It often makes its way into towns and
villages. Brehm records that he more than once found an _Efa_ in his
house at Khartoum, and that on one occasion he discovered one of these
vipers coiled up beneath the covering of his bed. At another time,
getting up in the night, he put his foot on one of these animals and
was not bitten, the reptile being very fortunately just at that moment
in the act of devouring a tame bird which it had seized.

It hardly ever happens that a native of Egypt can bring himself to
destroy an _Efa_, of which he has the greatest dread. If, as often
occurs, he finds one of these reptiles in his house, he addresses
himself to the _Hani_ or juggler, in order that, by his magic art, he
may expel the dangerous visitor. From this custom the juggler evidently
derives no small advantage, for, as is only right, he does not ply his
craft for nothing. In many cases, indeed, the juggler releases a snake
in a house, and then goes and informs the owner that he knows that a
reptile is concealed in his dwelling, and that, in consideration of a
stipulated reward, he will rid him of it (Brehm).

[Illustration: FIG. 41.--_Echis coloratus._ (After G. A.
Boulenger, _op. cit._)]

(2) _E. coloratus_ (fig. 41).--Scales on the snout and vertex convex,
smooth or bluntly keeled, 13-15 from eye to eye; no supraocular shield;
17-22 scales round the eye; 12-15 supralabials; scales on the body in
31-35 rows; 174-205 ventrals; 42-52 subcaudals. No cruciform mark on
the head.

Total length, 750 millimetres; tail 80.

_Habitat_: Palestine, Arabia, Socotra.

(f) =Atheris.=

Head very distinct from neck, covered with imbricate scales; eyes
large, with vertical pupils, usually separated from the labial shields
by small scales; nostrils lateral. Body slightly compressed; scales
keeled, with apical pits. Tail moderate, _prehensile_; subcaudal scales
in a single row.

(1) _A. chlorechis._--No supraciliary horn-like scales; 9-11 scales
from eye to eye; 25-36 rows of scales in the middle of the body,
strongly keeled; 154-165 ventrals; 53-62 subcaudals.

Colour green, uniform or with small yellow spots; end of tail yellowish
or blackish.

Total length, 520 millimetres; tail 85.

_Habitat_: West Africa, from Liberia to the Ogowai.

(2) _A. squamiger._--No supraciliary horn-like scales; 7-8 scales from
eye to eye; 15-25 rows of scales in the middle of the body, strongly
keeled; 153-173 ventrals; 51-95 subcaudals.

Colour olive, uniform or with more or less regular, narrow yellow
cross-bands, or yellow with green spots; belly pale olive, marbled with
black or yellow, or uniform yellow.

Total length, 550 millimetres; tail 100.

_Habitat_: West Africa, from the Cameroons to Angola.

(3) _A. ceratophorus._--Several erect, supraciliary horn-like scales;
9-10 scales from eye to eye; 25 rows of scales in the middle of the
body, strongly keeled; 142 ventrals; 55 subcaudals.

Colour dark olive, with black spots forming cross-bands; belly pale
olive, speckled with black.

Total length, 210 millimetres; tail 65.

_Habitat_: East Africa.

(g) =Atractaspis.=

(Fig. 42.)

This genus is characterised by enormous poison-fangs, a few teeth on
the palatines, and none on the pterygoids. The mandible, which is
edentulous in front, has only two or three small teeth in the middle
of the dentary bone. Head small, not distinct from the neck, covered
with large symmetrical shields; nostril between two nasal shields; eyes
minute, with round pupils; postfrontal bone absent. Body cylindrical;
scales smooth, in 17-37 rows; ventrals rounded. Tail short; subcaudals
in 1 or 2 rows.

(1) _A. hildebrandtii._--Six supralabials; no præocular shields;
frontal shorter than the parietals; scales on the body in 17 rows;
ventrals 167-174.

Colour uniform dark brown.

Total length, 450 millimetres; tail 53.

_Habitat_: East Africa.

(2) _A. congica._--Five supralabials, of which the fourth is the
larger; postocular in contact with a large temporal; one præocular;
frontal as long as or slightly shorter than the parietals. Scales on
the body in 19-21 rows; 209-230 ventrals; 19-23 subcaudals.

[Illustration: FIG. 42.--SKULL OF _Atractaspis
aterrima_ (African Viperine). (After G. A. Boulenger, _op. cit._)]

Colour uniform dark brown or black.

Total length, 450 millimetres; tail 35.

_Habitat_: Congo, Angola.

(3) _A. irregularis._--Characters as before, but scales on the body in
25-27 rows; 220-257 ventrals, subcaudals 22-28 pairs.

Colour uniform black or dark brown.

Total length, 560 millimetres; tail 35.

_Habitat_: West Africa, from the Gold Coast to the Congo; Central
Africa.

(4) _A. corpulenta._--Postocular shield in contact with a large
temporal; second lower labial very large, fused with the chin-shields.
Scales on the body in 23-27 rows; 178-193 ventrals; 23-27 subcaudals.

Colour uniform blackish-brown; tail sometimes white.

Total length, 345 millimetres; tail 33.

HABITAT: West Africa, from Liberia to the Gaboon.

(5) _A. rostrata._--Snout very prominent, cuneiform. Third lower labial
very large; first lower labial in contact with its fellow, behind the
symphysial. Scales on the body in 19-23 rows; ventrals 227-248.

Colour uniform dark brown, or blackish.

Total length, 600 millimetres; tail 37.

_Habitat_: East and Central Africa.

(6) _A. bibronii._--Characters as before. Snout prominent,
subcuneiform. Ventral scales, 221-260.

Colour dark purplish-brown above, dull yellow or pale brown on the
belly.

Total length, 600 millimetres; tail 25.

_Habitat_: Eastern districts of Cape Colony, Natal, Namaqualand, Angola.

(7) _A. aterrima._--Characters as before. Snout rounded; 251-300
ventral scales.

Colour uniform dark brown or black.

Total length, 650 millimetres; tail 30.

_Habitat_: West and Central Africa.

(8) _A. dahomeyensis._--Characters as before. Symphysial shield in
contact with the chin-shields. Scales on the body in 31 rows; 240
ventrals; 24 subcaudals.

Colour black above, brown on the belly.

Total length, 490 millimetres; tail 32.

_Habitat_: Dahomey.

(9) _A. micropholis._--Temporal shields small, 2 + 3 or 4; fourth
or fifth infralabial larger; scales on the body in 25 rows; 210-215
ventrals; 29-30 subcaudals. Frontal shield slightly longer than broad,
much longer than the parietals.

Colour uniform dark brown.

Total length, 330 millimetres; tail 28.

_Habitat_: Cape Verd.

(10) _A. leucomelas._--Characters as before. Frontal one and two-fifths
as long as broad, as long as the parietals.

Colour black, with a vertebral white line, occupying one row and two
half rows of scales; ventrals and subcaudals white; neck black, head
white, with a black spot covering the nasals and upper head-shields.

Total length, 575 millimetres; tail 40.

_Habitat_: Somaliland.

(11) _A. microlepidota._--Characters as before. Scales on the body in
29-37 rows; 212-245 ventrals; 26-37 subcaudals.

Colour uniform dark brown.

Total length, 540 millimetres; tail 45.

_Habitat_: Central and East Africa.

_D.--AUSTRALIA AND THE LARGE ADJACENT ISLANDS._

The Sunda Islands and the whole of Malaysia are rich in poisonous
snakes. Those that are found there belong for the most part to species
that we have already met with in India or the Malay Peninsula. We shall
therefore not describe them again here.

All those that inhabit Australia are included in the great Family
COLUBRIDÆ and the Subfamily _Elapinæ_. There are no
VIPERIDÆ; but certain genera of poisonous COLUBRIDÆ
are peculiar to this continent.

These reptiles have been particularly well studied by Gérard Krefft,
formerly Director of the Australian Museum at Sydney, from whose
work[5] we shall borrow a considerable portion of the following notes,
and the figures accompanying them.

The genera represented in Australia are:--

(a) _Ogmodon._
(b) _Glyphodon._
(c) _Pseudelaps._
(d) _Diemenia._
(e) _Pseudechis._
(f) _Denisonia._
(g) _Micropechis._
(h) _Hoplocephalus._
(i) _Tropidechis._
(j) _Notechis._
(k) _Rhinhoplocephalus._
(l) _Brachyaspis._
(m) _Acanthophis._
(n) _Elapognathus._
(o) _Rhynchelaps._
(p) _Furina._

(a) =Ogmodon.=

This genus is characterised by the maxillary bones extending forwards
as far as the palatines, and bearing, in addition to the poison-fangs,
6-7 grooved teeth. The head is not distinct from the neck; the eyes are
very small. The body is cylindrical, and covered with smooth scales in
17 rows. Tail short; subcaudal scales in 2 rows.

_O. vitianus._--Snout elongate, pointed; 139-152 ventral scales; 27-38
subcaudals.

Colour dark brown, lighter on the sides; belly brown or white, more or
less spotted with black; tail black.

Total length, 360 millimetres; tail 45.

_Habitat_: Fiji Islands.

[Illustration: FIG. 43.--SKULL OF _Glyphodon tristis_
(Australian Colubrine).

(After G. A. Boulenger, _op. cit._)]

(b) =Glyphodon.=

General characters the same; snout rounded; poison-fangs followed,
after a wide interspace, by 6 small grooved teeth; anterior mandibular
teeth strongly developed (fig. 43). Head and eyes small; pupils round
or vertically subelliptic; nostrils pierced between 2 nasal shields.
Body cylindrical; scales smooth, in 17 rows; tail short; subcaudals in
2 rows.

_G. tristis._--Ventral scales 165-179; subcaudals 38-52.

Colour dark brown; occiput often yellowish, or pale reddish-brown;
belly yellow.

Total length, 900 millimetres; tail 125.

_Habitat_: North-eastern Australia and South-eastern New Guinea.

Maxillaries extending forwards as far as the palatines, with a pair
of large grooved poison-fangs, and, after a wide interval, 8-12 small
grooved teeth. The anterior mandibular teeth are of large size, almost
like fangs. Head hardly distinct from the neck; eyes small, with
vertically elliptic pupils. Body cylindrical; scales smooth, in 15-17
rows. Tail moderate or short; subcaudal scales in 2 rows.

(1) _P. muelleri._--Scales in 15 rows. Nasal shield divided, in contact
with the præocular; 2 + 2 temporals; 139-176 ventral scales; 21-35
subcaudals.

Colour brown, with a light vertebral line; a more or less distinct
dark, light-edged streak on each side of the head, passing through the
eye; belly yellowish or coral-red; uniform or spotted with black.

Total length, 500 millimetres; tail 70.

_Habitat_: Moluccas, New Guinea, New Britain.

(2) _P. squamulosus_.--Scales in 15 rows. Nasal shield divided, in
contact with the præocular; 1 + 2 temporals; 170-183 ventrals; 34-52
subcaudals.

Colour brown, with a yellowish streak round the snout and through the
eyes to the nape; belly whitish, with confluent black spots forming
lines on each side.

Total length, 375 millimetres; tail 55.

_Habitat_: New South Wales.

(3) _P. krefftii_ (fig. 44).--Nasal shield entire, in contact with the
præocular; 1 + 2 temporals; 146-156 ventrals; 26-38 subcaudals.

Colour dark brown, with a light longitudinal line on each scale; a
yellowish cross-band on the occiput, connected with another yellow band
which encircles the snout.

Belly yellowish in front, black behind; subcaudals white, with a
longitudinal black band running between them.

[Illustration: FIG. 44.--_Pseudelaps krefftii._]

[Illustration: FIG. 45.--_Pseudelaps harriettæ._]

[Illustration: FIG. 46.--_Pseudelaps diadema._]

Total length, 255 millimetres; tail 33.

_Habitat_: Queensland.

(4) _P. harriettæ_ (fig. 45).--Nasal shield entire, in contact with
or narrowly separated from the præocular; 1 + 2 temporals; 176-193
ventrals; 29-35 subcaudals.

Colour dark brown, with a light longitudinal line on each scale; a long
yellow blotch on the nape, and, connected with this, a yellow ring
round the snout; ventrals and subcaudals brown or black, edged with
white.

Total length, 415 millimetres; tail 45.

_Habitat_: Queensland.

(5) _P. diadema_ (fig. 46).--Nasal shield entire, widely separated
from the præocular; 2 + 2 temporals; third and fourth upper labials
entering the eye; 164-203 ventrals; 40-62 subcaudals. Colour pale brown
or reddish, with a brown edging to each scale forming a reticulate
pattern; a yellow cross-band on the occiput; belly uniformly white.

Total length, 600 millimetres; tail 80.

_Habitat_: Eastern, Northern, and Western Australia.

(6) _P. warro._--Characters the same as in the previous species; 143
ventrals. Colour brown; a broad lunate black collar on the nape; head
black above, but paler than the collar.

_Habitat_: Port Curtis, Queensland.

(7) _P. sutherlandi._--Characters as before. Scales on the body in 17
rows; 160 ventrals; 40 subcaudals. Colour red-brown on the back, yellow
on the belly; a broad lunate black collar on the nape, with a lighter
edging; light bars across the head, body, and tail.

_Habitat_: Norman River, Queensland.

(d) =Diemenia.=

[Illustration: FIG. 47.--_Diemenia psammophis._]

[Illustration: FIG. 48.--_Diemenia olivacea._ (Northern
Australia and New Guinea).

(After Krefft.)]

[Illustration: FIG. 49.--_Diemenia textilis._]

Maxillary bones extending forwards as far as the palatines, with a
pair of large grooved poison-fangs, followed, after an interspace, by
7-15 small grooved teeth; anterior mandibular teeth much elongated,
resembling poison-fangs. Head scarcely distinct from the neck: eyes
rather large, with round pupils; nasal shield entire or divided;
frontal elongate.

Body cylindrical; scales smooth, in 15-19 rows (more on the neck). Tail
moderate or long; subcaudals all or for the most part in 2 rows.

Coloration very variable, orange-yellow, olive, red-brown, or pale
brown.

Average length, 1,000-1,700 millimetres.

_Habitat_: South-eastern New Guinea, and Australia.

Seven species of this genus are known, divided into two groups as
follows:--

(1) Scales on the body in 15 rows.

_D. psammophis._ (fig. 47).--Internasal shields at least half as long
as the præfrontals.

_D. torquata._--Internasals more than half as long as the præfrontals.

_D. olivacea._ (fig. 48).--Internasals not more than half as long as
the præfrontals; snout broad.

[Illustration: FIG. 50.--_Diemenia nuchalis._]

(2) Scales in 17 or 19 rows.

_D. modesta._--154-165 ventrals.

_D. textilis_ (Brown Snake, fig. 49).--190-232 ventrals.

_D. nuchalis_ (fig. 50).--184-224 ventrals.

(e) =Pseudechis.=

Maxillary bones extending forwards as far as the palatines, with a
pair of large grooved poison-fangs followed by 2-5 small solid teeth;
anterior mandibular teeth long. Head distinct from the neck; eyes
rather small, with round pupils; nostril between two nasal shields.
Body cylindrical. Scales smooth, in 17-23 rows (more on the neck). Tail
moderate; subcaudals in 2 rows, or partly single, partly in 2 rows.

[Illustration: FIG. 51.--_Pseudechis porphyriacus._]

Total length, 1,500-2,000 millimetres, sometimes more.

_Habitat_: Australia and New Guinea.

This genus includes eight species.

(1) _P. porphyriacus_ (Black Snake; fig. 51).--Frontal shield longer
than broad; 180-200 ventrals; 50-60 subcaudals.

Colour black on the back; outer row of scales red at the base; ventrals
red, edged with black.

(2) _P. cupreus._--199-210 ventrals; 57-72 subcaudals.

Colour coppery above, brown or orange below, all the scales and shields
edged with brown.

(3) _P. australis._--199-220 ventrals; 57-70 subcaudals; frontal shield
once and two-thirds to twice as long as broad.

Colour pale brown on the back, yellowish on the belly.

(4) _P. darwiniensis._--Frontal as broad as long; 212 ventrals; 54-64
subcaudals.

Colour reddish-brown; head pale brown; belly yellowish-white.

(5) _P. papuanus._--Scales in 19-21 rows (26 or 27 on the neck);
221-224 ventrals; 49-55 subcaudals.

Colour uniform black; chin white.

(6) _P. scutellatus._--Subcaudal shields in 2 rows; scales on the body
in 23 rows (25-30 on the neck); 230-233 ventrals; 61-78 subcaudals.

Colour pale brown or dark brown; snout and cheeks pale brown or
yellowish; belly yellow.

(7) _P. microlepidotus._--30-36 scales across the neck, 23 across the
middle of the body; 232-237 ventrals; 61-66 pairs of subcaudals.

Colour dark brown on the back, yellowish-grey on the belly; head
sometimes blackish.

(8) _P. ferox._--Snout very broadly rounded. Scales on the body in 23
rows; 235 ventrals; 60 pairs of subcaudals.

Colour black above, yellowish beneath.

(f) =Denisonia.=

Maxillary bones prolonged as far as the palatines, with a pair of large
grooved poison-fangs, followed by 3-5 small solid teeth; anterior
mandibular teeth greatly developed. Head fairly distinct from the body;
eyes small, with round or vertically elliptic pupils; nasal shield
entire or divided. Body cylindrical; scales smooth, in 15-19 rows; tail
moderate or short; subcaudals in a single row, except in one species.

According to the British Museum Catalogue, the genus _Denisonia_
includes twenty-one species, the principal characters of which are as
follows:--

[Illustration: FIG. 52.--_Denisonia superba_ (The Copperhead).]

(1) _D. superba_ (The Copperhead. Fig. 52).--Scales in 15-17 rows;
nasal shield entire, in contact with the præocular; ventral scales
145-160; subcaudals 41-50.

Colour brownish to dark olive on the back, often yellow or salmon-red
on the sides; belly yellowish or greyish-olive.

Total length, 1,010 millimetres; tail 160.

_Habitat_: New South Wales, Southern Australia, Tasmania.

(2) _D. coronata._--Scales in 15 rows; 138-151 ventrals; 38-51
subcaudals.

[Illustration: FIG. 53.--_Denisonia coronoides._]

Colour olive, with a black streak on each side of the head; belly
yellowish or pale olive.

Total length, 480 millimetres; tail 95.

_Habitat_: Western Australia and New South Wales.

(3) _D. coronoides_ (fig. 53).--Scales in 15 rows; 136-151 ventrals;
39-57 subcaudals.

Colour brown, lips yellow; belly salmon-red to dark olive-grey; end of
tail salmon-red.

Total length, 440 millimetres; tail 80.

_Habitat_: Southern Australia and Tasmania.

(4) _D. muelleri._--Scales in 17 rows; 118 ventrals; 38 subcaudals.

Colour grey-brown; lips and chin with yellow spots; belly grey.

Total length, 292 millimetres; tail 52.

_Habitat_: Queensland.

(5) _D. frenata._--Scales in 19 rows; 167 ventrals; 35 subcaudals.

Colour olive-brown; upper lip yellow; belly white.

Total length, 390 millimetres; tail 54.

_Habitat_: Lake Elphinstone, Queensland.

(6) _D. ramsayi_ (fig. 54).--Scales in 15 rows; 164 ventrals; 51
subcaudals.

[Illustration: FIG. 54.--_Denisonia ramsayi._]

Colour dark olive-green above, yellow beneath; subcaudals nearly black.

Total length, 265 millimetres; tail 50.

_Habitat_: New South Wales.

(7) D. signata (fig. 55).--Scales in 17 rows; 153-170 ventrals; 41-56
subcaudals.

[Illustration: FIG. 55.--_Denisonia signata._]

Colour dark olive or black, head brown; belly dark grey or black.

Total length, 640 millimetres; tail 120.

_Habitat_: Queensland, New South Wales.

(8) _D. daemelii._--Scales in 17 rows; 147-168 ventrals; 33-45
subcaudals.

Colour olive, head darker; belly yellowish-white.

Total length, 380 millimetres; tail 60.

_Habitat_: Queensland.

(9) _D. suta._--Scales in 19 rows; 157-164 ventrals; 25-30 subcaudals.

Colour pale olive-brown, head dark brown, nape black; upper lip and
belly yellow.

Total length, 200 millimetres; tail 23.

_Habitat_: Southern Australia.

(10) _D. frontalis._--Scales in 19 rows; 154 ventrals; 30 subcaudals.

Colour light brown, with a vertebral black line; belly pearly-white,
with a median bronze-coloured band.

Total length, 400 millimetres; tail 50.

_Habitat_: New South Wales.

(11) _D. flagellum._--Scales in 17 rows; 132-138 ventrals; 25-27
subcaudals.

Colour pale brown; vertex, occiput, and nape black; upper lip and belly
white.

Total length, 380 millimetres; tail 40.

_Habitat_: Victoria.

(12) _D. maculata._ (fig. 56).--Scales in 17 rows; 121-136 ventrals;
20-30 subcaudals.

[Illustration: FIG. 56.--_Denisonia maculata._]

Colour dark grey-brown, or brown; a large dark olive-green or brown
blotch on the head, with two or three unequal light grey spots; belly
white.

Total length, 400 millimetres; tail 55.

_Habitat_: Queensland.

(13) _D. punctata._--Scales in 15 rows; 160 ventrals; 25 subcaudals.

Colour pale brown; head and nape orange; upper lip and belly yellow.

Total length, 350 millimetres; tail 36.

_Habitat_: North-Western Australia.

(14) _D. gouldii_ (fig. 57).--Scales in 15 rows; 140-170 ventrals;
22-23 subcaudals.

[Illustration: FIG. 57.--_Denisonia gouldii._]

Colour brownish-yellow; nape black; head covered with a broad
greenish-blue blotch, extending from the nose to the neck; upper lip
and belly yellow.

Total length, 435 millimetres; tail 50.

_Habitat_: Western and Southern Australia.

(15) _D. nigrescens._--Scales in 15 rows; 170-200 ventrals; 30-46
subcaudals.

Colour dark olive; head black; belly yellow.

Total length, 545 millimetres; tail 75.

_Habitat_: New South Wales and Queensland.

(16) _D. nigrostriata._--Scales in 15 rows; 180-184 ventrals; 50-64
subcaudals.

Colour yellow, streaked with black; head dark brown; upper lip and
belly yellowish-white.

Total length, 380 millimetres; tail 52.

_Habitat_: Queensland.

(17) _D. carpentariæ._--Scales in 15 rows; 166-183 ventrals; 31-43
subcaudals.

Colour brown; upper lip and belly yellowish-white.

Total length, 285 millimetres; tail 47.

_Habitat_: Northern Queensland.

(18) _D. pallidiceps._--Scales in 15 rows; 170-178 ventrals; 37-38
subcaudals.

Colour dark olive-brown; head somewhat paler; belly yellowish. Total
length, 590 millimetres; tail 80.

_Habitat_: Northern Australia.

(19) _D. melanura._--Scales in 15 or 17 rows; 165-171 ventrals; 38-48
subcaudals.

Colour dark brown; head and sides usually reddish; belly yellow; tail
black.

Total length, 1,000 millimetres; tail 140.

_Habitat_: Solomon Islands.

(20) _D. par._--Scales in 16 rows; 164-166 ventrals; 40-49 subcaudals.

Colour reddish-brown, in broad bands with white intervals; head
blackish-brown; belly white; tail with red rings.

Total length, 750 millimetres; tail 110.

_Habitat_: Faro and Howla Islands, Bougainville Straits, Solomon
Islands.

(21) _D. woodfordii._--Scales in 17 rows; 166-172 ventrals; 41-45
subcaudal pairs.

Colour brownish-white, with a reticulate pattern; head dark brown;
belly white.

Total length, 670 millimetres; tail 100.

_Habitat_: New Georgia, Solomon Islands.

(g) =Micropechis.=

Maxillary bones extending forward as far as the palatines, with a pair
of large grooved poison-fangs, followed by three small solid teeth;
mandibular teeth longer in front. Head distinct from the neck; eyes
very small, with round pupils; nostril between two nasal shields. Body
cylindrical; scales smooth, in 15 or 17 rows. Tail short; subcaudals in
2 rows.

(1) _M. ikaheka._--Scales in 15 rows; 180-223 ventrals; 39-55
subcaudals.

Colour yellow and black, in irregular cross-bars; head and tail black
above; belly yellow.

Total length, 1,550 millimetres; tail 180.

_Habitat_: New Guinea.

(2) _M. elapoides._--Scales in 17 rows; 208 ventrals; 35 subcaudals.

Colour cream, with 22 black bands, broader than the interspaces between
them; snout and ocular region black.

Total length, 750 millimetres; tail 75.

_Habitat_: Florida Island, Solomon Group.

(h) =Hoplocephalus.=

Characters the same as in _Micropechis_. Scales in 21 rows; ventrals
angulate and notched laterally. Tail moderate; subcaudals in a single
row.

(1) _H. bungaroides_ (Syn. _H. variegatus_. The Broad-headed
Snake).--204-221 ventrals; 40-56 subcaudals.

Colour black on the back, with yellow spots forming more or less
regular cross-bands on the body; upper lip yellow, margined with black;
belly blackish, yellow on the sides.

Total length, 1,620 millimetres; tail 210.

_Habitat_: New South Wales.

(2) _H. bitorquatus_ (fig. 58).--Ventral scales strongly angulate
laterally, 191-227; subcaudals 44-59.

[Illustration: FIG. 58.--_Hoplocephalus bitorquatus._]

Colour olive-green; head pale olive, with a bright yellow occipital
blotch, and a large black blotch on each side of the nape; a pair of
small spots in front of and between the eyes; three black transverse
blotches on the vertex; belly greyish-olive or brown.

Total length, 510 millimetres; tail 95.

_Habitat_: Queensland, New South Wales.

(3) _H. stephensii._--239 ventrals; 60 subcaudals.

Body barred alternately with black and white; the black bars are twice
as broad as the white ones; head dark, spotted with yellow; a W-shaped
yellow mark on the back of the head.

Total length, 760 millimetres.

_Habitat_: Port Macquarie, New South Wales.

(i) =Tropidechis.=

Same general characters; nasal shield entire; scales on the body
strongly keeled, in 23 rows. Tail moderate; subcaudals in a single row.

_T. carinatus._--Colour dark olive, with darker cross-bands; belly
yellow, more or less tinged with olive-green.

Total length, 730 millimetres; tail 120.

_Habitat_: New South Wales, Queensland.

(j) =Notechis.=

Same general characters; pupil round; nasal shield entire. Body
cylindrical; scales smooth, disposed obliquely, in 15-19 rows, the
lateral scales shorter than the dorsals. Tail moderate; subcaudals in a
single row.

_N. scutatus_ (Syn. _Hoplocephalus curtus_. The Tiger Snake. Fig.
59).--Colour dark olive; belly yellow or olive; the shields often
dark-edged.

[Illustration: FIG. 59.--_Notechis scutatus_ (The Tiger
Snake.)]

Total length, 1,280 millimetres; tail 170.

_Habitat_: Australia and Tasmania.

(k) =Rhinhoplocephalus.=

Dentition as in _Hoplocephalus_. Head but little distinct from the
neck; eyes small, with round pupils; no internasal shields. Body
cylindrical, rigid. Scales smooth, in 15 rows. Tail short; subcaudals
in a single row.

_R. bicolor._--Colour greyish-olive on the back, yellowish-white on the
belly; tongue white.

Total length, 395 millimetres; tail 55.

_Habitat_: Australia.

(l) =Brachyaspis.=

Characters the same, but head distinct from the neck; eyes small, with
vertically elliptic pupils; nostril between two nasal shields. Body
stout, cylindrical; scales smooth, slightly oblique, in 19 rows. Tail
short; subcaudals in a single row.

_B. curta._--Colour uniform olive-brown; belly yellowish.

Total length, 490 millimetres; tail 70.

_Habitat_: Western Australia.

(m) =Acanthophis= (_Death Adder_).

(Figs. 60, 61.)

Maxillary bones extending forwards as far as the palatines, with a pair
of large grooved poison-fangs, followed by two or three small teeth;
anterior mandibular teeth elongate, fang-like. Head distinct from the
neck; eyes small, with vertically elliptic pupils; nostril in the upper
part of a single nasal shield. Body stout, cylindrical. Scales more or
less distinctly keeled, in 21-23 rows. Tail short, compressed at the
end and terminating in a sort of long spine, turned upwards; anterior
subcaudals in a single row, posterior in 2 rows.

[Illustration: FIG. 60.--SKULL of _Acanthophis
antarcticus_. (After G. A. Boulenger, _op. cit._)]

_A. antarcticus_ (The Death Adder; fig. 61).--Supraocular shields
often raised and angular, assuming the shape of little horns; scales
on the crown of the head rugose and striated; 113-130 ventrals; 41-51
subcaudals (the last 5-27 are divided).

Colour yellow-brown or reddish, with more or less distinct dark
cross-bands; black spots or small dark bars on the lips; belly
yellowish-white; end of tail yellow or black, covered with spiny scales.

[Illustration: FIG. 61.--_Acanthophis antarcticus_ (The Death
Adder).]

Total length, 850 millimetres; tail 150.

_Habitat_: Moluccas, New Guinea, Australia.

(n) =Elapognathus.=

Maxillary bones extending forwards as far as the palatines, with a pair
of moderately large grooved poison-fangs; no other maxillary teeth;
mandibular teeth subequal. Eyes moderate, with round pupils; nasal
shield entire. Body cylindrical; scales smooth, in 15 rows; ventrals
rounded; tail moderate; subcaudals in a single row.

_E. minor._--Colour dark olive, with a black occipital blotch in the
young; belly yellow or greenish-grey.

Total length, 460 millimetres; tail 95.

_Habitat_: South-west Australia.

(o) =Rhynchelaps.=

Maxillary bones extending forwards as far as the palatines, with a pair
of moderately large grooved poison-fangs, and two small teeth near the
posterior extremity of the bone; anterior mandibular teeth the longest.
Head small, not distinct from the neck; eyes small, with vertically
elliptic pupils; nostril in a single nasal shield. Body short,
cylindrical; scales smooth, in 15-17 rows. Tail very short; subcaudals
in 2 rows.

(1) _R. bertholdi._--Scales in 15 rows; 112-126 ventrals.

Colour yellow, with 19-40 black annuli, usually narrower than the
interspaces; head brown, with a large black blotch on the nape, and
another on the vertex and temples.

Total length, 270 millimetres; tail 22.

_Habitat_: Southern and Western Australia.

(2) _R. australis_ (fig. 62).--Scales in 17 rows; 152-163 ventrals;
18-20 subcaudals.

[Illustration: FIG. 62.--_Rhynchelaps australis._]

Colour red on the body, with ill-defined cross-bars formed of yellowish
black-edged scales; a black blotch on the head, covering the vertex and
temples, and surrounding the eyes; another large blotch on the nape;
snout and occiput yellow; belly white.

Total length, 290 millimetres; tail 25.

_Habitat_: Queensland.

(3) _R. semifasciatus._--Scales in 17 rows; 143-170 ventrals; 17-25
subcaudals.

Colour yellow, with brown cross-bands; large brown blotches on the head
and nape; belly white.

Total length, 300 millimetres; tail 30.

_Habitat_: West Australia.

(4) _R. fasciolatus._--Scales in 17 rows; 145-161 ventrals; 22-27
subcaudals.

Colour red, with numerous blackish-brown cross-bands; large
blackish-brown blotches on the head and nape; belly white.

Total length, 335 millimetres; tail 30.

_Habitat_: West Australia.

(p) =Furina.=

(Figs. 63 and 64.)

Maxillary bones extending forwards beyond the palatines, bearing a
pair of moderately large grooved poison-fangs, and one or two small
teeth near their posterior extremities; mandibular teeth subequal. Head
small, not distinct from neck; eyes very small, with round pupils;
nostril in a single nasal shield. Body cylindrical; scales smooth, in
15 rows. Tail very short, obtuse; subcaudals in 2 rows.

(1) _F. calonota._--Six supralabial shields; 126-131 ventrals; 29-30
subcaudals.

Colour yellow, with a black vertebral stripe; a black bar across the
end of the snout; a large black blotch covering the vertex and the
parietals; belly white.

Total length, 215 millimetres; tail 33.

_Habitat_: West Australia.

(2) _F. bimaculata._--Scales in 15 rows; 181-200 ventrals; 21-25
subcaudals.

[Illustration: FIG. 63.--SKULL OF _Furina
occipitalis_. (After G. A. Boulenger, _op. cit._)]

[Illustration: FIG. 64.--_Furina occipitalis._]

Colour yellow, with large black blotches on the snout, middle of head,
and occiput; belly white.

Total length, 330 millimetres; tail 25.

_Habitat_: West Australia.

(3) _F. occipitalis_ (fig. 64).--Scales in 15 rows; 180-234 ventrals;
14-25 subcaudals.

Entire body ringed with black and white, annuli narrower on head
black, with a broad white band across the occiput, and another narrower
and irregular one across the snout; nose black.

Total length, 590 millimetres; tail 36.

_Habitat_: Australia.

* * * * *

There are no poisonous snakes in New Zealand. In New Caledonia no
_terrestrial_ poisonous snakes are known, but _Hydrophiidæ_ abound on
its shores, as on those of the majority of the islands of the Pacific.

In Australia, especially in New South Wales and farther to the north,
fatalities due to the bites of poisonous snakes are not rare. The most
dangerous species are: _Acanthophis antarcticus_ (the Death Adder),
_Diemenia textilis_ (the Brown Snake), _Pseudechis porphyriacus_ (the
Black Snake), and _Notechis scutatus_ or _Hoplocephalus curtus_ (the
Tiger Snake).

The health authorities of this country have accordingly taken
the wise precaution of circulating very widely among the public
coloured placards bearing illustrations of these four species, with
a description of the essential anatomical details by which they may
be recognised. Similar placards are exhibited in all the schools,
and a generous distribution is made of instructions, printed on
handkerchiefs, indicating the most effective method of treating
poisonous bites.

In Queensland, according to information furnished to me by Mr. C. W.
De Vis, late Director of the Queensland Museum, Brisbane, the number
of deaths resulting from the bites of poisonous snakes has been only
twenty-seven in ten years.

_E.--AMERICA._

The fauna of the New World includes only a very small number of
poisonous snakes belonging to the family COLUBRIDÆ. The Genus
_Elaps_ alone is represented there by twenty-eight species, scattered
over Mexico, Central America, Bolivia, Ecuador, Peru, Colombia, and
Brazil.

VIPERIDÆ, on the other hand, are extremely numerous, and
belong exclusively to the subfamily CROTALINÆ; there are no
VIPERINÆ.

I.--COLUBRIDÆ.

(a) =Elaps.=

(Fig. 65.)

[Illustration: FIG. 65.--SKULL OF _Elaps marcgravii_.
(After G. A. Boulenger, _op. cit._)]

The characters of this genus are: Maxillary bones very short, extending
beyond the palatines, and bearing a pair of large poison-fangs;
pterygoid teeth few or absent; mandibular teeth all of equal length.
No postfrontal bones; præfrontals meeting, or narrowly separated on
the median line. Head small, not distinct from neck; eyes small, with
vertically elliptic or sub-elliptic pupils; nostril between two nasal
shields. Body cylindrical; scales smooth, in 15 rows. Tail short;
subcaudal scales in 2 rows, or partly single, partly in 2 rows.

(1) _E. surinamensis._--Seven supralabials, of which the fourth enters
the eye; frontal shield very narrow; 167-182 ventrals.

Colour red, with black annuli disposed in threes (the middle one
broader), separated by narrow yellow interspaces; 7 or 8 sets of annuli
on the body; the red scales dotted with black; head red above, with
the shields black-edged, followed by a black cross-band behind the
parietals.

Total length, 740 millimetres; tail 95. Grows to 1,900 millimetres.

_Habitat_: Venezuela, Guianas, Northern Brazil, North-east Peru.

(2) _E. heterochilus._--Six supralabials, second and third entering the
eye; snout narrow; 209 ventrals.

Colour red, with black annuli, as in _E. marcgravii_.

Total length, 553 millimetres; tail 43.

_Habitat_: Brazil.

(3) _E. euryxanthus_ (Sonoran Coral Snake).--Seven supralabials,
third and fourth entering the eye; internasals nearly as long as the
præfrontals; 215-241 ventrals; 21-29 subcaudals.

Colour red, with 11 black annuli edged with yellow; head black.

Total length, 400 millimetres; tail 33.

_Habitat_: Arizona, Colorado, North-western Mexico. It is found in
Arizona up to an altitude of nearly 6,000 feet (1,800 metres).

(4) _E. gravenhorstii._--First lower labial in contact with its fellow;
posterior nasal not reaching the præocular: 191 ventrals; 23 subcaudals.

Colour: Seven sets of black annuli disposed in threes, median annulus
the broadest; head black, with a yellow transverse band behind the eyes.

Total length, 550 millimetres; tail 50.

_Habitat_: Brazil.

(5) _E. langsdorffii._--Ventrals 204-225; subcaudals 37-54; 1 + 1
temporals.

Colour dark brown, with 63 transverse series of cream-coloured spots,
each occupying one scale; belly yellow, with red cross-bands.

Total length, 300 millimetres.

_Habitat_: Upper Amazons.

(6) _E. buckleyi._--203-211 ventrals; 39-43 subcaudals; 1 + 2 temporals.

Colour orange, with 48-60 black annuli edged with small yellow spots;
head black; temples yellow.

Total length, 505 millimetres; tail 70.

_Habitat_: Northern Brazil, Eastern Ecuador.

(7) _E. anomalus._--227 ventrals; 29 subcaudals; 1 + 1 temporals.

Colour: Body with 55 black annuli separated by narrow brownish-white
bands; belly yellowish; anterior half of head black, posterior half
yellow; tail yellow or red, with 4 black rings.

Total length, 280 millimetres; tail 23.

_Habitat_: Colombia.

(8) _E. heterozonus._--Scales in 15 rows; 210-219 ventrals; 16-23
subcaudals; 1 + 1 temporals.

Colour red or brown, with 17 to 23 black rings, mostly narrower than
the interspaces; a black band on the head across the eyes.

Total length, 900 millimetres; tail 40.

_Habitat_: Eastern Ecuador, Eastern Peru, Bolivia.

(9) _E. elegans._--Scales in 15 rows; 189-221 ventrals; 29-47
subcaudals; 1 + 1 temporals.

Colour: Black annuli in sets of three, separated by reddish-brown
interspaces; 12-17 sets; head black, with yellow blotches.

Total length, 730 millimetres; tail 70.

_Habitat_: Mexico and Guatemala.

(10) _E. annellatus._--Scales in 15 rows; 200-211 ventrals; 30-45
subcaudals; 1 + 1 temporals.

Colour black, with 41-49 narrow white rings on the body, 4-7 on the
tail; a white ring on the head.

Total length, 490 millimetres; tail 70.

_Habitat_: Eastern Peru.

(11) _E. decoratus._--Scales in 15 rows; 196-213 ventrals: 29-37
subcaudals.

Colour red, with 15-16 sets of black annuli disposed in threes; head
yellow, with end of snout black, and a black band across the eyes.

Total length, 625 millimetres.

_Habitat_: Brazil.

(12) _E. dumerilii._--Scales in 15 rows; 197-204 ventrals; 50-53
subcaudals.

Colour: 8-9 sets of three black annuli on red and yellow; head black,
with a yellow band on the occiput.

Total length, 410 millimetres; tail 65.

_Habitat_: Colombia.

(13) _E. corallinus_ (The Coral Snake).--Scales in 15 rows; 179-231
ventrals; 30-47 subcaudals; 1 + 1 temporals.

Colour: Body with black annuli, separated by red interspaces edged with
yellow; head bluish-black; temples yellow; a blue line from behind the
eye to the lower jaw; tail white.

Total length, 790 millimetres; tail 70.

_Habitat_: Tropical South America and Lesser Antilles (St. Thomas, St.
Vincent, Martinique).

(14) _E. hemprichii._--Scales in 15 rows; 168-181 ventrals; 22-29
subcaudals; 1 + 1 temporals.

Colour: Black, with red or yellow annuli, a broad annulus between the
narrow ones; occiput, upper lip, and temples yellow.

Total length, 720 millimetres; tail 65.

_Habitat_: Guianas, Colombia, Peru.

(15) _E. tschudii._--Scales in 15 rows; 207-221 ventrals; 21-28
subcaudals.

Colour: Body with black annuli broader than the interspaces, disposed
in sets; interspaces red and yellow; snout and occiput black.

[Illustration: FIG. 66.--_Elaps fulvius_ (The Harlequin Snake,
or Coral Snake). (After L. Stejneger.)]

Total length, 430 millimetres; tail 35.

_Habitat_: Peru.

(16) _E. dissoleucus._--Scales in 15 rows; 200 ventrals; 19 subcaudals.

Coloration as in foregoing species.

Total length, 1,070 millimetres; tail 35.

_Habitat_: Venezuela.

(17) _E. fulvius_ (Harlequin, or Coral Snake, fig. 66).--Scales in 15
rows; 180-237 ventrals; 30-59 subcaudals.

Colour: Body with black, red, and yellow annuli; tail with black and
yellow annuli; snout black.

Total length, 990 millimetres; tail 85.

_Habitat_: Eastern North America, from Southern Virginia, the Ohio
River, and the Missouri to the Rio Grande, Mexico. Central America.

(18) _E. psyches._--Scales in 15 rows; 188-214 ventrals; 32-47
subcaudals.

Colour: Body with alternate black and brown annuli, and 48-52 narrow
yellow rings; head black, blotched with yellow.

Total length, 495 millimetres; tail 80.

_Habitat_: Guianas.

(19) _E. spixii._--Scales in 15 rows; 201-219 ventrals; 22-29
subcaudals.

Colour red, with 20-38 black rings disposed in threes; a black
occipital collar, followed by a wide red space.

Total length, 1,400 millimetres; tail 70.

_Habitat_: Venezuela and Northern Brazil.

(20) _E. frontalis._--Scales in 15 rows; 197-230 ventrals; 15-26
subcaudals. Tail ending very obtusely.

Colour: Body with black annuli disposed in threes, with red and yellow
interspaces; head black, spotted with yellow or red.

Total length, 1,350 millimetres; tail 70.

_Habitat_: Southern Brazil, Uruguay, Paraguay, Argentina.

(21) _E. marcgravii._--Scales in 15 rows; 210-240 ventrals; 23-42
subcaudals.

Colour: Body with black annuli in 6-10 sets of three, separated by
broad red interspaces, the middle annulus usually wider; snout yellow,
the end usually black; back of head red.

Total length, 1,120 millimetres; tail 100.

_Habitat_: Tropical South America.

(22) _E. lemniscatus._--Scales in 15 rows; 241-262 ventrals; 30-39
subcaudals.

Colour: Body with 11-14 sets of black annuli disposed in threes,
separated by red interspaces; head yellow; end of snout and a band
across the middle of the head black.

Total length, 1,000 millimetres; tail 80.

_Habitat_: Guianas, Brazil.

(23) _E. filiformis._--Scales in 15 rows; 290-308 ventrals; 35-45
subcaudals.

Colour: Body with black annuli disposed in threes, with red
interspaces; head yellow; end of snout black; a black band across the
eyes.

Total length, 575 millimetres; tail 40.

_Habitat_: Amazons, Colombia.

(24) _E. mipartitus._--Scales in 15 rows; 210-278 ventrals; 24-34
subcaudals.

Colour black, with 40-68 narrow white annuli; head black to between the
eyes, elsewhere yellow.

Total length, 610 millimetres; tail 50.

_Habitat_: Central America and Tropical South America.

(25) _E. fraseri._--Scales in 15 rows; 303 ventrals; 25 subcaudals.

Colour black, with 75 narrow whitish rings with broken outlines; head
black in front, yellow behind.

Total length, 780 millimetres; tail 40.

_Habitat_: Ecuador.

(26) _E. mentalis._--Scales in 15 rows; 255-268 ventrals; 30-31
subcaudals.

Colour: Body black, with 58-70 narrow white annuli, which become wider
on the belly; snout black, occiput yellow; tail annulate, black and
orange.

Total length, 490 millimetres; tail 30.

_Habitat._--Colombia and Ecuador.

(27) _E. ancoralis._--Scales in 15 rows; 258 ventrals; 31 subcaudals.

Colour: Body with 16 sets of black annuli disposed in threes, the
middle one of each set a little wider; head light in front, spotted
with black; an anchor-shaped black mark on the occiput and nape.

Total length, 780 millimetres; tail 57.

_Habitat_: Ecuador.

(28) _E. narduccii._--Scales in 15 rows; 240-315 ventrals; 15-33
subcaudals.

Colour black, beneath with yellow or red cross-bands or transversely
oval spots, sometimes extending as triangular blotches up the sides;
head with a yellow cross-band.

Total length, 720 millimetres; tail 50.

_Habitat_: Eastern Ecuador, North-eastern Peru, Bolivia.

The species of the genus _Elaps_, which are remarkable for the
brightness and beauty of their colours, are generally found in forests.

“The traveller,” says Neuwied, “who ventures into the great Brazilian
forests, where the ground is covered with leafy plants, is astonished
to see shining through the verdure the black and red rings of the
beautiful Coral Snake. Uncertainty as to whether the creature is
dangerous alone prevents him from seizing it. The body of the snake
is not lithe enough to enable it to climb trees. Its food consists of
small animals.”

Dr. Lacerda relates that the Austrian naturalist Wertheimer, when in
the Brazilian settlement of Philadelphia, was bitten by a Coral Snake
in the back of the hand. The usual symptoms of poisoning manifested
themselves immediately, and the unfortunate man died twelve hours
later. Nevertheless, the small size and slenderness of the fangs, the
narrowness of their canals, and the considerable distance between the
fangs and the anterior opening of the mouth, must necessarily render
the bites of these snakes less serious and of rarer occurrence.

II.--VIPERIDÆ.--CROTALINÆ.

The _Solenoglypha_ are infinitely more formidable in the two divisions
of the New World. They are represented by a large number of species,
some of which are feared in consequence of their size and ferocity,
even more than on account of the deadliness of their venom (fig. 67).

[Illustration: FIG. 67.--HEAD AND SKULL OF _Crotalus
horridus_.]

The American CROTALINÆ are divided into two groups:--

The first of these comprises snakes not provided with the caudal
appendage, which is characteristic of the Rattle-Snakes. It consists of
two genera:--

(a) _Ancistrodon._

(b) _Lachesis._

The second group includes only those snakes the tails of which are
terminated by the scaly appendage known as the “rattle.”

These are likewise divided into two genera:--

(d) _Crotalus._

(a) =Ancistrodon.=

Usually with 9 shields on the head, or internasals and præfrontals
broken up into scales. Body cylindrical: scales smooth or keeled, with
apical pits. Tail moderate or short; subcaudals single or in 2 rows.

[Illustration: FIG. 68.--_Ancistrodon piscivorus_ (Water
Viper). (After Stejneger.)]

(1) _A. piscivorus_ (Water Viper, or Cotton-mouth; fig. 68).--Snout
rounded, soft above. Scales on the body strongly keeled, in 25 (rarely
27) rows; 130-147 ventrals; 33-51 subcaudals, all single or the
posterior divided.

Colour pale reddish-brown to dark brown above, with more or less
distinct dark brown cross-bands, or with alternating C-shaped dark
markings each enclosing a central spot. Belly dull yellow spotted with
black, or almost black.

Total length, 1,170 millimetres; tail 200.

_Habitat_: Eastern North America, from North Carolina and Indiana to
Florida and Texas. The Water Viper lives for the most part in the
vicinity of rivers, and feeds upon fish, but also devours small
warm-blooded animals. The Creoles call it the Congo Snake. It is fairly
common in the environs of New Orleans. In summer time it conceals
itself in the branches of trees at the edge of the water. It frequents
inundated rice-fields, and is a terror to the blacks. It attacks
readily, and opens its jaws some seconds before it bites.

(2) _A. bilineatus._--Snout obtusely pointed. Scales more or less
strongly keeled, in 23 (rarely 25) rows; 135-141 ventrals; 52-64
subcaudals, anterior single, posterior divided.

Colour dull yellow or reddish-brown, with more or less distinct darker
cross-bands, or alternating transverse blotches, with yellow edges;
a vertical yellow line on the rostral shield, and a fine yellow line
round the snout; belly brownish or blackish, with white spots.

Total length, 1,100 millimetres; tail 200.

_Habitat_: Mexico, Guatemala, Honduras.

(3) _A. contortrix_ (The Copperhead).--Snout rounded or truncate.
Scales strongly keeled, in 23 (rarely 25) rows; 145-155 ventrals; 31-52
subcaudals, anterior single, posterior divided.

Colour dull yellow or reddish-brown, with dark brown or brick-red
cross-bars; these bars are sometimes interrupted on the vertebral line,
and form alternating triangles; belly yellow or reddish, more or less
spotted with grey or brown.

Total length, 990 millimetres; tail 110.

_Habitat_: North America, from Massachusetts and Kansas to Northern
Florida and Texas.

This snake is often more dreaded than a Rattle-Snake.

(b) =Lachesis.=

In _Lachesis_ the caudal rattle is represented by a series of 10 or
12 rows of spiny scales, which are slightly hooked at the tips. The
head is covered with small shields or smooth or keeled scales, with or
without apical pits. The maxillary is much reduced; the transverse or
pterygoid bone, on the contrary, is greatly developed.

The name is derived from one of the Parcæ, daughters of Night, who
placed the thread on the spindle, and upon whom depended the fate of
men.

In addition to the 19 Asiatic species, of which we have already given
descriptions, the genus _Lachesis_ includes 21 American species.

(1) _L. mutus_ (Bushmaster, or Surucucu).--Two or three scales
separating the internasals in front; 10 to 15 scales on a line between
the supraoculars; 9 or 10 supralabials. Scales tubercularly keeled,
feebly imbricate, in 35 or 37 rows; 200-230 ventrals; 32-50 subcaudals.

[Illustration: FIG. 69.--_Lachesis lanceolatus_
(_Fer-de-lance_ OF MARTINIQUE). (After Stejneger.)]

Colour yellow or pinkish on the back, with a series of large rhomboidal
brown or black spots enclosing smaller light spots; a black streak from
the eye to the angle of the mouth.

Total length, 1,995 millimetres; tail 170.

_Habitat_: Central and Tropical South America.

(2) _L. lanceolatus_ (known as the Fer-de-lance in Martinique, and
Jararacussu in Brazil; fig. 69).--Snout obtuse, slightly turned up;
upper head-scales small, imbricate, more or less strongly keeled, in
5-10 longitudinal series between the supraoculars, which are large;
7 or 8 supralabials. Scales in 23-33 rows, sharply keeled; 180-240
ventrals; 46-70 subcaudals, all or the greater part in two rows.

Coloration very variable, grey, brown, yellow, olive, or reddish;
uniform or with more or less distinct dark spots, or cross-bands, or
with dark triangles on the sides enclosing pale rhombs; a dark streak
from the eye to the angle of the mouth; belly yellowish, uniform, or
spotted with brown.

Total length, 1,600 millimetres; tail 190.

_Habitat_: Tropical America; Mexico, Martinique, St. Lucia, Bequia
Island near St. Vincent, Venezuela, Guianas, Rio de Janeiro.

This snake does not exist in Guadeloupe. “In the islands in which it is
found,” says Dr. Rufz de Lavison, “its presence makes itself felt even
where man has built his dwelling and cultivates the soil. Because of
it no one can carelessly lie down to rest in the shade of a tree; no
one can walk in the woods or enter unconcernedly into the pleasures of
the chase.” It is especially abundant in coffee and sugar plantations,
and is met with from the sea-level up to the summits of the highest
mountains in Martinique and St. Lucia. It not infrequently makes its
way into human habitations, and is not uncommon in gardens, even
entering those of the town of Fort-de-France.

It does not seek its prey by day, but remains on the alert, always
ready to bite. With open mouth, and fangs projecting forwards, it
strikes with the rapidity of lightning. It swims in the rivers and
moves over the ground with great speed. Oviposition takes place in
July, and the young are hatched forthwith, the usual number being from
about 50-60.

It feeds upon lizards and rats, but also destroys a certain number of
fowls and turkeys. All the large animals are afraid of it. Its bite is
extremely dangerous, and causes about a hundred deaths in Martinique
every year.

In striking at its prey or at a man, the _Fer-de-lance_ throws back
its head and opens its jaws widely, with the fangs directed forwards.
It drives in its poison-teeth as with the blow of a hammer, and
quickly draws back again. When very excited, it resumes its position
and strikes afresh. It never becomes tame, but is capable of living a
fairly long time in captivity. I have kept a number of specimens of it
for more than two years, caged in my laboratory.

(3) _L. atrox_ (Labaria).--Closely resembling _L. lanceolatus_, but
bulkier; the enormous head is armed with powerful fangs, which are
often more than a centimetre in length; 7 supralabial shields; scales
in 25-29 rows, strongly keeled; 161-216 ventrals; 47-73 pairs of
subcaudals.

Colour brown, with dark cross-bands or triangular blotches, with the
apices adjacent on the vertebral line; a dark streak from the eye to
the angle of the mouth; belly yellowish-white, speckled with brown, or
brown spotted with yellowish-white.

Total length, 1,110 millimetres; tail 180.

_Habitat_: from Central America to Peru and Northern Brazil.

(4) _L. pulcher._--Two postocular shields and a subocular, separated
from the labials by one series of scales; 7 supralabials; scales in 21
or 23 rows, strongly and tubercularly keeled; 156-172 ventrals; 58-64
pairs of subcaudals.

Colour olive-grey, with brown, light-edged cross-bands, which are
continuous or broken on the vertebral line; a light streak from the eye
to the angle of the mouth; belly covered with minute confluent brown
markings, with darker and lighter spots on the sides.

Total length, 685 millimetres; tail 115.

_Habitat_: Andes of Ecuador.

(5) _L. microphthalmus._--Snout short, rounded; eyes very small; 7
supralabials, of which the third and the sixth or seventh are the
largest; scales in 23 rows, dorsals tubercularly keeled; 159-161
ventrals; 52-55 subcaudal pairs.

Colour yellowish-brown or pale olive on the back, with dark brown
triangles on the sides; posteriorly, the united triangles form
cross-bands; a yellowish band from the eye to the side of the neck;
belly dark brown with yellowish spots.

Total length, 630 millimetres; tail 100.

_Habitat_: Peru, Ecuador.

(6) _L. pictus._--Snout obliquely truncate; two series of scales
between the eye and the labials; scales in 21-23 rows, strongly keeled;
157-172 ventrals; 40-74 pairs of subcaudals.

Colour pale brown, with a dorsal series of large black-edged brown
spots, which may form a vertebral zigzag band; a black streak behind
the eye, and a vertical bar below the eye; belly yellowish, spotted
with brown.

Total length, 310 millimetres; tail 43.

_Habitat_: Peru.

(7) _L. alternatus._--Head narrow, elongate; 8-9 supralabials; scales
in 29-35 rows, very strongly keeled; 167-181 ventrals; 34-51 pairs of
subcaudals.

Colour brown, very elegantly marked with opposite or alternating pairs
of large C-shaped markings, which are dark brown, edged with black and
yellow, and separated by narrow interspaces of the ground colour; head
dark·brown above, with a ⅄̅-shaped light marking, the transverse bar
between the eyes; belly whitish, spotted with brown or black.

Total length, 1,190 millimetres; tail 110.

_Habitat_: Southern Brazil, Paraguay, Uruguay, Argentina.

(8) _L. neuwiedii_ (known as the _Urutù_ in Brazil; fig. 70).--Snout
obtusely pointed; supraocular large, separated from its fellow by
6-9 longitudinal series of scales; 8 or 9 supralabials; scales very
strongly keeled, in 21-27 rows; 168-182 ventrals; 41-53 subcaudals.

Colour yellowish or pale brown, with dark brown black-edged spots;
the spots on the back form a single series or a double alternating
series; a dark spot on the snout; a pair of dark bands from the vertex
to the nape, and another from the eye to the angle of the mouth; belly
yellowish, more or less powdered with brown.

Total length, 770 millimetres; tail 120.

_Habitat_: Brazil, Paraguay, Argentina.

[Illustration: FIG. 70.--_Lachesis neuwiedii_ (known as the
_Urutù_ in Brazil). (After Lacerda.)]

(9) _L. ammodytoides._--Snout turned up, in the shape of a wart; two
series of scales between the eye and the labials; scales in 23 or 25
rows, very strongly keeled; 149-160 ventrals; 30-38 pairs of subcaudals.

Colour pale brown, with large brown black-edged spots or cross-bands,
which may alternate and form a zigzag band; a dark streak behind the
eye; belly yellowish, spotted with brown.

Total length, 460 millimetres; tail 55.

_Habitat_: North-eastern Patagonia and Argentina.

(10) _L. xanthogrammus._--Head elongate, snout short; scales in 27
rows, feebly keeled; 196 ventrals; 54 subcaudals.

Colour very dark olive, with a yellow zigzag line on each side from the
head to the base of the tail; the angular parts enclose rhombic spaces
and lateral triangles; top of head black, with a pair of undulating
yellow bands from the nape to the vertex; a bright golden band round
the snout; labials bright yellow; ventral shields black, paler in the
middle, with yellow triangular spots at their extremities.

Total length, 1,530 millimetres; tail 190.

_Habitat_: Eastern Ecuador, Andes of Colombia.

(11) _L. castelnaudi._--Head narrow and elongate; scales on the head
smooth or feebly keeled, small; body-scales strongly keeled, in 25
or 27 rows; 230-253 ventrals; 72-83 subcaudals, all or majority in a
single row.

Colour greyish or brown, with dark or light-edged spots or cross-bands;
head with dark spots, one of which occupies the middle of the snout;
a dark band from the eye to the angle of the mouth; belly brown or
blackish, spotted with yellow.

Total length, 1,220 millimetres; tail 180.

_Habitat_: Brazil, Ecuador, Eastern Peru.

(12) _L. nummifer._--Snout broad, rounded; 10 or 11 supralabials;
scales in 23-27 rows, strongly keeled; 121-134 ventrals; 26-36
subcaudals, all or the majority single.

Colour pale brown, with a dorsal series of rhomboidal spots, which may
form a zigzag band; belly whitish, uniform or spotted with dark brown.

Total length, 800 millimetres; tail 90.

_Habitat_: Mexico and Central America.

(13) _L. godmani._--Snout broad, rounded; 9 or 10 supralabials; scales
in 21 rows, strongly keeled; 135-142 ventrals; 22-34 subcaudals in a
single row.

Colour brown, with or without a dorsal series of large darker spots;
belly yellowish, more or less spotted with grey or blackish.

Total length, 610 millimetres; tail 60.

_Habitat_: Guatemala.

(14) _L. lansbergii._--Snout pointed, turned up at the end, as in
Vipera aspis; scales in 25-27 rows, strongly keeled; 152-159 ventrals;
29-35 subcaudals in a single row.

Colour yellowish-brown, pale brown, or grey, with a dorsal series of
large rhomboidal or squarish spots, usually divided by a narrow yellow
or orange vertebral line; cheeks blackish; belly powdered with brown,
with or without whitish spots.

Total length, 575 millimetres; tail 70.

_Habitat_: from Southern Mexico to Colombia, Venezuela, and Brazil.

(15) _L. brachystoma._--Similar to the foregoing species; scales in 23
(rarely 25) rows; 132-150 ventrals; 27-38 subcaudals.

Total length, 500 millimetres; tail 50.

_Habitat_: Southern Mexico and Central America.

(16) _L. bilineatus._--Snout rounded; 7 or 8 supralabials; scales in
27-35 rows, strongly keeled; 198-218 ventrals; 59-71 subcaudals, all or
majority in two rows. _Tail prehensile._

Colour green, uniform or spotted with black; a lateral yellow streak;
belly white; end of tail reddish.

Total length, 840 millimetres; tail 125.

_Habitat_: Brazil, Bolivia, Peru, Ecuador.

(17) _L. undulatus._--Snout short, rounded; 11 supralabials; scales
in 21 rows, the dorsals strongly or very strongly keeled; 149-171
ventrals; 41-49 pairs of subcaudals. _Tail prehensile._

Colour olive or brown, sometimes speckled with black, with a dorsal
series of rhomboidal dark spots or an undulous or zigzag band; belly
yellowish or brownish, powdered with blackish.

Total length, 570 millimetres; tail 75.

_Habitat_: Mexico.

(18) _L. lateralis._--Snout rounded; 9 supralabials; scales in 21 or 23
rows, rather strongly keeled; 171 ventrals; 59 subcaudals, in a single
row. _Tail prehensile._

Colour green, with a yellow line on each side of the body.

Total length, 485 millimetres; tail 75.

_Habitat_: Costa Rica.

(19) _L. bicolor._--Very similar to the foregoing; scales in 21 rows;
164-167 ventrals; 62-67 subcaudals, in a single row.

Colour uniform green, yellowish on the belly.

Total length, 375 millimetres; tail 60.

_Habitat_: Guatemala.

(20) _L. schlegelii._--Snout rounded; 8 or 9 supralabials; scales in
19-25 rows, more or less strongly keeled; 138-162 ventrals; 47-62
subcaudals, in a single row. _Tail prehensile._

Coloration very variable, green or olive, spotted with black, or with
pinkish, reddish, or purplish black-edged spots or cross-bars; belly
yellow, spotted with green, or variegated; end of tail generally red.

Total length, 600 millimetres; tail 115.

_Habitat_: Central America, Colombia, Ecuador.

(21) _L. nigroviridis._--Snout short, rounded; 9-11 supralabials;
19 rows of scales, rather feebly keeled; 134-146 ventrals; 49-54
subcaudals, in a single row. _Tail prehensile._

Colour green or olive, spotted with black; head with a black streak on
each side; belly yellowish.

Total length, 535 millimetres; tail 90.

_Habitat_: Costa Rica.

(22) _L. aurifer._--Snout short and broad; 9 or 10 supralabials; scales
in 19 rows, rather strongly keeled; 154-158 ventrals; 53-61 subcaudals,
single. _Tail prehensile._

Colour green, spotted with yellow; a black streak on the temple; belly
greenish-yellow.

Total length, 825 millimetres; tail 145.

_Habitat_: Guatemala.

Head very distinct from neck, covered above with nine large symmetrical
shields; eyes rather small, with vertical pupils. Body cylindrical;
scales keeled, with apical pits; tail short, ending in a segmented
horny apparatus (rattle), producing a special sound; subcaudals all or
the majority in a single row.

(1) _S. miliarius_ (Ground Rattle-Snake).--9-11 supralabials; scales
in 21 or 23 rows, strongly keeled; 127-139 ventrals; 27-36 subcaudals;
rattle short, consisting at the most of 10 segments.

Colour greyish, yellowish, or brown, the vertebral line often orange;
two undulating dark stripes from between the eyes to the occiput, the
enclosed space usually orange; belly whitish, spotted with dark brown
or black.

Total length, 520 millimetres; tail 70.

_Habitat_: South-eastern North America, from North Carolina to Texas.

(2) _S. catenatus_ (Prairie Rattle-Snake, or Massasanga, fig.
71).--Two or three series of scales between the eye and the labials;
11-14 supralabials; scales in 23 or 25 rows; 136-153 ventrals; 20-31
subcaudals.

Colour the same as in _S. miliarius_: a dark spot on the parietal
shields.

Total length, 680 millimetres; tail 80.

_Habitat_: Great Lakes district; United States east of the Rocky
Mountains and west of the Mississippi; Northern Mexico.

(3) _S. ravus._--11 or 12 supralabials; scales in 21 or 23 rows; 147
ventrals; 26 subcaudals.

Colour yellowish-brown, with a dorsal series of dark brown spots,
longer than broad, and a series of transverse dark bars on each side;
belly yellowish, spotted with blackish-brown.

[Illuatration: FIG. 71.--_Sistrurus catenatus_ (Prairie
Rattle-Snake, or Massasanga). (After Holbrook and Stejneger.)]

Total length, 200 millimetres; tail 22.

_Habitat_: Vera Cruz, Mexico.

(d) =Crotalus= (Rattle-Snakes).

These snakes differ from all others in that the end of the tail bears a
series of large conical scales, forming rattles, each fitting into the
next and movable in such a manner that when the reptile causes them to
move they produce a strident sound (fig. 72).

[Illustration: FIG. 72.--A, Horny appendage (rattle) of
_Crotalus horridus_ (three-quarters natural size. After Garman).
B, longitudinal section of the same. C, separated segments of the
appendage: _a_, terminal point; _h_, basal segment (after Czermak).]

The length of these animals often exceeds 2,000 millimetres. The head
is flat, very large and expanded posteriorly, and terminated in front
by a short, truncate snout; it is covered above with scales or small
shields.

Rattle-Snakes are armed with enormous fangs enclosing a complete canal,
which extends throughout almost their entire length. The poison-glands
are of the size of a large almond.

The number of segments in the rattle is variable, but rarely exceeds 18
or 20. At the time of the shedding of the skin these segments fall
off and are at once replaced. Contrary to the belief which was long
entertained, their number bears no relation to the age of the snake.

[Illustration: FIG. 73.--_Crotalus terrificus_ (Dog-faced
Rattle-Snake, Cascavella in Brazil). (After Stejneger.)]

Rattle-Snakes are met with especially in stony and arid localities, or
among brushwood near water. They hardly ever bite except when surprised
or attacked.

(1) _C. terrificus_ (Dog-faced Rattle-Snake, _Cascavella_ in Brazil;
fig. 73).--Snout very short; three or four series of scales between the
eye and the supralabial shields; body-scales in 23-31 rows, dorsals
very strongly keeled; 160-199 ventrals; 18-30 subcaudals.

Colour brown, with a series of darker, light-edged rhombs, often
lighter in the centre; a dark streak from the eye to the angle of the
mouth; belly yellowish-white, uniform or spotted with brown; tail
generally brown or blackish.

Total length, 1,320 millimetres; tail 130.

_Habitat_: Arizona, New Mexico, and Texas to Southern Brazil, and
Northern Argentina.

(2) _C. scutulatus_ (Texas Rattle-Snake; fig. 74).--13-16 supralabials;
scales in 25 or 27 rows; dorsals striated and strongly keeled; 167-170
ventrals; 18-20 subcaudals.

Colour yellowish or greyish-brown, with a series of large dark brown
light-edged rhomboidal spots; an oblique dark streak below the eye;
belly uniform yellowish-white.

Total length, 760 millimetres; tail 65.

_Habitat_: Arizona, New Mexico, Texas, North Mexico.

(3) _C. confluentus_ (Pacific or Mottled Rattle-Snake; fig. 75).--Upper
head-scales small, striated; 13-18 supralabials; body scales in 25-29
rows, striated and strongly keeled; 168-197 ventrals; 17-34 subcaudals.

Colour yellowish, greyish, or pale brown, with a dorsal series of
large brown or red spots, usually rhomboidal or transversely elliptic
in shape; a light streak or triangular marking across the supraocular
shields; belly yellowish, uniform or spotted with brown.

Total length, 1,520 millimetres; tail 140.

_Habitat_: Western North America, from British Columbia to South
California, eastwards to Assiniboia, Dakota, Nebraska, Kansas, and
Western and Southern Texas; Northern Mexico.

* * * * *

According to Holbrook, this reptile feeds upon young rabbits,
squirrels, rats and other small mammals. It lays its eggs in August,
and the young are hatched at once, and are capable of seeking their own
food.

In captivity as well as under natural conditions the Mottled
Rattle-Snake is an excessively irritable species. “The noise of the
wind,” says Brehm, “or even the distant view of a man or animal, are
sufficient to irritate it. It then coils itself up in a spiral, and
places its head and tail in the centre of the disc thus formed, in
a state of absolute immobility. After a short interval the creature
raises its head to a height of about 8 to 12 inches above the ground,
curves its neck in the shape of an S, and elevates its tail into a
vertical position and shakes it vigorously, whereupon the strident
noise caused by the rattle is heard. So rapid are the movements
communicated by the _Crotalus_ to its tail that they can scarcely be
distinguished. So long as the _Crotalus_ believes itself menaced it
remains in the position that we have just described, and continues to
sound its rattle. If one withdraws from the irritated snake, the sound
gradually lessens and ceases, to begin again more vigorously when the
reptile is once more approached.”

The bite of these snakes is exceedingly dangerous. Pigs wage an
inveterate war against them and devour them.

At the Pasteur Institute at Lille, I have kept several of these
reptiles in captivity for eighteen months and longer. They invariably
refused their food, and I always had to resort to artificial feeding.
They are easily capable of withstanding a prolonged fast.

(4) _C. durissus_ (Common Rattle-Snake).--7 or 8 longitudinal series
of scales between the supraoculars, 3 or 4 series of scales between the
eye and the labials; 13-16 supralabials; scales in 25-29 rows, dorsals
strongly keeled; ventrals 169-181; 24-32 subcaudals.

[Illustartion: FIG. 74.--_Crotalus scutulatus_ (Texas
Rattle-Snake). (After Baird and Stejneger.)]

Colour pale greyish or brownish, with a dorsal series of large blackish
rhomboidal spots; a yellowish cross-line between the eyes; snout
blackish; end of tail usually black; belly yellowish, more or less
spotted with brown or black.

Total length may be as much as 8 feet (2,400 millimetres).

_Habitat_: South-eastern United States, from North Carolina to Florida
and the mouths of the Mississippi.

(5) _C. horridus._--Supraoculars considerably narrower than the space
between them, which is covered by 3-8 longitudinal series of small
scales; 12-16 supralabials; body scales in 23-29 rows, dorsals very
strongly keeled; 165-178 ventrals; 19-29 subcaudals.

Colour greyish-brown, usually with a rusty vertebral stripe, and
=V-= or =M-=shaped blackish cross-bands; head uniform above,
with a dark band from the eye to the angle of the mouth; usually a pair
of roundish or triangular dark spots on the nape; belly yellowish,
uniform or spotted with blackish; end of tail blackish.

Total length, 1,340 millimetres; tail 135.

_Habitat_: United States, from Massachusetts and Iowa to Northern
Florida and Texas.

(6) _C. tigris._--13-15 supralabials; scales in 23 or 25 rows, dorsals
strongly keeled; 166-181 ventrals; 26-46 subcaudals.

Colour yellowish or pale brown, with a dorsal series of brown spots
and cross-bands posteriorly; sides with smaller dark spots; belly
yellowish, spotted with brown.

Total length, 380 millimetres; tail 50.

_Habitat_: Southern California, Lower California, Nevada, Colorado,
Arizona, and Northern Mexico.

(7) _C. mitchelli._--14-16 supralabials; scales in 25 rows, striated,
dorsals strongly keeled; 178-198 ventrals; 24-26 subcaudals.

[Illustration: FIG. 75.--_Crotalus confluentus_ (Pacific or
Mottled Rattle-Snake). (After Baird and Stejneger.)]

Colour greyish-yellow to salmon-red, finely punctulated with brown,
with a dorsal series of transverse darker spots; belly yellowish.

Total length, 1,020 millimetres; tail 90.

_Habitat_: Desert regions of Southern California, Lower California, and
Arizona.

(8) _C. triseriatus._--9-13 supralabials; scales in 21-25 rows, dorsals
strongly keeled; 142-184 ventrals; 22-30 subcaudals.

Colour olive or brown, with a vertebral series of rather small dark
brown spots edged with black and white; belly yellowish, spotted with
dark brown, or dark grey-brown powdered with whitish.

Total length, 530 millimetres; tail 55.

_Habitat_: Mexico.

(9) _C. polystictus._--Closely allied to the foregoing, but 4
internasals, 14 or 15 supralabials, and scales in 27-30 rows; 123-151
ventrals; 18-23 subcaudals.

Colour yellowish-brown, beautifully marked with 6 or 7 longitudinal
series of alternating, elongate, dark brown, black- and white-edged
spots, separated by narrow interspaces of the ground-colour; a pair
of diverging dark bands on the top of the head, separated by a narrow
pinkish-white streak; belly pinkish or yellowish, spotted with dark
brown.

Total length, 600 millimetres; tail 60.

_Habitat_: Tableland of Mexico.

(10) C. LEPIDUS.--12 supralabials; scales in 21 or 23 rows,
dorsals strongly keeled; 153-169 ventrals; 24-31 subcaudals.

Colour brown or greenish-grey, with dark brown or jet-black light-edged
cross-bands, narrowing on the sides; two dark spots, or a =V-= or
heart-shaped black marking on the nape; belly dirty white, spotted with
brown.

Total length, 350 millimetres; tail 60.

_Habitat_: Western Texas, New Mexico, Arizona, North Mexico.

(11) _C. cerastes_ (Horned Rattle-Snake; fig. 76).--Supraocular
transformed into a raised horn-like process; 11-13 supralabials; scales
in 21 or 23 rows; dorsals feebly keeled, each scale along the middle
of the back with a central tubercular swelling; 146 ventrals; 17
subcaudals.

[Illustration: FIG. 76.--_Crotalus cerastes_ (Horned
Rattle-Snake.) (After Baird and Stejneger.)]

Colour yellowish, with a dorsal series of rather indistinct brown
blotches; a narrow brown streak from the eye to the angle of the mouth.

Total length, 250 millimetres; tail 20.

_Habitat_: Desert regions of Southern California, Nevada, Arizona, and
Utah.

_F.--HYDROPHIINÆ (SEA-SNAKES)._

The Sea-Snakes, which are found in great numbers on the shores of the
Indian Ocean, are common throughout the whole of the tropical zone of
the China Sea and the Pacific. They are met with from the Persian Gulf
to the west coast of Equatorial America, but are entirely absent from
the east coast of the same continent and the west and east coasts of
Africa.

They often travel in companies. All are poisonous, and very savage.
They never come to land, and move with difficulty if taken out of the
water, although they are excellent swimmers. It is impossible to keep
them in captivity in aquariums, and they die in two or three days.
Their food consists of fishes and crustacea. Their tail is prehensile,
and they make use of it as an anchor to attach themselves to coral
reefs when they wish to rest. They generally float on the surface
of the waves, but can dive to great depths, thanks to the extreme
dilatability of their lungs, which enables them to store up large
reserves of air. They are viviparous.

In these snakes, the head, which is always very small, is scarcely
distinct from the body. It is often covered with nine large shields.
The body is laterally compressed, and the tail, which serves as a fin,
is similarly flattened. The nostrils open on the upper surface of the
snout, between the nasal shields. The eyes are always very small.

The number of species at present known is considerable; they are
divided into _ten_ genera. We shall confine ourselves here to
mentioning the principal diagnostic characters of these genera, and to
describing the most common species.

[Illustration: FIG. 77.--SKULL OF _Hydrus platurus_.
(After G. A. Boulenger, _op. cit._)]

(1) =Hydrus.=

(Fig. 77.)

Maxillaries longer than the ectopterygoids, not extending forwards as
far as the palatines; poison-fangs grooved, rather short, followed,
after an interspace, by 7 or 8 solid, backwardly curved teeth. Snout
long, bearing the nostrils on its upper surface; head-shields large,
nasals in contact with each other. Body rather short; scales hexagonal
or squarish, juxtaposed; no distinct ventral scales.

[Illustration: FIG. 78.--_Hydrus platurus_ (syn. _Pelamis
bicolor_).

(After Krefft.)]

The principal species of this genus is _H. platurus_ (syn. _Pelamis
bicolor_, fig. 78).

Coloration black or brown and yellow, with very variable markings.

Total length, 700 millimetres; tail 80.

_Habitat_: Indian Ocean, Tropical and Sub-tropical Pacific.

(2) =Thalassophis.=

Poison-fangs followed by 5 small teeth. Snout short; nostrils superior,
horizontal, between two nasal shields and an internasal; frontal and
parietal shields large; præocular present. Body rather elongate; scales
hexagonal, juxtaposed; no distinct ventral scales.

_T. anomalus._--Body with dark annuli, wider on the back.

Total length, 810 millimetres; tail 84.

_Habitat_: Java.

(3) =Acalyptophis.=

Maxillaries longer than the ectopterygoids; frontal and parietal
shields broken up into scales. Body rather elongate; scales
subimbricate; no distinct ventrals.

_A. peronii._--Greyish or pale olive, with dark cross-bands; belly
whitish.

Total length, 890 millimetres; tail 115.

_Habitat_: Western Tropical Pacific.

(4) =Hydrelaps.=

Snout short; 6 teeth behind the poison-fangs; nostril in a single nasal
shield; head-shields large. Body feebly compressed; scales imbricate;
ventral scales small, but well developed.

_H. darwiniensis._--Body with yellowish-white and blackish annuli, the
black rings narrower on the belly; head dark olive spotted with black.

Total length, 435 millimetres; tail 43.

_Habitat_: North Australia.

(5) =Hydrophis.=

(FIG. 79.)

[Illustration: FIG. 79.--_Hydrophis coronatus._ (After Sir
Joseph Fayrer.)]

Poison-fangs large, followed by a series of 7-18 solid teeth. Head
small; nostrils on the upper surface of the snout, pierced in a single
nasal shield; head-shields large; præocular present. Body long, often
very slender anteriorly; scales on the anterior part of the body
imbricate, rectangular, keeled or tubercular; ventrals more or less
distinct, very small.

A considerable number of (at least 22) species of HYDROPHIS
are known. Those most frequently met with are the following:--

_H. spiralis._--Olive above, yellowish beneath, with black rings; head
black above, with a horse-shoe-shaped yellow mark, the convexity of
which rests on the præfrontal shields; end of tail black.

Total length, 400 millimetres. Grows to 1,800 millimetres.

_Habitat_: Coasts of India, and the Malay Archipelago.

_H. cærulescens._--Grey above, with black cross-bands, which form
complete rings, or are interrupted on the belly; head uniform black.

Total length, 665 millimetres; tail 75.

_Habitat_: Bombay Coast, Bay of Bengal, Straits of Malacca.

_H. nigrocinctus._--Pale olive on the back, yellowish on the belly,
with black annuli, which are broader on the back.

Total length, 1,000 millimetres; tail 100.

_Habitat_: Bay of Bengal and Straits of Malacca.

[Illustration: FIG. 80.--_Hydrophis elegans._ (After Krefft.)]

_H. elegans_ (fig. 80).--Yellowish-white, back with transverse
rhomboidal black spots, separated by a series of small black spots;
belly with black spots or cross-bars; head blackish, with a more or
less distinct light crescentic marking across the snout, from above the
eyes.

Total length, 710 millimetres; tail 60.

_Habitat_: North coast of Australia.

_H. gracilis._--Bluish-black or greyish, olive above in the adult,
with more or less distinct lighter cross-bands anteriorly. Young
sometimes with rhombic black cross-bands extending to the belly, or
sub-interrupted on the sides.

Total length, 1,020 millimetres; tail 90.

_Habitat_: Coasts of Persia, India, and Ceylon; Malay Archipelago.

_H. cantoris._--Body dark olive or blackish anteriorly, with yellowish
cross-bands above; posterior part of body olive above, yellowish on
the sides; tail with olive vertical bars; a blackish streak along the
belly.

Total length, 1,100 millimetres; tail 90.

_Habitat_: Bay of Bengal.

_H. fasciatus._--Head and neck black, the latter with yellowish
cross-bands; body pale, with black annuli, which are broader on the
back.

Total length, 1,000 millimetres; tail 85.

_Habitat_: From the coasts of India to China and New Guinea.

_H. obscurus_ (syn. _H. stricticollis_).--Olive or dark green above,
with yellowish cross-bars, which form complete rings round the slender
anterior part of the body; a yellow spot on the snout, and a yellow
streak on each side of the upper surface of the head.

Total length, 970 millimetres; tail 105.

_Habitat_: Bay of Bengal, Malay Archipelago.

_H. leptodira.-_-Black, with yellow cross-bars on the neck, and
complete annuli on the body, the bars and annuli numbering 77.

Total length, 525 millimetres; tail 40.

_Habitat_: Mouths of the Ganges.

(6) =Distira.=

(Fig. 81.)

Poison-fangs large, followed by 4-10 grooved teeth. Head larger than in
HYDROPHIS; body more or less elongate; scales on the anterior
part of the body imbricate; ventrals more or less distinct, and always
very small.

The species of this genus, 18 in number according to the British Museum
Catalogue, are found in the Indian and Pacific Oceans, from the Persian
Gulf to Japan and New Caledonia.

The most important are:--

_D. ornata._--Uniform blackish-olive on the back, whitish on the belly.

Total length, 1,200 millimetres; tail 130. _ Habitat_: From the Mouth
of Persian Gulf, and the coasts of India and Ceylon to New Guinea, and
North Australia.

_D. subcincta._--Trunk with 41 broad dark cross-bands, about as broad
as the interspaces, not extending downwards to the middle of the side;
a series of small roundish, blackish spots along the lower part of the
sides.

Total length, 1,070 millimetres; tail 100.

_Habitat_: Indian Ocean.

[Illustration: FIG. 81.--SKULL OF _Distira_.

(After G. A. Boulenger, _op. cit._)]

_D. cyanocincta._--Greenish-olive above, with dark olive or black
cross-bars or annuli, broader on the back, and sometimes joined by a
black band along the belly, or yellowish, with a black vertebral stripe
and a few bars on the neck.

Total length, 1,500 millimetres; tail 140.

_Habitat_: From the Persian Gulf and the coasts of India to China,
Japan, and Papuasia.

_D. jerdonii._--Olive above, yellowish on the belly, with black
cross-bands forming complete rings in young and half-grown specimens;
a black spot sometimes present between each pair of annuli.

Total length, 910 millimetres; tail 100.

_Habitat_: Bay of Bengal, Straits of Malacca, Borneo.

(7) =Enhydris.=

Two large poison-fangs, and 2-4 small feebly grooved teeth. Body short
and stout; scales hexagonal or squarish, juxtaposed, disappearing
almost completely on the belly.

_E. curtus._--Above with dark transverse bands, broadest in the middle;
end of tail black.

Total length, 750 millimetres; tail 75.

_Habitat_ Coasts of India and Ceylon.

[Illustration: FIG. 82.--_Enhydrina valakadien_ (syn. _E.
bengalensis_).]

(8) =Enhydrina.=

Two large poison-fangs, followed by 4 solid non-grooved teeth. Body
moderately elongate; scales imbricate; ventrals distinct but very small.

_E. valakadien_ (syn. _E. bengalensis_; fig. 82).--Colour olive or
grey, with black transverse bands, usually less distinct in the adult;
sides and belly whitish.

[Illustration: FIG. 83.--SKULL OF _Platurus
olubrinus_.

(After G. A. Boulenger, _op. cit._)]

Total length, 1,300 millimetres; tail 190.

_Habitat_: From the Persian Gulf along the coasts of India and Burma,
to the Malay Archipelago and Papuasia.

(9) =Aipysurus.=

Maxillaries a little longer than the ectopterygoids; poison-fangs
moderate, followed, after a short interval, by 8-10 grooved teeth;
anterior mandibular teeth feebly grooved. Snout short; head shields
large, or broken up into scales. Body moderate; scales imbricate;
ventrals large, keeled in the middle.

_A. australis._--Brown, or cream-colour, with brown spots forming more
or less distinct cross-bars.

Total length, 930 millimetres; tail 110.

_Habitat_: Coasts of New Guinea and Australia.

Other species of AIPYSURUS (_A. eydouxii_, _annulatus_, and
_lævis_) are found on the coasts of Singapore, Java, Celebes, and the
Philippine and Loyalty Islands.

[Illustration: FIG. 84.--_Platurus laticaudatus_ (syn. _P.
fischeri_).

(After Sir Joseph Fayrer.)]

(10) =Platurus.=

(Figs. 83, 84.)

Two large poison-fangs, and only one or two small solid teeth near the
posterior extremity of the maxillary. Head shields large; nostrils
lateral, the nasal shields separated by the internasals. Body greatly
elongate; scales smooth and imbricate; ventrals and subcaudals large.

Four species, distributed in the eastern parts of the Indian Ocean and
in the Western Pacific.

_P. laticaudatus_ (syn. _P. fischeri;_ fig. 84).--Olive above,
yellowish on the belly, with 29-48 black annuli.

Total length: 970 millimetres; tail 90.

_Habitat_: From the Bay of Bengal to the China Sea and the Western
South Pacific Ocean.

_P. colubrinus_ (fig. 83).--Olive above, yellowish on the belly, with
28-54 black annuli, some or all of which may be interrupted below.

Total length, 1,270 millimetres; tail 125.

_Habitat_: From the Bay of Bengal to the China Sea and the Western
South Pacific Ocean.

_P. muelleri._--62 black annuli, some of which are interrupted on the
belly.

_Habitat_: Only found in the South Pacific Ocean (subtropical zone), as
far as the New Hebrides and the shores of Tasmania.

_P. schistorhynchus._--Coloration and size as in _P. colubrinus_: body
with 25-45 annuli.

_Habitat_: Western Tropical Pacific.

_G.--GEOGRAPHICAL DISTRIBUTION OF THE PRINCIPAL GENERA OF
POISONOUS SNAKES IN THE FIVE DIVISIONS OF THE WORLD._

(1) _EUROPE._

FAMILIES SUB-FAMILIES GENERA GEOGRAPHICAL AREA

{Borders of the Mediterranean
COLUBRIDÆ _Dipsadomorphinæ Cœlopeltis_ { in France and Spain;
{ Italy {only in Liguria).

{France, Italy, Switzerland,
{ Austria-Hungary, Germany,
{ Belgium, Sweden
VIPERIDÆ _Viperinæ Vipera_ { and Norway, Gt. Britain,
{ Spain and Portugal, Bosnia
{ and Herzegovina,
{ Southern Russia, Turkey
{ and Greece.

(2) _ASIA._

{_Hydrus_ }
{_Thalassophis_}
{_Acalyptophis_}
{_Hydrelaps_ } Persian Gulf, Indian Ocean,
{_Hydrophis_ } Bay of Bengal, Straits
{_Hydrophiinæ_ {_Distira_ } of Malacca, China Sea,
{ {_Enhydris_ } Philippines, and Malay
{ {_Enhydrina_ } Archipelago.
{ {_Aipysurus_ }
{ {_Platurus_ }
{
COLUBRIDÆ { {India, Ceylon, Burma,
{ {_Bungarus_ { Indo-China, Southern China,
{ { { Dutch Indies, Borneo.
{ { {India, Ceylon, Burma,
{ {_Naja_ { Indo-China, Dutch Indies,
{ { { Philippines.
{_Elapinæ_ {_Hemibungarus_ {South-eastern Asia, India,
{ { Japan, Philippines.
{ {South-eastern Asia, India,
{_Callophis_ { Formosa, Burma, Indo-
{ { China, Southern China.
{_Doliophis_ {Indo-China, Malay Peninsula.
{ { {Turkestan, Ural, Siberia,
{ {_Vipera_ { Caucasus, Persia, Armenia,
{ { { Western China,
{ { { India, Ceylon, Himalayas.
{ {
{ _Viperinæ_ {_Pseudocerastes_ Persia.
{ {_Cerastes_ Arabia, Palestine.
{ {
{ {_Echis_ {Persia, Arabia, India, Baluchistan,
VIPERIDÆ { { Afghanistan.
{
{ { {Transcaspia, Turkestan,
{ { { Himalayas, Southern
{ {_Ancistrodon_ { China, Formosa, Japan,
{_Crotalinæ_ { { Ceylon, Java.
{ {
{ { {South-eastern Asia, India,
{ {_Lachesis_ { Southern China, Indo-China,
{ { { Formosa, Sumatra.

(3) _AFRICA._

{_Boulengerina_ Central Africa.
{_Elapechis_ Central and South Africa.
{
{ {Egypt, Central and West
{_Naja_ { Africa, Morocco, Congo,
{ { Angola.
{
{_Sepedon_ {South Africa, Cape of Good
COLUBRIDÆ _Elapinæ_ { { Hope.
{
{_Aspidelaps_ {South and South-east Africa,
{ { Mozambique.
{
{_Walterinnesia_ Egypt.
{
{_Homorelaps_ {South Africa, Cape of Good
{ { Hope.
{
{ {Central and South Africa,
{_Dendraspis_ { Angola, Great Lakes,
{ { Congo, Transvaal.
{ {West Africa, Gambia, Great
{_Causus_ { Lakes, Congo, Angola,
{ { Transvaal.
{
{_Vipera_ {Morocco, Algeria, Tunis,
{ { Egypt, Mozambique.
{
{ {Zanzibar, Zambesia, the
{_Bitis_ { Cape, Transvaal, Congo,
{ { the Gaboon, Benguella,
{ { Angola, Senegal, Nigeria.
{
{_Cerastes_ North Africa, the Sahara.
{
VIPERIDÆ _Viperinæ_ { {North Africa, Lake Chad,
{_Echis_ { Soudan, Egypt, Somaliland,
{ { Socotra.
{
{ {Tropical Africa, Dahomey,
{_Atheris_ { Lagos, the Cameroons,
{ { the Gaboon, Congo.
{
{ {Tropical and South Africa,
{ { Congo, Angola, Lake
{_Atractaspis_ { Chad, the Gaboon, Dahomey,
{ { Gold Coast, Zanzibar,
{ { Somaliland, Natal,
{ { and the Cape.

(4) _OCEANIA._

FAMILIES SUB-FAMILIES GENERA GEOGRAPHICAL AREA

{ {_Hydrus_ }
{ {_Thalassophis_ }
{ {_Hydrelaps_ } Equatorial and Sub-tropical
{ {_Hydrophis_ } Pacific Ocean, the
{_Hydrophiinæ_ {_Distira_ } Moluccas, Papuasia, New
{ {_Enhydris_ } Guinea, Celebes, Timor,
{ {_Enhydrina_ } Australia, Tasmania, New
{ {_Aipysurus_ } Caledonia, New Hebrides.
{ {_Platurus_ }
{
{ {_Ogmodon_ Fiji Islands.
{ {
{ {_Glyphodon_ {Northern Australia, New
COLUBRIDÆ { { { Guinea.
{ {
{ {_Pseudelaps_ {Australia, the Moluccas,
{ { { Papuasia.
{ {
{ {_Diemenia_ Australia, New Guinea.
{ {_Pseudechis_ Australia, New Guinea.
{ {
{ {_Denisonia_ {Australia, Solomon Islands.
{ { { Tasmania
{ {
{_Elapinæ_ {_Micropechis_ New Guinea, Solomon Islands.
{ {_Hoplocephalus_ Australia.
{ {_Tropidechis_ Australia.
{ {_Notechis_ Australia, Tasmania.
{ {_Rhinhoplocephalus_ Australia.
{ {_Brachyaspis_ Australia.
{
{ {_Acanthophis_ {Moluccas, Papuasia, Northern
{ { { Australia.
{ {
{ {_Elapognathus_ Australia.
{ {_Rhynchelaps_ Australia.
{ {_Furina_ Australia.

(5) _AMERICA._

FAMILIES SUB-FAMILIES GENERA GEOGRAPHICAL AREA

{Mexico, Central America,
COLUBRIDÆ _Elapinæ_ _Elaps_ { Bolivia, Ecuador, Peru,
{ Colombia, Brazil.

{_Ancistrodon_ {North America, Florida,
{ { Texas, Mexico, Guatemala.
{
{_Lachesis_ {Central and South America,
{ { Martinique, St. Lucia.
{ {
VIPERIDÆ _Crotalinæ_ {_Sistrurus_ {North America east of the
{ { Rocky Mountains, Mexico.
{ {
{ {Southern Canada, British
{ { Columbia, Central America,
{_Crotalus_ { Guiana, Venezuela,
{ { Brazil, Uruguay, Northern
{ { Argentina.

PART II.

CHAPTER IV.

_SECRETION AND COLLECTION OF VENOM IN SNAKES._

_Non-poisonous_ as well as _poisonous_ snakes possess _parotid_ and
_upper labial_ glands capable of secreting venom. In the former the
organs of inoculation are wanting, but we shall see later on that the
toxic secretion of their glands is just as indispensable to them as to
the snakes of the second category for the purpose of enabling them to
digest their prey.

For the morphological, histological, and physiological demonstration of
the existence of these glands in harmless reptiles we are indebted to
Leydig (1873), whose discovery has since been confirmed and extended
by the researches of Phisalix and Bertrand, Alcock, L. Rogers, and L.
Lannoy.

The parotids of Grass Snakes are mixed glands of the sero-mucous type.
The serous tubes are situate almost exclusively in the posterior
portion of the gland. As we proceed towards the anterior portion, we
find that these serous tubes are interspersed with others which are
exclusively mucous or sero-mucous, and they become entangled with those
of the upper labial gland, properly so-called. The substance of the
gland is divided into several lobes by bands of connective tissue;
the tubes are separated by _septa_ of the same tissue, in extremely
delicate layers (Lannoy).

In poisonous snakes these glands are much more developed, especially
in their hinder portions, which sometimes assume enormous dimensions.
They may attain the size of a large almond (_Crotalus_, _Naja_), and
they then occupy the spacious chamber already described (Chap. I., p.
10), which is situated behind the eye on each side of the skull.

Each gland is surrounded by a thick capsule of fibrous tissue, two
prolongations of which, the one anterior, the other posterior, keep it
in its place beneath the _masseter_ muscle. A portion of the latter
is inserted in the capsule itself, in such a way that when the snake
closes its jaws to bite, the gland is forcibly compressed and the
contained liquid is squeezed into its excretory duct.

Between the muscle and the envelope of the gland there is a serous
pouch, which enables the one to slide over the other.

The excretory duct runs along the outer side of the upper jaw,
and opens by a slit at the base of the poison-fang, with which it
inosculates at right angles in a little muscular mass forming a
_sphincter_.

In the normal position of repose, the poison-fang is always concealed
by a gingival fold of mucous membrane, in the substance of which are
buried a few fibres of the tendon of the internal pterygoid muscle.
When the latter contracts, the tooth is almost completely exposed, and
the efferent duct of the gland then assumes an oblique position, which
allows of the direct discharge of the venom through the canal which
runs along the greater portion of the length of the tooth.

When the poison-fangs are folded back in their sheath, the poisonous
secretion can escape freely into the buccal cavity by the slit situated
at the base of the fangs.

At the moment when the animal is about to bite, when it throws back its
head and opens its jaws, directing its fangs forwards, the muscles that
come into action (_masseters_, _temporals_, and _pterygoids_) compress
the glands on each side, and cause the venom to be expelled in a sudden
jet, as if by a sort of ejaculatory process. In the case of certain
species the venom may be projected to a distance of more than a yard.

The quantity of venom secreted by the glands varies greatly, according
to the length of time which has elapsed since the animal took its last
meal, and in accordance with a number of other conditions not very easy
to determine.

The Common Viper of Europe yields scarcely 10 centigrammes of poison,
while an adult Indian Cobra may excrete more than 1 gramme.

* * * * *

Freshly collected venom is a syrupy liquid, citron-yellow or slightly
opalescent white in colour.

When dried rapidly _in vacuo_ or in a desiccator over calcium chloride,
it concretes in cracked translucent lamellæ like albumin or gum arabic,
and thus assumes a crystalloid aspect. In this condition it may be kept
indefinitely, if protected from light, air, and moisture. It dissolves
again in water just as readily as albumin or dried serums.

I regularly weighed the dry residue from eleven bites made on a
watch-glass by two _Naja haje_, received at my laboratory from Egypt
at the same time, and placed in the same case. Both snakes were
approximately of equal length, 1,070 millimetres. Throughout the entire
course of the experiment, which lasted _one hundred and two days_,
neither of them took any food, but they drank water and frequently
bathed.

The results that I obtained are shown in the table on next page.

It will be seen that in one hundred and two days, an adult _Naja haje_
is capable of producing on an average 0·632 gramme of liquid venom,
equal to a mean weight of 0·188 gramme of dry extract; and we may
conclude that 1 gramme of _liquid_ gives 0·336 gramme of _dry_ venom.

In Australia it has been found by MacGarvie Smith, of Sydney, that
_Pseudechis porphyriacus_ yields at each bite a quantity of venom
varying from 0·100 gramme to 0·160 gramme (equal to 0·024 gramme to
0·046 gramme of dry venom), and that a _Hoplocephalus curtus_ (Tiger
Snake) yields 0·065 gramme to 0·150 gramme of liquid venom, with 0·017
gramme to 0·055 gramme of dry residue. In all the experiments of this
physiologist, the proportion of dry residue varied from 9 to 38 per
cent. of the liquid venom excreted by the reptile.

A _Lachesis lanceolatus_ (Fer-de-lance) from Martinique, of medium
size, when both of its glands were squeezed, furnished me with 0·320
gramme of liquid venom, and 0·127 gramme of dry extract.

+---------+----------+-------------------+-------------------+
| | | _NAJA HAJE_ I. | _NAJA HAJE_ II. |
|Number of| Date | WEIGHT OF VENOM | WEIGHT OF VENOM |
| bite | +---------+---------+---------+---------+
| | | Fresh | Dry | Fresh | Dry |
+---------+----------+---------+---------+---------+---------+
| | | Gramme | Gramme | Gramme | Gramme |
| 1 | April 20 | 0·119 | 0·031 | -- | -- |
| 2 | “ 23 | -- | -- | 0·151 | 0·043 |
| 3 | May 14 | 0·124 | 0·035 | -- | -- |
| 4 | “ 21 | -- | -- | 0·132 | 0·037 |
| 5 | “ 28 | -- | -- | 0·091 | 0·019 |
| 6 | June 2 | 0·127 | 0·039 | -- | -- |
| 7 | “ 19 | -- | -- | 0·121 | 0·043 |
| 8 | July 1 | -- | -- | 0·078 | 0·026 |
| 9 | “ 2 | 0·122 | 0·048 | -- | -- |
| 10 | “ 25 | -- | -- | 0·111 | 0·034 |
| 11 | “ 26 | 0·079 | 0·021 | -- | -- |
+---------+----------+---------+---------+---------+---------+
| | Totals | 0·581 | 0·174 | 0·684 | 0·202 |
+---------+----------+---------+---------+---------+---------+

Two large _Cerastes_ vipers, from Egypt, yielded me, one 0·123 gramme,
the other 0·085 gramme of liquid venom, which, after desiccation, left
respectively 0·027 gramme and 0·019 gramme of dry residue.

Under the same conditions, a magnificent _Crotalus confluentus_
(Mottled Rattle-Snake), for which I was indebted to the kindness of Mr.
Retlie, of New York, yielded, two months after reaching my laboratory,
0·370 gramme of liquid venom and 0·105 gramme of dry extract in _a
single bite_.

The total quantity of liquid venom that I found contained in the two
glands of the same reptile, when extirpated after death, and after the
snake had been in the laboratory for five months, amounted to 1·136
gramme, which gave 0·480 gramme of dry extract.

We see, therefore, that the proportion of dry residue, including
albumin, salts, the _débris_ of leucocytes, and the toxic substance,
oscillates between 20 and 38 per cent. Its strength varies with the
length of time that has elapsed since the snake’s last bite or last
meal.

* * * * *

From the _histological standpoint_, the process of the secretion of
venom, in the cells of the glands, may be divided into two stages:--

(_a_) A stage of nuclear elaboration.

(_b_) A stage of cytoplasmic elaboration.

These two stages are superposed and successive.

In addition to the passive exchanges between the nucleus and the
cytoplasm, the nuclear mass actively participates in the secretion.
This participation is rendered evident:--

(1) By the difference of chromaticity in the granules of chromatin.

(2) By the emission of formed granules into the cytoplasm, granules
which are spherical and of equal bulk, with the chromatic reactions of
differentiated intranuclear chromatin.

(3) By the exosmosis of the dissolved nuclear substance, accessorily
formed in an ergastoplasmic shape.

These formations constitute, on the one hand, the granules of
_venogen_; on the other, the ergastoplasmic venogen. In the poison-cell
of _Vipera aspis_, and in the serous cell of the parotid glands of
_Tropidonotus natrix_ (Grass Snake) the venogen is elaborated chiefly
in granular form.

On entering the perinuclear cytoplasm, the granule of venogen and the
ergastoplasmic venogen may either disappear immediately, as happens
in periods of cellular stimulation, or else continue to exist for
some time within the cell, indicating a period of saturation by the
elaborated material.

During cytoplasmic activity the granule of venogen and the
ergastoplasmic venogen disappear.

Nuclear elaboration and cytoplasmic elaboration constitute two
different cycles of secretion. The effect of the nuclear cycle is to
furnish the cytoplasm with the elements necessary for the work of
secretion properly so-called. Cytoplasmic elaboration is not confined
to the basal protoplasm, but takes place throughout the entire cell: it
is especially active in the perinuclear cytoplasm.

The granule of venogen is distinguished from the granule of elaborated
venom by its affinity for Unna’s blue, safranin, and fuchsin. The
granule of venom has an affinity for eosin; it is never excreted in
granular form, but after intracellular dissolution.

Venogen is never met with in the lumen of the gland-tube.[6]

COLLECTION OF VENOM.

Venom can be extracted from the poison-glands of either freshly killed
or living snakes.

In cases in which the venom of dead snakes has to be collected, the
best method of extraction consists in fixing the head of the animal to
a sheet of cork and carefully dissecting out the gland on each side.
The reptile being placed on its back, the lower jaw is removed with a
pair of scissors; two strong pins or two tacks are thrust through the
skull, in the median line, in order to keep the head from moving. The
poison-fangs are next drawn out of their sheaths, and, without injuring
them, the two poison-ducts, which open at their bases, are isolated and
tied with a thread in order to prevent the poison from running out.

The dissection of the glands is then very easy; they are lifted out
and placed in a saucer. The end of the duct is cut between the gland
and the ligature, and with a pair of fenestrated or polypus forceps the
whole of the glandular mass is gently squeezed from behind forwards,
the liquid which flows out being received in a large watch-glass.

If pressed for time, a more simple method of operating is to hold
the head of the snake in the left hand, with the mouth open and the
lower jaw directed downwards. A watch-glass, capsule, or receptacle of
some sort, such as a cup or plate, is then introduced by an assistant
between the jaws, and, with the index finger and thumb of the right
hand, the whole of the region occupied by the glands on each side of
the upper jaw is forcibly compressed from behind forwards; the poison
flows out by the fangs.

* * * * *

The extraction of the venom from living snakes is effected in the same
manner. The animal being firmly held by the neck, as close as possible
to the head, so that it cannot turn and bite; it can be made to eject
the greater portion of the liquid contained in its two glands by
compressing the latter with force from behind forwards, as one would
squeeze out the juice from a quarter of an orange (fig. 85).

It is necessary to take care that the reptile cannot coil itself round
furniture or other objects in the vicinity of the operator, for if
this should happen there would be the greatest difficulty in making it
let go, especially if dealing with a strong animal such as a Cobra,
Rattle-Snake, or Fer-de-lance.

Snakes of the last-mentioned kind are especially difficult to manage.
In order to avoid the risk of being bitten, it is always wise to
begin by pinning down the head of the animal in a corner of its cage
by means of a stick, and to seize it with a pair of long fenestrated
tongs shaped like forceps. The operator then easily draws the reptile
towards him and grasps it firmly by the neck with his left hand, always
as close to the head as possible, at the same time raising the body
quickly in order to prevent it from taking of anything. In this way
the most powerful snake is perfectly under control.

[Illustration: FIG. 85.--COLLECTING VENOM FROM A
_Lachesis_ AT THE SEROTHERAPEUTIC INSTITUTE AT SÃO PAULO
(BRAZIL).]

[Illustration: FIG. 86.--CHLOROFORMING A COBRA IN ORDER TO
COLLECT VENOM, AT THE FRENCH SETTLEMENT OF PONDICHERRY, IN INDIA
(STAGE I.).]

At Pondicherry, where is collected the greater portion of the venom of
_Naja tripudians_ used by me for the vaccination of the horses that
produce antivenomous serum, it is customary to chloroform the snakes in
order to render them easier to manipulate.

The reptile is placed in a large covered jar, containing a pad of
absorbent wool impregnated with chloroform (figs. 86, 87), and in a few
minutes it is stupefied. It is then grasped by the neck with the hands,
and the edge of a plate is slipped between its jaws. On compressing the
two poison-glands with the fingers, the venom dribbles out on to the
plate.

A detailed description of this technique will be found in a note kindly
drawn up for me by my friend Dr. Gouzien, late head of the Medical
Staff of the French Settlements in India, and reproduced further on in
the section of this book devoted to documents. The note in question was
accompanied by figs. 17, 18, 19, 86, 87, and 88, which are reproduced
from photographs, for which I am indebted to the kindness of M.
Geracki, Engineer of the Savanna Spinning Mill at Pondicherry, Dr.
Lhomme, and M. Serph, Assistant Surgeon-Dispenser.

The collection of the venom having been completed, the snake is put
back into its cage again, the tail and the body being introduced first,
and then the head. The lid or trap-door is half closed with the left
hand, and, with a quick forward thrust, the right hand releases its
grasp of the reptile and is immediately withdrawn; at the same time the
left hand completes the closure of the cage. The snake is temporarily
dazed, as though stunned, and it is only after the lapse of a moment
that it thinks of darting open-mouthed at the walls of its prison.

When it is desired to procure large quantities of venom, as is
indispensable in laboratories where antivenomous serum is prepared,
the endeavour must be made to keep the snakes alive for the longest
possible time. It then becomes necessary to resort artificial feeding
in the manner previously described (see p. 17), for they very often
refuse to feed themselves.

[Illustration: FIG. 87.--CHLOROFORMING A COBRA IN ORDER TO
COLLECT VENOM, AT THE FRENCH SETTLEMENT OF PONDICHERRY, IN INDIA
(STAGE II.).]

Except when a snake is _moulting_, the venom can be extracted from its
glands about every fortnight; and it is better that the extraction be
not performed concurrently with artificial feeding, since, owing to the
fact that the venom serves the animal as digestive juice, the reptile
will soon perish if deprived of the means of digesting the food that it
is obliged to receive. It is best, therefore, to select one day of the
week for artificial feeding, and the corresponding day of the following
week for the extraction of the venom.

When the venom has been collected, it must immediately be in a
desiccator over calcium chloride or sulphuric acid, in order to dry
it rapidly. In hot countries, and where no laboratory specially
equipped for the purpose exists, it will suffice to dry the venom in
a current of air, or even in the sun. It then concretes in scales of
a citrin colour, more or less dark, according to the concentration
of the liquid. In this dry condition, placed in well-corked bottles,
protected from damp air, it may be kept almost indefinitely without
losing anything of its original toxic power. On the contrary, if the
desiccation be imperfect it undergoes a somewhat rapid change, and
assumes a disagreeable odour of meat peptone. I have kept samples of
various venoms, dried as described, for _fifteen_ years without any
sensible diminution of their activity.

[Illustration: FIG. 88.--COLLECTING COBRA VENOM AT PONDICHERRY
(STAGE III.).]

CHAPTER V.

_THE CHEMICAL STUDY OF SNAKE-VENOMS._

In the condition in which they are received on issuing from the
glands, venoms always present the appearance of a thick saliva, of
an oily consistency and more or less tinged with yellow, according
to the species of snake by which the poison has been produced. They
are entirely soluble in water, the addition of which renders them
opalescent. Tested with litmus they exhibit a slightly acid reaction;
this acidity, which is due to the presence of a very small quantity
of an indeterminate volatile acid, disappears on desiccation, so that
solutions of dried venom are neutral. The taste of venoms is very
bitter. Their density, which is slightly greater than that of water,
varies from 1030 to 1050.

Venoms are composed of a mixture, in variable proportions, of proteid
substances, mucus and epithelial _débris_, fatty matters and salts
(chlorides and phosphates of lime, ammonia and magnesia), with from 65
to 80 per cent. of water.

The elementary analysis of Cobra-venom made by H. Armstrong[7] gave the
following results:--

Carbon 43·04 per cent.
Hydrogen 7·00 “
Nitrogen 12·45 “
Sulphur 2·50 “
Residue Small quantities.

Not much is to be learnt from these figures; it would be of far greater
importance to know the exact constitution of the proteid substances
to which venom owes its physiological properties. Unfortunately, our
knowledge of the chemistry of the albuminoid matters is still too
imperfect for it to be possible for us to determine their nature.

* * * * *

As early as 1843 it was pointed out by Lucien Bonaparte that in the
venom of _Vipera berus_ the most important principle is a proteid
substance to which he gave the name of _viperin_ or _echidnin_, and
which he compared to the digestive ferments. Later on Weir Mitchell
and Reichert, and subsequently Norris Wolfenden, Pedlar, Wall,
Kanthack, C. J. Martin, and MacGarvie Smith, showed that venoms, like
diastases, exhibit a great complexity in composition; that all their
characteristic toxic constituents are precipitable by absolute alcohol,
and that the precipitate, when redissolved in water, recovers the
properties possessed by the venom before precipitation.

According to Armand Gautier,[8] venoms contain alkaloids. The latter
may be obtained, in very small amounts, however, by finely pulverizing
dried venom with carbonate of soda, and systematically exhausting the
mixture with alcoholic ether at a temperature of 50° C. These alkaloids
have yielded crystallized chloraurates and chloroplatinates, and
slightly deliquescent crystallized chlorhydrates. The latter produce
Prussian blue when treated with very dilute ferric salts, and mixed
with a little red prussiate. They therefore represent reductive bodies
analogous to ptomaines.

Norris Wolfenden did not succeed in extracting these alkaloids from
Cobra-venom, whence they had nevertheless been isolated by Armand
Gautier. Wolcott Gibbs, and afterwards Weir Mitchell and Reichert,
likewise failed to find them in _Crotalus_-venom. The toxicity of these
bases is, moreover, but very slight, for the totality of the alkaloids
extracted by A. Gautier from 0·3 gramme of Cobra-venom did not kill a
small bird.

It is therefore to the _toxalbumins_ that the toxic properties of
venoms are essentially due.

All venoms are not equally affected by heat. The venoms of
COLUBRIDÆ (_Naja_, _Bungarus_, _Hoplocephalus_, _Pseudechis_)
and those of the HYDROPHIIDÆ are entirely uninjured by
temperatures approaching 100° C., and even boiling for a short time.
When the boiling is prolonged, or when venoms are heated beyond
100° C., their toxic power at first diminishes, and then disappears
altogether. At 120° C. it is always destroyed.

The venoms of VIPERIDÆ (_Lachesis_, _Crotalus_, _Vipera_) are
much less resistant. By heating to the coagulating point of albumin,
_i.e._, to about 70° C., their toxic properties become attenuated, and
they are entirely suppressed between 80° and 85° C. _Lachesis_-venoms
are the most sensitive; their toxicity is lost if they be heated beyond
65° C.

On separating the coagulable albumins of the venoms of
COLUBRIDÆ, by heating to 72° C., followed by filtration,
we obtain a perfectly limpid liquid, which is no longer injured by
boiling, and in which the toxic substance remains wholly in solution.
The albuminous precipitate, when separately collected and washed, is
no longer toxic. The clear liquid, after being filtered, is again
precipitated by absolute alcohol, and the precipitate, redissolved in
an equal quantity of water, is just as toxic as the original filtered
liquid.

The venoms of VIPERIDÆ, when coagulated, by heating them to
a temperature of 72° C., and filtered, are almost always inert. The
albuminous coagula, if washed, redissolved in water, and injected into
the most sensitive animals, produce no harmful effect whatever.

* * * * *

The results of dialysis likewise differ when we experiment with the
venoms of COLUBRIDÆ and VIPERIDÆ. The former pass
slowly through vegetable membranes, and with greater difficulty through
animal parchment. The latter do not dialyse.

Filtration through porcelain (Chamberland candle F) does not sensibly
modify the toxicity of the venoms of COLUBRIDÆ; on the
contrary, it diminishes that of the venom of VIPERIDÆ by
nearly one-half.

By using a special filter at a pressure of 50 atmospheres, C. J.
Martin has succeeded in separating from the venom of an Australian
_Pseudechis_ two substances: a non-diffusible _albuminoid_, coagulable
at 82° C., and a diffusible, non-coagulable _albumose_. The former
produces hæmorrhages; the second attacks the nerve-cell of the
respiratory centres.

* * * * *

All venoms exhibit most of the chemical reactions characteristic of the
proteids:--

_Millon’s reaction._

_Xantho-proteic reaction_ (heating with nitric acid and subsequent
addition of ammonia = orange coloration).

_Biuret reaction_ (caustic potash and traces of sulphate of copper).

_Precipitation by picric acid_, disappearing on being heated,
reappearing when cooled.

_Precipitation by_ saturation with _chloride of sodium_.

_Precipitation by_ saturation with _sulphate of magnesium_.

_Precipitation by_ saturation with _ammonium sulphate_.

_Precipitation by a 5 per cent. solution of sulphate of copper._

_Precipitation by alcohol._

According to C. J. Martin and MacGarvie Smith, the albumoses of the
venoms of COLUBRIDÆ are _hetero-albumoses_, _proto-albumoses_,
and perhaps _deutero-albumoses_ in small quantities. They can be
separated in the following manner:--

The solution of venom is heated to 90° C., and filtered in order to
separate the albumins coagulable by heat. The filtrate, saturated with
sulphate of magnesium, is shaken for twelve hours. By this means there
is obtained a flocculent precipitate, which is placed upon a filter and
washed with a saturated solution of sulphate of magnesium. The filtrate
is dialysed for twenty-four hours in a stream of distilled water, and
then concentrated, likewise by dialysis, in absolute alcohol. Thus
we obtain a few cubic centimetres of liquid, which contains a small
quantity of _proteids_ in solution. These _proteids_ can be nothing but
a mixture of _proto-_ and _deutero_-albumoses with peptones. That there
is actually no trace of the latter can easily be ascertained.

Neumeister[9] has shown that it is impossible to precipitate all the
_proto-albumoses_ of a solution by saturation with neutral salts, and,
since the filtrate becomes slightly turbid when a few drops of a 5 per
cent. solution of sulphate of copper are added to it, we must conclude
that it contains a small proportion of these _proto-albumoses_.

The deposit retained upon the filter after washing with sulphate of
magnesium is redissolved in distilled water, and dialysed for three
days. An abundant precipitate then becomes collected in the dialyser.
This is centrifuged. The clear liquid is decanted with a pipette, then
concentrated by dialysis in absolute alcohol, and finally evaporated
at 40° C. until completely desiccated. The solid residue is washed and
centrifuged several times in distilled water, after which it is dried
on chloride of sodium.

This method enables us to separate two albumoses, both precipitable
by saturation with sulphate of magnesium, and belonging to the class
of _primary albumoses_: one of these, _proto-albumose_, is soluble in
distilled water, the other, _hetero-albumose_, is insoluble; but the
latter can be dissolved in dilute solutions of neutral salts. These
bodies are respectively identical with those obtained by the pepsic
digestion of proteids.[10]

In order to study separately the local and general effects of these
different albumoses, C. J. Martin and MacGarvie Smith performed the
following experiment:--

They introduced beneath the skin of the belly of a guinea-pig,
previously shaved and rendered aseptic, two small pieces of sterilized
sponge, about 2 c.mm., one of which was impregnated with the solution
of proteid, while the other served as control. The two small incisions,
one on either side of the median line, were then sutured and covered
with collodion. In this way the maximum of local effect and the minimum
of general effects was obtained. The solutions of albumoses introduced
by this method into the organism produced an enormous œdema, which, in
from six to eight hours, extended along the whole side of the abdomen
containing the sponge charged with poison.

To test the general toxic effects, the solutions were injected into a
vein or into the peritoneal cavity. It was thus found that the _proto-_
and _hetero-albumoses_ killed the animals in a few hours.

It must therefore be concluded from these facts that the active
principles of venom are _proto-_ and _hetero-albumoses_, the albumins
that it contains being devoid of all toxic power.

* * * * *

Many chemical substances modify or destroy venoms, and we shall see in
another chapter that several of them, by reason of their properties,
may be very usefully employed for the destruction, in the actual wound
resulting from a venomous bite, of the venom that has not yet been
absorbed in the circulation.

Among these substances the most important are:--

A 1 per cent. solution of _permanganate of potash_ (Lacerda).

A 1 per cent. solution of _chloride of gold_ (Calmette).

_Chloride of lime_ or even _hypochloride of calcium_ (Calmette), in
a solution of 1 in 12, which is augmented, at the moment of use, by
5 to 6 volumes of distilled water, so as to bring it to the standard
strength of about 850 cubic centimetres of active _chlorine_ per litre
of solution.

A 1 per cent. solution of _chromic acid_ (Kaufmann).

Saturated _bromized water_ (Calmette).

A 1 per cent. solution of _trichloride of iodine_ (Calmette).

All these chemical bodies also modify or destroy the diastases and the
microbic toxins. The venoms, although more resistant to the influence
of heat, behave, therefore, like these latter, and exhibit the closest
affinity with them. Moreover, like all the normal glandular juices,
they possess very manifest zymotic properties, which singularly
complicate their physiological action, and upon which we shall dwell
later on.

* * * * *

_Electricity_, employed in the form of continuous electrolytic currents
passing through a solution of venom, destroys the toxicity of the
latter, because under these conditions there is always formed, at the
expense of the salts accompanying the venom, a sufficient quantity
of chlorinated products (hypochlorites, chlorates, &c.), and a small
amount of ozone, the oxidizing action of which is extremely powerful.

With alternating currents of high frequency, Phisalix, repeating the
experiments that Arsonval and Charrin had performed upon diphtheria
toxin, thought that he had succeeded in attenuating venom to the
point of transforming it into vaccine.[11] But it has been shown by
Marmier that this attenuation was simply the result of thermic actions.
When, by means of a suitable arrangement, any rise of temperature was
carefully avoided, no modification of toxicity was obtained.[12]

* * * * *

The influence of _light_, which has no effect upon venom preserved in
a dry state, is, on the contrary, very marked upon venom in solution.
Solutions of venom that are destined for physiological experiments
should therefore not be employed without controls, if they be several
days old. Apart from the fact that, if care be not taken to render
them aseptic, they very soon become contaminated with the germs of all
kinds of microbes, it is found that they gradually lose a large part of
their activity, especially when they remain in contact with the air.
By filtering them through a Chamberland candle and keeping them in the
dark, in a refrigerator, in perfectly closed phials, they may be kept
unimpaired for several months.

The addition of _glycerine_ in equal parts to a concentrated solution
of venom is also an excellent means of preservation.

* * * * *

Phisalix has shown that the emanations from _radium_ attenuate and then
destroy the virulence of Cobra- and also of Viper-venom.

“Dry Viper-venom, dissolved in _aqua chloroformi_ in the proportion of
1 in 1,000, is put up in four tubes, three of which are irradiated, the
first for six hours, the second for twenty hours, and the third for
thirty-six hours. Three guinea-pigs, of equal weight, are inoculated
with equal quantities of the irradiated venom; a control receives
the non-irradiated venom. The latter dies in ten hours; the animal
inoculated from the first tube dies in twelve hours; the one inoculated
from the second tube in twenty hours, and the third proves resistant
without any symptom of poisoning. A second inoculation produces a
transitory lowering of the animal’s temperature by half a degree. At
the end of four days it dies after inoculation with a lethal dose.”

The nature of the solvent exerts a great influence upon the action of
the emanations from radium: if the same experiment be performed with
venom dissolved in a 50 per cent. mixture of glycerine and water, the
attenuation is merely relative after six hours.

* * * * *

Auguste Lumière and Joseph Nicolas, of Lyons, conceived the idea of
studying the effect upon venom of the prolonged action of the intense
_cold_ produced by the evaporation of liquid air.[13] The Cobra-venom
employed by these investigators was in solution at a strength of 1
in 1,000. It was submitted to the action of liquid air, partly for
twenty-four hours and partly for nine days at -191° C. Its toxicity was
in no way diminished.

* * * * *

Lastly, I must mention the recent researches of Hideyo Noguchi,[14]
with reference to the photodynamic action of _eosin_ and _erythrosin_
upon the venoms of the Cobra, _Vipera russellii_, and _Crotalus_. It
was found by the scientist in question that the toxicity of these
various venoms is more or less diminished in the presence of these
aniline colours, when the mixtures are insolated. Cobra-venom is the
most resistant, just as it is in regard to the other physical or
chemical agents. That of _Crotalus_, on the contrary, is the least
stable.

CHAPTER VI.

_THE PHYSIOLOGICAL ACTION OF SNAKE-VENOMS._

A.--PHYSIOLOGY OF POISONING IN MAN AND IN ANIMALS BITTEN BY
THE DIFFERENT SPECIES OF POISONOUS SNAKES.

(_Colubridæ; Viperidæ; Hydrophiidæ._)

The bites of poisonous snakes produce very different effects according
to the species of snake, the species to which the animal bitten
belongs, and according to the situation of the bite. It is therefore
necessary to take these various factors into account, in describing the
symptoms of poisoning in different animals.

When the quantity of venom introduced into the tissues by the bite of
the reptile is sufficient to produce fatal results--which is happily
not always the case--the venom manifests its toxic action in two series
of phenomena: the first of these is local and affects only the seat and
surroundings of the bite; the second, or general series, is seen in the
effects produced upon the circulation and nervous system.

It is remarkable to find how great is the importance of the local
disorders when the venomous reptile belongs to the _Solenoglypha_
group (VIPERIDÆ), while it is almost _nil_ in the case of the
_Proteroglypha_ (COLUBRIDÆ and HYDROPHIIDÆ).

The effects of general intoxication, on the contrary, are much more
intense and more rapid with the venom of _Proteroglypha_, than with
that of _Solenoglypha_.

In considering the usual phenomena of snake-poisoning in man, we must
therefore take this essential difference into account, and draw up
separately a clinical description of the symptoms observed after a
bite from a _Cobra_ (COLUBRIDÆ), for instance, and another
list of those that accompany a bite from _Lachesis_ or _Vipera berus_
(VIPERIDÆ).

The bite of a _Cobra_, even of large size, is not very painful; it is
characterized especially by numbness, that supervenes in the bitten
part, rapidly extends throughout the body, and produces attacks
of syncope and fainting. The patient soon experiences a kind of
lassitude and irresistible desire to sleep; his legs scarcely support
him; he breathes with difficulty and his respiration becomes of the
diaphragmatic type.

By degrees the drowsiness and the difficulty of breathing become
greater; the pulse, which at first is more rapid, becomes slower and
gradually weaker, the mouth contracts, and there is profuse salivation,
the tongue appears swollen, the eyelids remain drooping, and, after
a few hiccoughs frequently accompanied by vomiting and involuntary
emissions of urine or fæcal matter, the unfortunate victim falls
into the most profound coma and dies. The pupils react to luminous
impressions up to the last moment, and the heart continues to beat
sometimes for two hours after respiration has ceased.

All this takes but a few hours, most frequently from two to six or
seven, rarely more.

When the reptile by which the bite is inflicted is one of the
_Solenoglypha_, such as a _Lachesis_ for example, the seat of the bite
immediately becomes very painful and red, then purple. The surrounding
tissues are soon infiltrated with sanguinolent serosity. Sharp pains,
accompanied by attacks of cramp, extend towards the base of the limb.
The patient complains of intense thirst, and extreme dryness of
the mouth and throat; the mucous membranes of the eyes, mouth, and
genitalia become congested.

These phenomena often continue for a very long period, even for more
than twenty-four hours, and are sometimes accompanied by hæmorrhages
from the eyes, mouth, stomach, intestines, or bladder, and by more or
less violent delirium.

If the quantity of venom absorbed be sufficient to cause death,
the patient exhibits, a few hours after being bitten, stupor,
insensibility, and then somnolence, with increasing difficulty of
respiration, which ends by becoming stertorous. Loss of consciousness
seems complete a good while before coma appears. Asphyxia then ensues,
and the heart continues to beat for nearly a quarter of an hour after
respiratory movements have entirely ceased.

In certain exceptional cases death is very rapid; it may supervene
suddenly in a few minutes, even before the local phenomena have had
time to manifest themselves; in this case the venom, having penetrated
directly into a vein, has produced almost immediate coagulation of the
blood, thus causing the formation of a generalized embolism.

If the venom be introduced in a highly vascular region, or directly
into a vein, the result is almost invariably fatal. On the contrary,
if the derm be scarcely broken, or if the clothing has acted as a
protection, scarcely any absorption will take place. We are here
confronted with the same factors of gravity as in the case of bites
inflicted upon human beings by animals suffering from _rabies_.

In experiments we are able to eliminate all these factors, and to
follow in an animal inoculated with a known quantity of venom the
whole series of phenomena of poisoning, the intensity of which can
be graduated. Let us see, then, how the various animals that it is
possible to make use of in laboratories behave with regard to venoms of
different origins.

B.--THE PHYSIOLOGY OF EXPERIMENTAL POISONING.

In the monkey, the first apparent sign of the absorption
of _Cobra_-venom, or of the venom of any other species of
COLUBRIDÆ, is a sort of general lassitude; the eyelids next
become half closed. The animal appears to be seeking a suitable spot
in which to rest; it gets up again immediately, and walks with a
jerky action; its limbs have a difficulty in supporting it. It is
soon attacked by nausea, vomiting and dyspnœa; it rests its head upon
the ground, raises it, trying to get breath, and carries its hand to
its mouth as if in order to pluck a foreign body from its throat. It
totters upon its limbs, and lies down upon its side with its face
against the ground. Ptosis increases, and complete asphyxia soon
supervenes. The heart continues to beat for some time after respiration
has ceased, and then stops in diastole.

Cadaveric rigidity very rapidly sets in, and persists for a long time,
even after putrefaction has commenced. During the last moments of
life the pupil remains very sensitive; the animal appears to retain
unimpaired its sense of hearing and sensibility to pain. The electric
excitability of the muscles of the face persists, but that of those
of the limbs and body almost entirely disappears. The application of
volta-faradic currents from the nape to the diaphragm produces no
respiratory movement when asphyxia begins to manifest itself. The
sphincters of the bladder and anus relax after a few spasms, which, in
case of males, frequently provoke the ejaculation of semen; the urine
and fæces immediately escape.

The autopsy reveals slight hæmorrhagic œdema at the point of
inoculation, and hyperæmia of all the viscera, especially of the liver
and spleen, with, very frequently, small hæmorrhagic patches on the
surface of these organs, and on that of the intestine and kidneys. The
serous membranes, especially the meninges, endocardium, pleuræ, and
peritoneum, exhibit ecchymoses; the lungs are besprinkled with small
infarcts, the more numerous the slower the intoxication. The blood
remains fluid and laccate.

* * * * *

In poisoning by the venoms of VIPERIDÆ, the hæmorrhagic
phenomena appear at the outset, and are more intense. Death is always
preceded by a period of asphyxia, indicating that the bulbar nuclei
of the pneumogastric nerve have become affected. At the autopsy,
however, the blood, instead of remaining fluid, is always found to
be coagulated into a mass in all the vessels; it afterwards gradually
becomes redissolved in six or eight hours, and then appears laccate, as
after poisoning by _Cobra_-venom, but darker.

* * * * *

All mammals exhibit the same symptoms after inoculation with lethal
doses of venom. The same applies to birds; but in the latter the
period of asphyxia is much longer, probably on account of the reserves
of air accumulated in their air-sacs and pneumatic bones. They gape
like pigeons that are being suffocated, rest the tip of the beak on
the floor of the cage, and frequently have convulsive spasms of the
pharynx, accompanied by flapping of the wings. Small birds and even
pigeons are extremely sensitive to venom; fowls are more resistant.

Frogs, thanks to their cutaneous respiration, succumb very slowly. I
have seen some survive for thirty hours after being inoculated with a
quantity of venom which, when subcutaneously injected into a rabbit,
causes death in ten minutes.

* * * * *

Lizards and chameleons succumb very rapidly. Grass Snakes and
non-venomous snakes in general withstand doses of venom that in
proportion to their weight are fairly large; nevertheless, as indeed we
shall see in the sequel, they do not possess any real immunity. It is
only poisonous snakes that are unaffected by enormous doses of their
own venom, as has already been shown by Fontana, Weir Mitchell, and
Viaud Grand Marais. They are, however, quite capable of being poisoned
by snakes belonging to altogether different species; strong doses of
_Crotalus_- or _Lachesis_-venom are fatal to Cobras or Kraits, and,
when several poisonous snakes are shut up together in the same cage,
they are not infrequently seen to kill each other as the result of
repeated bites.

Fishes, which are particularly sensitive to the venom of
HYDROPHIIDÆ, readily succumb to inoculation with other venoms,
such as that of the Cobra. At Saigon, in 1891, I made experiments upon
the action of this latter venom on two specimens of the fighting
fishes, that the natives of Annam rear in aquariums in order to witness
their combats and make bets on them. The fishes died five hours after
intramuscular inoculation with a dose which kills a pigeon in twenty
minutes.

Many invertebrates, such as leeches, crayfish, and gastropod molluscs
(snails), are killed by inoculation with very small quantities of venom.

C.--DETERMINATION OF THE LETHAL DOSES OF VENOM FOR DIFFERENT
SPECIES OF ANIMALS.

It is very difficult to specify, even within broad limits, the dose
of venom necessary to kill a human being. The quantity of poison
introduced by the bite of a venomous snake depends, as has already
been stated, upon a large number of factors, and, very fortunately,
this quantity is not always sufficient to cause death. Thus in India,
that is to say in the region in which snakes are most numerous and
most dangerous, the mean mortality seems scarcely to exceed 35 to 40
per cent., so far as it is possible to judge from official statistics.
But, by experimenting upon animals, and commencing with known doses of
venom, which has first been dried and then dissolved again in always
the same quantity of physiological saline solution or sterile distilled
water, we can determine exactly, _for each kind of venom, and for each
species of animal_, the minimum lethal dose _per kilogramme of animal_.

The entire series of data collected by investigators who have devoted
themselves to this study may be summed up as follows:--

Minimal doses lethal in twenty-four hours for a _guinea-pig_ weighing
from 600 to 700 grammes:--

_Colubridæ._

Venom of _Naja tripudians_ 0·0002 gramme
“ _Bungarus cæruleus_ 0·0006 “
“ _Naja haje_ 0·003 “

_VIPERIDÆ._

Venom of _Vipera berus_ 0·04 gramme
“ _Vipera russellii_ (_Daboia_) 0·001 “
“ _Lachesis lanceolatus_ 0·02 “
“ _Lachesis mutus_ (_Surucucu_) 0·02 “
“ _Lachesis neuwiedii_ (_Urutù_) 0·02 “
“ _Lachesis flavoviridis_ 0·007 “
“ _Ancistrodon contortrix_ 0·015 “

_Cobra_-venom. Dose lethal in twenty-four hours for different animals:--

Dog 0·0008 gramme per kilogramme
Rabbit 0·0005 “ “
Guinea-pig 0·0004 “ “
Rat 0·0001 “ 150 grammes
Mouse 0·000003 “ 25 “
Frog 0·0003 “ 30 “

Venom of _Bungarus cæruleus_ (Common Krait), according to Elliot,
Sillar, and Carmichael.[15] Minimal lethal doses for:--

Frog 0·0005 gramme
Rat 0·001 “
Rabbit (by subcutaneous injection) 0·00008 “ per kilogramme
Rabbit (by intravenous injection,
according to G. Lamb) 0·00004 “ “

Venom of _Enhydrina valakadien_ (according to Elliot and Fraser).[16]
Minimal lethal doses per kilogramme:--

Rat 0·00009 gramme
Rabbit 0·00006 “
Cat 0·0002 “

Venom of _Enhydris curtus_:--

Rat 0·0005 to 0·0006 gramme per kilogramme

Venom of _Notechis scutatus_ (syn. _Hoplocephalus curtus_; the Tiger
Snake of Australia):--

Rabbit (by intravenous injection,
according to Tidswell) 0·00006 gramme per kilogramme

Venom of _Vipera russellii_ (Daboia):--

Rabbit (by intravenous injection,
according to G. Lamb) 0·00005 gramme per kilogramme

Venom of _Lachesis gramineus_ (Green Pit-Viper, India):--

Rabbit (by intravenous injection,
according to G. Lamb) 0·002 gramme per kilogramme

Venom of _Crotalus adamanteus_ (Californian Rattle-Snake):--

Rabbit (by intravenous injection,
according to McFarland, G. Lamb,
and Flexner and Noguchi) 0·00025 gramme per kilogramme

It will have been seen from the foregoing figures, that the respective
sensitiveness of the dog, cat, rabbit, guinea-pig, rat, mouse, and
frog, with regard to the same venom, is in no way proportional to the
weight of these animals.

The species mentioned are, per unit of weight, more or less resistant
to intoxication; and, on experimenting with other animals, as for
instance the monkey, pig, ass, and horse, we find that the monkey is
much more susceptible to intoxication than the dog, and that the ass
is extremely sensitive (0·010 gramme of Cobra-venom is sufficient to
kill it), while the horse is less so, and the pig is by far the most
resistant.

The same weight of dry Cobra-venom, let us say 1 gramme to be precise,
will enable us to kill 1,250 kilogrammes of dog, 2,000 kilogrammes of
rabbit, 2,500 kilogrammes of guinea-pig, 1,430 kilogrammes of rat, or
8,333 kilogrammes of mouse.

The lethal dose for a horse being, as I have ascertained by my own
experiments, about 0·025 gramme, 1 gramme of dry Cobra-venom will
therefore suffice to kill 20,000 kilogrammes of horse.

Assuming that man, in proportion to his weight, possesses a resistance
intermediate between that of the dog and that of the horse, we may
consider that the lethal dose for a human being is about 0·015 gramme.
It follows, therefore, that 1 gramme of venom would kill 10,000
kilogrammes of man, or, let us say, 165 persons of an average weight of
60 kilogrammes.

Another extremely important fact, which must not be lost sight of,
is that differences of toxicity, which are often considerable, are
exhibited by the venoms of different specimens of the same species of
snake, or by the venom of the same snake collected at different times.
I have found, for instance, in the case of the specimens of _Naja_ and
_Lachesis_ reared in my laboratory, that, according to the length of
time that the animals had been without food, and to the nearness or
otherwise of the moulting period, the venom was more or less active,
and that on evaporation it left behind a more or less considerable
quantity of dry extract. In certain cases, immediately after the moult
and after a prolonged fast, the venom was _ten times_ more active than
after a plentiful meal or before the moult.

The figures given above must therefore not be regarded as determining
the minimal lethal doses of the different venoms, except in a purely
comparative way, and they must be considered only as data useful
to know when it is desired to experiment upon animals with these
substances.

Variations of this kind are observed in the case of all species of
snakes. Thus Phisalix rightly insists upon the necessity of always
noting, besides the species of snake, the place of origin and the
season; for he has himself seen that, as regards French vipers,
those of the Jura, for example, produce in the spring a venom almost
devoid of local phlogogenic action; while vipers from the vicinity of
Clermont-Ferrand, though less toxic, produce much more serious local
effects.

On the other hand, it has been shown by Th. Madsen and H. Noguchi,
in a very interesting study of venoms and anti-venoms,[17] that,
when we examine the relation between dose and toxicity, we find
that the interval separating the moment of inoculation from that of
death diminishes only up to a certain point in proportion as the
dose is increased. In the case of the guinea-pig, with 0·0005 gramme
of Cobra-venom the interval is 3 hours 75 seconds; but after this,
an increase in the dose produces only a relatively inconsiderable
acceleration of death. There is therefore no strict ratio between the
dose inoculated and the time that elapses until death supervenes.

D.--EFFECTS OF VENOM IN NON-LETHAL DOSES.

When the quantity of venom introduced into the organism is insufficient
to cause death, the phenomena that precede and accompany recovery
differ very greatly according as the snake from which the venom was
derived belongs to the COLUBRIDÆ or VIPERIDÆ.

After a non-lethal bite from a Cobra or Krait, for example,
convalescence usually takes place very rapidly, and, apart from the
local œdema of the subcutaneous tissue surrounding the wound, which
in very many cases leads to the formation of a suppurating abscess,
no lasting injury to health is observed. The venom is eliminated by
the kidneys, without even causing albuminuria, and sensation gradually
returns, in twenty-four or forty-eight hours, in the part affected by
the original lesion.

If the bite has been inflicted by a Viperine snake, the local lesion,
which is much more extensive, almost always results in the formation
of a patch of gangrene. Hæmorrhages from the mucous membranes, and
sanguineous suffusions into the serous cavities, such as the pleura
or pericardium, may supervene more or less slowly. Pulmonary infarcts
are sometimes produced, as well as desquamation and hæmorrhage from
the kidneys, albuminuria, or hæmaturia. These lesions, which are more
or less severe, last for several days, and then slowly disappear after
a period of true convalescence. In many cases they leave behind them
traces which last for months and even years, and they then more or less
affect the health of the subjects according to the organs that were
most seriously affected.

In certain cases, in domestic animals such as dogs, and more rarely in
man, after recovery from the bite of a viper, total or partial loss of
sight, smell, or hearing, has been observed. Such results, however, are
fortunately exceptional.

CHAPTER VII.

_PHYSIOLOGY OF POISONING_ (_continued_).

EFFECTS OF THE VARIOUS VENOMS ON THE DIFFERENT TISSUES OF THE
ORGANISM.

The physiological effects of the various venoms are very different from
those that we have just described, when these toxic substances are
introduced into the organism otherwise than subcutaneously.

Their direct penetration into the blood-stream, whether by the bite
of the snake itself or by experimental intravenous injection, always
produces immediate results. With the venoms of VIPERIDÆ,
coagulation of the blood and, consequently, death are almost
instantaneous. With the venoms of COLUBRIDÆ, which, on the
contrary, destroy the coagulability of the blood, the toxic effects are
less rapid, but after the lapse of only a few minutes asphyxia ensues
and the death-struggle is very short.

Absorption by the serous membranes is slower, but is nevertheless
effected much more quickly than when it takes place in the subcutaneous
cellular tissue. When cobra-venom is injected into the peritoneal
cavity of a rabbit or a guinea-pig, the local effects upon the serous
membrane are almost _nil_. No leucocytic exudation is observed; death
supervenes before this has had time to take place. The venoms of
VIPERIDÆ, on the contrary, produce, directly after their
introduction into the peritoneum, an enormous afflux of sanguinolent
serosity; the capillary vessels of the serous membrane, immediately
becoming distended, allow the blood to filter through their walls, and
the animal succumbs after a few minutes, or a few hours, according to
the dose injected, with the peritoneum full of blood.

When deposited upon the mucous membranes of the eye, vagina, or
urethra, all venoms, those of COLUBRIDÆ like those of
VIPERIDÆ--but the latter with greater intensity--cause very
acute inflammation, comparable to that produced by jequirity; the
capillaries become distended, allow leucocytes to exude _en masse_,
and, as for instance upon the eye of the rabbit, a purulent ophthalmia
soon establishes itself.

Certain species of _Sepedon_ (COLUBRIDÆ), common on the
West Coast of Africa, especially in Senegambia and in the hinterland
of Dahomey, and to which the name _Spitting Snakes_ has been given,
possess the faculty of projecting little drops of venom to a distance
by forcibly expelling the air from their lungs, and the natives assert
that this venom, when it happens to come into contact with the eyes,
causes blindness. This is true to a certain extent, in so far as it
produces attacks of purulent ophthalmia which are often serious; but
these attacks, like those provoked experimentally in animals, can be
cured in a few days when properly treated.

When absorbed by the _digestive_ tract, the venoms of
COLUBRIDÆ often produce no ill-effects. It is otherwise with
those of VIPERIDÆ. The venom of _Lachesis_, for example, if
administered in sufficient doses, sets up acute inflammation of the
gastric mucous membrane, and the animals speedily succumb with attacks
of gastro-intestinal hæmorrhage, even before it has been possible for
the toxic effects upon the nerve-cells to become apparent.

These facts explain the contradictions that are to be found in the
works of different investigators upon this subject. It is affirmed
by some writers that venom can be swallowed without danger, and they
even advise the sucking of venomous wounds in order to hinder its
absorption. Others, including Sir Joseph Fayrer, Richards, and Weir
Mitchell, have killed pigeons and fowls by making them ingest venom
of _Vipera russellii_, or _Crotalus_. C. J. Martin, in experimenting
upon rats with the venom of _Pseudechis_ (COLUBRIDÆ), has
succeeded in keeping these animals alive for a whole week by providing
them every day with a ration of bread and milk mixed with a dose of
venom one hundred times greater than the lethal dose for a subcutaneous
injection. This innocuousness of the venoms of COLUBRIDÆ,
which I have frequently been able to establish by causing them to
be ingested by different animals, is explained by the fact that the
pancreatic juice and the ptyalin of the saliva very rapidly modify the
proteic substances to which these venoms owe their toxicity, so that
this disappears. No trace of them is found in the fæces.

The glandular secretions of persons bitten by venomous snakes, and
those of animals inoculated with doses of venom calculated to kill only
after a few hours, are not infrequently found to be toxic. In the case
of the urine in particular this has been shown to be so.

Observations have also been recorded by C. Francis[18] and Sir Joseph
Fayrer with reference to the passage of venom through the mammary
gland. In the year 1893 a poor Mussulman woman died at Madras from the
bite of a Cobra. She was nursing her child at the time, and the latter
succumbed in its turn a few hours later, with all the symptoms of
poisoning, although it had not itself been bitten, and had been suckled
by its mother only once since the bite.

The _histological lesions_ produced by snake poisoning have been
particularly well studied by Hindale,[19] Karlinski,[20] Nowak,[21]
Louis Vaillant-Hovius,[22] and Zeliony.[23]

(1) ACTION UPON THE LIVER.

Whether we are dealing with the venoms of VIPERIDÆ or
COLUBRIDÆ, the anatomo-pathological processes are alike, and
the changes produced are more or less profound, according to the degree
or the slowness of the intoxication.

The liver is more affected than any other organ. In cases in which
death has quickly followed the injection of the venom, the protoplasm
of the cells is merely cloudy, or granular, and the granulations
readily take a stain in their periphery, though the interior remains
uncoloured. If, on the contrary, the animal has survived for some
hours, the protoplasm becomes condensed in certain parts of the cell,
leaving vacuoles, the limits of which are not well defined. A portion
of the cellular protoplasm is necrosed and destroyed. In these cases
the nuclei have already undergone a change; although their contours
may be well defined, we discover in their interior only a very little
chromatin in the form of small granulations, and the nuclear fluid
takes a feeble stain with basic colours, since it contains a little
chromatin in solution.

When the protoplasm of the hepatic cells has suffered more pronounced
lesions, the changes in the nuclei are also more marked; the quantity
of nuclear chromatin diminishes and slowly loses its property of taking
stains, in proportion as the protoplasm of the hepatic cells undergoes
necrosis; finally, in the hepatic cell, there remains nothing more than
a small quantity of granular protoplasm without a nucleus (Nowak).

In certain cases we find extensive areas of fatty degeneration, or
small foci in which the hepatic tissue is absolutely destroyed. In the
case of the dog it may even happen that the microscopic structure of
the parenchyma has entirely disappeared. The arrangement of the hepatic
cells in lobules can no longer be distinguished; the trabeculæ are
ruptured and broken asunder, and we find nothing more than a confused
agglomeration of cells floating in the extravasated blood.

In animals which have lived for a long time after being poisoned,
lesions of the bile-ducts are also found. The epithelial cells have
undergone fatty degeneration, or else, in the case of small animals,
the ducts appear infiltrated with small mononuclear cells, which
penetrate between the epithelial cells of the canaliculi. Sometimes
also the latter cells are distended, and enclose large vacuoles.

Venom thus produces in the liver lesions of _fatty degeneration_, or
_necrosis_, and an infiltration of the bile-ducts by lymphatic cells.

(2) ACTION UPON THE KIDNEY.

The changes in the kidney are also very extensive. The three portions
of the glomerulus often exhibit lesions; the vessels of the tuft
show ectasia; their walls are sometimes ruptured, and the blood is
extravasated into the capsular cavity. The latter is filled with a
granular exudation, which varies in amount with the slowness of the
intoxication. The epithelial lining of _Bowman’s capsule_ is swollen;
the nucleus stains badly (Vaillant-Hovius).

In the _tubuli contorti_ the lesions in the cells greatly resemble
those seen in the liver. Granulations and vacuoles appear, and the
nucleus becomes diffuse. The lumens of the tubules are filled with
necrosed cells, and the _branches of Henle_ are found to be similarly
obliterated.

In the _straight tubes_ and in the _collecting tubes_ the epithelium
is sometimes detached in its entirety. Some of these canals are
obliterated by granular cylinders or by accumulations of epithelial
cells.

The vessels met with in the parenchyma of the kidney are always greatly
distended, and sometimes they are torn, whence there results the
formation of small foci of interstitial hæmorrhage. In many cases the
extravasated blood also destroys the parenchyma.

(3) ACTION UPON THE SPLEEN, HEART, AND LUNGS.

In the spleen, Nowak merely found a little fatty degeneration, and only
in cases in which the lesions in the liver and kidneys were very far
advanced. The same applies to the muscular fibres of the heart. This
organ exhibits, above all, hæmorrhagic infiltrations in its peripheral
portion, rarely in its substance.

The lungs are the seat of more important lesions. We find in them a
multitude of little infarcts. Around these the capillary vessels are
extremely dilated, and the pulmonary vesicles have become very small.

All these lesions of the visceral organs strangely resemble those
observed in the case of individuals who have died from _yellow fever_.
This observation has been made by several scientists, among others
by Sanarelli, and it is this perhaps that has suggested to some
(Dyer, of St. Louis, R. Bettencourt, of São-Paulo[24]) the idea of
treating--without much success, however--yellow fever by the antitoxin
of venom.

(4) ACTION UPON THE STRIATED MUSCLES.

The changes in the _striated muscles_ in places at which venom has been
injected do not present any specific character. The muscular fibres
already become necrosed half an hour after the injection; the diseased
tissue becomes permeated with an albuminous mass rich in fibrin, and
the blood is extravasated. A few hours later we observe, between the
bundles of degenerate muscle fibres, polymorphous leucocytes. The
number of these latter constantly increases, and attains its maximum
after one or two days. The muscular nuclei become distorted, appear
long or angular, and assume the aspect of myoblasts (sarcoblastic
muscle cells). In the protoplasm of the myoblasts we frequently find
particles of broken-down muscle, and globules of fat.

All these changes resemble those observed as the result of the action
of a host of other muscle poisons, especially the irritant or caustic
chemical substances.

(5) ACTION UPON THE NERVOUS CENTRES.

It is extremely difficult to determine with any degree of precision
the nature of the lesions produced by venoms in the _nervous system_.
The intensity of these lesions depends in the first place upon the
length of time that has elapsed between the introduction of the venom
into the organism and death. It depends, secondarily, in a large
measure, upon the origin of the venom. That of the VIPERIDÆ
acts almost exclusively upon the blood by coagulation, and exhibits
only a very slight degree of toxicity as regards the nerve-cell.
That of the COLUBRIDÆ, on the contrary, produces manifest
changes in the chromatic substance. Nissl’s bodies are completely
disintegrated, and transformed into a granular mass. In the majority of
the stichochromes neither the form of the bodies nor even the reticulum
is distinguishable. The nuclei are opaque, the nucleoli swollen and
broken up. The dendrites often become irregular and contracted (Ewing
and Bailey,[25] G. Lamb[26]).

It was found by Bailey that the majority of the cells of the anterior
cornua of the medulla are normal, but that a small number of them
exhibit indications of acute granular degeneration; a few cells were
found to have lost almost all their chromatic substance.

From the physiological point of view it is perfectly clear that
Cobra-venom especially affects the bulbar centres, and particularly
the nuclei of origin of the pneumogastric nerve. We observe in the
first instance the gradual suppression of the functions vested in the
nerve-cells that are found in connection with the vagus nerve, the
spinal accessory, and the hypoglossal. Later on the excitability of the
nerve-endings in the muscles is found to have been destroyed, and this
action presents great similarity to that of curare.

The venoms of VIPERIDÆ, when injected in very weak doses,
exercise a paralysing action upon the reflex excitability of the
medulla. But it is open to question whether these effects are
not exclusively due to the lesions of the blood, which are here
all-predominant; for no histological modification is observed in the
cells of the central nervous system.

I have made a number of experiments with a view to discovering whether
the cerebral, bulbar, or medullary substance of animals susceptible
to the action of Cobra-venom (rabbit, guinea-pig, fowl) possesses
the property of _fixing_ this venom as it fixes the toxin of tetanus
(Wassermann and Takaki). I found that, on pounding up a little of the
pulp of the cerebral hemispheres or bulb with doses of venom lethal in
two hours for the control animals, the injection of the mixture, well
washed and centrifuged in order to free it from all excess of non-fixed
venom, always caused death, but with a retardation of from four to ten
_hours_. We see, therefore, that partial fixation of the venom upon
the nervous elements really takes place, but we cannot conclude from
this that these elements exercise an antitoxic function, any more than
in the case of tetanus, for animals that receive cerebral emulsions in
one thigh and the dose of venom lethal in two hours in the other thigh,
succumb at the same time as the controls.

Major Rogers has made similar experiments with the venom of _Enhydrina_
(HYDROPHIIDÆ), and has obtained the same result on employing
the cerebral hemispheres of the pigeon.[27]

Flexner and Noguchi,[28] on their part, have compared, by aid of
the method of intra-cerebral injections, the toxicity of the venom
of _Crotalus_ with that of the venom of the _Cobra_. On employing
Cobra-venom heated to 75° C., they found that the convulsive and
paralytic effects were immediate, contrary to what takes place after
subcutaneous or intraperitoneal injections, but that the dose of venom
necessary to produce death was the same (0·1 milligramme for the
guinea-pig) as when the injection is made in the peritoneum or beneath
the skin.

With the venom of _Crotalus_ heated for half an hour at 75° C., which
contains but very little _neurotoxin_ and has lost all its hæmorrhagic
properties, 0·5 milligramme introduced directly into the brain of the
guinea-pig only produces transitory and non-lethal effects; while, if
fresh venom be employed, 0·05 milligramme is sufficient to cause death
in three hours, with severe hæmorrhagic lesions. Now this dose is
twenty times smaller than the minimal lethal dose for a subcutaneous
injection.

It is evident that the harmful matter, in the particular case of
_Crotalus_-venom, is not the _neurotoxin_, but an altogether different
substance, termed by Flexner and Noguchi _hæmorrhagin_, which acts upon
the elements of the blood and upon the endothelium of the blood-vessels.

We shall meet with this substance again in almost all VIPERINE
venoms, and shall study it further on.

CHAPTER VIII.

_PHYSIOLOGY OF POISONING_ (_continued_).

ACTION OF VENOMS ON THE BLOOD.

On making an autopsy of an animal which has succumbed to intoxication
by snake-venom, we find that the blood in the heart and large vessels
is sometimes coagulated into a mass, sometimes entirely fluid, and
that, in certain cases, it is as black as prune-juice, while in others
it is of a fine transparent red colour.

These differences in the effects of venom upon the blood are due to the
fact that the various venoms contain in variable proportions, besides
the _neurotoxic_ substance which represents the true venomous _toxin_,
other substances which act, some upon the plasmasia or fibrin-ferment,
or upon the fibrin, others upon the red corpuscles, others on the
leucocytes, and others again on the endothelium of the blood-vessels.

A.--EFFECTS OF VENOM ON THE COAGULATION OF THE BLOOD.

It was observed long ago by Fontana[29] that after viper-bites the
blood remains fluid, and Brainard[30] on the contrary, pointed out
that, in the case of animals that succumb very rapidly after having
been bitten by a _Crotalus_, the blood was always found coagulated into
a mass, while, when a certain interval of time had elapsed since the
bite, it remained fluid. Weir Mitchell[31] explained these differences
by the hypothesis that, in cases of rapid death, the blood had not had
time to become modified by the venom.

Later on it was found by Sir Joseph Fayrer, and subsequently by
Halford,[32] in Melbourne, C. J. Martin,[33] in Sydney, G. Lamb,[34]
in Bombay, and recently by Noc, in my laboratory, that the venoms
of COLUBRIDÆ, especially those of _Naja tripudians_ and
AUSTRALIAN species of this family, always leave the blood
fluid after death, while the venoms of VIPERIDÆ, on the
contrary, are usually coagulant.

On the other hand, it was observed by Phisalix,[35] and at an earlier
date by Mosso, of Turin, that the venom of _Vipera berus_ causes the
blood of the dog to lose its coagulability, while, on the contrary, the
same venom is actively coagulant as regards the blood of the rabbit.

How are these differences of action to be explained? It was found by
Delezenne,[36] who made an excellent study of the phenomena following
the injection of peptone, extracts of organs, and other anticoagulant
substances into the organism, that those of these substances that
render the blood non-coagulable always dissolve the leucocytes, and
thus set at liberty two antagonistic bodies which they contain. One of
these substances is coagulant and is found retained by the liver, while
the other remains in solution in the plasma, and keeps the blood fluid
after issuing from the vessels.

Now, certain extracts of organs, ricin, abrin and certain venoms in
weak doses, retard coagulation, while in large doses, on the contrary,
they produce partial or general intravascular clotting.

It is believed by Delezenne that the explanation of this phenomenon
may be that the doses, which are weak but sufficient to produce the
disintegration of the leucocytes, injure the red corpuscle in only a
slight degree, while the stronger doses are equally destructive to the
two kinds of blood corpuscles.

It follows that we must understand that there are two phases in the
action of venoms: one _negative_, when the dose absorbed does not
injure the leucocytes; the other _positive_, when the leucocytes are
destroyed.

If the blood of the dog remains non-coagulable when mixed with doses of
venom which, on the contrary, are actively coagulant for the blood of
the rabbit, the reason would be that the leucocytes of these animals
are not equally resistant to venom.

This conception, however, does not conform to the facts that I have
myself observed. I have always found that viper-venom, mixed with
citrate- or oxalate-plasma of the dog, rabbit, or horse, coagulates
these various plasmas when the venom is in weak doses, while with
strong doses coagulation is not produced. To be quite accurate, it
should be stated that the quantity of venom necessary to render the
plasma of the dog, or of the horse, non-coagulable is less than that
which must be employed in the case of the plasma of the rabbit.

I have caused Noc to take up anew the study of this question in my
laboratory, with venoms of nine different origins, and I here give a
_résumé_ of the results of his researches.[37]

I. COAGULANT VENOMS.

The venoms of VIPERIDÆ studied range themselves as follows
according to their coagulant power:--

CROTALINÆ: _Lachesis lanceolatus_ (Fer-de-lance, Martinique).
_Lachesis neuwiedii_ (Urutù, Brazil).
_Lachesis mutus_ (Bushmaster, or Surucucu, Brazil).
_Lachesis flavoviridis_ (Japan).
VIPERINÆ: _Vipera russellii_ (Daboia, India).

The venoms of _Ancistrodon contortrix_ and _A. piscivorus_
(CROTALINÆ) proved entirely inactive.

No COLUBRINE venom exhibited coagulant power, whatever the
dose employed.

There is, therefore, a very decided difference between venoms of divers
origins as regards their effects upon the coagulation of the blood.

Noc has determined more especially the coagulant action of the
venom of _Lachesis lanceolatus_ (Fer-de-lance of Martinique) upon
1 per cent. citrate-plasmas, 1 per cent. oxalate-plasmas, 4 per
cent. chloridate-plasmas, and upon blood rendered non-coagulable by
extract of leeches’ heads. He found that, while weak doses of venom
(1 milligramme per cubic centimetre of horse- or rabbit-plasma)
produce coagulation in a few minutes in the citrate-plasmas,
chloridate-plasmas, or those treated with extract of leeches, the doses
of the same venom greater than 4 milligrammes on the contrary suppress
the coagulability of these plasmas, even when there be added to them
doses of chloride of calcium (for the citrate- and oxalate-plasmas), or
of distilled water (for the chloridate-plasma), or of fibrin-ferment
(for the plasma treated with leech-extract) sufficient to cause rapid
coagulation in the control tubes that do not contain venom.

Noc also observed that the venom of the same species of snake
(_Lachesis lanceolatus_), when heated to 75° C., entirely loses its
coagulant properties; and that, with a temperature of 58° C., its
coagulant power already commences to diminish. When heated for thirty
minutes at a temperature of 65° C., a dose of 1 milligramme does not
coagulate more than 1 c.c. of citrate-plasma in one hour. G. Lamb has
likewise found that the venom of _Vipera russellii_ loses its coagulant
power when heated to 75° C.

The coagulant substance in these venoms is precipitable by alcohol at
the same time as the _neurotoxin_ and other active substances. The
precipitate, when dissolved again in physiological water, preserves all
the properties of the original solution.

Antivenomous _anticolubrine_ serum, that is to say, that furnished by
horses vaccinated against the venoms of the _Cobra_ and the _Krait_,
does not prevent coagulation by coagulant venoms. This need not
surprise us, since the coagulant substances in venoms are destroyed by
heating, and the animals vaccinated in order to obtain antitoxic serum
are usually inoculated exclusively with heated venoms.

It is easy, however, to obtain active serums specific against
the coagulant venoms; it is sufficient to treat these animals by
inoculation with progressively increasing doses of the same venoms
unheated. I have had no difficulty in achieving this result with
small laboratory animals (guinea-pigs and rabbits) and also with the
horse, but I have never had at my disposal a sufficient amount of the
venoms of _Lachesis_ or _Vipera russellii_ to undertake with them
the regular acquisition of large quantities of horse-serum, at once
_antineurotoxic_ and _anticoagulant_. The preparation of such a serum,
nevertheless, presents much interest for certain countries, such as
Burma, where the Daboia (_Vipera russellii_) is almost as common as
the Cobra, and Brazil, where nearly all the casualties due to venomous
snakes are produced by _Lachesis_.[38]

II.--ANTICOAGULANT VENOMS.

Contrary to what is observed with the venoms of VIPERIDÆ
in general, all the venoms of COLUBRIDÆ and, as exceptions
to the rule, the venoms of some North American CROTALINÆ
(_Ancistrodon contortrix_ and _A. piscivorus_) suppress the
coagulability of the blood _in vivo_ and _in vitro_. It is, however,
important to observe that, _in vivo_, the blood remains fluid after
death only if the dose of venom absorbed has been sufficient. _In
vitro_ this phenomenon is easier to study, and has been the subject of
several important memoirs.

Halford,[39] Sir Joseph Fayrer,[40] C. J. Martin,[41] Delezenne,[42]
Phisalix,[43] and lastly Noc,[44] have shown that the venoms of
COLUBRIDÆ exert a manifestly anticoagulant action upon
citrate-, chloridate-, or oxalate-plasmas, and also upon blood mixed
with venom on issuing from the vessels.

On adding 1 milligramme of _Cobra_-, _Bungarus_-, Australian
_Pseudechis_-, or _Ancistrodon_-venom to 1 c.c. of citrate-, oxalate-,
or chloridate-plasma, and supplementing the mixture, after varying
periods of contact, with a quantity of chloride of calcium (for the
citrate- or oxalate-plasmas), or distilled water (for the saline
plasma) sufficient to produce coagulation in a few minutes in the
control tubes without venom, we find that coagulation no longer
takes place after one hour in the tubes containing _Cobra_- or
_Bungarus_-venom, and after ten minutes in those that contain the venom
of _Ancistrodon_.

In doses less than 1 milligramme for 1 c.c. of plasma, these venoms
by themselves never produce coagulation as do those of _Lachesis_
or _Vipera russellii_. They are thus sharply differentiated in this
respect.

If fresh blood issuing from the arteries of an animal be received in
a vessel containing a sufficient quantity of COLUBRINE-venom
(that of the Cobra for example), and steps be immediately taken to
ensure the perfect mixture of the venom and the blood, we find that the
latter has entirely lost its coagulability, just as though it had been
mixed with peptone or extract of leeches’ heads.

Again, if a mixture be made _in vitro_ of coagulant venoms, such as
that of the _Lachesis_, with anticoagulant venoms such as that of the
_Cobra_ or of _Ancistrodon_, it is found that these mixtures, when
properly effected, become neutral, so that the respective effects of
the component venoms are entirely destroyed. Assuming, for instance,
that 1 milligramme of _Lachesis_-venom coagulates in two minutes 1 c.c.
of 1 per cent. citrate rabbit-plasma, if we add to the plasma firstly
1 milligramme of _Ancistrodon_-, or 1 milligramme of _Cobra_-venom,
and then 1 milligramme of _Lachesis_-venom, the plasma remains
non-coagulated, yet coagulates perfectly on the subsequent addition of
1 c.c. of a ½ per cent. solution of chloride of calcium.

There is, therefore, a real antagonism between the actively coagulant
substance contained in certain VIPERINE venoms and the
anticoagulant substance comprised in the venoms of certain other
VIPERIDÆ (_Ancistrodon_), belonging to the subfamily
CROTALINÆ, and in those of all the COLUBRIDÆ.

The conclusion to be deduced from the foregoing facts is that the
venoms of COLUBRIDÆ and those of certain VIPERIDÆ
are decidedly _anticoagulant_, while the majority of the venoms
of VIPERIDÆ, on the contrary, possess strong _coagulant_
properties, even when mixed with blood in infinitesimal doses.

The question therefore arises why these _coagulant_ VIPERINE
venoms suppress the coagulability of the blood when mixed with it
_in vitro_ in strong doses (for example, in doses beginning from 4
milligrammes of _Lachesis_-venom, or 7 milligrammes of the venom of
_Vipera russellii_ for 1 c.c. of 1 per cent. citrate rabbit-plasma).

The explanation of this apparently contradictory phenomenon is
furnished by the intense proteolysis that these VIPERINE
venoms exert upon fibrin, in solution or coagulated. This proteolysis
actually manifests itself with weak coagulant doses, for the compact
clots formed at the outset soon become soft and then dissolve, like
a cube of egg-albumen in an experiment in artificial digestion by
trypsin. We shall revert to the subject later on.

III.--MECHANISM OF THE ANTICOAGULANT ACTION OF VENOMS ON THE
BLOOD.

The anticoagulant action of the venoms of COLUBRIDÆ and of
_Ancistrodon_ upon the blood appears to take effect in the first place
upon the fibrin-ferment, and afterwards upon the fibrin by proteolysis.
The action on the fibrin-ferment seems manifest when we experiment with
anticoagulant venoms which are feebly proteolytic, like the venom of
the _Cobra_.

I have already stated that a mixture of fresh blood with a sufficient
dose of _Cobra_-venom is non-coagulable, as though the blood on issuing
from the animal had been mixed with peptone or leech-extract. But,
while blood when peptonised or mixed with leech-extract coagulates
readily on the subsequent addition of fibrin-ferment, blood mixed with
venom remains positively non-coagulable. It is the same with citrate-
or oxalate-plasmas, which no longer coagulate when chloride of calcium
is added to them, and with 4 per cent. saline plasma on the addition of
distilled water.

The anticoagulant substance in the venoms of COLUBRIDÆ and
_Ancistrodon_ is precipitable by alcohol, like the coagulant substance
in the venoms of VIPERIDÆ and like the _neurotoxins_, from
which it is difficult to separate them. The separation can nevertheless
be effected by the aid of heat, if we make use of certain venoms that
are particularly resistant to high temperatures, such as those of the
_Cobra_ or the _Krait_. These latter venoms, when heated for one hour
at 70° C., cease to be anticoagulant, and _preserve their toxicity
unimpaired_. It is, however, impossible to suppress the toxicity
without at the same time destroying the anticoagulant substance.

_Antivenomous serum_ completely protects citrate- or chloridate-plasmas
against the anticoagulant action of venoms. It is sufficient to mix
½ c.c. of 4 per cent. saline antivenomous serum with 1 c.c. of 4
per cent. saline plasma to ensure that the subsequent addition of 1
milligramme of _Cobra_-venom to this mixture remains without effect
upon the coagulability of the latter. If, after a contact of two hours
or more, 2 c.c. of distilled water be added, coagulation is produced
just as in saline plasma without venom.

B.--EFFECTS OF VENOM UPON THE RED CORPUSCLES.

(1) _Hæmolysis._--The hæmolytic properties of venoms, that is to say,
their faculty of dissolving the red corpuscles, have been the subject
of very important researches on the part of a number of investigators
during the last few years (W. Stephens,[45] Flexner and Noguchi,[46]
Calmette,[47] Phisalix,[48] Preston Kyes and Hans Sachs,[49] Noc[50]).

The different venoms are all hæmolytic, but in very variable doses.
It is possible to make a very precise comparative study of them from
this special point of view by taking as a base for each venom, as was
done by Noc, the unital dose of 1 milligramme (or one-tenth of a cubic
centimetre of a 1 per cent. solution freshly prepared and not filtered,
the filtration through porcelain retaining an appreciable part of the
active substance), and noting the time strictly necessary for this dose
of 1 milligramme to dissolve completely, _in vitro_, 1 c.c. of a 5 per
cent. dilution of red corpuscles of the horse in physiological saline
solution.

It is very important, before allowing the venom to act on the red
corpuscles, to first wash the latter by means of several successive
centrifugings with 8 per 1,000 physiological saline solution.

It is also better to choose the corpuscles of the horse in preference
to those of other species of animals, since they exhibit a nearly
constant mean sensitivity. The corpuscles of the ox, goat, sheep, and
rabbit are less sensitive. Those of man, the guinea-pig, and the rat,
on the contrary, are more so.

On experimenting with _washed_ corpuscles, it is found that venom alone
is incapable of dissolving them. In order that dissolution may take
place, we are obliged to add to the mixture either a small quantity of
normal horse-serum, preferably _heated_, and, consequently, deprived of
alexin (Calmette), or ½ c.c. of a 1 in 10,000 solution of _lecithin_ in
physiological saline water (P. Kyes).

Venom, therefore, is capable of hæmolysing red corpuscles only when
it is _quickened_, either by heated normal serum, or by lecithin. The
solution of lecithin employed for this purpose should be prepared
by dissolving 1 gramme of lecithin in 100 grammes of pure methylic
alcohol. Taking 1 c.c. of this dilution we add it to 9 c.c. of 8 in
1,000 saline solution, and make a second dilution of 1 c.c. of the
foregoing mixture in 9 c.c. of saline water. This latter dilution of 1
in 10,000 is utilised as the reagent.

Let us now see how the serum or lecithin acts. It has been shown by
P. Kyes that with either of these substances the mechanism of the
hæmolytic action is the same, for the serum quickens the venom only
through the agency of the free lecithin it contains. The lecithin takes
part in the reaction by combining with the venom to form a hæmolysing
_lecithide_ more resistant to heat than its two components, for it may
be heated for several hours at a temperature of 100° C., without the
loss of any of its properties.

When venom is brought into contact with certain kinds of highly
sensitive red corpuscles, those of the rat for example, these
corpuscles, although washed and freed from serum, may undergo
hæmolysis. This result is due to the fact that these corpuscles contain
sufficient quantities of lecithin, which becomes liberated from
their protoplasm and, uniting with the venom, constitutes the active
_lecithide_.

It was already known that lecithin is capable of combining with various
albuminoid matters and with sugars to form _lecithides_. We must not,
therefore, be surprised to find that such a combination may take place
with the proteic substances in venom. The combination in this case is
a truly chemical one. Lecithin in its natural state, or that which is
normally found in serums which quicken venom, such as horse-serum,
even when heated to 65° C., therefore plays the part of _complement_
according to Ehrlich’s theory, or that of _alexin_ according to the
theory of Bordet, while venom itself would be an _amboceptor_ or
_sensitiser_.

This is not, however, the way in which the phenomenon should be
understood, for it is impossible to admit the identification of heated
serum or lecithin with the complementary substances or alexins, seeing
that the essential characteristic of the latter is that they are
intolerant of heat and become entirely inactive on being raised to a
temperature of 58° C., or even by simply being kept for a few days
exposed to the air and light. We must therefore suppose, with P. Kyes
and H. Sachs, that the red corpuscles themselves contain substances
capable of playing the part of complements (_endo-complements_), and
that it is with these that the venom combines when quickened by the
presence of lecithin or heated serum, the latter only acting because it
contains free lecithin.

All substances that contain lecithin, such as bile, hot milk, or
cephalin, are capable of exerting the same quickening action, but do
not themselves possess any inherent hæmolytic power.

_Cholesterin_, on the contrary, represents a kind of antidote to
lecithin, as also to normal serums. It prevents hæmolysis of the red
corpuscles in a mixture of washed corpuscles and venom, yet it does not
in any way modify the properties of true alexins or complements.

Moreover, no correlation exists between _lecithides_ and the
_neurotoxin_ in venoms. The combination lecithin + venom possesses
_hæmolytic_ action, but is in no way _neurotoxic_. Conversely, venom
can be freed from its groups of molecules combinable with lecithin, and
remain _neurotoxic_.

_Lecithide_ is insoluble in ether and acetone, but soluble in
chloroform, alcohol, toluene, and water. Its properties are therefore
entirely distinct from those of its two components. It precipitates
slowly from its aqueous solutions, without losing its hæmolytic power;
it does not show _biuret_-reaction; it dissolves with equal readiness
the red corpuscles of all species of animals, and its effects, like
those of venom, are impeded by cholesterin.

Kyes has succeeded in obtaining lecithides with all the hæmolytic
venoms that he was able to study: thus he has prepared lecithides
from _Lachesis lanceolatus_, _Naja haje_, _Bungarus_, _Lachesis
flavoviridis_, and _Crotalus_. It is therefore probable that the
_lecithinophile_ group exists in all venoms, even when these differ as
regards their other properties.

A wide range of difference is exhibited by the various venoms, as
regards their hæmolysing power in the presence of normal heated serum
or lecithin. The venom of _Naja_ and that of _Bungarus_ are the most
active. The action of the venoms of VIPERIDÆ, and especially
of those of _Crotalus_, is very weak. For example, while 1 milligramme
of _Cobra_-venom dissolves in from five to ten minutes 1 c.c. of a 5
per cent. dilution of red corpuscles in the presence of lecithin or
normal heated serum, the same dose of the venom of _Vipera russellii_
takes thirty minutes to effect the dissolution, and the venom of
_Lachesis lanceolatus_ takes three hours.

P. Kyes and H. Sachs have discovered the apparently paradoxical
fact that, if to the red corpuscles of certain species of animals
_Cobra_-venom be added in increasing doses, hæmolysis augments up
to a certain point, beyond which the destruction of the corpuscles
shows progressive diminution. In a large dose _Cobra_-venom no
longer produces any effect upon the corpuscles of the horse, for
example, even when the venom is added in presence of a great excess
of lecithin or heated serum. It would seem, then, that, according to
the theory of Ehrlich, under the influence of an exaggerated amount
of venom-amboceptor there is produced a deviation on the part of the
complement (serum or lecithin), and that the latter, instead of fixing
itself upon the corpuscles, becomes united with the surplus fraction of
the amboceptors, which has remained free in the liquid.

Noguchi,[51] resuming the study of this extremely curious action of
strong doses of venom, observed that the red corpuscles of certain
species of animals (such as the horse for example), when previously
washed and held in suspension in a physiological solution of sea-salt
containing 4 per cent. of _Cobra_-venom, acquire a considerable
augmentation of resisting power with regard to various physical and
chemical agents. In consequence of this they are no longer hæmolysed by
distilled water, ether, or saponin.

Nevertheless, acids or alkalies, except ammonia, destroy corpuscles
treated with venom more easily than those in their normal condition.

If corpuscles, previously treated with a strong dose of venom, are
subjected to repeated washings in physiological saline solution,
the special resistance acquired by them in the presence of the
venom disappears; they even become more sensitive to the action of
destructive agents, such as water, ether, or saponin.

The principle contained in venom, to which must be attributed the
protective action, is not destroyed by heating to 95° C., although
at this temperature _Cobra_-venom becomes partially coagulated.
Moreover, the protective substance is contained in the coagulum, while
the _hæmolysin_ remains entirely in the filtrate. The agglutinin of
venom, on the other hand, is destroyed at a temperature of 75° C. The
protective substance, therefore, can be identified neither with the
hæmolysin nor with the agglutinin.

It follows that it is impossible to accept the hypothesis of the
“deviation of the complement” suggested by Kyes and Sachs to explain
the innocuousness of strong doses of venom. Besides, it would be
difficult to reconcile this hypothesis with the fact, observed by
Noguchi, that venom in a strong dose protects corpuscles, not only
against the action of lecithin (complement), but also against distilled
water, ether, &c.

Noguchi, seeking more thoroughly to elucidate the mechanism of this
protective action, finds that _Cobra_-venom forms a precipitate with
blood-serum, when the latter is relatively poor in salts or when it is
dilated with water. It likewise forms a precipitate with the aqueous
extract of red corpuscles, and precipitates the globulins, hæmoglobin,
or globin of the corpuscle, when treated separately. The precipitates
are insoluble in water, but dissolve with the assistance of a small
quantity of acid or alkali, and also in a great excess of saline
solution.

Noguchi supposes that red corpuscles, when treated with strong
solutions of venom, are protected against destructive agents on account
of the formation by the venom and certain constituents of the corpuscle
(chiefly hæmoglobin) of a compound insoluble in water. When this
compound is removed by repeated washings in physiological solution, the
corpuscles can easily be hæmolysed afresh by the ordinary destructive
agents. Venom, none the less, exerts a noxious influence upon the
corpuscles in all cases; but when strong solutions are employed, this
effect is masked by the protective action.

All kinds of red blood corpuscles are not equally sensitive to the
protective action of strong doses of venom. In this respect all degrees
are observed in the action of venom. Thus the corpuscles of the dog are
not protected at all by _Cobra_-venom. But it is interesting to observe
that this venom in no way precipitates either the aqueous extract of
dog’s corpuscles, or the hæmoglobin, or the globin of this animal.

The venom of _Crotalus_ and that of _Ancistrodon_ likewise possess
protective power, which is, however, less marked than in the case of
_Cobra_-venom.

Noguchi finally points out that corpuscles treated with venom are
not hæmolysed by fluorescent substances such as eosin. They are also
refractory to the hæmolysing action of tetanolysin.

The resistance of the hæmolysins of venom to heat (which, according to
Morgenroth, may extend to heating for thirty minutes at a temperature
of 100° C.) explains how it is that the serum of horses immunised by
means of venoms heated to 72° C. is distinctly antihæmolysing, and
capable of perfectly protecting the red corpuscles _in vitro_ and _in
vivo_.

I have been able to prove that the _antineurotoxic_ property of
antitoxic serums with regard to the venoms of COLUBRIDÆ is
pretty much on a par with their antihæmolysing property, so that
it is possible to measure _in vitro_ the antitoxic activity of a
serum by establishing the degree of its antihæmolysing activity.
Thus we see that a serum, which is antitoxic and antihæmolytic with
respect to the venom of _Naja_, is likewise antihæmolytic as regards
the other COLUBRINE-venoms, and even certain venoms of
VIPERIDÆ. Here we have a very important fact, for it enables
us to measure _in vitro_ the activity of antivenomous serums.

(2) _Precipitins of Venoms._--The serum of rabbits treated with
increasing doses of _Cobra_-venom precipitates the latter in more
or less concentrated solution. It has no effect as regards other
venoms. On the other hand, the serum of a strongly immunised horse,
the antivenomous power of which was pretty considerable, gave no
precipitate with _Cobra_-venom; the formation of precipitate is
therefore entirely independent of that of antitoxins (G. Lamb).[52]

(3) _Agglutinins of Venoms._--Besides their hæmolytic action,
it is easy to observe that certain venoms, especially those of
VIPERIDÆ, agglutinate the red corpuscles, and that the
substance that produces this agglutination is different from the
hæmolysing substance; for it acts rapidly at a temperature of O° C.,
at which hæmolysin manifests its effects only with extreme slowness.
Heating to 75° C. destroys this agglutinant property (Flexner and
Noguchi).

C.--EFFECTS OF VENOM UPON THE WHITE CORPUSCLES: LEUCOLYSIN.

The white corpuscles themselves do not escape the action of venom. It
is possible _in vitro_ to prove this action upon leucocytic exudations
obtained, _e.g._, by injecting sterilised cultures of _Bacillus
megatherium_ into the pleura or peritoneum of the rabbit. After a few
hours this exudation is removed by means of capillary tubes, and, on
mixing these with weak doses of venom, we see, in the course of a
microscopic examination, that the large mononuclear cells are the first
to be dissolved, then the polynuclears, and lastly the lymphocytes. The
leucolysis is much more intense and more rapid with _Cobra_-venom than
with that of _Crotalus_ (Flexner and Noguchi, Noc).

CHAPTER IX.

_PHYSIOLOGY OF POISONING_ (_continued_).

PROTEOLYTIC, CYTOLYTIC, BACTERIOLYTIC AND VARIOUS DIASTASIC
ACTIONS OF VENOMS: DIASTASIC AND CELLULAR ACTION ON VENOMS.

A.--PROTEOLYTIC ACTION.

The proteolytic action of venoms on gelatine, fibrin, and egg-albumen
has been studied by Flexner and Noguchi,[53] Delezenne,[54] and
subsequently by Noc[55] in my laboratory. It was already known that
_in vivo_ certain venoms exert a manifestly dissolving action on the
endothelium of blood-vessels and on the muscular tissues themselves.

Delezenne, on his part, has established the existence in snake-venoms
of a _kinase_ analogous to the kinase of leucocytes and enterokinase.
Venom alone does not attack egg-albumen coagulated by heat, but it
confers an exceedingly strong digestive power on inert pancreatic
juices.

_Lachesis_-venom has been found to be much the richest in kinase. It
digests gelatine perfectly, and when this substance has been subjected
to its action it is no longer capable of being solidified.

_Lannoy_,[56] on the other hand, experimenting upon albuminoid
substances (casein, albumins of ox-serum) in solution, has shown
that _Cobra_-venom and that of _Vipera_ disintegrate the albuminoid
molecule; but the latter remains soluble after the addition of formol
and is no longer precipitable by acetic acid. The hydrolysis never
leads to the stage of peptone, but only to the formation of albumoses
which give biuret-reaction.

The action of venoms upon fibrin may be demonstrated _in vitro_
by bringing sufficient quantities of venom, 1 centigramme, for
example, into contact with small fragments of non-heated fibrin,
derived from blood clots from an ox, rabbit, or birds, and carefully
washed. These fragments soon separate from each other, and become
dissolved in a space of time which varies according to the venom used.
The VIPERINE-venoms, especially those of _Lachesis_ and
_Ancistrodon_, are the most active. _Viper_-venom is much less so, and
the venoms of COLUBRIDÆ are the slowest.

This proteolytic action of the various venoms corresponds pretty
exactly to their coagulant and decoagulant action on rabbit- or
horse-plasma, so that, as I have already stated, we must suppose that
the property possessed by VIPERINE-venoms of more or less
rapidly dissolving blood which they have caused to coagulate, results
from the fact that these venoms contain, in addition to a coagulant
substance, another substance which is strongly proteolytic.

The latter is destroyed by heating. _Lachesis_-venom, when heated to
70° C., no longer has any dissolving action on either gelatine or
fibrin. Moreover, antivenomous serum furnished by horses vaccinated
against heated venoms does not prevent proteolysis by non-heated
venoms. On the other hand, the serum of animals vaccinated against
VIPERINE-venoms, simply filtered by the Chamberland process
and non-heated, affords perfect protection to gelatine and fibrin
against the dissolving action of these venoms.

B.--CYTOLYTIC ACTION.

Simon Flexner and Noguchi[57] have observed that the venoms of
_Naja_, _Ancistrodon_, _Crotalus_, _Vipera russellii_, and _Lachesis
flavoviridis_, contain substances which possess the property of
dissolving a large number of the cells of warm-blooded and cold-blooded
animals, and that these _cytolysins_ are very markedly resistant to
high temperatures.

They employed for their experiments 5 per cent. emulsions of organs,
spermatozoids, or ova in physiological saline solution. The solution
of venom at a strength of 1 per cent. was kept in contact with the
different kinds of cells for three hours at a temperature of 0° C.; the
liquid was then centrifuged and examined with the naked eye and under
the microscope.

The venoms experimented upon dissolved more or less rapidly the
parenchymatous cells of the liver, kidney and testicle of the dog,
guinea-pig, rabbit, rat and sheep. The most active venoms in this
respect were those of _Vipera russellii_, _Ancistrodon_ and the
_Cobra_; the venom of _Crotalus_ was the least active.

With regard to the nerve-cells, spermatozoids and ova of cold-blooded
animals (frogs, fish, arthropods, worms, and echinoderms) _Cobra_-venom
proved to be the most active; then that of _Ancistrodon_, and lastly
that of _Crotalus_.

These cytolysins are not destroyed by heating for thirty minutes at 85°
C. in a damp medium, nor by dry heating for fifty minutes at 100° C.

C.--BACTERIOLYTIC ACTION.

If we bring into contact with a 1 per cent. solution of _Cobra_-venom,
rendered aseptic by filtration through porcelain, sensitive
micro-organisms, such as the cholera vibrio, or the bacterium
of anthrax in a very young non-sporulated culture, or in its
non-spore-producing variety, we find that these microbes are dissolved
by the solution of venom in varying periods of time.

On making a direct microscopical examination we see that Koch’s vibrios
become immovable, then break up into granulations and disappear in the
liquid. The bacteriolysis is even more distinct in the case of the
bacterium. The enveloping membrane seems to dissolve, and the microbe
appears as though composed of a series of granulations placed end to
end, which finally disperse and disappear.

By my instructions this bacteriolytic property of venom with respect
to different species of micro-organisms was studied by Noc. It was
especially clearly seen with the non-spore-producing bacterium of
anthrax, the cholera vibrio, _Staphylococcus aureus_, the bacillus
of diphtheria, and _B. subtilis_ in a young culture; it is less
distinct with _B. pestis_, _B. coli_, and _B. typhi_, is almost _nil_
with the pyocyanic bacillus and _B. prodigiosus_, and _nil_ with _B.
tuberculosis_.

Investigations have likewise been made by Noc, and subsequently by
Goebel,[58] in order to determine whether cobra-venom dissolves
Trypanosomes. These hæmatozoa are more resistant than bacteria, but
they nevertheless end by being dissolved after twenty to thirty
minutes’ contact in the 1 per cent. solution.

The bacteriolytic substance in venom is distinct from that which
produces proteolysis, for the latter is destroyed at 80° C., while
the former only disappears with a temperature of and beyond 85°
C. maintained for half an hour. It is likewise distinct from the
hæmolysin, for this resists temperatures considerably higher than 85°
C. Moreover, venom which has dissolved microbes until the saturation
point has been reached, is found to have preserved in its entirety
its hæmolytic power upon the red corpuscles of the horse. Neither
does it act upon the microbes owing to the presence of a _cytase_
or _alexin_. The well-known characteristics of alexins are not met
with here--destruction at 55° to 56° C., sensitivity to light, rapid
alteration at ordinary temperatures, &c.

We cannot, again, compare the bacteriolytic action of venom to that
of rat-serum, which dissolves _B. anthracis_ by aid of a substance
distinct from vibrionicide alexin. According to the researches of
Malvoz and Y. Pirenne, the lysin of rat-serum appears to be a basic
substance, the neutralisation of which destroys its activity. Now
_Cobra_-venom in a very active solution is perfectly neutral to
sensitive litmus papers, while these are turned blue by rat-serum.
Moreover, venom acts not only upon microbes of the same kind, but
also on very different species which are not affected by rat-serum,
especially upon _B. pestis_, for which, on the contrary, this serum,
when fresh, proves a favourable culture medium. The bacteriolytic power
of _Cobra_-venom therefore constitutes a special property of venom.

“In their work on the cytolysins of venom, S. Flexner and Noguchi have
shown that animal cells, when heated to 55° C. and rendered inactive,
do not undergo complete dissolution under the influence of venoms which
destroy the fresh cells. The authors in question infer the existence
of cellular receptors (_endo-complements_, according to the theory
of Ehrlich), which fix the amboceptors of venom. Pursuing the same
order of ideas, I have observed that bacteria killed by heating for
one hour at 60° C. do not undergo total disintegration as do living
bacteria. But, while Flexner and Noguchi infer the plurality of the
cytolysins in venom for different animal cells, I have not been able
to prove the same thing with regard to the bacteriolysin; venom
saturated with cholera vibrios to such an extent that vibrios added at
repeated intervals are no longer dissolved, is incapable of dissolving
another highly sensitive species of microbe, such as the asporogenous
bacterium, and _vice versâ_. Besides, it would be difficult to
understand the existence in venom of cytolysins specific for a whole
series of species of micro-organisms” (Noc).[59]

Antivenomous serum, in a dose of 0·01 or 0·05 c.c., neutralizes the
bacteriolytic action of 1 milligramme of _Cobra_-venom, while normal
serum heated, even in larger doses, is without effect. The lysin and
the antivenomous serum appear also to enter into stable combination; by
heating to 80° C., after dilution of the mixture neutral antivenomous
serum + venom, the property of dissolving is not restored to the latter.

Pursuing his researches upon the bacteriolytic actions, Noc has also
shown that the _fresh_ serums of the rabbit, horse, guinea-pig, rat,
and man are capable of destroying them completely. We must conclude
from this that venom has the property of fixing the alexin of these
fresh serums, and in fact it is easy to show that this fixation takes
place by experimenting with hæmolytic alexin, which is much more
easy to study; it is sufficient to eliminate the intervention of the
hæmolysin proper to _Cobra_-venom.

With this object, Noc employed horse-corpuscles (which are readily
dissolved by fresh rat-serum), and neutralised the hæmolysin proper
to the venom by antivenomous serum, which has no effect upon fresh
horse-corpuscles and upon the alexin of rat-serum.

For experimental purposes six tubes are prepared with contents as
follows:--

(1) 0·5 c.c. of fresh rat-serum.

(2) 0·5 c.c. of fresh rat-serum + 0·5 milligramme of Cobra-venom (0·5
c.c. of a solution of 1 in 1,000).

(3) 0·5 c.c. of fresh rat-serum + 1 milligramme of venom (after fifteen
minutes’ contact of the venom with the alexin in tubes 2 and 3 the
venom is neutralised by 1 c.c. of antivenomous serum in the case of
tube 2, and by 2 c.c. in that of tube 3).

(4) 1 milligramme of venom.

(5) 1 c.c. of antivenomous serum.

(6) 0·5 c.c. of fresh rat-serum + 1 c.c. of antivenomous serum.

To each tube 2 drops of defibrinated horse-blood are added, and the
tubes are placed in the stove at a temperature of 35° C.

In tubes 1 and 6, which contain fresh rat-serum alone, and fresh serum
+ antivenomous serum, hæmolysis appears in a few minutes. In tube 4,
which received venom alone, hæmolysis is also produced in one hour. It
is not produced at all in tubes 2 and 3, which received the neutral
mixture of fresh serum and venom, proving that the hæmolytic alexin has
been fixed by the venom. The latter, therefore, here plays the part of
a true fixator or _amboceptor_.

Venom behaves, in short, after the manner of extracts of organs. The
fixation of hæmolytic alexin by extracts of organs, the tissues, and
animal cells (liver, spleen, spermatozoids, &c., &c.), has already been
demonstrated by V. Dungern, P. Müller, Levaditi, and E. Hoke. The same
fact is also observed with solutions of peptone. The fixation of alexin
is therefore a general property of certain albuminoid molecules.

It was interesting to endeavour to reproduce, with _Cobra_-venom, J.
Bordet’s experiments upon alexins and anti-alexins. It was to be hoped
that we had in this substance an anti-alexic body capable of being
preserved for an indefinite time and constant in its activity, which
would enable us easily to measure the dose of alexin contained in a
small quantity of a serum, or other liquid of leucocytic origin.

The experiment proved to Noc that, contrary to the ideas of Ehrlich
and his pupils, and conformably to the results obtained by Bordet
with serums and toxins, the neutralisation of venom takes place in a
variable ratio.

If a dose A of fresh serum is capable of neutralising exactly 5
milligrammes of _Cobra_-venom with regard to a sensitive microbe, on
employing a dose of the strength of 2 A we ought to find a bactericidal
dose, 1 A, in the excess of serum, according to the theory of definite
proportions. No such bactericidal action is seen, however; the serum,
on the other hand, acts in the contrary direction by means of its
nutritive substances, and in the mixture 2 A + _venom_ we obtain a
larger number of colonies of micro-organisms than in the mixture A +
venom.

We see, then, that the property of cells of fixing in excess the active
substance in serums, discovered by Bordet for the hæmolysins (staining
phenomena), is met with again in the case of extracts of organs, at
least with regard to the bacteriolytic substance of _Cobra_-venom.

It results, then, from the foregoing facts that _Cobra-venom contains a
cytolysin, which acts upon micro-organisms and is capable of fixing the
alexin of normal serums_.

The application of these data to the living animal is evidently full
of difficulties, by reason of the complexity of the substances that
come into play. Let us see, however, to what extent they are capable
of serving to explain the phenomena that are produced as the result of
poisoning.

It was observed by Kaufmann that the cadavers of animals which have
died from snake-bite are very rapidly invaded by the bacteria of
putrefaction. Welch and Ewing, referring to these phenomena of rapid
putrefaction in cases of death from venom, explained them as being due
to the loss of the bactericidal power of the serum. In hot countries,
even when snake-bites are not fatal, they are frequently complicated by
local suppuration or gangrene, occasioned by micro-organisms introduced
at the time of the bite. The minute analysis of the phenomena of
poisoning shows, in reality, that the organism undergoes different
modifications according to the quantity of venom injected and its
channel of penetration.

When the dose of venom is rapidly lethal, whether because it penetrates
into the veins or because a larger amount of it is diffused beneath the
skin, it occasions a transient hypoleucocytosis, which is, moreover,
a reaction common to injections of venom, pro-peptone, extracts of
organs, and microbic toxins (Delezenne, Nolf). It follows that blood
collected a short time after the injection may be totally bereft of
its bactericidal power, in consequence of the disappearance of the
leucocytes, which have migrated into the organs.

Thus it was observed by S. Flexner and H. Noguchi that the serum of
a rabbit, treated with 10 milligrammes of _Cobra_-venom, showed,
fifty-seven minutes after the injection, a great loss of bactericidal
properties. But it is impossible to conclude, from the diminution of
bactericidal power in this experiment, that the alexin becomes fixed by
the venom. Since the secretion of alexin is connected with the presence
of leucocytes, the hypoleucocytosis due to the venom is sufficient to
explain the loss of bactericidal power.

Nevertheless, the action of venom is not confined to these
physiological phenomena; in diffusing itself through the organism
it stays more especially in parts where the circulation has become
slower, in the capillaries of the organs where the leucocytes that
have disappeared from the general circulation are already to be found
agglomerated and altered. Here the cytolysins of the venom, continuing
their effects, are capable of neutralising the alexins set at liberty
by the destruction of the leucocytes, and thus the rapid multiplication
of the bacteria of putrefaction, which have come from the intestine or
were carried in with the bite, is easily explained. In the same way, we
can account for the suppuration that is met with as a complication of
non-lethal bites, in spite of the hyperleucocytosis consequent upon the
penetration of a weak dose of venom; immediate neutralisation of the
alexin set at liberty at the level of the wound has sufficed to enable
micro-organisms to multiply.

D.--VARIOUS DIASTASIC ACTIONS OF VENOMS.

So long ago as 1884, de Lacerda, in his “Leçons sur le venin des
serpents du Brésil,” described the results of his researches upon
the diastasic actions of venom. He proved that venom emulsifies
fats, causes milk to curdle, and does not saccharise starch. But the
solutions of venom employed by this author were not sterile, so that
putrefactive phenomena may be believed to have occurred in the course
of his experiments.

The subject has been studied afresh by Wehrmann[60] in my laboratory,
and afterwards by Lannoy.[61] These two investigators have shown that
venoms do not hydrolyse either starch or inulin. _Cobra_-venom and that
of _Vipera_ change saccharose very slightly. They do not modify the
glucosides (amygdalin, coniferin, salicin, arbutin, and digitalin);
they therefore do not contain emulsin.

On the other hand, these venoms possess, as I have already stated,
very interesting _kinasic_ properties, which have been pointed out
by Delezenne.[62] They consist in the fact that while venom alone
is incapable of digesting cooked albumin, we have only to add to a
pancreatic juice, in itself devoid of effect upon albumin, a trace of
venom, to see this albumin immediately become digested.

_Lachesis_-venom is especially active in this respect. In Delezenne’s
experiments it was generally sufficient to add to 1 c.c. of inactive
pancreatic juice, 0·5 to 1 c.c. of a 1 in 1,000 solution, that is 0·5
to 1 milligramme of venom, to obtain the digestion of a cube of albumin
weighing 0·5 gramme in the space of from ten to twelve hours. Much
weaker doses, ⅕, ⅒, sometimes even 1/80 of a milligramme still gave the
same result, with this sole difference that digestion took twenty-four,
forty-eight, and even seventy-two hours to become complete.

_Cobra_-venom was found to be a little less active than the foregoing,
but still its action was usually evident enough when it was employed in
a dose of 0·5 milligramme or even 0·1 milligramme. As for the venom of
_Vipera berus_, it was often necessary to employ it in doses from five
to ten times stronger in order to obtain the same result.

Delezenne has ascertained, on the other hand, that these venoms
entirely lose their kinasic power when they are subjected to ebullition
for fifteen minutes.

This _kinase_ or diastase, capable of quickening the inert pancreatic
juice, must evidently be of very great utility to the reptile in
enabling it to digest its prey. Venom, therefore, is not, as has long
been believed, a purely defensive secretion; it corresponds to a
physiological necessity, like that of the intestinal or pancreatic
juice. Herein is to be found the explanation of the fact that the
non-poisonous snakes, although destitute of organs of inoculation,
possess supralabial or parotid glands which produce venomous saliva.

Experiments have been made by Ch. Féré[63] to determine the effect
upon the development of the embryo of the introduction of venom into
the albumen of the egg of the fowl. He found that 83 per cent. of
the embryos, developed in eggs intoxicated with 0·05 milligramme of
viper-venom and opened after being incubated for seventy-two hours,
exhibited various anomalies in development.

E.--ACTION OF VARIOUS DIASTASES UPON VENOMS.

Venoms are modified or destroyed by certain normal diastases of the
organism. It was shown long ago by Lacerda, Weir Mitchell, Sir Joseph
Fayrer, and Lauder Brunton, that it is possible to introduce without
danger into the stomachs of adult animals amounts of venom many times
greater than the lethal dose. I have repeatedly verified this, but have
nevertheless observed that young mammals, while being suckled, readily
absorb venom by their alimentary canal, and succumb to the ingestion
of doses scarcely larger than those which kill when subcutaneously
injected. Here we have a very important fact, which once more proves
how easily the intestinal mucous membrane of young animals is permeated
by toxins. By my instructions Wehrmann[64] and Carrière,[65] in my
laboratory, have studied the modifications undergone by venoms in the
alimentary canal of rabbits. We have seen that these animals can ingest
without inconvenience doses of venom 600 times greater than the lethal
dose, and that, if we cause these ingestions to be repeated several
times, contrary to the assertion of Fraser[66] (of Edinburgh), we
never succeed in obtaining immunity to the subcutaneous injection of a
simple lethal dose, and no antitoxin is formed in the blood.

The _ptyalin_ of the saliva, _pancreatic juice_, and _bile_ destroy
_Cobra_-venom _in vitro_. We must, therefore, assume that these
diastases are veritable agents of destruction for ingested venom. The
intestinal microbes play no part, any more than the intestinal juice by
itself. The gastric juice has very little effect. Papain is almost as
active as the pancreatic juice.

It had already been proved by Fraser, so long ago as 1895, that bile,
after prolonged contact and in a sufficient dose, has a strongly
destructive effect upon Cobra-venom; but, contrary to the opinion of
this investigator, it is not antitoxic, for it possesses no preventive
or curative property, and its effects are produced only _in vitro_.

We see from what has been stated above, that venoms introduced into a
sensitive organism are capable of producing extremely complex effects
upon the various tissues or humours. They act on the nerve-cells
by their _neurotoxin_, on the endothelium of the blood-vessels by
their _hæmorrhagin_ (Flexner and Noguchi), on the red corpuscles by
their _hæmolysin_, on the fibrin of the blood and muscles by their
_proteolytic diastase_, and on the fibrin-ferment itself by their
_thrombase_.

They also act on the leucocytes, according to the experiments of
Chatenay,[67] performed under the direction of Metschnikoff, and
according to those of Flexner and Noguchi,[68] already cited.

Thus we understand how complex must likewise be the means of defence
that have to be employed in order to afford an effective protection
against such poisons.

The slightly intoxicated organism at first reacts by the intervention
of the leucocytes; a _hyperleucocytosis_ is produced, accompanied by
a more or less considerable rise of temperature. After a few hours
everything returns to its normal condition, and if the injection of a
lethal dose of venom is repeated several times, at intervals of a few
days, it is not long before antitoxic substances are found to appear in
the serum.

When the dose of venom injected is sufficient to cause death, we
observe, a very few moments after the injection, a _lowering of
temperature_ and a _hypoleucocytosis_, which is the more pronounced in
proportion to the nearness of the dose of venom to the minimal lethal
dose. With very strong doses the hypoleucocytosis has not time to
manifest itself.

It is therefore probable that, in intoxication by venoms as in that by
the toxins of micro-organisms, the protective _rôle_ of the leucocytes
is all-important, not only because these cells are capable of digesting
venoms owing to their protoplasmic digestive juices, but also because
they constitute if not the only, at any rate the principal source of
the _antitoxic substances_ or _amboceptors_.

CHAPTER X.

_TOXICITY OF THE BLOOD OF VENOMOUS SNAKES._

Several physiologists, among whom it is right to mention Fontana,[69]
Leydig,[70] Reichel,[71] Raphael Blanchard,[72] Phisalix and
Bertrand,[73] and S. Jourdain,[74] have pointed out the presence of
poison-glands in _Tropidonotus natrix_ or other non-venomous snakes,
and have explained the immunity enjoyed by these animals with regard to
venom as being due to the existence of an internal secretion of this
poison.

We also know, from the writings of Phisalix and Bertrand, that the
blood of the viper, and that of the salamander and toad are toxic.
For my part I have found[75] that the blood of _Naja_, _Bungarus_,
_Lachesis_, and _Cerastes_ possesses the same properties, and a
comparative study has been made by Wehrmann,[76] in my laboratory, of
the toxicity of the blood of the viper and of that of the blood of the
eel, already established by Mosso (of Turin).[77]

It is remarkable to find that the blood of the various venomous or
non-venomous snakes, like that of certain fishes, such as eels,
produces, when injected beneath the skin or into the peritoneum, local
and general effects very similar to those of venoms. Injections of
0·5 c.c. to 1 c.c. of the blood of the viper or of the common snake,
beneath the skin of the guinea-pig, provoke an intense local reaction,
which always results in the formation of an eschar. The injection of
slightly stronger doses, 1 c.c. to 2 c.c., into the peritoneum, almost
always kills these animals, like venom, with symptoms of respiratory
asphyxia.

The blood of _Naja tripudians_, injected subcutaneously, is lethal to
the mouse in a dose of 0·25 c.c.

When this blood is heated, after having been suitably diluted with
three or four parts of distilled water, in order to prevent it from
coagulating, it is found that a temperature of 70° C. maintained for
fifteen minutes is sufficient to cause it to lose all toxic effect.
The same applies to the blood of the other poisonous or non-poisonous
snakes, and to that of the _Murænidæ_.

Now, since the majority of venoms resist even prolonged heating at
this temperature, it cannot be supposed that the toxicity of the blood
is due to its containing venom derived from the internal secretion of
the poison-glands, as was thought by Phisalix and Bertrand. On the
contrary, it is probable that the toxicity results from the fact that
the blood contains diastasic substances of cellular origin, which
themselves represent certain of the constituent elements of venoms.

These substances, moreover, possess some of the properties of venoms,
as, for instance, the faculty of producing hæmorrhages and of being
influenced by antivenomous serum, which causes them to lose a large
portion of their toxic qualities.

I have found that they can even be utilised to vaccinate animals
against venom; by injecting weak, non-lethal, and repeated doses of
dilute _Cobra_-blood into guinea-pigs and rabbits, I have succeeded in
rendering them immune to doses of _Cobra_-venom several times greater
than the lethal dose.

There is no doubt that it is to these substances that the poisonous
and non-poisonous snakes owe the partial immunity that they
themselves enjoy with respect to venoms. We know, in fact, that
common snakes suffer without danger many bites from vipers (Phisalix
and Bertrand[78]), and that the _Cobra_ is relatively little
affected by inoculation with its own venom or with that of other
COLUBRIDÆ, such as _Bungarus_, or even of VIPERIDÆ,
such as _Vipera russellii_.

This immunity, however, is far from being absolute; I have killed
common snakes (_Tropidonotus natrix_) with doses of _viper_-venom
ten times greater than the lethal one for the rabbit, and _Lachesis
lanceolatus_ (from Martinique) with 0·02 gramme of the venom of _Naja
tripudians_.

Phisalix,[79] on his part, has shown that, while it was necessary to
inject from 100 to 200 milligrammes of _viper_-venom into other vipers
or common snakes, beneath the skin or into the peritoneum, in order to
cause death, the introduction of only 2 to 4 milligrammes of this venom
into the brains of these reptiles was sufficient to kill them with the
same symptoms of intoxication. This dose, however, is only twenty-five
to thirty times greater than the lethal one for the guinea-pig.

The practical lesson to be learnt from the establishment of the
foregoing facts is that poisonous snakes of different species must
never be placed in the same cage, for these animals sometimes bite each
other, and may thus kill one another.

Simon Flexner and Noguchi[80] have studied the action of the serums of
_Crotalus_, _Ancistrodon_, and a non-poisonous species, the pine snake
(_Pituophis catenifer_), on the venoms of _Naja_, _Ancistrodon_, and
_Crotalus_. They found that the serum of _Crotalus_ rapidly dissolves
the red corpuscles of man, the dog, rabbit, guinea-pig, sheep, rat,
pigeon, and horse.

The serum of the pine snake affects the same red corpuscles, but in
a lesser degree. Heating to 58° C. suppresses the hæmolytic power of
these serums, but they can be restored to activity by the addition of a
very small quantity of the same serum in a fresh condition, of fresh
serum derived from other snakes, or of fresh serum from the guinea-pig.

Antivenomous serum also, when added in a suitable dose, entirely
suppresses the hæmolytic action of snake-serums; it has, however,
greater effect upon the hæmolysin of _Cobra_-blood than upon that of
the blood of other snakes. This observation had previously been made by
W. Stephens,[81] and it has been verified by Noc in my laboratory.

_Crotalus_-serum dissolves the red corpuscles of the mongoose
(_Herpestes ichneumon_) of Jamaica, whose extraordinary resistance to
venom is well known. But if variable doses of _Ancistrodon_-venom and
_Crotalus_-serum be made to act simultaneously upon these corpuscles,
the latter are no longer dissolved. Again, if, instead of red
corpuscles which are but little sensitive, like those of the mongoose,
we employ the highly sensitive corpuscles of the guinea-pig, the result
is the same. These experiments are regarded by Flexner and Noguchi
as proving that the amboceptors of the toxic serum become fixed, in
conformity with Ehrlich’s theory of the lateral chains, upon the
receptors of the sensitive erythrocytes, and leave no more receptors
free for the fixation of the venom.

The same investigators have endeavoured to determine the respective
toxicity of the tissues of the different organs of _Crotalus_. They
found that the most toxic organs are the spleen and the liver; the
toxicity of the spinal cord, kidney and muscles is much less. It
appears that this toxicity is intimately connected with the quantity of
blood that the tissues retain, for the physiological effects observed
are identical with those that follow the injection of blood or serum
alone.

They also ascertained that the contents of the eggs of _Crotalus_ are
especially rich in poison, and this poison appears to consist for
the most part of _neurotoxin_, since it does not cause hæmorrhages.
Phisalix has observed that the ovules of the viper exhibit analogous
toxicity.[82]

Summing up what has been stated above, we find that the blood of
both poisonous and non-poisonous snakes contains toxic substances,
destructible by heating to 68° C., and physiologically distinct from
venoms, but like the latter possessing the property of dissolving
the red corpuscles of the majority of vertebrates and of producing
hæmorrhages.

CHAPTER XI.

_NATURAL IMMUNITY OF CERTAIN ANIMALS WITH RESPECT TO SNAKE-VENOMS._

It was long ago pointed out that certain warm-blooded animals,
including the mongoose (_Herpestes ichneumon_, Family _Viverridæ_),
hedgehog (_Erinaceus europæus_, Family _Erinaceidæ_), pig (_Sus
scrofa_, Family _Suidæ_), and some herons (_Ajaja_, Subfamily
_Plataleinæ_; _Cancroma_, Subfamily _Cancrominæ_; _Botaurus_, Subfamily
_Ardeinæ_; _Mycteria_, Subfamily _Ciconiinæ_), known in Colombia under
the names _Culebrero_ and _Guacabo_, exhibit a natural immunity with
respect to snake-bites.

Pigs devour vipers with great readiness, and in the region of North
America which adjoins the Mississippi and its tributaries they are even
trained to destroy the young rattle-snakes and other poisonous serpents
with which the valleys of these watercourses are infested.

During my stay in Indo-China I inoculated a young pig, beneath the skin
of the back, with a dose of _Cobra_-venom (10 milligrammes) capable of
killing a large-sized dog. The animal withstood the injection, but I
am inclined to think that this is not a case of true immunity; it is
probable that the pig owes its resistance to venom to the fact that
its skin is lined with an enormous layer of adipose tissue, which is
but very slightly vascular, and in which absorption takes place very
slowly. This opinion is corroborated by my discovery that the serum
of this animal is entirely destitute of any antitoxic substance. I
mixed a dose of _Cobra_-venom, lethal for the rabbit, with 3·5 and 8
c.c. of pig-serum. These mixtures killed rabbits in the same time as
the controls that received the venom diluted with equal quantities of
rabbit-serum or physiological saline solution.

The natural immunity of the mongoose and the hedgehog rests upon more
scientifically established facts.

My own experiments upon the immunity of the mongoose were made with
six specimens of these little carnivores captured in Guadeloupe
(French West Indies), an island in which no poisonous snakes exist;
consequently their immunity could not have arisen from their having
become accustomed to the bites of venomous reptiles.

I first introduced a mongoose into a cage containing a _Naja bungarus_
(_Ophiophagus_) of large size. The snake rose up immediately, dilated
its hood, and struck savagely at the little animal, which, darting
nimbly out of the way, escaped being seized and, frightened for a
moment, took refuge in a corner of the cage. Its stupor, however, was
but of brief duration, for at the very moment when the hamadryad was
preparing to strike at it again, the mongoose, with open mouth and
snarling, sprang upon the reptile’s head, bit it hard in the upper jaw
and crushed its skull in a few seconds. This scene is in every respect
reminiscent of the admirable description given by Rudyard Kipling, in
his celebrated “Jungle Book,” of the great war that _Rikki-tikki_ (the
Mongoose) fought with Nag (the Cobra) “through the bathrooms of the big
bungalow in Segowlee cantonment”:--

“Nag was asleep, and Rikki-tikki looked at his big back, wondering
which would be the best place for a good hold. ‘If I don’t break his
back at the first jump,’ said Rikki, ‘he can still fight; and if he
fights--O Rikki!’ He looked at the thickness of the neck below the
hood, but that was too much for him; and a bite near the tail would
only make Nag savage.

“’It must be the head,’ he said at last; ‘the head above the hood; and
when I am once there, I must not let go.’

“Then he jumped. The head was lying a little clear of the water-jar,
under the curve of it; and, as his teeth met, Rikki braced his back
against the bulge of the red earthenware to hold down the head. This
gave him just one second’s purchase, and he made the most of it. Then
he was battered to and fro as a rat is shaken by a dog--to and fro
on the floor, up and down, and round in great circles; but his eyes
were red, and he held on as the body cart-whipped over the floor,
upsetting the tin dipper and the soap-dish and the flesh-brush, and
banged against the tin side of the bath. As he held he closed his jaws
tighter and tighter, for he made sure he would be banged to death, and,
for the honour of his family, he preferred to be found with his teeth
locked. He was dizzy, aching, and felt shaken to pieces, when something
went off like a thunderclap just behind him; a hot wind knocked him
senseless, and red fire singed his fur. The big man had been wakened
by the noise, and had fired both barrels of a shot-gun into Nag just
behind the hood.”[83]

From the experimental point of view, these stirring battles between
mongooses and cobras only show that a mongoose of the size of a large
squirrel makes a plucky and victorious attack upon a venomous reptile
of the most dangerous species and of very large dimensions; but it is
impossible to tell with certainty whether the mongoose has been bitten.

I therefore inoculated a second mongoose with 2 milligrammes of
venom, a lethal dose for 4 kilogrammes of rabbit. The animal did not
experience the slightest malaise.

I then took blood from three other mongooses, by tying a carotid
without killing the animals. This blood, mixed with venom or injected
as a prophylactic into rabbits, exhibited an antitoxic power, which,
though evident, was of little intensity, and insufficient in all cases
as a certain preventative of death. All the rabbits that received a
preventive dose varying from 2 to 7 c.c. of mongoose-serum succumbed to
inoculation with venom, but with a considerable retardation (from two
to five hours) as compared with the controls.

I endeavoured to determine the limit of tolerance of the mongoose
with respect to venom. Two of these animals, which had never been
inoculated, received doses of venom respectively four times and six
times lethal for the rabbit. The first mongoose remained perfectly
well; the second was ill for two days, and then recovered. A third
mongoose, into which I injected a dose eight times lethal for the
rabbit, succumbed in twelve hours.

[Illustration: FIG. 89.--MONGOOSE SEIZED BY A COBRA.

(For this illustration I am indebted to the kindness of M. Claine, late
French Consul at Rangoon.)]

It must be concluded from these facts that the West Indian mongoose
is but little sensitive to venom; that it is capable of withstanding,
without malaise, doses which are considerable in proportion to its
size, but that its immunity is far from being absolute. If it is
generally the victor in its combats with poisonous snakes, the result
is mainly due to the extreme agility with which it is endowed.

A number of experiments have been made by Lewin,[84] and by Phisalix
and Bertrand,[85] upon the immunity of the hedgehog to the venom of
_Vipera berus_.

It had long been known that hedgehogs are inveterate hunters of vipers,
which they devour with avidity. Thanks to the long and sharp spines by
which their bodies are protected, they avoid being bitten and contrive
to catch the reptiles very cleverly, but it occasionally happens that
they do not escape being struck. However, even in these cases they
rarely succumb.

Inoculation with fairly large quantities of venom does not make them
ill: the dose of _viper_-venom lethal for these small animals is about
forty times greater than that which kills the guinea-pig. Their power
of resistance is therefore beyond doubt.

It may be asked whether this is due to their blood normally containing
antitoxic substances. In order to elucidate this question, Phisalix
and Bertrand first proved that the blood of normal hedgehogs is toxic
to laboratory animals, especially to the guinea-pig. A mixture of this
blood with viper-venom cannot therefore be harmless. But it sufficed to
heat hedgehog blood to 58° C. to cause it to lose its toxicity, and it
was found that it then became antitoxic. Guinea-pigs inoculated in the
peritoneum with 8 c.c. of heated hedgehog-serum were able to withstand,
immediately afterwards, twice the lethal dose of viper-venom.

It really seems, therefore, that the resistance of the hedgehog to
venom is due to the presence of antitoxic substances in its blood. But,
as in the case of the mongoose, there is no question here of genuine
_immunity_.

The same is probably true with respect to the herons of Colombia, the
_Culebrero_ and _Guacabo_, which eagerly search after young snakes for
food. No investigations, however, have yet been made upon this subject.

These birds, moreover, are few in number; hunters pursue them for the
sake of their brilliantly coloured plumage, and it is to be regretted
that no attempt is made to prevent their destruction or to acclimatise
them in countries in which poisonous snakes constitute a veritable
calamity, such as Martinique, St. Lucia, or India.

CHAPTER XII.

_SNAKE-CHARMERS._

In all the countries of the globe where poisonous snakes are formidable
to man, there are certain individuals who profess to be secure from all
ill-effects from the bites of these reptiles, whether because they are
immune to venom, or because they possess secrets which enable them to
cure themselves when they happen to have been bitten. Not unnaturally
these secrets are sometimes turned to profitable account, and the
possessors of them generally enjoy considerable popular influence, and
are very highly venerated. Intimate relations with the divinities are
freely attributed to them.

Among the Romans the jugglers who carried on the profession of
snake-charmers and healers of snake-bites were known as _Psylli_.
Plutarch tells us that Cato, who loved not doctors because they were
Greeks, attached a certain number of them to the army of Libya. They
were accustomed to expose their children to serpents as soon as they
were born, and the mothers, if they had failed in conjugal fidelity,
were infallibly punished by the death of their offspring. If, on the
contrary, the children were lawful, they had nothing to fear from the
bites of the reptiles. “_Recens etiam editos serpentibus offerebant;
si essent partus adulteri, matrum crimina plectabantur interitu
parvulorum; si pudici, probos ortus a morte paterni privilegium
tuebatur_” (Solinus).

The Libyian Psylli of antiquity still have their representatives in
Tunis and in Egypt. Clot Bey writes as follows with reference to the
Egyptian Psylli:--

“The _Ophiogeni_, or Snake-charmers, have been renowned from all
time. Strabo speaks of them, and Prosper Alpinus was a witness of the
singular effects of their art. The majority of modern travellers who
have visited Egypt have been equally struck with the freedom with which
they handle poisonous reptiles and animals.

“The Psylli go from house to house, calling forth and charming the
snakes that they may happen to contain. They claim to attract them by
means of a particular power. Armed with a short wand, they enter the
chamber to be purged from these venomous guests, make a smacking noise
with their tongue, spit upon the ground, and pronounce the following
incantation: ‘_I adjure you, by God, if you are without or within, to
appear_; _I adjure you, by the greatest of names; if you are obedient,
appear! If you disobey, die! die!_’ The snake, submissive to this
command, departs forthwith, issuing from a crack in the wall or
floor.”[86]

India is pre-eminently the country of snake-charmers. There exists an
entire caste of Hindus, called _Mal_, who are professional catchers and
vendors of snakes, but do not perform tricks with them.

The snake-charmers are recruited from among another caste, that of the
_Sangis_ or _Tubriwallahs_ of Bengal.

These men, who are usually clothed in yellow robes and wear large
turbans, manage the Cobra with really marvellous skill. All travellers
who have had the opportunity of crossing India or of touching at a port
on the coast or on that of Ceylon have witnessed scenes similar to that
described by Natalis Rondot (figs. 90 and 91):--

“Towards six o’clock in the evening a Hindu juggler comes on board.
He is poorly clad, and wears a turban decorated with three feathers,
and several necklaces of those amulet-sachets called _gris-gris_ in
Senegal. In a flat basket he carries a spectacled Cobra-di-Capello.

[Illustration: FIG. 90.--INDIAN SNAKE-CHARMER AT COLOMBO
(CEYLON).]

[Illustration: FIG. 91.--INDIAN SNAKE-CHARMER AT COLOMBO
(CEYLON).]

“This man instals himself on deck; we sit down on the seat provided for
the officer of the watch, and the sailors form a circle. The basket is
placed on the deck and uncovered; the Cobra is coiled up at the bottom
of it. The juggler squats a few paces off and commences to play a slow,
plaintive, and monotonous air, with a kind of small clarinet (fig. 92),
the sounds of which recall those of the Breton _biniou_.

[Illustration: FIG. 92.--MUSICAL INSTRUMENT USED BY INDIAN
SNAKE-CHARMERS TO CHARM COBRAS.

(For this figure I am indebted to the kindness of Dr. Pineau.)]

“By degrees the snake moves, extends itself, and then assumes an erect
posture, but without quitting the basket. It begins to appear uneasy
and endeavours to recognise its surroundings; it becomes agitated and
irritated, expands and spreads out its hood, breathes hard rather
than hisses, and frequently and quickly shoots out its slender forked
tongue; several times it makes a violent dart as though to attack the
juggler; it frequently trembles, or rather gives sudden starts. The
juggler keeps his eyes always fastened upon the snake, and gazes at
it with a singular fixed stare. After some time, about ten or twelve
minutes, the Cobra becomes less animated, grows quiet, and then sways
as though influenced by the slow and monotonous rhythm of the musician;
it keeps incessantly darting out its tongue. Little by little it is
brought to a sort of somnolent condition. Its eyes, which at first
watched the juggler as though in order to take him by surprise, are, to
a certain extent, fixed and fascinated by the latter’s gaze. The Hindu
takes advantage of this moment of stupefaction on the part of the snake
by approaching it slowly without ceasing to play, and touches the head
of the Cobra, first with his nose and then with his tongue. Although
this takes but an instant the reptile starts out of its sleep, and the
juggler has barely time to throw himself backwards so as not to be
struck by the snake, which makes a furious dart at him.

“We doubt whether the Cobra still has it fangs, and whether the Hindu
incurs any real danger in approaching it. Accordingly we promise our
man a Spanish piastre if he will make the snake bite a couple of fowls.
A black hen, which struggles violently, is taken and offered to the
Cobra, which half rises, looks at the bird, bites it, and lets it go.
The fowl is released and runs off terrified. Six-minutes later, by the
watch, it vomits, stretches out its legs, and dies. A second fowl is
placed in front of the snake, which bites it twice, and the bird dies
in eight minutes.”[87]

Certain jugglers exhibit snakes from which they have taken care to
extract the fangs; they offer the animal a piece of cloth or soft stuff
into which it drives its poison-teeth, and the fabric is then quickly
snatched away in order by this means to break off the poison-fangs that
have penetrated it. This operation is repeated at certain intervals
with a view to preventing the reserve fangs from coming into use, and
the reptiles can then be handled without any danger.

It is unquestionable, however, and I have personally satisfied
myself of the fact, that many genuine snake-charmers go through
their performances with Cobras whose poison-apparatus is absolutely
intact. That they almost always avoid being bitten is due to a perfect
knowledge of the habits and movements of these reptiles. Nevertheless,
accidents sometimes happen to them, and every year a few of them
succumb in pursuit of their calling (see p. 370). Still, it may be
asserted that some of them really know how to vaccinate themselves
against venom, by making young Cobras bite them from time to time.

It is stated by E. C. Cotes,[88] formerly of the Calcutta Museum, that
the Indian snake-charmers do not extract the poison-fangs from their
snakes. Even though deprived of its fangs, the snake would still be
dangerous on account of its other teeth, the punctures of which would
provide another channel for the penetration of the venom.

Snake-charmers pretend that they owe their immunity to graduated
inoculations. This is not yet conclusively proved; what is better
established is that they take the greatest care to avoid being bitten,
and that in so doing they display the most remarkable skill.

Even in France we are acquainted with professional viper-catchers,
who employ the method of graduated inoculations in order to render
themselves immune to the bites of indigenous reptiles. One of these
men, who lives near Arbois (Jura), takes good care to get himself
bitten, at least once a year, by a young viper; when he forgets this
precaution and happens to be bitten, he always feels the effects much
more severely.

Fraser[89] (of Edinburgh) thinks that the repeated ingestion of small
quantities of venom may suffice to confer immunity, and he mentions
a certain number of experiments performed by him upon white rats and
kittens, from which it would appear that the ingestion of venom,
continued for a long time, finally renders these animals absolutely
refractory to subcutaneous inoculation with doses of the same venom
several times greater than the lethal one. He therefore concludes
that this process of vaccination may probably be in use among
snake-charmers.

I have submitted this hypothesis to the test of experiment. I succeeded
in making _adult_ rabbits, guinea-pigs, and pigeons absorb enormous
doses of _Cobra_-venom by way of the alimentary canal. In this manner
I have administered doses as much as a thousand times greater than the
lethal one, yet I have never been able to prove that the serum of these
animals became antitoxic.

On the other hand, I have succeeded in vaccinating very young
guinea-pigs and young rabbits which were still being suckled, by making
them absorb, every second day, minimal and certainly innocuous doses of
very dilute venom. In the case of young animals, venom is not modified
by the digestive juices, and a portion of it is absorbed by the mucous
membrane of the intestine. When the dose ingested is suitably reduced
they withstand it, and when these ingestions are repeated every second
or third day during the first weeks of life, the animals become
perfectly vaccinated against doses certainly lethal for controls of the
same age and weight. But it is always difficult to push the vaccination
far enough for the serum to acquire antitoxic properties, and I have
never been able to prove the appearance of the latter.

I think, however, that it ought to be possible to arrive at this result
by experimenting upon animals such as lambs, kids, calves, or foals,
the intestine of which remains permeable to toxins for a sufficiently
long period.

It may be that certain snake-charmers, who claim to possess family
secrets which they transmit from father to son, employ an analogous
method in order, in their infancy, to confer immunity to venoms upon
those of their male children who are to inherit their strange and
lucrative profession.

In Mexico, certain Indians called _Curados de Culebras_ know how to
acquire the privilege of being able to be bitten by poisonous snakes
without the least danger to life, by inoculating themselves several
times with the teeth of rattle-snakes.

Dr. Jacolot,[90] a naval surgeon, while staying at Tuxpan, made
enquiries as to these _Curados de Culebras_, and was able to satisfy
himself that their immunity is an actual fact.

The process of vaccination employed by the natives of Tuxpan is as
follows:--A preparatory treatment is necessary. On the very day on
which a man is to inoculate himself or get himself inoculated, he takes
from 5 to 15 tubers of a plant known by the name of _Mano de Sapo_
(_i.e._, Toad’s hand, _Dorstenia contrayerva_, Family _Urticaceæ_).
These tubers must--and this is absolutely necessary--be administered
on a _Friday_, and always in an odd number, 5, 7, 9, &c., up to 15,
according to the tolerance of the subject.

If the plant be gathered on the first Friday in March it possesses
its marvellous properties in the highest degree; in this case, even
if it be dry, it is still excellent for the preparatory stage of the
inoculation.

The physiological effects of _mano de sapo_ are not very marked:
the circulation is slightly diminished and a sensation of cold is
experienced, but there are no nervous troubles. The subject frequently
has attacks of vomiting or nausea. The inclination to vomit must be
fought against, for if the plant should happen to be rejected it would
be dangerous to submit to the inoculation.

The root of the _mano de sapo_ is usually taken fresh. There is another
indispensable precaution: while undergoing this treatment it is
necessary to abstain from all sexual intercourse for three days after
the first inoculation, for two days after the second, and for one day
after the third.

For the inoculation a large snake’s tooth, that is to say, one of the
fangs, is employed, and the fangs of the most poisonous snakes, such as
the rattle-snake (_cuatro narices_), are selected. The snake must be
killed on a _Friday_, and the fangs extracted the same day. The same
fang may serve for several years!

The inoculation is commenced on the dorsal surface of the left foot;
care must be taken to avoid coming into contact with a vein. The skin
is torn with the point of the fang, so that it bleeds a little, and the
incision is in the shape of a square.

From the left foot the operator passes to the right wrist (anterior
surface), then to the right foot (dorsal surface), and left wrist
(anterior surface), always changing from one side of the body to the
other.

Operations are continued on the left thigh, then on the right arm,
right thigh, and left arm; in this way all the limbs are inoculated. On
the body an inoculation is made in the centre of the sternum; another
is made in the nape, and a final one in the centre of the forehead. The
finishing touch is given with the semblance of a square incision in the
tongue.

At least seven series of similar inoculations are necessary to protect
a man from the spells of the serpent, and at the same time to confer
upon him the faculty of curing by suction the bites of the venomous
snakes that are most dreaded.

During the whole of the period in which the Indian thus submits to
successive inoculations, his health shows no noteworthy derangement.
He feels a slight headache and a strange inclination towards alcoholic
drinks. But when the moon is at the full, then indeed, an excitement
which is dangerous in another way takes possession of him. His
cerebral faculties become over-excited, and he feels that his senses
are deserting him; his eyes become bloodshot, and he is pursued and
tormented by an irresistible impulse to bite. He has itching sensations
in his gums, his mouth burns, and salivation is greatly increased. He
feels that he is going to give way to the necessity to bite, and then
he flees to the woods, where he bites the trees viciously, tears their
bark and discharges his venom. His poisonous saliva mingles with the
sap, and, surprising phenomenon, the tree withers and dies!

Woe to the man or animal who happens to be bitten by a _Curado de
Culebra_ in a fit of passion. The victim will die as quickly as if he
had been bitten by a snake!

Almost all the semi-savage people of Guiana, and of the valleys of the
Orinoco and the Amazons, as also the tribes of Central Africa and the
races of India, possess witch-doctors, who pretend to be in possession
of means to preserve themselves from snake-bites, which are just as
ridiculous and infallible as the procedure described above.

The archives of a criminal anthropology contain the story of a Lyonnese
gold-seeker, who had himself immunised against venom by an aboriginal
native of Guiana:[91]--

“The Indian took, from a bottle which contained several of them, a
tooth of the _Grage_ (_Lachesis atrox_), an extremely poisonous snake,
and with it made upon my instep three incisions about 3 centimetres
in breadth. He allowed the wounds to bleed for a minute. I then
experienced a fainting sensation, and large drops of sweat rolled from
my forehead. The wounds were next rubbed with a blackish powder. I
have since learnt that this powder was composed of the liver and gall
of the animal, dried in the sun and pounded up with the poison-glands.
The blood immediately ceased to flow. The Indian chewed some leaves
of a tree mixed with this powder, and, applying his lips to the sore,
injected into it as much saliva as he could, making an effort as though
to inflate a balloon. This completed the operation.

“Since then I have been bitten seven times by different species of
very dangerous snakes, such as the _Grage_, coral-snake, &c., and have
never even had an attack of fever. The Galibi, Boni, and Emerillon
Indians, the Bosse negroes, and all the aboriginal natives of Guiana
employ the same method of procedure. They even pretend that this kind
of vaccination is transmissible to their offspring, and that the
hereditary immunity is maintained through several generations.”

Some years ago Mons. d’Abbadie communicated to the Académie des
Sciences[92] a note from Colonel Serpa Pinto relating to another method
of vaccination employed by the natives of Mozambique, which the Colonel
himself consented to undergo.

“I was vaccinated,” writes Colonel Serpa Pinto, “at Inhambane (on
the East Coast of Africa), among the Vatuas. These people extract
the poison of a snake which is known in Portuguese as the _Alcatifa_
(_i.e._, carpet), and is so called on account of the variegated colour
of its skin, which resembles a carpet. I am not acquainted with the
means employed in order to obtain the poison, which is mixed with
vegetable substances, and forms with the latter a dark brown viscid
paste.

“Two parallel incisions, 5 millimetres in length, are made in the skin,
and into these is introduced the paste containing the poison. These
incisions are made on the arms, near the junction of the radius and
ulna with the carpal bones, on the back of the hand, on the back, on
the shoulder-blades, and on the feet, near the great toes. After the
operation the natives exact an oath that the vaccinated one will never
kill a poisonous snake, because they say that henceforth the snake is
his intimate friend, and they throw upon him an Alcatifa snake, which
does not bite him.

“After undergoing this operation my whole body was swollen up for a
week, and I underwent every possible kind of suffering.

“I have never been bitten by any snake, and cannot vouch for the
infallibility of this remedy. The Vatuas do so, however, and they never
kill a snake.

“A short time after having been vaccinated, I was stung, when in the
Seychelle Islands, by a scorpion, which did me no harm. Ten years
later, at the time of my journey across Africa, I was stung by another
scorpion which hurt me dreadfully, and for a week I thought that I was
going to die or lose my arm.”

Mystification and superstitious ideas play, as we see, a very great
part in this preventive treatment, which is undergone by the natives of
certain countries and snake-catchers or charmers. But it is not very
surprising that, thanks to successive and repeated inoculations, a man
can succeed in acquiring sufficient immunity to preserve himself from
snake-bites.

In ancient times it was even pretended that it was possible for this
immunity to be transmitted in certain cases by heredity, and thus we
can understand how the profession of snake-charmer was hereditary in
certain native families in India or Egypt.

With reference to this subject, Professor Landouzy, in his fine work
on serum therapeutics, quotes a passage from “The Pharsalia” of Lucan
describing, in the year 60 A.D., the customs of the Psylli, a
people encountered by the army of Cato during its sojourn in Africa.
This passage is so interesting that I cannot refrain from reproducing
it:--

“Alone unharmed of all who till the earth
By deadly serpents, dwells the Psyllian race.
Potent as herbs their song; safe is their blood,
Nor gives admission to the poison germ
E’en when the chant has ceased. Their home itself
Placed in such venomous tract and serpent-thronged
Gained them this vantage, and a truce with death,
Else could they not have lived. Such is their trust
In purity of blood, that newly born
Each babe they prove by test of deadly asp
For foreign lineage. So the bird of Jove
Turns his new fledglings to the rising sun,
And such as gaze upon the beams of day
With eyes unwavering, for the use of heaven
He rears; but such as blink at Phœbus’ rays
Casts from the nest. Thus of unmixed descent
The babe who, dreading not the serpent touch,
Plays in his cradle with the deadly snake.”[93]

The only scientific conclusion to be drawn from the facts and
statements that we have just set before the reader is that, under
certain circumstances, man can unquestionably acquire the faculty of
resisting intoxication by snake-venom, by conferring upon himself a
veritable _active immunity_ by means of repeated inoculations of venom.
We shall shortly see that the case is the same with regard to animals.

PART III.

ANTIVENOMOUS SERUM THERAPEUTICS.

CHAPTER XIII.

_VACCINATION AGAINST SNAKE-VENOM--PREPARATION OF ANTIVENOMOUS
SERUM--ITS PREVENTIVE PROPERTIES AS REGARDS INTOXICATION BY
VENOM._

So long ago as the year 1887 it was shown by Sewall, in an important
paper on “Rattlesnake-Venom,”[94] that it is possible to render pigeons
gradually more resistant to the action of this venom by injecting them
with doses at first very small, and certainly incapable of producing
serious effects, and then with stronger and stronger doses. In this
way, although these little animals are very sensitive, he succeeded in
making them withstand doses ten times greater than the minimal lethal
dose.

A little later Kaufmann[95] obtained the same result with the venom of
French vipers. He did not, however, succeed in producing tolerance of
doses more than two or three times greater than the lethal one.

In 1892, at the time of my first experiments with cobra-venom at
Saigon,[96] I arrived at the conclusion that it was possible, by means
of successive inoculations with heated venoms, to confer on animals a
certain degree of resistance to doses invariably lethal to the controls.

From 1894 onwards, the investigations pursued simultaneously at
the Paris Natural History Museum, by Phisalix and Bertrand, upon
viper-venom, and at the Paris Pasteur Institute by myself, upon that of
the cobra, and subsequently upon other venoms of various origins, led
to much more definite results. These investigations show, on the one
hand, that by vaccinating guinea-pigs or rabbits, and taking certain
precautions, it is possible to confer upon these small animals a really
strong immunity to venom; on the other hand, that animals vaccinated
against cobra-venom are perfectly immune to doses of viper-venom
or that of other snakes (_Bungarus_, _Cerastes_, _Naja haje_,
_Pseudechis_) certainly lethal to the controls; and lastly, that _the
serum of the vaccinated animals contains antitoxic substances capable
of transmitting the immunity to other animals_.[97]

According to Phisalix and Bertrand, who, as we have stated,
experimented only with viper-venom, the best method of vaccinating
the guinea-pig consists in inoculating a dose of 0·4 milligramme of
this venom heated for five minutes at 75° C., and, forty-eight hours
afterwards, the same dose of non-heated venom. The latter is always
lethal to the control guinea-pigs in from six to eight hours.

Vaccination against cobra-venom, which is much more toxic, is most
surely effected by the method recommended by me, which consists in
at first injecting small doses of this venom mixed with an equal
quantity of a 1 per cent. solution of hypochlorite of lime. By degrees
the quantity of venom is increased and that of the hypochlorite
progressively diminished, and the injections are repeated every three
or four days, while attentively following the variations in the weight
of the animals. The inoculations are suspended as soon as emaciation
supervenes, and resumed when the weight becomes normal again. After
four injections of chloridated venom the chloride is omitted, and a
direct inoculation made with one-half the minimal lethal dose of pure
venom; then, three or four days afterwards, the injection is increased
to three-fourths of the minimal lethal dose; and finally, after the
lapse of another three or four days, a lethal dose is injected.

If the animals prove resistant, the vaccination can thenceforth be
pushed on rapidly, and the quantity of venom injected each time can be
increased, testing the susceptibility of the organism by the variations
in weight.

As a rule, three months are necessary for the vaccination of a rabbit
against twenty lethal doses. In six months we can succeed in making it
very easily withstand 100 lethal doses.

The serum of rabbits thus treated soon, _i.e._, after they have
received from five to six lethal doses, exhibits antitoxic properties
_in vitro_; these, however, are not very pronounced until after
prolonged treatment. They gradually become just as intense as those
observed in the case of animals vaccinated against diphtheria or
tetanus.

In 1895 Fraser confirmed these results,[98] and on May 15 in that year
exhibited before the Medico-Chirurgical Society of Edinburgh a rabbit
vaccinated against a dose of cobra-venom fifty times lethal.

At once considering the possibility of obtaining serums highly
antitoxic against snake-venoms, and of practical utility in the
therapeutics of snake-bites, I prepared to vaccinate a certain number
of large animals, horses and donkeys, in order to procure great
quantities of active serum. I at first experienced some difficulties
in providing myself with a sufficient store of venom. But thanks on
the one hand to the obliging collaboration of some of my old pupils
or colleagues, and on the other to the valuable co-operation of the
Colonial Governments of Indo-China, the French Settlements in India,
and Martinique, I soon received poisonous snakes and dried venom in
abundance.

[Illustration: FIG. 93.--VACCINATING A HORSE AGAINST VENOM AT THE
PASTEUR INSTITUTE AT LILLE.]

After this I was not long in pushing the vaccination of a few horses
until I made them resist, in a single injection, 2 _grammes_ of dry
cobra-venom, a dose about _eighty times lethal_; for I was able to
satisfy myself that about 0·025 gramme of cobra-venom was sufficient to
kill fresh horses in from twelve to twenty-four hours.

The immunisation of horses to this very high degree of tolerance of
venom is not obtained without difficulties; many animals succumb in
course of treatment from endocarditis or acute nephritis; in the case
of others, each injection of venom leads to the formation of enormous
aseptic abscesses, which have to be opened and drained. It may be said
that on an average an interval of _sixteen months_ is necessary in
order to obtain a serum sufficiently antitoxic.

[Illustration: FIG. 94.--ASEPTICALLY BLEEDING A HORSE VACCINATED
AGAINST VENOM IN ORDER TO OBTAIN ANTIVENOMOUS SERUM AT THE PASTEUR
INSTITUTE AT LILLE.]

When a horse is well vaccinated and tolerates without a reaction 2
_grammes_ of dry cobra-venom in a single subcutaneous injection, it may
be bled on three consecutive occasions in the space of ten days, and in
this way 20 litres of blood may be drawn from it (fig. 94).

The bleeding is arranged in the following manner: _Twelve days_ after
the last injection of venom the horse is bled for the first time to the
extent of 8 litres; five days later it is bled for the second time to
the extent of 6 litres; five days later still the third bleeding takes
place, when 6 litres are again withdrawn.

The animal is then allowed to rest for three months and supplied with
strengthening food, and during this period 2 _grammes_ of venom are
again injected on two occasions at the end of a month, followed, a
month and a half later, by the injection of 2 more _grammes_. The
antitoxic power of the serum is thus maintained approximately at the
same standard.

The serum drawn off at each bleeding must be severely tested, which is
done by gauging its antitoxic power _in vitro_, when mixed with venom,
and also its preventive effect.

An antivenomous serum may be considered to be utilisable when a mixture
of 1 c.c. of serum with 0·001 gramme of cobra-venom produces no
intoxicating effect in the rabbit, and when a preventive subcutaneous
injection of 2 c.c. of serum into a rabbit of about 2 kilogrammes
enables it to resist, two hours later, subcutaneous inoculation with 1
milligramme of venom.

The _preventive power_ may be very quickly tested by injecting a
rabbit, _in the marginal vein of the right ear_ for example, with
2 c.c. of serum, and injecting, _five minutes afterwards_, _in the
marginal vein of the left ear_, 8 milligramme of venom. This dose of
1 milligramme generally kills the control rabbits in less than thirty
minutes when introduced into the veins, and in from two to three hours
when injected beneath the skin.

This rapid proof by _intravenous injection_ is extremely striking and
demonstrative; it can be effected in public during a class or lecture
in less than an hour, and enables an immediate estimate to be formed
of the value of an antivenomous serum. When it is intended to adopt
this method, it is essential to make use of a recent solution of venom,
for solutions from a week to a fortnight old, although sterile, have
already lost a large portion of their toxicity, and, if these be
employed, the dose of venom calculated to kill the control animals in
thirty minutes, for example, takes an hour or more to do so.

I always prepare my test solutions of venom in the following manner:--

Ten milligrammes of dry cobra-venom are weighed in a delicate balance.
The venom is dissolved in 10 c.c. of 0·8 per cent. physiological salt
solution, which takes a few minutes. When the venom is thoroughly
dissolved it is transferred to a test-tube, which is immersed for
three-quarters of an hour in a water-bath heated to + 72° C. In
this way the non-toxic albumins are coagulated without modifying
the neurotoxic substance. The solution is poured on to a filter
of sterilised paper, and the clear liquid which is collected is
immediately put up in glass phials, which are hermetically sealed,
or in small sterilised bottles. Its toxicity is tested upon control
animals, and it may be kept for five or six days if protected from
light, or for several weeks in a refrigerator at about 0° C.

_One-tenth of this solution corresponds exactly to 1 milligramme of dry
venom._

As for the antivenomous serum, as soon as its antitoxic value has been
ascertained by the methods that I have just described, and it has
been separated from clots and red corpuscles by suitable decantation,
it is portioned out, with the usual aseptic precautions, into small
sterilised bottles of 10 c.c. capacity, without the addition of any
antiseptic.

In order to ensure that it will keep for a long time, care is then
taken to heat the hermetically sealed bottles in a water-bath at a
temperature of 58° C. for one hour, and this operation is repeated for
three days in succession.

Serum prepared in this way preserves its antitoxic power unimpaired
for about two years, _in all climates_. I have had occasion at various
times to receive bottles which had been sent eighteen months and two
years previously to India and Indo-China, and I was able to show
that their standard had not perceptibly deteriorated. It was only the
appearance of the contained liquid that was slightly changed; it was
discoloured, and when shaken small white flakes were seen floating
through it. These flakes are not a sign of deterioration; they are
composed of deposits of precipitated albumin. They can be partly
dissolved again by violent shaking, or they may be separated before use
by filtration through sterilised paper.

In a dry state, antivenomous serum may be kept for an almost indefinite
period, in hermetically sealed glass tubes. In this condition it is
usually divided into doses of 1 gramme, and when it is desired to make
use of it, it is sufficient to dissolve a dose in 10 c.c. of water
which has been boiled and allowed to cool, which takes two or three
minutes. This solution is then injected beneath the skin, as though it
were liquid serum.

The Pasteur Institute at Lille prepares in this way large quantities
of antivenomous serum, which are sent all over the world to those
countries in which poisonous snakes are most dangerous.

Recently, special laboratories for the production of this preparation
have been instituted at Bombay and at Kasauli, in the Punjab, by
Drs. G. Lamb and Semple; at Philadelphia, by Professor McFarland;
at São-Paulo, in Brazil, by Dr. Vital Brazil; and at Sydney, by Dr.
Tidswell.

* * * * *

_Specificity and Polyvalence of Antivenomous Serums._--By means of a
large number of experiments I have proved that snake-venoms, whatever
their origin, contain two principal substances: _neurotoxin_, which
exerts its effects upon the elements of the nervous system, and
_hæmorrhagin_ (Flexner and Noguchi), or _proteolytic diastase_, the
effects of which remain exclusively local when the venom is introduced
subcutaneously into the cellular tissue, but which produces coagulation
of the blood when the venom is injected directly into the blood stream.

The venom of COLUBRIDÆ in general is characterised by the
constant predominence of _neurotoxin_, to which it owes its extreme
toxicity, which is especially intense in the case of cobra-venom. It
contains no, or scarcely any _hæmorrhagin_; for this reason the local
symptoms of poisoning by COLUBRINE venom are almost _nil_.
This _neurotoxin_, as we have seen, shows itself very highly resistant
to heat.

The venom of VIPERIDÆ, on the contrary, especially that
of _Lachesis_, is characterised by the almost total absence of
_neurotoxin_, while its richness in _hæmorrhagin_ is considerable.
Consequently, heating for a few minutes at + 75° C. renders it almost
entirely inactive, since _hæmorrhagin_ is very sensitive to heat.

Given venom of some kind or other, the origin of which is unknown, it
is therefore possible to ascertain whether the snake from which it was
extracted belonged to the COLUBRIDÆ or VIPERIDÆ, by
determining its richness in _neurotoxin_ resistant to heating at + 85°
C.

Certain VIPERINE venoms, such as those of the European
_Vipera berus_ and _Vipera aspis_, the African _Cerastes_ and American
_Crotalus_ contain at the same time a small proportion--varying greatly
in amount according to the species--of _neurotoxin_, and a much larger
proportion of _hæmorrhagin_. It is for this reason that these venoms,
although greatly attenuated and deprived of their local action by
heating, still remain toxic when injected in large doses into animals
after having been heated to + 75° C.

On the other hand, some COLUBRINE venoms, such as those of
_Bungarus cæruleus_, which are very rich in _neurotoxin_, contain a
quantity of hæmorrhagin sufficient to differentiate their effects in
appearance from those produced by cobra-venom, when they are injected,
not beneath the skin, but directly into the veins. In this case their
effects upon the blood are added to those of their neurotoxin.

It would seem, too, that the venoms of Australian COLUBRIDÆ
(_Hoplocephalus_, _Pseudechis_) form a special group, which is richer
in _hæmorrhagin_ than are those of the COLUBRIDÆ of the Old
World.[99]

On studying, in the case of these various venoms, the action _in vitro_
and _in vivo_ of a purely _antineurotoxic_ antivenomous serum, such as,
for example, that of an animal vaccinated against cobra-venom heated
to + 75° C., it is found that this serum has a very decided effect
upon cobra-venom, and likewise upon that of snakes belonging to allied
species (_Naja bungarus_, _Naja haje_), and that its action upon the
other venoms is less in proportion as they contain less _neurotoxin_.
It prevents hæmolysis _in vitro_, and suppresses the effects of
intoxication on the nervous system, but does not modify in any way the
phenomena of coagulation or of proteolysis.

If this serum be made to act _in vitro_ on those VIPERINE
venoms that, when heated to + 75° C. and deprived of their hæmorrhagin,
remain neurotoxic, like the venom of the common viper, it is found
that it renders them entirely innocuous. Therefore, in the case
of all species of poisonous snakes, and perhaps also in that of
other poisonous animals (such as scorpions), it appears that the
_neurotoxic_ substance is _one and the same_, and always neutralisable
by an _antineurotoxic_ serum like that of animals vaccinated against
cobra-venom.

_Neurotoxin_ being the essentially active substance in venoms, and that
to which the dangerous properties of poisonous snakes, as regards man
and domestic animals, are especially due, it is the effects of this
that it is most necessary to prevent. Consequently, the first quality
that an antivenomous serum ought to exhibit, in order to be capable
of being used in the therapeutics of poisoning, is the possession of
an _antineurotoxic_ power as high as possible. This antineurotoxic
power is easily obtained by employing cobra-venom for the fundamental
immunisation of the horses destined for the production of the serum.

_Antineurotoxic_ serum thus prepared shows itself perfectly capable
of preventing all effects of intoxication from cobra-bites, which
are much the most frequent in India. In the same way it shows itself
quite sufficiently efficacious with regard to COLUBRINE
and VIPERINE venoms, the neurotoxic activity of which may
cause death. But it does not possess any preventive action upon the
local effects of _hæmorrhagin_, to which the noxiousness of certain
VIPERINE venoms--such as those of _Lachesis_--are almost
exclusively due.

In countries in which VIPERIDÆ are very common, we must
therefore not confine ourselves to vaccinating the animals that produce
serum solely against the _neurotoxin_ of cobra-venom, for instance; we
must prepare these animals, after having immunised them to cobra-venom,
by injecting them with progressively increasing doses of the various
venoms derived from the snakes that are most frequently met with in the
district.

Nothing, moreover, is easier than to train animals vaccinated against
cobra-venom to tolerate strong doses of the venoms of _Lachesis_,
_Vipera russellii_, _Crotalus_, _Hoplocephalus_, or _Pseudechis_. In
a few months we succeed in obtaining serums very active against these
different venoms.

Utilising the horse as producer of antitoxin, I have prepared by this
method _polyvalent_ serums capable of preventing the local action of
VIPERINE venoms, and of suppressing _in vitro_ their coagulant
and proteolytic effects upon the blood.

Unfortunately, great as has been the kindness of the many persons
who have most obligingly given me their assistance in the course of
the fifteen years during which I have studied this question, I have
found it impossible to procure sufficient quantities of venoms of
various origins to furnish each country with the polyvalent serums
corresponding to its particular needs. I have therefore been obliged to
confine myself to preparing for the most part _antineurotoxins_, which
I have been able to do, thanks to the abundant provision of _Cobra_-
and _Bungarus_-venoms, for which I am indebted to the liberality of the
Government of the French Settlements in India, and to that of my pupils
and friends who are at the present time in charge of the Colonial
Laboratories of Indo-China. Moreover, the recent foundation of the
Serum-Therapic Institutes of Bombay and Kasauli, Sydney, São-Paulo, and
Philadelphia, to-day renders it very easy for each country to provide
itself with antivenomous serum, either specific or polyvalent. Other
institutes will doubtless be established for the purpose of extending
the benefits of a method, the efficacy of which is sufficiently evident
for its adoption to be incumbent upon all those who are concerned with
safeguarding human existence.

CHAPTER XIV.

_NEUTRALISATION OF VENOM BY ANTITOXIN._

It is difficult, in the present state of our knowledge on the subject
of toxins and antitoxins, to determine the precise nature of the
reactions that are produced in the living organism as the result of
serum injected for the purpose of preventing the toxic action of venom.

I maintained, some years ago,[100] that the phenomenon in this case
was a purely physiological one, which I considered to be proved by the
fact that, if we mix _in vitro_, in determinate proportions, venom and
antivenomous serum, and if we heat this mixture at 68° C. for half an
hour, the injection of the heated mixture kills animals as if they were
inoculated with venom alone, although with a considerable retardation.
I concluded from this that, in all probability, antitoxic serum does
not modify the toxin with which it is mixed, but that it confines
itself to displaying a parallel and opposite action by preventing the
noxious effects. I therefore supposed that no chemical combination
is produced between these two substances, or, at least, that the
combination effected is very unstable.

My experiments were subsequently repeated by Martin and Cherry,[101]
who showed that the results as stated above were perfectly correct when
the mixture of venom and antitoxin was heated less than ten minutes
after it had been made, but that, if the heating did not take place
until twenty or thirty minutes later, the toxicity of the venom no
longer reappeared.

On the other hand, the admirable researches of Kyes and Sachs, and
subsequently those of Morgenroth, pursued under the direction of
Ehrlich at the Laboratory of Experimental Therapy at Frankfort, have
proved the readiness of venom to enter into chemical combination with
certain elements of normal serums, in particular with _lecithin_,
a combination which results in the formation of _hæmolysing_ and
non-toxic _lecithides_, the _neurotoxin_ being left free.

It therefore seemed impossible to deny the existence of a chemical
reaction between the venom and the serum, which was until quite
recently considered as proved. We shall see presently that this is not
the case. But let us first endeavour to determine the laws that govern
the neutralisation of variable quantities of venom by antivenomous
serum.

If, in a series of test-tubes, we bring the same quantity of
cobra-venom (_e.g._, 0·00005 gramme, a dose which is invariably lethal
to the mouse in two hours) into contact with progressively increasing
quantities of an antivenomous serum (_e.g._, 0·01 c.c., 0·02 c.c.,
&c., up to 0·1 c.c.), and, after thirty minutes of contact, inject
these different mixtures subcutaneously into a series of mice, we find
that all those that have received the mixtures containing less than
0·05 c.c. of serum succumb after variable intervals, while all the
rest survive. It is evident that, under these conditions, the serum
experimented upon has shown itself capable of neutralising _in vitro_,
in a dose of 0·05 c.c., 5 centimilligrammes of venom.

The same serum should therefore neutralise 1 milligramme of venom in a
dose of 1 c.c., that is to say, that this mixture injected into a mouse
ought to be entirely innocuous. Experiments show, however, that in
reality it is necessary to mix 1·2 c.c. of serum with 1 milligramme of
venom in order that the inoculated mouse may not succumb.

This proves that, in the initial mixture of 0·00005 gramme of venom +
0·05 c.c. of serum, there remained an exceedingly small quantity of
non-neutralised venom, and that this quantity of venom in a free state
was insufficient to cause the death of the animal, or even any apparent
malaise. When multiplied by twenty, however, it becomes capable of
producing toxic effects; it is for this reason that, when it is desired
to inoculate a mouse with twenty times the lethal dose of 0·00005
gramme _neutralised_, it is necessary to mix with this twenty times
lethal dose a dose of serum _a little larger_ than twenty times that
which renders 0·00005 gramme of venom innocuous to the mouse, that is
to say, 1·2 c.c.

If, instead of making use of the _mouse_ as test animal, we employ the
_rabbit_, it is found that the same serum, in a dose of 0·75 c.c.,
neutralises 0·001 gramme of venom sufficiently for the mixture to be
innocuous when inoculated. It is clear that, in this mixture, the whole
of the venom was not neutralised by the serum, but the small quantity
left free is incapable of producing harmful effects.

By this method of employing mixtures of the same dose of venom with
variable quantities of antivenomous serum, we are therefore enabled to
determine with the greatest exactness the antitoxic power _in vitro_ of
each specimen of serum. But it must not be forgotten that _the result
obtained applies only to the species of animal into which the mixtures
were injected_.

I have already stated (Chapter VIII.) that a fairly close parallelism
exists between the _neurotoxic_ action of venoms and their _hæmolytic_
action, and I have established that, in order that the sensitive red
blood-corpuscles may be dissolved under the influence of venom, it is
indispensable that the reaction take place in the presence of normal
serum, since venoms have no effect upon red corpuscles freed from serum
by several successive washings and centrifugings.

Preston Kyes has explained this phenomenon very well by showing that
the venom combines with the lecithins in the serum, or with those
contained in the stroma of the corpuscle, so as to constitute a
hæmolysing _lecithide_.

The knowledge of this fact enables us to determine, by means of a very
neat and simple method, and with a sufficient degree of accuracy for
practical purposes, the antitoxic power of an antivenomous serum by
measuring its _antihæmolytic_ power.[102]

To this end it is sufficient to cause variable doses of serum to act
on a given quantity of defibrinated horse- or rat-blood, to which a
constant dose of venom is then added. We employ, for example, a 5 per
cent. dilution of defibrinated horse-blood, which is portioned out in
doses of 1 c.c. into a series of test-tubes. To each of these tubes in
succession is added a progressively increasing quantity of the serum
for titration, starting with 0·01 c.c., and continuing with 0·02 c.c.,
0·03 c.c., &c., up to 0·1 c.c. A control tube receives no serum. There
are then introduced into all the tubes 1 decimilligramme of venom and
0·2 c.c. of normal horse-serum, deprived of alexin by previous heating
for half an hour at 58° C. At a temperature of about 16° C. hæmolysis
commences to manifest itself in the control tube in from fifteen to
twenty minutes. It takes place in the other tubes with a retardation
which varies with the dose of serum added. Tubes are to be noticed in
which it does not occur even after the lapse of a couple of hours.

Experience shows that we may consider as good for therapeutic use
serums which, in a dose of 0·05 c.c., completely prevent hæmolysis by
1 decimilligramme of COLUBRINE venom, such as that of Cobra,
Krait, &c., and those that in a dose of 0·7 c.c., prevent hæmolysis by
1 milligramme of the venom of _Lachesis_ or _Vipera berus_.

By a method calculated upon the foregoing, it is likewise possible
to measure the _antihæmorrhagic_ activity of an antivenomous serum,
for the parallelism existing between the _antineurotoxic_ and
_antihæmolytic_ actions of serums occurs again, as I have been able to
establish in conjunction with Noc, between the _antihæmorrhagic_ and
_antiproteolytic_ action of the same serums.

Now, the _antiproteolytic_ action is easily determined by means of
a series of test-tubes containing the same quantity of 20 per cent.
gelatinised _bouillon_, rendered imputrescible by the addition of
a small quantity of thymol. The gelatine being kept liquid in the
incubating stove, a progressively increasing quantity of serum is
poured into each tube. The same dose of venom, say 1 milligramme, is
then added in each case. The tubes are placed in the stove for six
hours at 36° C. They are then withdrawn and immersed in a bath of cold
water. Those in which the gelatine solidifies are noted, and thus we
establish the dose of antivenomous serum that inhibits the proteolysis
of this substance.

These different methods of control enable us to verify the activity
of antivenomous serums with great exactness, without the necessity of
having recourse to experiments upon animals.

* * * * *

In a very important memoir on the reconstitution of the toxins from a
mixture of _toxin_ + _antitoxin_, J. Morgenroth[103] has shown that
the venom, after being naturalised by the antivenomous serum, can be
dissociated from its combination by means of a method which consists in
adding to the latter a small quantity of hydrochloric acid.

Previous experiments by Kyes had established:--

(1) That antivenomous serum, the antitoxic action of which is so
manifest when it is mixed _in vitro_ with cobra-venom, remains entirely
inert when brought into contact with the combination _lecithin_ +
_venom_, that is to say, with _cobra-lecithide_.

(2) That the addition of lecithin to a neutral combination of _venom_ +
_antivenomous_ serum does not set the venom free again, and that under
these conditions no _lecithide_ is formed.

If, in a neutral mixture of _cobra-hæmolysin_ and _antitoxin_ we could
succeed in dissociating the two constituent elements, and in then
making the _cobra-hæmolysin_ combine with the _lecithin_, we should
have a toxin and antitoxin side by side; for the reasons indicated
above, this toxin (_lecithide_) and antitoxin (_antivenomous_ serum)
would be no longer capable of combining; but the toxin (_lecithide_),
thanks to its hæmolytic properties, could easily be demonstrated.

It is precisely this desideratum that J. Morgenroth has succeeded in
realising, by means of hydrochloric acid, which renders it possible
to dissociate the neutral mixture, _toxin_ + _antitoxin_, into its
constituent elements, and then to obtain a _lecithide_.

Experiments show that the quantity of lecithide thus restored
absolutely corresponds to that of the cobra-hæmolysin originally added
to the antitoxin, and that the antitoxin set free is not injured by
the hydrochloric acid, even after twenty-four hours of contact. It is
sufficient to add the quantity of soda or of ammonia necessary for the
neutralisation of the acid, in order to see the antitoxin reappear in
its original strength.

It is therefore possible, by causing hydrochloric acid (in a solution
not stronger than 3 per cent.) to act on a neutral mixture of
cobra-hæmolysin (toxin) and antitoxin, to set the former at liberty
in the form of _lecithide_, to withdraw the latter from the action of
the antitoxin, and to demonstrate its presence, owing to its hæmolytic
properties.

It has been found by Kyes and Sachs that, under the influence of
hydrochloric acid, cobra-hæmolysin becomes resistant to heat to such an
extent that it is not destroyed even by prolonged heating at 100° C.

If to a neutral mixture of toxin + antitoxin we add a small quantity of
hydrochloric acid, and then heat the mixture at 100° C., the antitoxin
being in this case destroyed, we shall recover the whole of the toxin
originally employed.

Therefore, as was shown by me so long ago as 1894, if the mixture of
toxin + antitoxin produces a chemical combination between the two
substances, this combination is unstable, and can be effectively broken
up into these two constituent elements by various influences.

CHAPTER XV.

_TREATMENT OF POISONOUS SNAKE-BITES IN MAN AND ANIMALS._

_OBJECTS OF THE TREATMENT: TECHNIQUE OF ANTIVENOMOUS SERUM-THERAPY._

In all countries the remedies recommended for the bites of poisonous
snakes are innumerable, and native pharmacopœias abound in so-called
infallible recipes.

Pliny himself wrote on this subject as follows:--

“For poisonous bites, it is customary to employ a liniment made of
fresh sheep-droppings, cooked in wine. Rats cut in two are also
applied; these animals possess important properties, especially at the
epoch of the ascension of the stars, seeing that the number of a rat’s
fibres wax and wane with the moon.

“Of all birds, those that afford most assistance against snakes are
vultures. The black ones are the weaker. The odour of their feathers
when burnt puts snakes to flight. Provided with a vulture’s heart one
need not fear encounters with snakes, and can also defy the wrath of
wild beasts, robbers, and princes.

“Cock’s flesh, applied while still warm, neutralises the venom of
snakes. The brains of the bird, swallowed in wine, produce the same
effect. The Parthians, for this purpose, make use of chicken’s brains.
The fresh flesh of the pigeon and the swallow, and owls’ feet burned,
are good against snake-bites.

“If one has been bitten by a snake or by any venomous animal, another
method of cure is to take salt fish and wine from time to time, so as
to vomit in the evening. This remedy is chiefly efficacious against
the bite of the _Chalcis_, _Cerastes_, _Seps_, _Elaps_ and _Dipsas_.”

* * * * *

In Equatorial America, and especially in India, a multitude of plants
are credited with marvellous properties, which they possess only in
the imagination of the snake-charmers or medicine-men by whom they are
employed. None of them stand the test of experiment, any more than the
more or less compound drugs, numbers of specimens of which from all
sources have passed through my hands.

It cannot, however, be denied that certain chemical substances, of
well-defined composition, are very useful, not as physiological
antidotes to venoms, but as agents for their modification or
destruction in the poisoned wounds, when they have not yet been
absorbed. In this way _permanganate of potash_, _chromic acid_,
_chloride of gold_, and the _alkaline hypochlorites_, especially
_hypochlorite of lime_, may be extremely useful under many
circumstances.

_Permanganate of potash_ was recommended in 1881 by Professor de
Lacerda,[104] of Rio de Janeiro, as the result of experiments made by
him with venoms of Brazilian snakes. When a few cubic centimetres of
a 1 per cent. solution of permanganate of potash are quickly injected
into the actual wound caused by the bite and around the point of
inoculation, there can be no doubt that the venom not yet absorbed is
destroyed. When mixed _in vitro_ with venom, permanganate renders the
latter innocuous.

Here, however, it is a case of actual destruction by direct contact. If
we inject a lethal dose of venom into the right thigh of an animal, for
example, and several cubic centimetres of permanganate solution into
different parts of the body, or beneath the skin of the left thigh,
neither the general intoxication nor the local effects of the venom are
modified.

The same may be said with regard to _chromic acid_ (1 per cent.
solution), recommended by Kaufmann[105] for the bite of the common
viper.

No other effect is produced by a 1 per cent. solution of _chloride of
gold_, or the _alkaline hypochlorites_, which I have shown to possess
a strong oxidising action on the different venoms, even on those that
are most rapidly diffusible, such as cobra-venom (see Chapter V.). They
possess, however, owing to their slight causticity, the advantage of
not producing severe local disorders, and in this respect they are to
be preferred.

The chemical reagent most to be recommended is _hypochlorite of lime_,
in a fresh solution of 2 grammes per cent., and containing about 90
c.c. of chlorine per 100 grammes. It immediately and surely destroys
the venom by simple contact, and the chlorine gas that it gives off,
owing to its great diffusibility, acts at a fairly long distance from
the point of inoculation on the venom which is already beginning to be
absorbed.

Professor Halford, of Melbourne, advises the direct injection into the
patient’s veins of from 10 to 20 drops of ammonia, diluted with an
equal quantity of distilled water. This is a means of reviving nervous
excitability in certain subjects at the commencement of intoxication;
but torpor soon reappears, and, if the dose of venom inoculated is
sufficient to cause death, a fatal ending takes place notwithstanding.
Experimentally the effects of ammonia are _nil_.

No better results are obtained by injections of strychnine, as
recommended by Dr. Mueller, in Australia. Moreover, the statistics
published by Raston Huxtable[106] positively condemn this therapeutic
method. They show that, in 426 cases of snake-bite, out of 113 treated
by strychnine 15 proved fatal, the ratio of mortality being 13·2 per
cent., while the 313 cases not treated by strychnine only resulted in
13 deaths, or a mortality of 4·1 per cent.

In the case of animals intoxicated by venom, injections of strychnine,
morphia, nicotine, or curare in small doses always prove ineffective;
they even considerably assist the progress of the intoxication and
hasten death. The use of these drugs in the case of human beings should
therefore be absolutely forbidden.

It appears, on the other hand, that alcohol and coffee, or tea,
absorbed by ingestion, are very often beneficial. Indeed, it was
long ago observed that the swallowing of alcohol until symptoms of
drunkenness appear retards or diminishes the phenomena of torpor and
paresis that precede the ultimate phase of the intoxication. Its use
may therefore be recommended when it is impossible to have recourse
to the only treatment really specific that modern science places in
our hands--_antivenomous serum-therapy_. It is important, however, to
state that, _when serum is used, alcohol must be forbidden_. The latter
hinders the effects of the former.

In practice, the rational treatment of the bite of a venomous snake
must be directed towards:--

(1) Preventing the absorption of the venom.

(2) Neutralising, by the injection of a sufficient quantity of
antitoxic serum, the effects of the venom already absorbed.

In order to prevent the absorption of the venom introduced into the
wound, the first precaution to be taken is to compress the bitten limb
by means of a ligature of some kind, such as a handkerchief, as close
as possible to the bite, and between it and the base of the limb. The
ligature must be tightly twisted, and, by compressing the tissues
around the bite, an attempt should be made to squeeze out the venom
that may have been introduced into them. The expulsion of the poison
should be hastened, either by making an incision 2 or 3 cm. in length
and 1 cm. in depth in the direction taken by the fangs of the reptile
and also parallel to the axis of the bitten member, or by sucking the
wound hard.

The ligature on the limb should not be applied for more than half an
hour; if it were kept on longer it would interfere with the circulation
to a dangerous degree, and would certainly injure the vitality of the
tissues. The period in question also usually affords sufficient time
for taking the patient to a place where help can be obtained, and for
the preparation of everything necessary for his subsequent treatment.

The wound should then be freely washed with a fresh 2 _per cent._
solution of _hypochlorite of lime_, or with a 1 in 1,000 solution of
_chloride of gold_. In default of hypochlorite of lime or chloride of
gold, either _eau de Javel_, diluted with tepid water to a strength
of 1 in 10, or a 1 per cent. solution of permanganate of potash, may
be employed. These reagents should be made to penetrate as deeply as
possible into the tissues, and a few cubic centimetres of them should
even be injected with a Pravaz syringe into the punctures caused by the
bite and all round them.

The wound being then covered with a damp dressing by means of
compresses saturated with hypochlorite of lime, or at least with
pure alcohol, the next thing to be done is to prepare to apply the
serum-therapic treatment in order to arrest the general intoxication,
if this has already commenced to take effect, or to prevent it from
setting in.

For the employment of serum it is necessary to be in possession of a
sterilisable syringe of the capacity of 10 c.c., similar to those used
in the treatment of diphtheria.

If the life of the patient be not immediately in danger, care should
first be taken to have the syringe boiled, or at least to rinse it out
with boiling water, making sure that the piston fits tightly, and that
the syringe itself is in good working order.

Should a syringe of 10 c.c. not be available, any kind of Pravaz
syringe, previously washed out with boiling water, may be employed, but
in this case the use of so small an instrument renders it necessary to
give several painful injections.

The entire contents of a bottle of serum (10 c.c. of liquid serum, or
1 gramme of dry serum dissolved in 10 c.c. of boiled water) should be
injected into the subcutaneous areolar tissue of the abdomen, on the
right or left side. There is no advantage in making the injection at
the actual spot bitten; the serum is best and most rapidly absorbed
when injected into the loose tissues of the abdominal wall (fig. 95).

[Illustration: FIG. 95.--TECHNIQUE OF THE INJECTION OF ANTIVENOMOUS
SERUM BENEATH THE SKIN OF THE ABDOMEN.]

If it has been impossible to apply the treatment until several hours
after the bite, and if the latter has been inflicted by a poisonous
snake of large size or belonging to a very dangerous species, such as
the Cobra or Indian Krait, it is preferable to inject into the patient
three whole doses of serum at once.

In cases in which the phenomena of serious intoxication have already
appeared, and when asphyxia threatens, one must not hesitate to inject
10 or even 20 c.c. of serum directly _into a vein_. For such an
injection it is most convenient to choose a superficial vein at the
elbow or wrist, or on the back of the hand.

The introduction of serum into the veins is never dangerous if good
care be taken not to allow either bubbles of air or particles of
precipitated albumin to enter.

It is not advisable to repeat the injections beneath the skin or into
the veins unless the general symptoms appear to become more acute.

In most cases the local pain, excitement, and attacks of cramp and
nausea disappear within a few minutes after the first injection.
Improvement progresses very rapidly, and by the following day the
patient has recovered.

The administration of ammonia, alcohol, morphia, or ether by the mouth
is entirely superfluous. These drugs, as I have already stated, may
even be harmful to the patient and hinder the effects of the serum. All
that should be done is to give copious hot drinks, tea or coffee, and
to cover up the patient warmly in order to induce abundant perspiration.

The bitten member should not be cauterised with red hot iron or with
chemical agents of any kind, since such cauterisations only lead to
injuries which are too often prejudicial to the normal action of the
affected organs.

_Treatment of Poisonous Bites in the Case of Domestic Animals._--It
often happens that dogs, horses, or cattle are bitten and succumb to
the poisoning in a few hours or in two or three days. Such accidents
are especially frequent among sporting dogs, even in Europe, in regions
in which _vipers_ are found.

In most cases, dogs, horses, and cattle are bitten on the nose, and
such bites are immediately followed by a very painful swelling,
which arouses the suspicion of the owners of the animals. It is then
necessary, as soon as possible, to inject subcutaneously in the
right or left flank, or at the base of the neck, one or two doses of
antivenomous serum, according to the gravity of the effects observed.

The injection of the serum and the dressing of the wound should be
performed as in the case of poisonous bites in human beings.

_Influence of the Doses of Antivenomous Serum injected, and of the Time
that has elapsed since the Venomous Bite._--I have stated above that
antivenomous serum possesses a preventive and curative power of such
intensity, that it is capable in a few minutes of rendering animals
into which it has been injected absolutely insensible to the most
strongly neurotoxic venoms, such as those of _Naja_ or _Bungarus_. On
the other hand, I have established the fact that, the more sensitive
are the animals to intoxication by venom, the greater is the quantity
of antivenomous serum necessary to immunise them passively or to cure
them.

In experimenting upon mice, guinea-pigs, and rabbits, it is found
that in order to preserve, let us say, a mouse of 25 grammes
against inoculation with half a milligramme of venom, which is ten
times the lethal dose for this little animal, it is necessary to
give a preventive injection of 1 c.c. of serum; while half a cubic
centimetre of the same serum is sufficient to render the dose of half
a milligramme of venom innocuous, when venom and serum are mixed _in
vitro_ before being injected.

In the case of the guinea-pig, it is likewise found that the dose of
serum to be injected preventively, in order to protect the animal from
intoxication by ten times the lethal dose of venom, is about _twice as
much_ as the quantity of the same serum that it is sufficient to mix
_in vitro_ with venom, in order to render ten times the lethal dose of
venom innocuous.

If we inject into animals first venom, in doses calculated to kill
the controls of the same weight in from two to three hours, and the
serum _fifteen minutes afterwards_, it is found that the quantity of
serum that must be injected in order to prevent death is about _thrice
as great_, as that which neutralises _in vitro_ the dose of venom
inoculated.

It is also found that _the amount of curative serum that an animal
intoxicated by venom must receive is inversely proportional to its
weight_.

The experiments upon dogs, performed at the Pasteur Institute at
Lille by my collaborator C. Guérin, are highly demonstrative in this
respect.[107]

A dog of 12 kilogrammes, inoculated with 9 milligrammes of venom (a
dose lethal to controls of the same weight in from five to seven
hours), is completely cured on receiving, _two hours after inoculation
with the poison_, 10 c.c. of serum.

When the treatment does not take place until _three hours after the
injection of the venom_, it is necessary to inject 20 cc. of serum in
order to prevent the animal from dying. With a longer delay than this,
death is inevitable, since the bulbar centres are already affected, and
paralysis of the respiratory muscles commences to appear.

These facts show that:--

(1) _The more sensitive animals are to venom, the greater is the
quantity of serum necessary in order to prevent their intoxication by a
given dose of venom._

(2) _For a given species of animal and a given dose of venom, the
longer the delay in applying the remedy, the greater is the quantity of
serum that must be injected in order to arrest the poisoning._

It will be understood from what has been already stated, that a man
weighing 60 kilogrammes, if bitten by a snake which injects, let us
say, what would amount to 20 milligrammes of venom if collected in the
dry state (the mean quantity that a _Naja_ is able to inoculate in a
single bite), would only require, in order to escape death, to receive
the quantity of antivenomous serum sufficient to neutralise the portion
of venom in excess of the amount that he could tolerate without dying.

Let us suppose, for the sake of example, that the man of 60 kilogrammes
can withstand intoxication by 14 milligrammes of _Naja_-venom. It
follows that, in the case with which we are dealing, we must inject
sufficient serum to neutralise 20-14 (=6) milligrammes of venom;
that is to say, the injection of serum being made immediately after
the bite, 6 _c.c._, if the serum employed neutralises _in vitro_ 1
milligramme of venom per cubic centimetre.

Of course, if the serum is more powerful, less of it will be necessary,
while more will be required if the remedy is applied later, or if the
quantity of venom inoculated by the snake is supposed to have been
greater.

For this reason, in practice, but very little serum is usually
necessary in order to augment the natural resistance of a man of
average weight or of a large animal; it is sufficient in most cases
to give an injection of 10 or 20 c.c. in order to cure human beings
who have been bitten. The clinical proof of this is, moreover, to be
found in the cases, already very numerous, that have been published
in the course of the last few years in the scientific journals of all
countries. I have gathered together a few of these in the concluding
pages of this book, and I would beg the reader to be good enough to
refer to them.

PART IV.

VENOMS IN THE ANIMAL SERIES.

CHAPTER XVI.

1.--_INVERTEBRATES._

Besides reptiles, many other animals possess poison-glands and
inoculatory organs which they employ, either to defend themselves
against their natural enemies, or to capture the living prey upon which
they feed.

The venoms that they produce are still, for the most part, but little
understood. A few of them, however, have excited the curiosity of
physiologists, especially those secreted by certain batrachians, such
as the _Toad_, and certain fishes, such as the _Weever_. Some of them
exhibit close affinity to snake-venom, and are composed, like the
latter, of proteic substances modifiable by heat and precipitable by
alcohol; others possess altogether special characters, and resemble
alkaloids.

The lowest animal group in which these secretions begin to be clearly
differentiated is that of the _Coelenterates_.

A.--COELENTERATES.

It has been shown by Charles Richet[108] that the tentacles of
sea-anemones (_Anemone scultata_) contain a toxic substance which has
the carious property of causing intense itching, pruritus, and even
urticaria. This poison is perfectly soluble in alcohol, and can be
prepared in the following manner:--

The tentacles are cut off close to the body of the animal, and immersed
for a few days in an equal weight of alcohol at 95° C. The red liquid
that results is decanted, and then filtered. The insoluble material is
compressed, and yields large quantities of fluid, which is filtered and
mixed with the previous liquid.

The whole is then evaporated _in vacuo_ until there remains a thick
oily liquid, which forms a red deposit. Filtration through paper
is again employed, in order to separate this colouring matter, and
to the filtered liquid is added an equal amount of alcohol at 95°
C. By this means there is precipitated a blackish, gummy matter,
insoluble in alcohol. The remaining liquid is decanted and once more
evaporated until it is reduced to a smaller volume than before. It
is again treated with twice its volume of absolute alcohol, when
it precipitates, in addition to salts and gummy matter, a white
flocculent substance, which is crude _thalassin_. This can be purified
by redissolving it in alcohol at a temperature of 98° C. On cooling
it separates from the fluid in the form of crystals, which are placed
on a filter and can then be redissolved in a small quantity of water.
Absolute alcohol, added to this solution, precipitates the _thalassin_
in the shape of very pure crystals, which contain 10 per cent. of
azote, and melt at 200° C.

This substance, in aqueous solutions, rapidly deteriorates owing to
ammoniacal fermentation. When injected intravenously into dogs it
produces pruritus, sneezing, and erythema, with intense congestion of
the mucous membranes; 1 decigramme per kilogramme is a dose sufficient
to produce these symptoms. It is not very toxic, since 1 centigramme is
not lethal.

One kilogramme of anemones is capable of furnishing about 3 grammes of
pure crystallised poison.

In addition to _thalassin_, Richet succeeded in isolating from the
tentacles of the same sea-anemones another poison insoluble in alcohol
at 50° C., and richer in azote (14 per cent.), to which he has given
the name _congestin_. This is not destroyed by heating to 107° C. It
is prepared by precipitating, by four times its volume of alcohol, a
solution of anemone-tentacles in 5 per cent. fluoride of sodium. The
solid matter, after being precipitated and dried, is redissolved in
six times its volume of water, and then filtered. On adding to the
filtered and fluorescent liquid its volume of alcohol at 90° C., the
_congestin_ is precipitated. It is purified by redissolving it in
water, and freeing it by dialysis from the fluoride of sodium that
it has retained. In this way there is obtained, after evaporation, a
product sufficiently toxic to kill dogs in twenty-four hours in a dose
of 2 milligrammes per kilogramme.

_Congestin_ exerts a sensitising or anaphylactic effect upon
animals as regards _thalassin_, and is lethal in a dose of about 5
milligrammes per kilogramme of animal, and sometimes even in a dose of
7 decimilligrammes. It is therefore a very active poison.

Dogs, on the other hand, into which is injected first _thalassin_,
and then, some time afterwards, _congestin_, are perfectly resistant
to inoculation by the latter. _Thalassin_ is therefore _antitoxic_ or
antagonistic to _congestin_.

The latter, on the contrary, if injected first of all in non-lethal
doses, renders animals so sensitive to inoculation with _thalassin_,
that from 4 to 5 milligrammes are sufficient to cause death.

The tentacles of these anemones therefore contain two toxic substances
antagonistic to each other, which can easily be separated, since one
(_thalassin_) is soluble in concentrated alcohol, while the other is
completely insoluble in this reagent.

These poisons are not only extremely interesting from a physiological
point of view, but also possess a practical interest, since it is
at the present time almost a matter of certainty that they are the
cause of a malady which specially affects _sponge-divers_ in the
Mediterranean.

A good description of the disease has been given by Dr. Skévos Zervos,
of Athens.[109] It is observed exclusively in men who dive quite naked,
without a diving-dress. Now, beside the bases of the sponges and
sometimes on their surface there live numbers of anemones which secrete
a viscid substance, which is extremely virulent, especially in the
month of August.

The first symptoms that supervene after contact with these Cœlenterates
are an intense itching and burning sensation; a papule of a horny
consistency appears at the outset at the spot at which contact took
place; this is soon surrounded by a red zone, which becomes bluish and
then black, and spreads to a greater or lesser extent, according to
the region attacked and the virulence of the venom. After a few days
the skin sloughs and leaves a deep ulcer, which suppurates in spite of
antiseptic treatment. The onset of the disease is marked by a febrile
attack with shivering, which is soon accompanied by cephalalgia,
thirst, and pains in the back and limbs.

Zervos reproduced these disorders experimentally by rubbing an anemone,
held with forceps, on the shaven abdomen of a dog. In a few minutes the
region affected became quite red and pruriginous; twenty-five minutes
later phlyctenæ full of serum appeared; three days afterwards five
abscesses of different sizes developed, while at the place where it had
been touched by the venom the skin assumed a deep blue colour; on the
fifth day an area 2 cm. in diameter was completely gangrenous.

When ingested, anemones possess toxic properties which are well known
to the sponge-fishers, for they frequently make use of them for the
purpose of poisoning domestic animals. With this object they cut them
up into small fragments, and mix them with bread or meat, which is
given to the animals to eat; the latter die in convulsions in a few
minutes.

In order to preserve the divers from the harmful effects produced
by contact with the anemones, they should be advised to cover their
bodies with a layer of grease, a simple artifice which constitutes an
efficient protection.

B.--ECHINODERMS.

The _Echinoidea_ (Sea-urchins) are provided with soft prehensile
organs, the _pedicellariæ_, of which four kinds are distinguished:
gemmiform, tridactyle, trifoliate, and ophiocephalous.

These pedicellariæ contain a special venom, which causes the paralysis
and death of animals into which it is injected. Uexkull, who was the
first to mention it, considered that the gemmiform pedicellariæ alone
are toxic.

From this point of view various species of sea-urchins,
_Strongylocentrotus lividus_, _Arbacia æquituberculata_, _Sphærechinus
granularis_ and _Spatangus purpureus_, have recently been studied by V.
Henri and Mdlle. Kayalof.[110]

The pedicellariæ were removed and pounded up in sea-water, and the
pulp was injected into crabs, holothurians, star-fish, cuttle-fish,
frogs, lizards, and rabbits; in the case of cuttle-fish and rabbits the
injection was made intravenously; in that of the other animals into the
body-cavity.

For crabs the lethal dose was from 20 to 30 gemmiform pedicellariæ of
_Strongylocentrotus lividus_.

The holothurians, star-fish, and frogs proved immune.

In the case of rabbits weighing 1½ kilogrammes, 40 pedicellariæ of
_Sphærechinus granularis_, pounded up in 1 c.c. of water, produce death
by asphyxia and general paralysis in from two to three minutes. The
heart continues to beat after respiration has ceased.

For lizards and fishes the toxic dose is the same as for the crab. The
cuttle-fish is paralysed and killed in two hours by 50 pedicellariæ.

This venom resists ebullition for fifteen minutes.

V. Henri and Mdlle. Kayalof made experiments in immunisation. Rabbits
that receive every third day increasing doses of gemmiform pedicellariæ
of _Sphærechinus granularis_ tolerate well, after four injections, the
toxin of 40 pedicellariæ, a lethal dose. The serum of these rabbits is
not protective for either rabbit, crab, or fishes.

Frog serum (1 c.c.) injected into the body cavity of a crab, protects
this animal against the pulp of pedicellariæ injected immediately
afterwards.

The pedicellariæ easily become detached from sea-urchins. They remain
fixed to objects which come into contact with them, and the urchin
abandons them like poisoned arrows.

On touching a point on the surface of the body of an urchin, the spines
are seen to incline towards the spot touched, and the pedicellariæ
stretch themselves out and lean with their valves open towards the
seat of the stimulus. In _Sphærechinus granularis_ the heads of the
gemmiform pedicellariæ are covered with sticky mucus forming a tiny
drop, visible under the lens. A specimen of this species possesses more
than 450 pedicellariæ.

C.--ARTHROPODS.

(a) =Araneida= (=Spiders=).

Almost all Arachnids possess poison-glands, which are connected,
in some cases with the buccal apparatus, in others with a special
inoculatory organ situated at the posterior extremity of the body. The
_spiders_ and _scorpions_ belong to this group, and their venom is
particularly active.

On each side of the mouth of spiders is found an appendage ending in a
fang (_chelicera_), at the extremity of which opens the excretory duct
of a more or less developed poison-gland. The venom produced by these
glands is instantly fatal to all small animals upon which spiders
feed. In man and large mammals their bite produces sensations of pain
accompanied by swelling and muscular contractions as though caused by
localised tetanus.

The venom of certain species of spiders sometimes causes very serious
and even fatal results. _Latrodectus malmignattus_ (the _malmignatte_
of the South of France and Italy), and especially _Latrodectus
mactans_, of Chile (fig. 96), are greatly dreaded.[111] The area
of distribution of the latter includes the whole of Tropical and
Sub-tropical America. It is said that it frequently causes the death of
milch cows, and that in man its bite produces tetanic effects, which
last for several days, but are in most cases amenable to treatment.

[Illustration: FIG. 96.--_Lactrodectus mactans_ (_formidabilis
olim_).

1, Female, twice natural size; 1_a_, its eyes, greatly enlarged.]

Another dangerous spider is the _Katipo_ (_Latrodectus scelio_), of New
Zealand. This creature is confined to the sea-shore, and the natives
are often bitten when collecting shell-fish or sea-weed. The Maoris
are so much afraid of the bite of the _Katipo_ that, when one of them
has been bitten in his hut, and the animal cannot be found, they do
not hesitate to burn the dwelling to the ground. Moreover, they are
convinced that the death of the spider is absolutely necessary for the
recovery of the patient.[112]

Kobert[113] has made an experimental study of the venom of species
of _Latrodectus_ and _Epeira_. That of _Latrodectus erebus_ (the
_Karakurte_ of South Russia) is particularly toxic.

If a dry extract of these spiders be prepared and injected into
the veins of dogs or cats, it is found that a few milligrammes per
kilogramme are sufficient to cause death, with phenomena of dyspnœa,
convulsions, and progressive paralysis of respiration and the heart.
Rabbits, rats, birds, frogs, and leeches are also sensitive to this
poison, though the hedgehog is almost refractory. The young spiders,
and even the eggs, are more toxic than the adults.

Spider-venom is destroyed by heating for forty minutes at + 70° C.,
and is precipitated by alcohol. When absorbed by ingestion it has no
effect: it is hæmolytic and coagulates blood.

The study of _arachnolysin_ by Ehrlich’s methods has been undertaken
afresh by Hans Sachs,[114] who has shown that rat’s and rabbit’s blood
are most rapidly dissolved. Twenty-eight milligrammes of extract of
_Epeira_ are capable of completely dissolving 0·05 c.c. of blood.

By immunising guinea-pigs and rabbits, Sachs succeeded in obtaining a
strongly antitoxic serum, which entirely prevents the hæmolysis of the
sensitive red corpuscles.

(b) =Scorpionidea= (=Scorpions=).

The poison-apparatus of the scorpion is constituted by the last
abdominal segment (_telson_), which is swollen and globular, and
terminated by a hard, curved spine, with a very sharp point, near which
can be distinguished, under the lens, two small oval orifices by which
the poison is enabled to escape (fig. 97).

The poison-glands are two in number, symmetrically placed in cavities,
each of which is completely filled by the gland. They are separated
from each other by a muscular septum formed of striated fibres inserted
in the chitinous skeleton; by the contraction of this septum the animal
is enabled to eject its venom.

[Illustration: FIG. 97.--_Scorpio occitanus._ (After
Joyeux-Laffuie.)

1, Scorpion seizing a spider, and piercing it with its sting (natural
size); 2, extremity of the abdomen (telson) enlarged, showing the
poison-apparatus; 3, poison-apparatus detached from the abdomen,
showing an isolated poison-gland.]

The scorpion never stings _backwards_, but always _in front_ of itself.
It delivers stabs with its sting in two distinct ways. For the purpose
of defending itself from attack it elevates its abdomen into a bow, and
then regains its former position by suddenly unbending it. To strike
an animal, such as a spider, which serves it for food, the scorpion
seizes it with its pincers and holds it as in a vice. Then it raises
its abdomen, brings the end of it close to its captive, and, with
a lever-like movement, drives the sting into its body. The victim
immediately becomes paralysed and motionless.[115]

The poison-glands of a _Scorpio occitanus_ from the South of France
contain about 1 to 10 centigrammes of a toxic liquid, capable of
furnishing 10 to 15 per cent. of dry extract. This liquid is decidedly
acid; it reddens litmus paper and is miscible with water.

Its physiological effects are especially intense in the case of the
arthropods upon which the scorpion habitually feeds, and in that of
vertebrates in general. Batrachians, fishes, birds, and mammals are
extremely susceptible to this poison. Half a milligramme of dry extract
injected subcutaneously is sufficient to kill a guinea-pig, and 1
milligramme is lethal to the rabbit.

In poisoned animals there is first observed a period of violent
excitement, accompanied by very acute pains; these are followed by
muscular contractions, and finally by paralysis of the respiratory
muscles, as in the case of intoxication by cobra-venom.

The effects of scorpion-poison, which clearly indicate the presence of
a _neurotoxin_, have been very well described by Valentin,[116] Paul
Bert[117] and Joyeux-Laffuie. Kyes[118] has prepared a _lecithide_ from
scorpion-venom, which hæmolyses red corpuscles as do the lecithides
of cobra-venom, and I myself[119] have established the fact that
the antivenomous serum of a horse vaccinated against cobra-venom
effectively protects mice and guinea-pigs against intoxication by the
venom of _Scorpio occitanus_; this has been verified by Metchnikoff.
There is, therefore, a close affinity between this venom and that of
COLUBRINE snakes.

On the other hand, it has been shown by the investigations of C.
Nicolle and G. Catouillard that the same antivenomous serum has
no effect upon the much weaker venom of the scorpion of Tunis
(_Heterometrus maurus_), which, in the case of man and mammals in
general, scarcely does more than produce a transient œdema at the point
of inoculation.

The venom of _Heterometrus maurus_ is, however, toxic enough to the
sparrow. When one of these little birds is inoculated in the pectoral
muscles with the contents of the poison-glands of a single scorpion
belonging to this species, the following symptoms are observed:
Immediate rigidity, doubtless connected with the pain, then, after
a few seconds, depression and relaxation of the muscles. The bird
remains upright, but its body sinks down more and more until it comes
into contact with the ground; if on a perch, it soon becomes unsteady
and drops off. There is dyspnœa, which any effort increases, and
death supervenes suddenly; all at once the sparrow falls on its side,
stiffens, sometimes has a few convulsions, and then finally becomes
still. The time occupied by these phenomena is always short, although
it varies from two minutes to half an hour.

Scorpion-venom is a strong irritant to the mucous membranes. When
dropped into the eye of a rabbit it produces acute ophthalmia.

It has often been asserted that scorpions kill themselves with their
own venom if enclosed in a circle of fire. This is an absolute myth,
for it is easy to prove by experiment, as was done by Bourne at
Madras,[120] that these animals cannot be intoxicated by their own
poisonous secretion, nor by that of other individuals of the same
species. Moreover, it has been established by Metchnikoff,[121] in very
definite fashion, that the blood of the scorpion is antitoxic. If 0·1
c.c. of this blood be added to a dose of venom lethal to mice in half
an hour, a mouse injected with this mixture resists indefinitely. This
antitoxic power is exhibited both by _Scorpio afer_ and the Algerian
_Androctonus_.

It has been shown by Phisalix and Bertrand that certain species of
Myriopods, including those of the genus _Julus_ (Order _Chilognatha_,
_e.g._, _Julus terrestris_), secrete throughout the entire extent of
their body a volatile venom, which these authors compared to _quinone_.

The species of the genus _Scolopendra_ (Order _Chilopoda_; _Scolopendra
cingulata_, found in the South of France, Spain and Italy; _S.
gigantea_ and other forms, common in Africa, India, Indo-China and
Equatorial America), have the second pair of post maxillary appendages
transformed into formidable poison-claws, with which they can inflict
bites which are very painful to human beings.

[Illustration: FIG. 98.--_Scolopendra morsitans_ (S. Europe).

(After Claus.)]

The tropical species may attain a length of 10 or even 15 cm. Their
bodies are composed of 21 segments, each provided with a pair of
jointed legs. They live in shady places, such as woods, hidden under
stones, dead leaves, or the bark of old trees. They feed upon small
insects, spiders, and larvæ, which they kill with their venom. The
latter is secreted by a racemose gland situated at the base of the
poison-claws; it escapes by a duct which opens at the apex.

This venom, the physiological study of which was commenced by Dubosq,
is an acid, opalescent liquid, hardly miscible with water.

More complete experiments on this subject have been made by A.
Briot,[122] who prepared a solution by sectioning the labium and
poison-claws, and crushing the whole in physiological salt solution.
When injected intravenously into rabbits, it produces immediate
paralysis, with coagulation of the blood; subcutaneously it leads to
the formation of enormous abscesses, with necrosis of the tissues.
Small animals, such as spiders, species of _Scutigera_, beetles, &c.,
are very sensitive to it.

The bite of _Scolopendridæ_ is very painful to human beings. In the
Tropics such bites often cause somewhat serious results: insomnia,
accelerated and intermittent pulse, and local œdema, which usually
disappears after twenty-four hours. Well-authenticated fatal accidents
have never been recorded (Bachelier,[123] Saulie[124]).

(d) =Insects.=

A very large number of insects produce acrid or irritant secretions,
which serve them as a means of defence, but cannot be considered as
true venoms; the species of _Meloë_ (oil-beetles) and _Cantharis_
(blister-beetles), are the most remarkable in this respect.

The Order _Hymenoptera_ is the only one that includes a multitude of
species really provided with poison-glands and an inoculatory apparatus.

[Illustration: FIG. 99.--POISON-APPARATUS OF THE BEE.

_gl.ac_, Acid gland and its two branches; _V_, poison-sac; _gl.al_,
alkaline gland; _gor_, gorget.

(After Carlet: figure borrowed from Hommel.)]

The poison-organs, which have been well studied, especially by
Leuckart,[125] Leydig,[126] Carlet,[127] and more especially by L.
Bordas,[128] Janet,[129] and Seurat,[130] always include two and
sometimes three kinds of glands: the _acid gland_, the _alkaline gland_
or gland of Dufour, and the _accessory poison-gland_ (fig. 99).

The acid gland comprises a glandular portion (which sometimes takes the
shape of a long flexuous tube, always bifid at its extremity, sometimes
that of two tubes, simple or ramified, or again is composed of a bundle
of cylindrical, simple or multifid canals), a poison-sac or reservoir,
ovoid or spherical in shape, and an excretory duct, which is usually
short.

The alkaline gland, or gland of Dufour, exists in all Hymenoptera, and
presents the appearance of an irregular tube, with a striated surface
and a spherical or conical upper extremity. Its excretory duct opens,
beside that of the acid gland, at the enlarged base of the gorget of
the sting (fig. 100).

[Illustration: FIG. 100.--INTERIOR OF THE GORGET OF THE
BEE, SEEN FROM ITS POSTERIOR ASPECT.

_cv_, Poison chamber; _gor_, gorget; _st_, stylet; _ca_, piston.
Between the two stylets is seen the cleft _fa_, by which the air is
able to enter into the air-chamber _cai_.

(After Carlet: figure borrowed from Hommel.)]

The accessory poison-gland, which is lanceolate or ovoid in shape,
consists of a small, granular mass, the extremely narrow excretory duct
of which opens at almost the same point as that of the alkaline gland.
It does not exist in all Hymenoptera.

The stings of hive bees (_Apis mellifica_), wasps (_Vespa vulgaris_),
violet carpenter bees (_Xylocopa violacea_), and humble bees (_Bombus
lapidarius_) cause considerable discomfort. The venom of the carpenter
bee, which is of some strength, has been studied by P. Bert, and I have
myself made experiments with that of the hive bee (_A. mellifica_).
The venom extracted from a couple of bees, by crushing the posterior
extremity of the body in 1 c.c. of water, is sufficient to kill a mouse
or a sparrow.

Death supervenes in a few minutes, from respiratory asphyxia, as in the
case of intoxication by the venom of Colubrine snakes (_Cobra_). In the
blood-vessels and in the heart the blood is black and remains fluid. It
therefore appears that this venom contains a very active _neurotoxin_.

The phenomena of intoxication caused by the venom of these insects are,
as a rule, slight, being limited to an acute pain, accompanied by a
zone of œdema and burning itching. Sometimes however, when the stings
are in the eyelids, lips, or tongue, they produce alarming and even
fatal results, as shown by the following incident:--

On September 26, 1890, a young girl of Ville-d’Avray was eating grapes
in the woods of Fausse-Repose, when she inadvertently swallowed a
wasp. The unfortunate girl was stung in the back of the throat, and
the wound became so rapidly inflamed that, in spite of the attentions
of a doctor, she died in an hour from suffocation, in the arms of her
friends.

Phisalix[131] has studied the physiological action of bee-venom on
sparrows inoculated either by the sting of the insect, or with an
aqueous solution obtained by crushing the glands. In both cases a local
effect, paralysis of the part inoculated, is first produced; this is
followed by convulsions, which may last for several hours; the final
stage is marked by coma and respiratory trouble, which ends in death.

After being heated for fifteen minutes at 100° C. the venom has no
further local action; the general phenomena are merely diminished.
If heated at 100° C. for thirty minutes, the venom ceases to cause
convulsions, but remains stupefactive. Exposure for fifteen minutes to
a temperature of 150° C. renders it completely inert.

This venom therefore comprises: (1) A phlogogenic substance, destroyed
by ebullition, contained in the acid gland of the bee; (2) a poison
causing convulsions, which does not resist a temperature of 100° C.,
if prolonged, and is probably produced by the alkaline gland; (3) a
stupefactive poison, which is secreted by the acid gland, and is not
entirely destroyed until a temperature of 150° C. is reached.

The poison-glands can easily be extracted by gently pulling at the
stings of bees anæsthetised by chloroform.

The eggs of bees, like those of the toad and the viper, contain
the specific venom. The amount, however, is small, since in order
to produce lethal results in the sparrow it was found necessary to
inoculate an emulsion obtained by crushing 926 eggs.

Phisalix[132] makes the approximate calculation that, in the egg the
weight of the toxic substances amounts to the one hundred and fiftieth
part of the whole. Their effects are similar to those produced by the
venom itself, but the convulsions are not so severe. The predominant
poison in the egg appears to be that causing paralysis.

I have easily succeeded in vaccinating mice against doses of bee-venom
certainly lethal, by repeatedly inoculating them with very small doses.
Moreover, we find the same thing in the case of human beings, for we
know that those who are in the habit of handling hives become quite
accustomed to bee-stings, and finally feel not the slightest effect
from them.

It has been shown by J. Morgenroth and U. Carpi,[133] in a paper
recently published, that the venom of bees, like that of the scorpion,
possesses the property of hæmolysing the red corpuscles of several
species of animals (the rabbit, guinea-pig, and goat), and that it is
capable of combining with the lecithin to form a _lecithide_ analogous
to _cobra-lecithide_, the curious properties of which we have studied
in detail.

This lecithide of bee-venom is from 200 to 500 times more hæmolysing
than the venom itself, and resists ebullition like that of the cobra.
In order to isolate it Morgenroth and Carpi employed the method
recommended by P. Kyes: 1½ c.c. of a solution of pure venom is mixed
with 1½ c.c. of a 5 per cent. solution of lecithin in methylic alcohol.
After being kept for twenty-four hours at 37° C., 22 c.c. of absolute
alcohol are added; the liquid is decanted, and the clear filtrate is
mixed with 150 c.c. of ether. There is slowly formed a somewhat copious
flocculent deposit, which is collected on a filter, washed several
times with ether, and finally dried. The lecithide that remains on the
filter dissolves completely in physiological salt solution.

It must be remarked that bee-venom, without the addition of lecithin,
gives a scanty precipitate with ether. This precipitate, dissolved
in physiological salt solution, possesses no hæmolysing power.
The lecithide, on the contrary, dissolves red corpuscles almost
instantaneously.

Normal horse-serum considerably inhibits hæmolysis by bee-venom +
lecithin. This protective action of normal serums has already been
observed by Langer; it is perhaps attributable to the cholesterin that
they contain.

Among other Hymenoptera capable of inflicting very severe stings may be
mentioned the species of _Polistes_ and certain Pompilids, especially a
species of _Pompilus_ found in Natal, the painful stings of which have
sometimes been experienced and described by travellers (P. Fabre, of
Commentry).[134]

In the family _Crabronidæ_ the females are provided with a sting and
venom, which usually has little effect upon man, but is toxic to other
insects. Thus, _Cerceris bupresticida_ is remarkable for the stupefying
effect of its venom upon the _Buprestidæ_ destined for the food of its
larvæ. It stings the beetles between the first and second segments of
the thorax, with the result that the victim is paralysed, though in
other respects its bodily functions appear to continue; in fact, its
intestine is seen to empty itself at long intervals. These effects are
attributed by Mons. J. H. Fabre, of Avignon, to the direct action of
the venom upon the ganglia of the thoracic nervous system.

Instances of Hymenoptera belonging to the tribe _Entomophaga_ actually
depositing their eggs beneath the skin of man are mentioned by Raphaël
Blanchard.[135]

According to P. Fabre, the best treatment for wasp- or bee-stings
would appear to consist in the application of strong saline solution,
or a liniment of ammonia and olive oil. For my own part, I have tried
_hypochlorite of lime_, in a 1 in 60 solution, or _eau de Javel_
diluted to 1 per cent., and have always obtained such excellent results
from these remedies that I do not hesitate to advise their use.

D.--MOLLUSCS.

Certain Gastropodous Molluscs, chiefly _Murex brandaris_ and _M.
trunculus_, possess purple glands from which it is possible to extract
a very active venom (Raphaël Dubois)[136] by crushing them up with
sand and alcohol. The alcoholic liquid, filtered and evaporated in a
water-bath, yields a brown oily fluid. The subcutaneous injection of
a few drops of this into a frog is sufficient to produce very decided
toxic effects. Sluggishness and slowness of movement are seen to
supervene fairly quickly; reflex actions are still exhibited, but the
animal is no longer able to jump.

If the dose be not too strong, this condition of paresis lasts for
several hours, and then disappears. In most cases, however, the
paresis is succeeded by complete paralysis, and the animal appears
as though suffering from curare. Yet the fact is that the venom is
neither curare-like nor cardiac; the heart, muscles, motor endplates,
and motor and sensory nerves are spared; the nervous centres alone
are attacked, especially the encephalon. The animal dies without
convulsions.

Sea and fresh-water fishes (golden carp) are very sensitive to this
venom; warm-blooded animals are refractory. It is therefore probable
that, in the species of _Murex_, the purple gland is a poison-gland
serving for defence, or for the capture of the prey upon which these
molluscs feed.

Among the Cephalopods, the Octopods (_Octopus vulgaris_, common
octopus, _Eledone moschata_, musky octopus, of the Mediterranean)
possess two pairs of salivary glands, a small anterior pair, and a
posterior pair of considerable size.

The Decapods (cuttle-fishes [_Sepia_], &c.), have only posterior
salivary glands, of smaller dimensions in proportion to the size of the
body.

On being crushed and macerated in water, the anterior glands yield a
limpid and slightly acid juice; the posterior glands produce a viscid,
ropy fluid, filterable with difficulty and neutral. The latter has an
immediate paralysing effect upon Crustacea. It contains a substance
of a diastasic nature, precipitable by alcohol, and destructible by
heating for an hour at 58° C.

Owing to the poisonous properties of this juice, Octopods succeed
in overpowering large prey, such as lobsters and crabs. Once they
are seized by the tentacles of the octopus, or cuttle-fish, a bite
inoculates these animals with venom that immediately destroys their
power of movement, and the Cephalopod is able to continue its meal in
perfect security, without having to fear the pincers of its prey.

An experimental study of this venom has been made by A. Briot,[137] who
found that crabs are very sensitive to it, while rats, frogs, rabbits,
and fish do not appear to experience any inconvenience.

CHAPTER XVII.

_VENOMS IN THE ANIMAL SERIES_ (_continued_).

2.--_VENOMOUS FISHES._

The means of defence in fishes are extremely varied. Some species
(torpedoes or electric rays, electric eels) destroy their enemies by
electric discharges; others are provided with true poison-glands and
inoculatory organs, usually represented by opercular spines or by
the fin-rays. The species of the genus _Muræna_, however, possess a
poison-apparatus connected with the buccal teeth, as in the case of
snakes.

It has been clearly established by Bottard[138] that at least three
very distinct types of venomous fishes exist, according as the
venom-apparatus is:--

(1) Entirely closed (_Synanceia_ type); (2) half closed
(_Thalassophryne_ type); (3) in more or less direct communication with
the exterior (_Trachinus_ and _Scorpæna_ type).

The greater part of the following statements has been borrowed from
the excellent work of the author referred to, from the writings of
A. Corre,[139] the fellowship thesis of Henry Coutière,[140] and
the magnificent atlas published at St. Petersburg in 1886 by P.
Savtschenko, of the Russian Imperial Navy.

Except in the case of the species of _Muræna_, the venom of fishes is
generally found in one or more special glands, situate at the base of
the dorsal or caudal fins, or beneath the opercular spines. When the
animal defends itself it inflicts wounds with these rays, and ejects
from its poison-glands a toxic or irritant liquid, which enters the
sores.

The flesh of these fishes is not usually poisonous, whereas a fairly
large number of other species, _which do not inflict wounds_, cause
intoxicating effects when eaten. These latter do not come within the
scope of this work; but the reader who may desire to obtain information
with regard to them will find them well described in J. Pellegrin’s
memoir,[141] in that by Dupont, and especially in the papers of A.
Corre.

_Venomous fishes_ almost all belong to sedentary species, as in the
case of the genera _Trachinus_, _Cottus_, _Scorpæna_, and _Synanceia_.
This fact suggested to Dissard and Noë[142] a very hazardous theory in
order to explain the existence of a poison-apparatus in these animals.
The venomous fishes being sedentary, say these authors, have no need of
a poison-apparatus; their prey offers itself to them without effort on
their part, and, on the other hand, they escape destruction by their
enemies. If, therefore, they possess a poison-apparatus it is because
the conditions under which they live entail the lowest value for the
co-efficient of respiration, diminish the quantity of the ambient
radiations and the oxygenation of the medium, and lead to diminished
hæmatosis. For these reasons the activity of anaerobic life becomes
greater, and the formation of venoms takes place.

This theory, derived from the conceptions of A. Gautier with regard
to the formation of toxic leucomaines, appears scarcely tenable, for
it is evident that the weever, for example, erects its first dorsal
spine as soon as it is seized, and that _Scorpæna_ and _Synanceia_
likewise protrude their venomous spines when conscious of danger. The
poison-apparatus of these fishes is therefore of an eminently defensive
character.

According to Bottard, the spawning season increases the activity of
the poison-glands and at the same time the toxicity of the secreted
product. Several species, such as those of the genus _Cottus_ and the
perch, possess no apparent secreting cells except at this period.
Certain _toxicophorous_ or poisonous fishes, such as the species of
_Tetrodon_, are particularly noxious at the time when their genital
glands are at their maximum activity.

A.--TELEOSTEI.--ACANTHOPTERYGII.

1.--=Triglidæ.=

The fishes of this family are all repulsively ugly. They have an
elongate and but slightly compressed body, covered with ctenoid scales,
and a large head in which the suborbital bones, which are broad, unite
with the præopercular so as to form an osseous plate in the malar
region. The pectoral fins are large, and provided with a few detached
rays, which perform the function of tactile organs; the ventral fins
are situate on the breast. These fishes are extremely voracious.

The most interesting type is the _Synanceia_ termed by the Creoles of
Réunion _Crapaud de mer_, and by those of Mauritius _Laffe_. In Java
it is called _Ikan-Satan_ (Devil-fish), and in Tahiti _Nohu_. It is
distributed throughout almost all the warmer regions of the Indian and
Pacific Oceans, and is found in Cochin-China and New Caledonia.

It is never taken in the open sea, but only among the fringing reefs,
where it lives constantly concealed in holes or buried in the sand. It
does not come out except to make a sudden dart at prey passing within
its reach. When irritated it does not eject venom; for the latter
to be expelled one has either to press hard upon the poison-sacs,
after pushing back with the fingers the membranes covering the dorsal
defensive armature, or the naked foot must be placed on the back of
the fish. The wound is very painful, and is accompanied by a series of
alarming symptoms, which sometimes terminate fatally: fishermen are
consequently much afraid of it.

There are a large number of species of this fish, peculiar to different
regions. _Synanceia brachio_ (fig. 101), the largest specimens of which
attain the length of 45 cm., is the most common form in the Tropical
Pacific.

[Illustration: FIG. 101.--_Synanceia brachio_, var.
_verrucosa_. (After Savtschenko.)]

The spiny rays of the dorsal fin of _Synanceia_ are sharp-pointed,
stout in the middle, and provided on each side with a small canal
hollowed out in the thickness of the spine. Towards the middle of the
latter there is attached a little double sac, or kind of closed pouch,
which, on being compressed, allows the venom to escape in a thin jet
which flows into the grooves of the spine. The expulsion of the venom
is therefore not a voluntary act on the part of the fish; in order that
it shall take place, pressure must be applied to the sacs in which it
is contained.

This venom, when extracted from the glands, is limpid, bluish, and
slightly acid. When introduced into the tissues, it produces very acute
local pain, which extends throughout the affected limb. The pain is
excruciating, and sufferers have been observed to become actually
delirious, striking and biting those around them, throwing themselves
from side to side, and beseeching that the limb should be cut off; some
of them have amputated the injured part themselves.

This condition is accompanied by considerable anxiety, and by attacks
of leipothymia and sometimes of syncope. In some cases syncope has
been followed by death; in others serious phlegmons, complicated by
septicæmia, supervene. The inoculated spot becomes bluish, and then
sphacelates over a larger or smaller area. These gangrenous wounds heal
very slowly, more especially since they are usually produced on the
sole of the foot (Bottard).

A single drop of the venom is sufficient to kill frogs in about three
hours.

[Illustration: FIG. 102.--_Cottus scorpius_ (Sea Scorpion).
(After Savtschenko.)]

The genus _Cottus_, which also belongs to the family TRIGLIDÆ,
includes some forty venomous species found in the seas of the northern
hemisphere, in Europe, Asia, and America.

In France the species of _Cottus_ are generally called _chabots_
(bullheads or miller’s thumbs), _chaboisseaux_ (sea-scorpions), or
_caramassons_. They are abundant on the coast of Normandy, and some of
them (river bullheads) live in fresh water; they do not exceed 25 cm.
in length. They have a liking for holes in rocks, and fishermen are
afraid of being stung by them (fig. 102).

Their poison-apparatus resembles that of the Weevers, but is less
developed. It is situated in the culs-de-sac formed by the opercular
spines. The culs-de-sac are lined with cells which produce a toxic
secretion only during the spawning season, from November to the end of
January. This fact explains how it is that the species of _Cottus_ are
declared by certain fishermen to be very venomous, while others say
that they are absolutely harmless.

The genera _Scorpæna_, _Pterois_ and _Pelor_ also belong to the same
group.

[Illustration: FIG. 103.--_Scorpæna grandicornis_ (Caribbean
Sea). (After Savtschenko.)]

In _Scorpæna_ the body is clothed with scales, and the head is large,
slightly compressed, armed with spines, and has a bare pit behind;
the single dorsal fin is provided with eleven spiny rays, and there
are seven branchiostegal rays. _Scorpæna grandicornis_ (fig. 103),
found in the Caribbean Sea, is from 30 to 50 cm. in length, and has
the back red and the eyes and belly yellow; _Scorpæna diabolus_
(fig. 104), which occurs in the Indian Ocean and Tropical Pacific,
is red and brown, obliquely striped with white and brown; a third
species, _Scorpæna porcus_ (_Scorpène truie_), of smaller size, is met
with in the Mediterranean. The venom of the latter has been studied
by A. Briot,[143] who sectioned the dorsal and opercular spines,
and macerated them either in physiological saline solution, or in
glycerine; he then tested the toxicity of these macerations on certain
animals--frogs, rabbits, and rats.

[Illustration: FIG. 104.--_Scorpæna diabolus_ (Indian and
Pacific Oceans). (After Savtschenko.)]

The frogs alone exhibited, as the result of subcutaneous injection
into a limb, slight transient paralysis. No effect was found to be
produced by the venom when injected intravenously into the rabbit, or
subcutaneously into the rat.

The poison-apparatus of _Scorpæna_ is situated in the spiny rays of
the dorsal and anal fins. These rays are enveloped in the inter-radial
membrane, which forms a sheath for them, and are scored with a double
cannelure. At the bottom of these grooves are the secreting cells,
which are elongate, pressed one against the other, and supported at the
base by a highly vascular substratum of connective tissue. The venom
flows out between the layer of cells and the ensheathing membrane,
which is capable of being pushed slightly back as the result of the
penetration of the spine into the tissues, and then exerts pressure
upon the reservoir. The latter is formed by the distension of the
sheath under the pressure of the secreted liquid.

[Illustration: FIG. 105.--_Pterois artemata_ (East Coast of
Africa, Indian and Tropical Pacific Oceans). (After Savtschenko.)]

There are twelve pairs of dorsal and three pairs of anal glands. The
pairs attached to the second anal spine are, as the direct result of
the size of the latter, more developed than those of the other spines.

In the _Rascasse_, the opercular spines of which are greatly developed,
there is a rudiment of a poison-apparatus at the bottom of the sheath
formed by the skin of the gills.

The species of _Pterois_ (fig. 105) are distinguished from those of
_Scorpæna_ by their dorsal fins, the rays of which are very long and
curved backwards, above the membrane by which they are united. They
are found in the Indian and Equatorial Pacific Oceans, and are very
beautiful in colour, varying from reddish-brown to bright rose.

The poison-apparatus of these fishes is situated in the dorsal fin, and
is precisely similar to that of _Scorpæna_.

[Illustration: FIG. 106.--_Pelor filamentosum_ (Family
_Triglidæ_, Mauritius).]

The species of _Pelor_ (fig. 106) present greater resemblance to those
of _Synanceia_, owing to their heads being crushed in in front. Their
eyes stand up above the head and are very close together, which helps
to give them an extremely ugly appearance. The skin is soft and spongy,
and bristles with jagged fleshy shreds.

Their poison-apparatus is placed in the dorsal fins, as in the case of
_Scorpæna_ and _Pterois_.

2.--Trachinidæ.

Genus _Trachinus_ (Weevers).--Four species of Weevers are found in
European seas: the Greater Weever (_Trachinus draco_), the Lesser
Weever (_T. vipera_), the Striped-headed Weever (_T. radiatus_), and
the Mediterranean Spider Weever (_T. araneus_); other species are met
with on the coast of Chile.

Weevers possess two sets of poison-apparatus, one of which is situated
on the operculum, the other at the base of the spines of the dorsal fin
(fig. 107).

[Illustration: FIG. 107.--_Trachinus vipera_ (Lesser Weever).]

The spine surmounting the operculum exhibits a double cannelure
connected with a conical cavity excavated in the thickness of the base
of the opercular bone. This spine is covered with a sheath, beneath
which lie the secreting cells. The gland is an offshoot from the skin,
and appears as a simple follicle invaginated in the opercular bone
(fig. 108).

The dorsal apparatus is composed of from five to seven spines, to which
the inter-radial membrane forms an adherent sheath which extends almost
to the end of the rays. Each spine exhibits a deep double cannelure.
The venom flows between the layer of cells clothing the cannelures and
the skin, which is distended to allow it to pass.

Towards the base of the spine, the edges of the cannelure are united,
and form a hollow, bony cone, the walls of which are lined with the
cells that secrete the toxic fluid.

[Illustration: FIG. 108.--_A_, Operculum and opercular spine
of the Lesser Weever (_Trachinus vipera_); _ar_, articular surface of
the operculum; _c. op_, body of the opercular spine; _c. an_, canal
of the spine; _z_, space occupied by the poison-gland. _B_, Spine
belonging to the first dorsal fin; _c. an_, efferent poison-canal in
the spine.]

Greater Weevers are usually from 12 to 30 cm. in length, and of a
reddish or yellowish-grey colour, with blue or violet spots. They are
caught in trawls and are fairly common on sandy bottoms. In the month
of June they approach the shore for the purpose of spawning.

The venom of the Weever has formed the subject of interesting studies
by Günther, Gressin,[144] Bottard, Phisalix,[145] and more recently by
Kobert[146] and A. Briot.[147]

In order to procure sufficient quantities of it for experimental
purposes, Briot cuts off the venomous spines and the surrounding tissue
with a pair of scissors; he then pounds the whole in a mortar, and
mixes the pulp with pure glycerine. After filtration through paper, a
toxic solution is obtained, which does not deteriorate by keeping, and
is neutral to litmus.

A few drops of this liquid are sufficient to kill guinea-pigs, which,
immediately after receiving an injection in the thigh, exhibit
paralysis of the leg with tetanic convulsions; twenty-four hours later
an eschar is formed, and death supervenes on the second or third day.

Two or three drops, introduced into the marginal vein of the ear of
a rabbit, cause death from asphyxia in from four to ten minutes. The
heart continues to beat for a fairly long time after respiration has
entirely ceased; the blood is not coagulated.

The toxicity of this venom is completely destroyed by heating it to
100° C., by chloride of lime, and by chloride of gold. Antivenomous
serum prepared from horses vaccinated against cobra-venom has
absolutely no effect upon it _in vitro_. There is therefore no affinity
between this venom and that of snakes.

Weever-venom dissolves the red corpuscles of the horse in the
presence of normal heated horse-serum, but does not dissolve them in
the presence of fresh serum. The non-heated serum, therefore, as I
have shown with reference to the action of cobra-venom on the blood,
contains a natural antihæmolysin.

Briot succeeded in vaccinating rabbits by accustoming them to the
venom, and in obtaining from them a serum capable of neutralising
the latter _in vitro_, and of immunising fresh rabbits against doses
several times lethal, even when injected intravenously.

According to Gressin, the following phenomena are produced in man as
the result of Weever-stings:--

“At first there is felt an excruciating, shooting, paralysing pain,
which, in the case of nervous persons, may cause attacks of leipothymia
ending in syncope. A kind of painful formication next pervades the
injured limb, which becomes swollen and inflamed, and may even, if
treatment be neglected, form the starting point of a gangrenous
phlegmon.

“This condition is frequently accompanied by certain general
phenomena--such as fever, delirium, and bilious vomiting, the duration
of which is variable, since they may only last for two or three hours,
or may continue for several days. Fishermen rightly consider this
variability to depend upon the amount of venom that has penetrated
into the wound, and especially upon the season at which the accident
takes place. The most serious results are recorded during the spawning
season, and fishermen regard the Lesser Weever as being the more
poisonous.”

3.--Gobiidæ.

In the fishes belonging to this family the body is elongated and
depressed, while the spines in the anterior dorsal fin and in the
ventral fins are slender, flexible, and seldom very solid. The ventral
fins are inserted on the breast or on the throat, and are either
separated or united together in the shape of a funnel. The skin is
naked or covered with large scales, and the mouth is furnished with
teeth. The males are distinguished by the presence of a long genital
papilla. These fishes are carnivorous.

[Illustration: FIG. 109.--_Callionymus lyra_ (Dragonet or
Skulpin. Family _Gobiidæ_).]

Several species of venomous =Gobiidæ= are met with on the shores
France and in the tropical zone. The most important of these belong to
the genus _Callionymus_ (_C. belennus_, _C. lacertus_, _C. vulsus_, and
_C. lyra_--fig. 109).

The Dragonet or Skulpin (_Callionymus lyra_), which is common on the
coast of Calvados, may attain the length of 30 cm. In France it is
popularly known as the _Doucet_, _Dragonnet_, _Lavandière_, _Cornaud_,
or _Capouri_. Its colours are very vivid, orange and deep lilac.

In this fish the præopercular bone ends in three strong, conical, and
very sharp points, diverging like the prongs of a trident. The upper
margin of the opercular bone bears another point, which is directed
upwards.

The skin of the gills forms a common sheath for this defensive
armature, and the base of the sheath is prolonged into two culs-de-sac,
the surface of which is clothed, during the spawning season, with
cylindrical cells, the secretion of which is poisonous.

This venom, which is small in amount, does not appear to have any
marked effect upon man (Bottard).

4.--Teuthididæ.

This family of _Acanthopterygii_ includes several species of
brilliantly coloured fishes with elongated and laterally compressed
bodies, provided with a long dorsal fin, and having, on each side of
the tail, a sharp spine placed in front of the anal fin. They are
herbivorous, and are confined to the tropical seas.

The principal genera are: _Teuthis_ (India), _Acanthurus_ (Tropical
Atlantic), _Prionurus_ (Japan), and _Naseus_ (Red Sea and Indian
Ocean). The fishermen of Réunion are much afraid of the wounds
inflicted by _Acanthurus luridus_, which they call _Marguerite Porc_
or _Grande Marguerite_. A sting from this fish causes a very acute
smarting pain, which may last for several hours, but usually has no
serious consequences.

The poison-apparatus of these fishes is situated in the dorsal and anal
fins, as in _Scorpæna_.

5.--Batrachiidæ.

The venomous species belonging to this family are few in number. They
are found in all tropical seas, but have no representatives in Europe.
The best-known species are _Batrachus tau_ (shores of Central America),
and _B. grunniens_, or Grunting Batrachus (fig. 110).

[Illustration: FIG. 110.--_Batrachus grunniens_ (West Indies).]

[Illustration: FIG. 111.--_Thalassophryne reticulata_ (Panama;
Tropical Pacific). (After Savtschenko.)]

The Grunting Batrachus, which does not exceed 30 cm. in length, is
especially common in West Indian waters. When taken from the water
it makes a peculiar grunting sound, whence its name is derived. The
pectoral fins are reddish, the back is brown, and the sides are yellow,
marbled with black. It has three spines in the anterior dorsal fin, and
a fourth spine on the top of the operculum, with a small poison-sac at
the base of each.

Next to this genus come the species of _Thalassophryne_, _T.
reticulata_ (fig. 111), found on the shores of Panama, and _T.
maculosa_, of Bahia (Brazil), which are provided with a precisely
similar poison-apparatus.

The physiological action of the venom of these two species has not yet
been studied, but it is probable that it does not differ from that of
the venom of the Weevers and the species of _Synanceia_.

[Illustration: FIG. 112.--_Lophius setigerus_ (China Sea and
Sea of Japan). (After Savtschenko.)]

6.--Pediculati.

The fishes belonging to this family are of large size and compact
shape, with the anterior part of the body greatly expanded. The head,
which is broad, bears venomous spines, and the mouth is furnished with
large teeth. These fishes are voracious, and lie in wait for their
prey at the bottom of the water in the mud of the shore. In order to
attract it, they make use of cutaneous appendages attached to their
spines, which they are able to elevate, and of filaments situated near
the mouth.

The principal genus is _Lophius_, one species of which, _L. setigerus_
(fig. 112), is found in the seas of China and Japan. Another species,
_L. piscatorius_ (the Sea Devil or Angler), occurs in the temperate
climates of Europe, North America, Asia and Africa.

Certain other _Acanthopterygii_ are _capable of inflicting wounds_,
but, although fishermen often believe them to be venomous, or such
properties are frequently attributed to them in stories, it is doubtful
whether they possess poison-glands. The accidents produced by them are
due rather to the fact that the spines in their fins are extremely
sharp, and that their flesh is toxic. Those belonging to the _Percidæ_
(the Perch family), especially the genus _Serranus_ and _S. ouatabili_
(fig. 113) in particular, are above all remarkable in this respect. The
last-mentioned fish has two or three spines on its operculum.

[Illustration: FIG. 113.--_Serranus ouatabili._ (After
Savtschenko.)]

The same may be said of certain _Squamipinnes_, another family of
_Acanthopterygii_, whose stout bodies are brightly coloured, and have
very sharp, spiny rays in their dorsal and anal fins. The most curious
genus among the fishes belonging to this family is _Holacanthus_, in
which the præoperculum is provided with an enormous spine like that of
the Weever. _Holocanthus imperator_ (fig. 114) is met with fairly often
in the Indian Ocean and Malay Archipelago.

[Illustration: FIG. 114.--_Holacanthus imperator_ (Indian
Ocean and Malay Archipelago). (After Savtschenko.)]

B.--TELEOSTEI.--PLECTOGNATHI.

The Order _Plectognathi_ (Family _Gymnodontes_) includes the genera
_Diodon_, _Tetrodon_ and _Triodon_, globular fishes, in which the jaw
is transformed into a beak and furnished with a sharp dentary plate.
Their œsophagus is dilated into a resonant air-pouch. When removed from
the water they swallow air and dilate the pouch, and the expulsion of
this air is accompanied by a loud noise.

Several species of _Tetrodon_ are armed with spines, which produce
very painful wounds. Their flesh is toxic, but it has not been proved
that poison-glands exist at the base of the spines.

On the shores of the Cape of Good Hope, Brazil, China, and Japan these
fishes are much feared. The principal species are _Tetrodon stellatus_
(Indian and Pacific Oceans; fig. 115) and _T. rubripes_ (Japan; fig.
116).

[Illustration: FIG. 115.--_Tetrodon stellatus_ (Indian and
Pacific Oceans). (After Savtschenko.)]

[Illustration: FIG. 116.--_Tetrodon rubripes_ (Japan). (After
Savtschenko.)]

Closely allied to _Diodon_, and feared like the foregoing on account
of their spines, which are sometimes scattered all over the body, are
the species of the genus _Chilomycterus_, the most important of which
are _C. orbicularis_ (fig. 117), and _C. tigrinus_ (fig. 118), both of
which are found in the Indian Ocean.

[Illustration: FIG. 117.--_Chilomycterus orbicularis_ (Indian
Ocean). (After Savtschenko.)]

[Illustration: FIG. 118.--_Chilomycterus tigrinus_ (Indian
Ocean). (After Savtschenko.)]

C.--TELEOSTEI.--PHYSOSTOMI.

This Order is characterised by the presence of a pneumatic duct to the
air-bladder. It consists of a large, number of families, only two of
which, the _Siluridæ_ and _Murænidæ_, include venomous species.

1.--Siluridæ.

The majority of the very large number of species belonging to this
family live in fresh water, and have the free margin of the lips almost
always furnished with barbules (_Silurus glanis_; fig. 119). A few of
them possess a poison-apparatus, which, however, attains its greatest
development in _Plotosus_, the only genus of Siluridæ found exclusively
in the sea.

The species of _Plotosus_ frequent the shores of the Indian Ocean, and
are met with in the Seychelles, Réunion, and Mauritius. In shape they
resemble eels, and they bury themselves in the sand or mud, a habit
which renders them very dangerous to fishermen.

[Illustration: FIG. 119.--_Silurus glanis_ (Rivers of Central
and Eastern Europe).]

_Plotosus lineatus_, which is of a greenish-brown colour, striped with
from four to six longitudinal whitish bands, is the most common. By
the Creoles of Mauritius and Réunion it is called _Machoiran_, by the
Malays _Sambilang_, and by the Abyssinians _Koomat_.

Its poison-apparatus is situated at the base of the dorsal and pectoral
spines. These spines are strong, sharp, slightly incurved, and
furnished with hooked denticulations, which cause them to remain in
the wound, in which they break off. Near their extremity there opens a
small canal, which communicates with the culs-de-sac situated at the
base of the spiny rays, which produce a venomous secretion. The dorsal
spine has only a single cul-de-sac, while the pectoral spines have two.

The contraction of the local muscles, by compressing these culs-de-sac,
can cause the venom to make its way into the canal of the spine, but
the fluid does not spurt forth in a jet as in the case of _Synanceia_.
The poison-apparatus is therefore passively defensive in character.
_Plotosus_ is capable of wounding only when the hand or foot is placed
on its dorsal or pectoral spines.

Fishermen who are stung immediately feel an excruciating pain, which is
soon accompanied by fever, and lasts for several days. Accidents caused
by this fish are of fairly common occurrence in Réunion.

2.--Murænidæ.

Of the fishes belonging to this family, the species of the genus
_Muræna_ alone concern us. They have an elongated body, without
pectoral fins, and a naked skin, covered with a thick layer of viscid
slime, as in the case of the eels. Their dentition is powerful, formed
of long, recurved fangs, arranged in one or more rows. These fishes
may attain a large size, exceeding 2 metres in length. More than one
hundred species are known, all of which live in tropical or subtropical
seas. _Muræna helena_ is common in the Mediterranean in the vicinity
of Nice and Toulon; _M. moringa_ (fig. 120) is found in the Tropical
Atlantic.

The species of _Muræna_ live in deep water, and feed upon fishes or
crustaceans. In hot countries they frequently venture into fresh water.
Their skins are adorned with brightly coloured markings, which vary
very greatly according to the species.

The poison-apparatus in _Muræna_ consists of a pouch situated above
the membrane of the palate, which may contain ½ c.c. of venom, and
three or four conical, curved teeth, with the convex surface in front,
as in the fangs of snakes. The teeth are not pierced by a central
canal, and the venom flows between them and the mucous membrane of
the palate, which forms a sheath. The latter is withdrawn to the base
of the teeth, while they are penetrating the tissues. The teeth are
mobile; they are articulated with the palatine bone, in which they are
inserted in small depressions, and a resistant fibrous tissue serves as
the means of union. They can be deflexed backwards against the mucous
membrane of the palate; in this position the first, second and fourth
tooth (when the latter exists) disappear completely between the folds
of the membrane. The third tooth normally remains erect, and it is this
by which wounds must in most cases be inflicted. None of these teeth
can be protruded beyond the vertical.

[Illustration: FIG. 120.--_Muræna moringa_ (Tropical
Atlantic). (After Savtschenko.)]

In addition to the palatine teeth there are, among the groups of
maxillary teeth, several mobile teeth, which are connected with the
poison-reservoir.

Besides its toxic action the venom of _Muræna_ has manifest digestive
properties, and, in the case of a fish which has been dead for some
little time the gland is no longer to be found, since its walls have
undergone a rapid autodigestion.

The venoms of all the fishes of which I have just given a brief
description, as regards their physiological action, present a fairly
close resemblance to the venom of the Weever, and show scarcely any
variation except in the intensity of their effects. They have been but
little studied hitherto, and it is desirable that they should be better
understood.

CHAPTER XVIII.

_VENOMS IN THE ANIMAL SERIES_ (_continued_).

3.--_BATRACHIANS. LIZARDS. MAMMALS._

A.--Batrachians.

By the ancients the venom of _salamanders_ and _toads_ was dreaded as
much as the most terrible poisons. These animals, however, are not
very formidable, since they are devoid of inoculatory organs; their
poison-apparatus is localised exclusively in the parotids and the skin.
It is represented simply by more or less confluent glands in the form
of sacs, secreting a viscid mucus, which has a nauseous odour and is
highly toxic, even to animals of large size.

The salamander belongs to the Order _Urodela_, which is characterised
by the persistence of the tail. Its body is heavy and thickset, and the
flanks and the sides of the tail exhibit a series of glandular crypts,
which secrete venom.

“The mucus which flows from the mouth, and resembles milk, eats away
human hair,” wrote Pliny; “the spot moistened by it loses its colour,
which subsequently returns. Of all venomous animals the salamander
is the most terrible; it is capable of annihilating whole nations
by poisoning the vegetation over a vast area. When the salamander
climbs a tree all its fruit is poisoned, and those who eat of it die
as surely as if they had taken aconite. Moreover, if bread be baked
with wood touched by the animal, it is dangerous, and may occasion
serious disorders. If the naked foot be defiled with the saliva of
this creature, the beard and hair soon fall out. Sextius says that a
salamander, preserved in honey, after the removal of the entrails,
head, and limbs, acts as a stimulant if taken internally.”

In ancient Rome, and also in Mediæval France, it was believed that the
most furious fire could be extinguished simply by contact with one of
these animals; charlatans sold the inoffensive salamander, which, if
cast into the most terrible conflagration, was bound, they declared, to
arrest its disastrous progress!

The explanation of this superstition is furnished by Duméril, who
writes: “On being placed in the middle of burning charcoal, these
victims of so cruel a curiosity, when put to the test, instantly
allowed to exude from the many pores with which their skins are riddled
a slimy humour, sufficiently abundant to form a viscid layer over that
part of the glowing charcoal with which the animals were in contact.
Since this surface, being no longer exposed to the air, immediately
became quite black, it was supposed to be extinguished; but the
salamanders sustained such severe burns that they soon succumbed.”[148]

The principal species of salamanders are:--

_Salamandra atra_ (Black Salamander), which is found in the Alps and
the mountains of Central Europe, close to the snow-line, and up to an
altitude of 3,000 metres.

_Salamandra maculosa_ (Spotted Salamander, fig. 121), distributed
throughout almost the whole of Europe, and also found in North Africa.

_Triton cristatus_ (Crested Newt), likewise common all over Europe.

_Triton marmoratus_ (Marbled Newt, fig. 122), which is met with in damp
and dark places, in Portugal, Spain, South and Central France, and as
far north as the Forest of Fontainebleau.

_Cryptobranchus japonicus_ (Great Japanese Salamander, fig. 123), which
often exceeds 1 metre in length, and has a clumsy body covered with
large warts, and an enormous head, broad behind and flattened in front.

This giant salamander is now confined to a few provinces in the centre
of Japan, between long. 34° and 36°, in damp, shady places, from 200 to
800 metres above sea-level. It is eaten by the Japanese, who also use
it as a remedy for, or prophylactic against, contagious disorders. By
nature it is extremely sluggish, but tries to bite when irritated, and
then covers itself copiously with slime.

[Illustration: FIG. 121.--_Salamandra maculosa_ (Europe and
North Africa).]

[Illustration: FIG. 122.--_Triton marmoratus_ (male).
(Europe.)]

The venom secreted by salamanders evidently serves to protect these
creatures against their enemies. So long ago as 1866, Zaleski[149]
isolated from it a substance soluble in alcohol, insoluble in ether,
and with a very strong alkaline reaction, to which he gave the name
_salamandarin_. This substance, which is better known to-day as
_salamandrine_, has been studied afresh by A. Dutartre,[150] Phisalix
and Langlois,[151] and subsequently by Edwin and S. Faust.[152]

[Illustration: FIG. 123.--_Cryptobranchus japonicus_ (Great
Japanese Salamander).]

The action of this poison on the frog is characterised by a period
of violent convulsions, with general tetanic crises, followed by a
period of paralysis, with arrest of respiration and complete muscular
relaxation. According to the quantity of poison absorbed, this
paralytic period may be followed by death, with arrest of the heart in
diastole, or else by return to life, with more or less acute recurrence
of convulsions.

S. Faust prepares salamandrine by pounding up whole salamanders in
a small quantity of physiological saline solution. The thick pulp
obtained in this way is filtered. One cubic centimetre of the filtrate,
taken as a unit, contains about 5 decimilligrammes of active substance,
which can be purified by treating the filtrate with alcohol, which
dissolves the salamandrine and precipitates all the proteic substances
that give biuret reaction. The salamandrine thus freed from proteins
is saturated with sulphuric or phosphoric acid, when there is formed a
crystallisable salt, which is washed and dried. This salt is soluble in
alcohol and in water. Its chemical composition is as follows:--

C^{52}H^{80}Az^4O^2 + H^2SO^4.

The toxicity of this substance is such that from 7 to 9
decimilligrammes per kilogramme represent the lethal dose for dogs,
when injected subcutaneously. The lethal dose for the rabbit is
still smaller. It produces convulsive phenomena, followed by arrest
of respiration. The administration of chloral to the subjects of the
experiment, either preventively or immediately after the poison,
prevents the latter from taking effect. Besides salamandrine, S. Faust
has isolated a second alkaloid, _salamandridine_, which, as a sulphate,
corresponds to the formula (C^{20}H^{31}AzO)^2 + H^2SO^4, crystallises
in rhombic prisms, and is soluble with difficulty in water. The only
difference between the two alkaloids is formed by a methylpyridic
group, and both are derivatives of quinoline. They must therefore be
considered as identical with the exclusively vegetable alkaloids.

S. Faust concludes from his physiological investigations that
salamandrine takes effect upon the central nervous system, especially
upon the respiratory centres. It is a convulsion-producing poison,
comparable to picrotoxin, but its effects differ from those of the
latter substance in that the convulsions are accompanied by tetanic
spasms.

The venom of the Japanese Salamander (_Cryptobranchus japonicus_) has
formed the subject of studies by Phisalix.[153] This investigator
has shown that this venom, which is highly soluble in water and in
glycerine, is very unstable; alcohol and heating for twenty minutes
at 60° C. are sufficient to destroy it. When inoculated into frogs
it produces œdema and hæmorrhage; if injected into warm-blooded
animals it causes necrosis. In sufficiently strong doses it kills by
arresting respiration. Its effects strongly resemble those produced by
VIPERINE venoms. This venom, if attenuated by being heated
at 50° C. and injected into mammals, vaccinates them and leads to the
formation in their blood of antitoxic substances, which are capable of
preventing intoxication by salamander-venom, and, curiously enough,
also confer immunity against viper-venom and the serum of the common
snake.

_Toads_ are easy to distinguish from frogs owing to their squat and
clumsy shape, and to the mass of glands with which each side of the
neck and a more or less extensive portion of the body is furnished
in these animals. According to G. A. Boulenger, the number of known
species amounts to seventy-six, which are found in the Old and New
Worlds, but have no representatives in Australia. The species that are
the most common, and most interesting from the point of view of their
venoms, are:--

The Common Toad (_Bufo vulgaris_), in which the skin, which is very
thick and rugose, is covered on the back with large rounded tubercles
with reddish summits. This species is a great destroyer of insects,
and, as such, is very useful to agriculturists.

The Natter-Jack (_Bufo calamita_), in which the digits are palmate at
the base. When irritated it contracts its skin and covers itself with a
white frothy exudation, which gives off an odour of burnt powder.

The Green Toad (_Bufo viridis_), which is especially abundant in
Southern Europe, the Levant, and North Africa.

The Musical Toad (_Bufo musicus_), a species distributed throughout
North America as far south as Mexico, and in which the back is covered
with pointed conical tubercles resembling spines.

The Brown Pelobates (_Pelobates fuscus_), common in the neighbourhood
of Paris, the skin of which is almost entirely smooth. Although it
appears to be nearly destitute of glands, this animal secretes a very
active venom, which has a penetrating odour and kills mice in a few
minutes, producing vomiting, convulsions, and tetanic spasms of the
muscles.

The toxicity of the venom of toads was long ago demonstrated by the
experiments of Gratiolet and Cloëz.[154] It is manifest only in the
case of small animals, and in man merely produces slight inflammation
of the mucous membranes, especially of the conjunctiva.

That this venom preserves its toxic properties for more than a year in
the dry state was shown by Vulpian, and satisfactory studies of its
composition and physiological action have been made by Fornara,[155] G.
Calmels,[156] Phisalix and Bertrand,[157] Schultz,[158] Pröscher,[159]
and S. Faust.[160]

Toad-venom was prepared by Phisalix and Bertrand in the following
manner: Holding the head of one of these batrachians under water, they
expressed the contents of the parotid glands with the fingers or with
a pair of forceps. They repeated the same operation with a second, and
then with a third toad, until they had sufficiently impregnated the
water, which serves to dissolve the venom. In this way they obtained an
opalescent, acid liquid, which they filtered with a Chamberland candle
under a pressure of from four to five atmospheres. There remained on
the filter a yellowish substance, with a highly acid reaction and
partly soluble in ether and chloroform, while there passed through
the pores a clear, reddish, and slightly acid liquid, which on being
evaporated left behind a greyish-white precipitate. This precipitate
was separated by filtration, washed in water, and redissolved in
absolute alcohol or chloroform. The albuminoid matters were thus
separated, and the liquid, after being rendered limpid by filtration,
was evaporated away. The substance obtained in this way represents one
of the two active principles of the venom. It acts on the heart of
the frog, and arrests it in systole. It assumes the appearance of a
transparent resin, the composition of which roughly corresponds to the
formula C^{119}H^{117}O^{25}. It is the _bufotalin_ of Phisalix and
Bertrand, and is probably identical with that obtained by S. Faust,
the formula of which, according to the latter author, is said to be
C^{11}H^{23}O^{5}.

Bufotalin is readily soluble in alcohol, chloroform, acetone, acetate
of ethyl, and acetic acid. When water is added to a solution of it in
alcohol it is precipitated, giving a white emulsion, which has a very
bitter taste.

From the aqueous extract whence the bufotalin has been separated, it
is possible to separate a second poison, which acts on the nervous
system and causes paralysis. In order to obtain it in a pure state,
the extract is treated with alcohol at 96° C., filtered and distilled;
the residue dissolved in water is defæcated with subacetate of lead
and sulphuretted hydrogen. The solution thus obtained is successively
exhausted with chloroform to extract the cardiac poison, and with
ether, which removes almost the whole of the acetic acid. The second
neurotoxic principle, called _bufotenin_, remains in the residue of the
solution after being evaporated _in vacuo_.

Toad-venom, therefore, contains two principal toxic substances:
_bufotalin_, which is of a resinoid nature, soluble in alcohol,
but scarcely soluble in water, and is the _cardiac poison_; and
_bufotenin_, which is readily soluble in those two solvents, and is the
_neurotoxic poison_.[161]

Pröscher, on the other hand, has extracted from the skins of toads a
hæmolytic substance, termed by him _phrynolysin_, which possesses all
the properties of a true toxin and is not dialysable. It is obtained by
pounding the skins with glass powder in physiological serum.

Phrynolysin dissolves the red corpuscles of the sheep very rapidly, and
(in order of sensitiveness) those of the goat, rabbit, dog, ox, fowl,
and guinea-pig. The red corpuscles of the pigeon, frog, and toad are
scarcely affected. When heated at 56° C. it loses its properties. By
the ordinary methods of immunisation it is possible to obtain a very
active antilysin.

There is, therefore, a very close analogy between the venoms of _toads_
and _salamanders_. These highly complex substances are composed of
mixtures of poisons, some of which are in all respects analogous to the
vegetable alkaloids, while others are closely related to the microbic
toxins and snake-venoms.

In the spawning season the cutaneous glands of the male toad are gorged
with venom, while those of the female are empty. Phisalix[162] has
shown that at this period the venom of the female is accumulated in the
eggs, which, if extracted from the abdomen at the moment of oviposition
and dried _in vacuo_, give off in chloroform a product that has all the
toxic properties of cutaneous venom (bufotalin and bufotenin). No trace
of this poison is to be found in the tadpoles.

B.--Lizards.

The Order LACERTILIA includes only a single venomous
species, which belongs to the family _Lacertidæ_, and is known as the
_Heloderm_ (_Heloderma horridum_, fig. 124). It is a kind of large
lizard, with the head and body covered with small yellow tubercles on
a chestnut-brown ground. It sometimes exceeds a metre in length, and
its habitat is confined to the warm belt extending from the western
slope of the Cordilleras of the Andes to the Pacific. It is met with
especially in the vicinity of Tehuantepec, where it inspires the
natives with very great dread. It is a slow-moving animal, and lives in
dry places on the edges of woods. Its body exhales a strong, nauseous
odour; when it is irritated, there escapes from its jaws a whitish,
sticky slime, secreted by its highly developed salivary glands. Its
food consists of small animals. Its bite is popularly supposed to be
extremely noxious, but, as a rule, the wound, though painful at first,
heals rapidly. Sumichrast caused a fowl to be bitten in the wing by a
young individual, which had not taken any food for a long time. After a
few minutes the parts adjacent to the wound assumed a violet hue; the
bird’s feathers were ruffled; a convulsive trembling seized its entire
body, and it soon sank to the ground. At the end of about half an hour
it lay stretched out as though dead, and from its half-open beak there
flowed a sanguinolent saliva. There was no movement to give any sign
of life, except that from time to time a slight shiver passed through
the hinder part of its body. After two hours, life seemed gradually
to return, and the bird picked itself up and crouched on the ground,
without, however, standing upright, and still keeping its eyes closed.
It remained thus for nearly twelve hours, at the end of which time it
once more collapsed, and expired.

[Illustration: FIG. 124.--_Heloderma horridum._]

A large cat which Sumichrast caused to be bitten in the hind leg
did not die, but immediately after being bitten the leg swelled
considerably, and for several hours the cat continued to mew in a way
that showed that it was suffering acute pain. It was unable to stand,
and remained stretched out on the same spot for a whole day, unable to
get up, and completely stupefied.

Interesting observations on the _Heloderm_ have been made by J.
Van Denburgh and O. B. Wight. The saliva of this lizard was found
to be highly toxic at certain times, and harmless at others. When
injected subcutaneously it produces various effects, such as miction,
defæcation, and abundant salivation, with accelerated respiration
followed by vomiting. The animal drinks with avidity, and remains
lying down, in a very depressed condition. Death finally supervenes,
from arrest of respiration and also of the heart’s action. The poison
likewise acts upon the arterial tension, which falls very rapidly and
very markedly. The sensory nerves are also attacked; irritability is
at first increased, then diminished, and at last entirely lost. These
changes take place from behind forwards, and from the periphery to
the centre. The coagulability of the blood is at first intensified
and then lessened, as when acted upon by VIPERINE venom (H.
Coupin).[163]

C.--Mammals.

The only mammal that can be considered to be provided with a
poison-apparatus belongs to the Order _Monotremata_, and is known as
the Duck-billed Platypus (_Ornithorhynchus paradoxus_ or _O. anatinus_,
fig. 125). The head of this animal is furnished with a kind of flat
duck’s bill, armed with two horny teeth in the upper jaw, while the
body, which is covered with dense fur, resembles that of a beaver. The
tail is broad and flat; the legs are short, and the feet are provided
with five toes, armed with strong claws and webbed.

This singular animal is found only in Australia and Tasmania. It lives
in burrows near watercourses, entered by holes which it digs in the
bank, one above the other on the water-level. It spends much of its
time in the water, and feeds upon worms and small fishes.

In the males the hind feet are armed with a spur, having an orifice at
the extremity. At the will of the animal, there is discharged from this
spur a venomous liquid secreted by a gland, which lies along the thigh,
and is in communication with the spur by means of a wide subcutaneous
duct (Patrick Hill).[164]

It has often been proved in Australia that this liquid, when inoculated
by the puncture of the spur, may give rise to œdema and more or less
intense general malaise. Interesting details with reference to the
effects produced by this secretion have been published by C. J. Martin,
in collaboration with Frank Tidswell.[165]

[Illustration: FIG. 125.--_Ornithorhynchus paradoxus._ (After
Claus.)]

When a dose greater than 2 centigrammes of dry extract of the venom
of _Ornithorhynchus_ is injected intravenously into the rabbit, it
produces phenomena of intoxication analogous to those observed after
inoculation with VIPERINE venoms.[166] Death supervenes in
from twenty-five to thirty minutes, and at the autopsy hæmorrhagic
patches are found beneath the endocardium of the left ventricle.

This venom has been studied afresh in my laboratory by Noc, thanks
to the acquisition of a small supply kindly forwarded to me by C. J.
Martin. Noc proved that it possesses _in vitro_ certain properties of
snake-venoms; like the venom of _Lachesis lanceolatus_, it induces
coagulation in citrate-, oxalate-, chloridate-, and fluorate-plasmas.
Heating at 80° C. destroys this coagulant power.

Contrary, however, to what is found in the case of the venoms of
_Vipera_ and _Lachesis_, the secretion of _Ornithorhynchus_ is devoid
of hæmolytic and proteolytic properties.

Lastly, its toxicity is very slight, at least five thousand times
less than that of the venoms of Australian snakes. A mouse is not
even killed by 5 centigrammes of dry extract, and in the case of the
guinea-pig 10 centigrammes only produce a slight painful œdema.

It has been remarked that the volume and structure of the poison-gland
exhibit variations according to the season of the year at which it is
observed. It is therefore possible that these variations also affect
the toxicity of the secretion (Spicer).[167]

By certain authors the poison of _Ornithorhynchus_ is considered to be
a defensive secretion of the males, which becomes especially active in
the breeding season, and this hypothesis is plausible. In any case it
would seem that as a venom the secretion is but very slightly nocuous.

It will have been seen from the papers quoted above that the chemical
nature and physiology of the various venoms, other than those of
snakes, are as yet little understood and need further investigation.

The main outlines of this vast subject have scarcely been traced,
and the study offers a field of interesting investigations, in which
the workers of the future will be able to reap an ample harvest of
discoveries, pregnant with results for biological science.

PART V.

DOCUMENTS.

I.--A FEW NOTES AND OBSERVATIONS RELATING TO BITES
OF POISONOUS SNAKES TREATED BY ANTIVENOMOUS SERUM
THERAPEUTICS.

A.--Naja tripudians (India and Indo-China).

I.--Case published by A. Beveridge, M.B., C.M., Surgeon S. Coorg
Medical Fund (_British Medical Journal_, December 23, 1899, p. 1732).

“A strong coolie, aged 26, was bitten by a cobra on the right ankle,
just above the internal malleolus. He was brought to the surgery about
one hour after being bitten, in a state of comatose collapse. The pulse
was rapid, and the surface of the body cold. He was given an injection
of 10 c.c. of Calmette’s antivenene deeply into the right flank. He was
kept under observation: the paresis and insensibility were very marked.
On visiting him some hours afterwards I found he could walk without
assistance, but staggered, and complained of weakness and pains in both
legs. Next morning he was much improved, the paresis gradually wore
off, and the pulse steadily gained strength. The patient returned to
work four days later, quite recovered.

“A few days previously a coolie had died after being bitten by a snake
under the same conditions, but without having been treated. Occurrences
like these point to the necessity that every Government or private
dispensary should be supplied with antivenene, which is certainly the
best remedy for snake-bite available.”

II.--Case reported by Robert J. Ashton, M.B., Kaschwa Medical Mission,
Mirzapur (N.W.P.).

“A coolie, aged 27, was bitten in the right foot by a cobra at 5.30
a.m., on September 16, 1900. Half an hour later 10 c.c. of antivenomous
serum were injected subcutaneously into the left forearm. The patient
experienced great pain in the foot, torpor, and great weakness.
Recovery, without complications.”

III.--Case reported by Dr. Simond (Saigon).

“Nguyen-Van-Tranc, an Annamese, aged 25, employed in the Botanical
Gardens at Saigon, was bitten at 10.30 a.m., on March 11, 1899, by a
cobra which had escaped from its cage. The bite was inflicted on the
palmar surface of the index finger of the right hand, and the fangs had
penetrated deeply.

“This native, to whom a sensible comrade had applied a ligature round
the wrist, was brought to the Pasteur Institute three hours later. He
was drowsy, with drooping eyelids; his speech was difficult and almost
unintelligible. Deglutition was impossible, and ingurgitated liquids
caused vomiting. The hand was greatly swollen at the seat of the bite,
and the œdema extended to the forearm. There was partial anæsthesia of
the skin. As soon as the patient arrived, I gave a single injection,
beneath the skin of the flank, of three doses of serum, that is, 30
c.c. In the evening I again injected 10 c.c. of serum. At 10 p.m. the
general condition of the patient seemed to be improving. Next morning
he was less depressed, spoke more easily, and was able to swallow.
Convalescence began from this moment; the œdema and numbness of the
hand and arm, however, persisted for several days.

“Recovery was complete on March 20. I have no doubt that in this very
serious case the antivenomous serum preserved the life of the patient,
since his condition was desperate when I saw him.

“This is the second instance within four months of the successful
treatment of snake-bites at Saigon by Calmette’s serum. In the former
case two natives were bitten by the same animal. One of them, who
permitted the injection of serum, which was performed by Dr. Sartre,
recovered; the other, who refused it, died within twenty-four hours.”

IV.--Case reported by the Fathers of the Khurda-Mariapur Mission
(India).

“At 1 p.m., on October 31, 1905, a woman, aged 35, who had been
bitten by a cobra, was brought to us from Khurda. After being at our
dispensary for about an hour she became drowsy; she paid no attention
to anything that was said to her, and merely replied that she felt
sick. We thereupon injected 10 c.c. of serum. The woman did not even
appear to feel the prick when the needle was driven into her calf.
Immediately after this was done she dozed and went to sleep. The pulse
was feeble, and the entire body cold. We were disposed to give a second
injection, but, since we had only two bottles left, we hesitated to
sacrifice one of them. At last, after sleeping for about half an hour,
the woman awoke of her own accord, sat up, and began to recover her
senses. Bodily heat returned almost immediately, and a few moments
later the patient asked to be allowed to go home; she was, however,
kept at the dispensary. In the evening she continued to complain of
headache, but on the following day she was able to walk, and was quite
well.”

V.--Case reported by Dr. Brau (Saigon).

"Nhuong, an Annamese agriculturist, on passing through a piece of waste
ground beside the barracks, at about 5.30 a.m. on Sunday, September 11,
felt himself suddenly bitten behind the right knee. He caught a glimpse
of a large blackish snake, with all the characteristics of a cobra,
including the raised head and dilated hood, gliding hurriedly away, but
was unable to overtake it.

"The seat of the bite merely showed two small blackish punctures. The
part soon became painfully swollen, and the patient began to feel
giddy. Other natives came to his help; he was lifted into a Malabar
cart and brought to the Military Hospital, whence he was sent to my
house, where he arrived about a quarter past six.

"I entered the vehicle, and immediately drove with the patient to
the Pasteur Institute. The only treatment that he had received was
a ligature round the middle of the right thigh. The lower leg was
enormously swollen, and the swelling was not stopped by the slight
barrier formed by the ligature, but had already extended to the base of
the limb.

"The patient lay stretched out between the two seats of the vehicle,
with head thrown back and eye-balls turned up and ghastly. His skin and
extremities were cold, and his pulse was scarcely perceptible. In order
not to lose time, he was not even taken up to the first floor of the
Institute, but was carried to an inoculating table. He was then made to
swallow black coffee and rum, and was given an injection of as much as
six doses of antivenomous serum, which had just been received from the
Pasteur Institute at Lille.

"Under the stimulus of this injection, somewhat drastic I admit, an
absolute resurrection took place in the sick man. The pulse became
strong and bounding, bodily heat returned, and, although the swelling
did not at once diminish, its progressive extension seemed to be
sharply arrested, while the pain was also greatly lessened. The patient
was able to sit up without assistance, and relate the incidents of his
misadventure.

"In a few minutes time I thought it possible to have him taken to
the Choquan Hospital, the Director of which Institution, First-class
Surgeon-Major Angier, has been good enough to furnish me with a note of
the subsequent history of this case.

“’The Annamese Nhuong, who entered the Choquan Hospital on September
11, suffering from snake-bite, was discharged on September 20.

“’On admission, heat and puffiness were observed in the calf and
thigh. Slight dyspnœa, severe fever, tendency to coma. September 12,
temperature 38°, 39·2° C. September 13, temperature 37·3°, 37·6° C.
September 17, temperature 36·8°, 37° C.

“’On discharge, slight œdema and puffiness in the region of the bite.
General condition good.’”

VI.--Case recorded by Dr. Robert Miller, Bengal-Nagpur Railway Company
(_Advocate of India_, Bombay, January 15, 1902).

“On the evening of October 23 I was called to a coolie woman, who
had been bitten by a large cobra about 7 o’clock; some two hours
had already elapsed since the accident. The woman was, so to speak,
moribund, unconscious, and suffering from paralysis of the throat,
after having exhibited all the characteristic symptoms of poisoning
by cobra-venom. I immediately injected 10 c.c. of Calmette’s serum,
without any hope of a successful result, however, so desperate did
the condition of the patient appear. The effect of the serum was
marvellous; fifteen minutes later she regained consciousness. I gave a
fresh injection of 10 c.c., and three hours after the first the patient
was out of danger. Dr. Sen, my assistant-surgeon, was present. I have
forwarded a note of this case to Dr. L. Rogers, Professor of Pathology
at the Calcutta Medical College.”

VII.--Case recorded by Captain H. A. L. Howell, R.A.M.C. (_British
Medical Journal_, January 25, 1902).

"Shortly before 4 p.m. on November 17, 1901, Lance-Corporal G., Royal
Scots, was bitten on the right forefinger by a snake. On being brought
to hospital, Assistant-Surgeon Raymond tied a tight ligature round the
finger, scarified the wound, and applied a strong solution of calcium
chloride. On my arrival I found the patient apparently quite well, and
not at all alarmed. As I could get no information as to the nature of
the snake, I injected into the patient’s flank at 4.30 p.m. 3 c.c. of
Calmette’s serum, and sent for the snake, which was the property of one
of the men in barracks. The snake was brought to me just before 6 p.m.,
and I found it to be a cobra about 3½ feet long, of the pale-coloured
variety that natives call Brahmini cobra. I at once injected 7 c.c. of
Calmette’s serum into the other flank. The patient thus received one
full dose of serum. The ligature was removed from the finger, which was
swollen and very painful.

"Up to half an hour after the bite the patient, a healthy and powerful
man, presented no abnormal symptoms: pulse, respiration, pupils,
temperature, and general appearance, all were normal. His pulse and
respiration began to increase in frequency, and the pulse became very
compressible, but quite regular. After the first injection of serum
his temperature was 98° F., pulse full, high tension, regular, 88, and
respirations greatly increased in frequency. He now became very drowsy,
and had to be roused when the second injection of serum was given.
Soon after this the patient’s general condition and pulse improved....
He had complete loss of sensation in the bitten finger, in the part
terminal to the site of the puncture, for some days.... The injection
of Calmette’s serum gave rise to no local reaction, and caused no pain.
It did not affect the temperature, but was followed in half an hour by
perspiration, which was very profuse four hours after the injection....
The patient made a complete recovery.... The serum used in this case
was fresh, having been prepared at Lille in July, 1901.”

VIII.--Note of case treated by Major Rennie, R.A.M.C., transmitted by
M. Klobukowski, French Consul-General at Calcutta, September 5, 1899:--

“A remarkable cure effected by Major Rennie, by means of Calmette’s
method, has just taken place at Meerut. Since the introduction of this
remedy three years ago, its efficacy has been abundantly proved, but
the present case is especially interesting, since it seems to show
that the serum can be successfully employed even in cases apparently
desperate. The well-known symptoms of poisoning by cobra-venom were
already so advanced that the patient, who was insensible, was kept
alive by artificial respiration in order to give time for the serum to
be absorbed and to take effect.

“The truth of the above statements is attested by six doctors, and is
also vouched for by the Commissioner and Magistrate of the military
cantonment, who, although not medical men, have, nevertheless, had long
experience of Indian matters.”

IX.--Case recorded by Binode Bihari Ghosal, Assistant-Surgeon, Jangipur
(“A Case of Snake-bite [Cobra?].--Recovery,” _Indian Medical Gazette_,
January, 1905, p. 18).

“While fastening her door about 10 o’clock one night a Hindu woman
was bitten by a cobra in the left foot, about 1 inch above the
metatarso-phalangeal joints of the second and third toes. About ten
minutes after the bite natives applied three strong ligatures, one
above the ankle, one below, and one above the knee-joint. Four hours
later ‘Fowl’ treatment was applied, which it appears gives marvellous
results. The author arrived about nine hours after the accident,
during the ‘Fowl’ treatment, for which nineteen chickens had already
been sacrificed. In spite of this the patient was pulseless (no radial
pulse--the brachial pulse was thready and flickering); respiration
about six per minute. An injection of strychnine improved her condition
for a few minutes. When the incision, which had been made over the
bite, was crucially enlarged, large quantities of dark blood were
withdrawn by cupping. In spite of this the patient’s condition grew
worse, and her respiration fell to three a minute; she then received
an injection of 10 c.c. of Calmette’s serum in the left buttock. The
pulse immediately became stronger, and respiration increased to ten
per minute. About half an hour after the first, a fresh injection of
10 c.c. of serum was given in the same place. Within five minutes the
appearance of the patient, who had seemed to be dying, became normal.
The pulse grew stronger, and respiration was about fifteen per minute.
One hour after the injections the patient was practically cured.

“The ‘Fowl’ treatment consists in applying directly to the wound, after
the latter has been slightly enlarged by means of an incision, the anal
apertures of living fowls, from which the surrounding feathers have
been removed. The fowl immediately becomes drowsy, its eyes blink, and
its head falls on its breast with the beak open, after which the bird
rapidly succumbs. Twenty fowls had been employed in the present case,
but in vain.” (The author does not appear to have troubled himself to
ascertain whether the fowls were really dead, or had merely fallen into
a hypnotic condition.)

X.--Case reported by Major G. Lamb, I.M.S., Plague Research Laboratory,
Parel, Bombay, October 18, 1900.

“Ten days ago I was bitten by a large cobra, from which I was
collecting venom. I had only some very old serum in the laboratory, but
I immediately gave myself an injection of 18 c.c. Three hours after
being bitten I felt faint, my legs became paralysed, and I was seized
with vomiting. In the meantime, fresh serum had been obtained at a
chemist’s, and I received an injection of 10 c.c. The symptoms improved
very rapidly, and an hour later I felt perfectly well. I applied no
local treatment, relying altogether upon the serum.”

XI.--Case reported by Dr. Angier, of Pnom-Penh (Cambodia).

“At 11.30 one night in April, 1901, His Majesty, the second King
of Cambodia brought to me in a carriage one of his wives who, when
crossing the courtyard of the palace at about 8 o’clock, was bitten by
a snake, which she said was a cobra (in Cambodian _Povek_).

“The bite was situated in the lower third of the leg, in front of
the internal malleolus. The patient complained continually; she was
suffering greatly from the leg, which was swollen as high as the knee.
Great lassitude. An injection of 10 c.c. of antivenomous serum was
given, half in the leg and half in the flank. The wound was washed,
squeezed and dressed. Twenty minutes later the pain had ceased, and the
patient went away, feeling nothing more than a slight dulness in the
injured limb.”

B.--Naja haje (Tropical Africa).

XII.--Cases reported by Dr. P. Lamy, of the Houdaille Expedition.

“Lamina, a Senegalese, bitten on the outside of the left thigh, on
February 18, 1898. Treated with serum. Recovery.

“Momo Bolabine, bitten in the heel on April 20, 1898. Ten c.c. of
serum. Recovery.”

XIII.--Case reported by Dr. Deschamps, of Thiès (Senegal).

“In the month of October, 1898, I was called to a native, a local
constable, who had just been bitten by a Naja. The Ouoloffs of Senegal
are much afraid of the bites of this reptile, since they are generally
fatal. In this case the man had been bitten in the forehead by a snake,
which was coiled up in his bed, as he was placing his head on the
pillow. Being in the dark, he got up greatly frightened, lit a candle,
and saw the snake glide from his bed and escape through the half-open
door. I arrived a few minutes after the accident; the constable already
felt very weak, and complained of nausea and of pains in the head and
back of the neck. In the middle region of the forehead I found two
adjacent wounds, around which the tissues were œdematous. I washed the
wounds with a solution of permanganate of potash, and had a telegram
sent to St. Louis asking for antivenomous serum. Half an hour after
the bite, the patient was seized with vomiting and cold sweats. At 6
a.m. on the following day there was considerable œdema of the face and
dyspnœa, while the pulse was small and intermittent. The patient, who
had not slept, was dull and depressed. He vomited a little milk which I
tried to make him take. Forty hours after the bite the patient, who was
already paralysed, became comatose; the face and neck were enormously
swollen. The dyspnœa had increased; it was difficult to hear the
respiratory murmur; the pulse was thready, slow, and intermittent; the
skin was cold; the temperature, taken in the axilla, was 35·8° C. At
this moment the serum asked for arrived from St. Louis. I injected into
the buttock the only dose that I possessed, 10 c.c. The coma persisted
throughout the evening and during part of the night; at 6 a.m. on the
following day, fourteen hours after the injection, the patient awoke
and said that he felt quite well. The œdema of the face and neck had
diminished, that of the eyelids had disappeared. Three days later the
constable returned to duty.”

XIV.--Case reported by Professors H. P. Keatenje and A. Ruffer (Cairo).

“A girl named Hamida, aged 13, while picking cotton on October 7,
1896, at Ghizeh, near Cairo, was bitten in the left forearm by a large
Egyptian cobra, which measured 3 feet in length. She cried out, and her
brother and others who were working with her ran up. She was brought
to hospital by the police at 7 p.m. in a state of complete collapse.
She was almost cold, with upturned eyeballs and imperceptible pulse.
The forearm had been bandaged with a dirty cloth, and the entire arm
was covered with a thick layer of Nile mud (a favourite remedy among
the Fellahîn). Above the wrist two deep punctures were clearly visible,
evidently corresponding to the fangs of the reptile. The patient, whose
condition seemed absolutely desperate, had no longer any reflexes;
she was completely insensible; the moderately dilated pupils scarcely
reacted at all to luminous impressions. Dr. Ruffer injected, with the
customary antiseptic precautions, 20 c.c. of Calmette’s antivenomous
serum beneath the skin of the abdomen. The child gave a groan while
this was being done; this was at 7.30 p.m. At 11 o’clock at night her
condition improved; the pulse was 140, and bodily heat returned; the
patient replied to questions that were put to her. A second injection
of 10 c.c. of serum was given in the flank. She slept for the remainder
of the night, and passed her water four times under her. At 8 a.m. on
October 8 she appeared to be out of danger. She took food, and dozed
throughout the day. On the 9th she was convalescent. There were no
complications resulting from the injection, neither eruptions nor pains
in the joints.”

XV.-Case reported by Dr. Maclaud, of Konakry (French Guinea).

“At 7.30 p.m., on June 22, 1896, there was brought to the Konakry
Hospital a native soldier, named Demba, who had just been bitten by a
snake. This man, who was employed in the bakery, was stacking firewood,
when he felt an extremely acute pain in the left foot; simultaneously
he saw a large snake making off; he succeeded in killing it, and found
it to be a black Naja. After having applied a stout ligature to the
limb, the injured man hastened to the hospital, where, immediately
afterwards, he fell into a condition verging on coma. The body was
bathed with cold sweat; the temperature was subnormal; the pulse, which
was small and thready, was 140. There was difficulty in breathing, and
severe vomiting. At intervals the patient was aroused by spasms, and
excruciating pains in the injured limb, which exhibited considerable
œdema above and below the ligature. Tendency to asphyxia. I washed
the wounds with 1 per cent. solution of permanganate of potash, and
injected a dose of antivenomous serum into the subcutaneous cellular
tissue of the left flank. In view of the severity of the symptoms I
gave two other injections of serum, an injection of 3 c.c., followed
by one of 2 c.c. The patient dozed all night. Next day the general
symptoms had entirely disappeared. Two days later Demba returned to
duty.”

C.--Bungarus fasciatus.

XVI.--Case reported by Surgeon-Captain Jay Gould (Nowgong, Central
India, _British Medical Journal_, October 10, 1896, p. 1025).

“On June 11, 1896, a punkah coolie was bitten on the dorsum of the left
foot, between the second and third toes. He had only the distinct mark
of an incisor, a very slight prick, with a stain of blood which marked
the spot. Within ten minutes we had injected 20 c.c. of Calmette’s
serum into the abdominal wall, after which we made a local injection
of a 1 in 60 solution of hyperchlorite of calcium. Two hours after
the injection the temperature was subnormal, the pulse full and slow.
Twelve hours later the patient was perfectly well and walking about.

“The snake was a Bungarus, full grown, measuring 28 inches.
Unfortunately the syces killed it; it died the very moment I arrived,
so that I was unable to test its virulence.”

D.--Bungarus cæruleus.

XVII.--Case reported by Major S. J. Rennie, R.A.M.C., Meerut, N.W.P.,
India.

“A twelve-year old Hindu boy, named Moraddy, was brought to me at
6 p.m., on July 10, in a semi-comatose condition, with commencing
paralysis of the respiratory muscles. I was told that the child was
sleeping on the ground, when he was bitten in the left hand. He
immediately felt very great pain and giddiness, and his arm began to
swell. Two small wounds were clearly visible, corresponding to the
marks of the fangs of a krait, or _Bungarus cæruleus_.

“The child had salivation, and ptosis of both eyelids. Respiration was
difficult, and deglutition impossible; the pulse was 110 and dicrotic.
The patient’s breathing was of an abdominal character; the surface of
the body was covered with cold sweat. The child soon became lethargic
and collapsed; his condition appeared absolutely desperate. I gave a
subcutaneous injection of 12 c.c. of antivenomous serum, and commenced
artificial respiration, which I continued for half an hour in order to
give the serum time to take effect. In forty-eight hours the symptoms
gradually disappeared, and the child became quite well. Diplopia of the
left eye persisted for a few days, but this also entirely passed away.

“This case shows that, in Calmette’s antivenomous serum, we have a
very powerful remedy against snake-bites, which may take effect even
in desperate cases. It further proves that the serum will keep for a
very long time, even when exposed to all the vicissitudes of the Indian
climate, for the serum employed by me had been in my possession for
nearly four years.”

E.--Sepedon hæmachates (Berg-Adder).

XVIII.--Case reported by Mr. W. A. G. Fox, Table Mountain, Cape of Good
Hope.

“On February 9, 1898, I was summoned to the Town Council’s Camp to
treat a native who had been bitten by a berg-adder in the left leg,
just below the knee. I immediately injected a dose of Calmette’s
antivenomous serum in the left flank, and the wounds were washed. The
injection was given two and a quarter hours after the accident. The
patient was already very ill when I saw him, and I have no doubt that,
without the antivenomous serum, he would have died.

“On the following day he had recovered, and I saw him again three
months later; since then he has not experienced any functional trouble.”

F.--Hydrophiidæ (Sea-Snakes).

XIX.--Case recorded by Mr. H. W. Peal, Indian Museum, Calcutta (_Indian
Medical Gazette_, July, 1903, p. 276).

“On April 1, 1903, at 7.30 p.m., a man was bitten at Dhamra, in
Orissa, by a sea-snake which had been caught in a fishing net. He was
not brought to me until 2.30 the next day, when he was in a state of
collapse, semi-unconscious, and unable to speak, with eyes dull and
almost closed. The bite was on the third finger of the left hand, just
above the first joint. The finger was swollen, tense, and stiff. I gave
the man an injection of 5 c.c. of antivenene ten minutes after he was
brought to me. Three or four minutes after the injection the man with
some assistance was able to sit up, and said he felt much better. He
complained of great pain at the back of the neck and also in the lumbar
region. He was able to speak fairly coherently after a little time. His
eyes were brighter and he seemed to be aroused from his lethargy.

“I had about one hundred living sea-snakes with me, belonging to the
three genera _Enhydrina_, _Hydrus_, and _Distira_. He identified
_Enhydrina valakadien_ as being the snake which bit him; so did the men
who were with him. The snake was said to be about 3½ to 4 feet long.

“The antivenene did the man so much good, that he himself asked me to
give him a second injection. This I gave him at 2.25 p.m. (5 c.c.).

“Date on bottle used, May 8, 1900.

“The pains in the joints had disappeared on the second injection
(which was given in opposite flank). At 5 o’clock the man walked away
with assistance. He was quite well a couple of hours after the second
injection, and when I saw him again on May 8 he was in perfect health.”

G.--European Vipers (_Pelias berus_ and _Vipera aspis_).

XX.--Case published by Dr. Marchand, of des Montils, Loir-et-Cher
(_Anjou médical_, August, 1897).

“About 11 a.m., on Friday, July 23, Jules Bellier, aged 26, was mowing
in a damp spot, when he was bitten in the heel by a large viper
(_Vipera berus_). The bite, which was deep, was situated on the outside
of the foot, 1 cm. behind the malleolus and 3 cm. above the plantar
margin; at this point there were two punctures in the skin, 1 cm.
apart. Directly after the accident the patient left his work, tied his
hankerchief tightly round the lower third of his leg, made the wound
bleed, and came to me with all speed, hopping on one foot for about a
kilometre. When I saw him scarcely twenty minutes had elapsed since
the accident; his general appearance was altered, and his pulse rapid.
The patient had vomited twice; he complained of pains in the head, and
of general weakness, and ’was afraid,’ he said, ‘of fainting.’ The
foot and leg were painful under pressure; a slight tumefaction was
visible in the peri-malleolar region, around the bites, which bled a
little. Forthwith, after washing the wound freely with a solution of
permanganate of potash, I injected 10 c.c. of Calmette’s serum into
the antero-external region of the middle part of the thigh; then I
enveloped the leg in a damp antiseptic dressing as high as the knee.
The patient breathed more freely and plucked up his spirits. After
lying down for quarter of an hour he went home on foot (he lives a
hundred yards from my house).

“In the evening I saw my patient again. He was in bed, with a
temperature of 37·2° C.; pulse 60; no malaise, no headache, no further
vomiting; he had taken a little soup, and a small quantity of alcoholic
infusion of lime-tree flowers. He complained of his leg, which was
swollen as high as the knee; the pain was greater in the calf than at
the malleolus. I applied a damp bandage. The patient had a good night,
and slept for several hours, but still had pain in the leg. On the
following morning, July 24, I found him cheerful, with no fever, and
hungry. Around the bite the œdema had become considerable, and had
extended to an equal degree as high as the instep; the calf and thigh
were swollen, but to a much less extent. I gave a second injection of
10 c.c. of antivenomous serum in the cellular tissue of the abdominal
wall. The day was good; indeed, the patient had no fever at any time;
the spots at which the injections were made were but very slightly
sensitive on pressure. In the evening the general condition of the
patient was satisfactory; he complained most of his calf. Thinking that
a contraction was possible, due to his having hopped along quickly on
one leg after the accident, I ordered him a bath.

“On July 25, the second day after he was bitten, the only symptom still
exhibited by the patient was a somewhat considerable amount of œdema in
the peri-malleolar region and lower third of the leg. This œdema was
slowly and gradually absorbed on the following days.

“_Remarks._--(1) At this season of the year viper-bites are both
frequent and dangerous in this district of the Loir-et-Cher. A year
never passes without several cases occurring, and it has very often
happened that deaths have had to be recorded in spite of the most
careful treatment.

“(2) The therapeutic effect of Calmette’s serum was rapid and
efficacious; the injections did not cause any pain or febrile reaction.

“(3) The œdema resulting from the bite was a long time in being
absorbed; this, indeed, was the only remarkable symptom after the
injection of the serum.”

XXI.--Case recorded by Dr. D. Paterne, of Blois (Anjou médical,
September, 1897).

“My _confrère_ and friend Dr. Marchand (des Montils) published in last
month’s _Anjou médical_ an interesting case of viper-bite, cured by
Calmette’s serum. May I send you particulars of another case, which can
only increase the interest of the one that you have already published?
The facts are as follows:--

“Léon Bertre, aged 55, living at 17, Rue du Puits-Châtel, Blois,
professes to be a snake-charmer, and really catches and destroys large
numbers of dangerous reptiles in the vicinity of Blois.

“On Sunday, the 30th of last May, he went among the rocks of the
Chaussée Saint-Victor on his favourite quest, and soon returned with
ten large female vipers, and amused himself by exhibiting them to a
group of interested spectators in an inn. A dog came up and began
to bark. Bertre, whose attention was momentarily distracted, ceased
to fix his gaze on the vipers, one of which, being no longer under
the influence of its fascination, bit him on the back of the right
hand, between the metacarpals of the thumb and index-finger. (I here
reproduce the account of the occurrence as I received it from the
snake-charmer’s own lips.) Bertre immediately felt an acute pain; his
hand swelled up _almost suddenly_, and, since he was perfectly aware
of the seriousness of what had happened, he ran with all speed in the
direction of my consulting-room. The unfortunate man, however, had
hardly gone 200 metres, when he fell insensible on the highway. He
was brought to me, and Dr. Moreau, of Paris, _locum tenens_ for Dr.
Ferrand, of Blois, who was away, rendered first aid. He washed the
wound, dressed it with perchloride of mercury, and injected 10 c.c. of
Calmette’s serum into the right flank. The accident took place a little
before 5 p.m., and the injection was given about 6 o’clock.

“Dr. Moreau, who was interested in the case, asked me to take charge of
it, which I gladly consented to do. The patient’s general condition was
very grave, since he remained two days and two nights without regaining
consciousness.

“On Tuesday, June 1, about 11 o’clock, Dr. Moreau gave a second
injection of 20 c.c. Considering the condition of the patient, we
hardly hoped for a successful result. To our great surprise, however,
the patient regained consciousness about 3 p.m., and the improvement
progressed rapidly.”

XXII.--Case recorded by Dr. Thuau, of Baugé (_Anjou médical_,
September, 1897).

“X., a young man of Volandry, a parish 10 kilometres from Baugé,
was bitten in the heel at 10 a.m. on the 6th of last August, by an
aspic, about 50 cm. in length, while engaged in harvesting. He at once
had himself taken to Baugé, knowing that there was an antivenomous
serum dispensary there, and about noon he arrived at the house of my
_confrère_ and friend Dr. Boell. The latter, in view of the grave
symptoms exhibited by the patient (nausea, vertigo almost amounting to
syncope, pain in the chest, profuse sweating, &c.), gave him, with all
the customary precautions, a first injection of 10 c.c. of Calmette’s
serum in the flank. After about half an hour, since the alarming
symptoms did not appear to diminish, he did not hesitate to give a
second injection of 10 c.c., and then had him sent to the Baugé Civil
Hospital, where he came under my care about 3 p.m. I then found that
this young man had been bitten in the left foot, a little below the
external malleolus, midway between the latter and the plantar margin.
The snake’s fangs had penetrated rather deeply; the two little wounds
were about a centimetre apart. About this time the patient experienced
great relief, and his general condition continued rapidly to improve.
The axillary temperature was 37·8° C.

“Locally the patient complained of somewhat acute pain in the entire
foot; the latter was purple and greatly swollen, and the swelling had
affected the whole of the lower leg and extended to a little above
the knee. I made a slight incision in the region of the two wounds
caused by the bite, made the place bleed a little, and washed it with a
solution of permanganate of potash, advising that the dressing should
be changed several times a day. In the evening the temperature was 37°
C., and never varied again from the normal until recovery was complete
on August 25.

“The two injections of antivenomous serum did not produce any painful
or inflammatory reaction.”

XXIII.--Case reported by Dr. Clamouse, of Saint-Epain, Indre-et-Loire.

“Léonie C., a servant at a farm, aged 19, bitten on June 1, 1900,
by a red viper on the dorsal face of the left ring-finger. Somewhat
serious symptoms of intoxication. In default of serum, injection of
Labarraque’s fluid, 1 in 12. Serum obtained from Tours was injected at
11 p.m. on June 2, thirty-eight hours after the accident.

“On the morning of June 3, very marked improvement. On June 7, general
condition excellent. Recovery.”

XXIV.--Case reported by Dr. G. Moreau, of Neung-sur-Beuvron,
Loir-et-Cher.

“A. B., aged 12, living at Villeny, in the canton of Neung-sur-Beuvron
(Loir-et-Cher), was bitten on June 23, 1900, on the left external
malleolus. The parents contented themselves with applying a ligature
above the wound, and did not bring the child to me until 12.15 p.m.

“Tumefaction of the entire foot. Ecchymosis of the skin extending
half-way up the leg. General condition excellent. I gave antiseptically
an injection of 10 c.c. of antivenomous serum in the right flank,
followed by a draught of acetate of ammonia and syrup of ether. Damp
bandage applied to wound and swollen part.

“I saw the child again on the following day. Generalised œdema and
tumefaction of the bitten limb. Heart excellent; no vomiting, no
fever. I again gave an injection of 20 c.c. of serum, and ordered a
continuance of damp phenic dressings to be applied to the entire limb.
Condition very good.

“On June 25, no fever at the time of my visit. Pulse irregular. Ordered
treatment to be continued.

“I did not see the patient for four days, when I was summoned by
telegram. I found that the child had fever, 39° C. Complete tumefaction
of the left leg, abdomen, and trunk, with ecchymosed patches.
Prescribed quinine. Arhythmia of pulse and heart. Prescribed digitalis
and Jaccoud’s tonic. The febrile condition was due to congestion of the
base of the right lung. I ordered cupping and sinapisms alternately.

“I saw the child again two days later. The congestion still continued.
Temperature 39° C., but the general tumefaction showed a tendency to
diminish.

“On July 4 I again saw the child. Now only slight œdema. General
condition very satisfactory. Temperature normal. The child was making
rapid strides towards recovery. The leg was doing well, and the wound
was almost healed.

“Summary: A very serious bite and, above all, great delay in injecting
serum (injection not given until four hours after the accident);
unforeseen complications in the lung, by which recovery was delayed.”

XXV.--Case reported by Mons. H. Moindrot, Assistant to Dr. Martel, of
Saint-Étienne (Loire).

“Claude L., aged 8, living at Ricamarie, was brought, on May 26, 1904,
to the Bellevue Hospital. The parents stated that about 10 o’clock the
same morning, while playing near a stack of faggots, the child was
bitten by a snake in the third finger of the right hand. Since the
wound caused by the bite seemed to them of little importance, they
contented themselves with squeezing the injured finger in order to make
it bleed a little. A few moments later, however, the child began to
complain of a feeling of distension in the region of the bite, caused
by œdema, which soon increased to an alarming extent. A doctor, who was
called in, carefully washed the wound, applied an aseptic dressing, and
at once sent the little sufferer to the Hospital.

“_On admission_, enormous œdema, including fingers, hand, entire right
arm, cervical region on the same side, and the anterior face of the
thorax, nearly as far as the inner margin of the false ribs. This œdema
was not very painful, though fairly tense, yielding but slightly to
pressure. In the affected region the skin was cold, of a dull livid
colour, with a few ecchymosed patches. In the bitten finger, a small
wound with no special characteristics.

“General condition bad; the child was unable to stand. He was
indifferent to what was passing around him, merely groaning a little
when examined. The pulse was feeble, thin, and easily compressible;
it was also very irregular. The extremities were cold. Lungs: nothing
abnormal on auscultation, rapidly performed, it is true. Respiration,
however, was distinctly accelerated, 30 per minute. Temperature not
taken on admission. No urine passed since the accident.

“The patient’s condition being so alarming, not to say desperate, we
thought it almost useless to have recourse to Calmette’s method, more
especially since at least seven hours had already elapsed since the
child was bitten. Nevertheless we gave a hypodermic injection of 20
c.c. of Calmette’s serum. At the same time the wound was crucially
incised, and bathed with a 1 in 1,000 solution of permanganate of
potash, after which a damp dressing was applied to the whole of the
swollen limb. The patient was put to bed, and kept warm. He was given
an injection of 50 centigrammes of caffeine, and 300 grammes of
artificial serum. In the evening the temperature was 36·8° C.

“May 27.--General condition more satisfactory; pulse still weak, but
less irregular. Persistence of dyspnœa, explained by a series of small
râles at the bases of both lungs. This morning the little patient
passed his urine, about 200 grammes. He is more lively, and replies
better to any questions addressed to him.

“May 28.--The improvement continues; the dyspnœa has almost entirely
disappeared; only a few râles are still heard at the extreme base. The
pulse is stronger and remains regular. The secretion of urine gradually
reappears. The temperature of the extremities has become normal.

“On May 29 and following days the œdema continued to diminish, and had
totally disappeared eight or ten days later.

“Recovery was complete by about June 15. The child was discharged on
June 23, 1904.

“It seemed to us worth while to report this case, in order to emphasise
the conclusion that forces itself upon us, namely that in all cases of
bites from poisonous snakes an injection of Calmette’s serum should be
given, without considering the efficacy of this therapeutic agent as
being rendered doubtful by the length of time that may have elapsed
since the bite was inflicted.

“In the present case, as we have seen, there was extensive
intoxication, which had seriously affected the functions of the various
organs, since we found cardiac arhythmia and pulmonary œdema, and that
the patient was threatened with collapse, algidity, hypothermia, and
anuria. Impregnation by the virus having continued for seven hours,
we might have felt ourselves justified, on the one hand in merely
employing the proper means for the relief of the general condition, on
the other hand in treating the local condition, without having recourse
to the serotherapeutic method, that seems to us in this case, in so
far as it is permissible to make such a statement, to have been the
determining factor in the recovery.”

XXVI.--Case recorded by Dr. Lapeyre, of Fontainebleau (from _L’Abeille
de Fontainebleau_ of June 27, 1902).

“M. X., who arrived at Fontainebleau on Sunday morning with a friend,
keeps grass snakes at home, in Paris; he finds his hobby as good a
means as any other to remind him of the forest and its charms. Human
nature includes all kinds of tastes, so that this particular one need
not be further discussed.

“The journey, therefore, had a twofold object: firstly to spend a whole
day in sunshine and in the open air, and secondly to catch grass snakes
to add to the collection.

“On leaving the train, our Parisian walked up the Amélie Road, and saw
a snake under a rock. Never doubting that it was one of the kind that
he knew so well, to kneel down, pass his left arm into the hole, and
seize the snake, was the work of a moment; he quickly succeeded, even
better than he intended, for instead of his seizing a grass snake, the
viper bit him so hard in the left forefinger, that he could only make
it let go by pulling it off with his other hand. Well knowing that he
had been dangerously bitten, he went down to the Station Road to get
the wound dressed, after which, thinking that all necessary precautions
had been taken he returned to the forest, but soon felt uncomfortable.
His arm and then his body swelled up, and he was seized with vomiting.
It was time to go to Fontainebleau to seek medical assistance, for he
had acute pain in the abdomen and stomach, his tongue was swollen, and
his body was turning black.

“Accompanied by his friend he reached the town. His condition becoming
more serious every moment; the injured man was carried into a hotel,
where Dr. Lapeyre administered injections of antivenomous serum. After
three hours--the same period as had elapsed between the accident and
the first treatment--the general condition of the patient, which had
never ceased to be alarming, showed marked improvement. By the end of
the day he appeared to be out of danger, and left for Paris on Tuesday
evening, delighted at having got off so cheaply.”

H.--Echis carinata.

XXVII.--Case recorded by Lieutenant C. C. Murison, I.M.S. (_Indian
Medical Gazette_, May, 1902, p. 171).

“G. W. R., a Mahomedan, aged about 12, was admitted into hospital on
March 10, 1902, at 9.30 p.m., having been bitten by a snake on the
dorsum of the right foot an hour and a half previously. The snake was
killed by his sister, and was subsequently identified at the Research
Laboratory, Bombay, as an _Echis carinata_ (Phoorsa).

“I saw the patient at about 9.45. The dorsum of the foot was swollen,
and the swelling extended above the ankle-joint. The knee reflexes
were very exaggerated, and the boy was somewhat drowsy. Since he was
gradually getting worse, I decided to inject 5 c.c. of Calmette’s
antivenene. I got the hospital assistant under my supervision to inject
it into the right calf, to cauterise the bite with silver nitrate, and
to apply a 1 in 40 carbolic poultice. Very soon (fifteen minutes) after
this the pain in the thigh, which had reached to the right groin, began
to disappear. During the night the patient was very sleepy, and the
attendants had great difficulty in keeping him awake.

“March 12.--This morning the patient is much better; there is still
considerable swelling of the foot, but the pain is much less. All other
symptoms are gone.”

XXVIII.--Case reported by Surgeon-Captain Sutherland I.M.S., Saugor,
C.P., India.

Case of a woman bitten on the finger on July 22, 1898, by an _Echis
carinata_. Treated six hours later with 10 c.c. of serum. Recovery.

I.--Cerastes.

XXIX.--Case reported by Dr. Moudon, of Konakry, French Guinea.

“On December 9, 1898, a Foulah woman, eight months pregnant, was
collecting wood when she was bitten in the heel, behind the internal
malleolus of the right foot, by a snake which, from the description
given, must have been a Horned Viper. When I saw her, four hours after
the accident, the whole of the lower leg was swollen and painful.
The swelling extended to the groin, and the patient complained of
vertigo and nausea. I immediately gave her an injection of 10 c.c. of
antivenomous serum in the right flank, followed by a second injection
at 10 p.m. Ten days later, with the Commandant of the _Fulton_, I
saw her again at her village; she had no symptom of malaise, and the
pregnancy was taking its normal course.”

XXX.--Case of a bite from a Horned Viper reported by Dr. Mons, in
charge of the Military Hospital of Laghouat, Algeria.

“Mohamed ben Naouri, a day labourer, aged 26, during the summer catches
Horned Vipers, which he stuffs and sells.

“On August 3 a _Cerastes_, which he was holding down on the sand with a
forked stick, disengaged itself and fastened on his hand. The snake was
a large one, about 50 cm. in length.

“The accident happened at 6.30 a.m., 6 kilometres from Laghouat, and
the man was bitten on the joint between the second and third phalanges
of the third finger of the right hand. He applied a ligature to his
wrist, and started to run as fast as he could towards the Military
Hospital, where he arrived an hour later.

“He was immediately given an injection of antivenomous serum, in
accordance with the instructions, and, around the bite, five or
six injections of permanganate of potash, 1 in 20. On the next and
following days, tense œdema of the arm and left side of the chest.
Extensive purplish ecchymosis of the inner face of the arm; no fever.
The phenomena gradually diminished, and, on August 17, there was merely
a trifling wound where the bite had been inflicted. The patient was
discharged at his own request.

“Like Dr. Marchand (des Montils), we can certify that the action of
Calmette’s serum was rapid and efficacious. The injection did not cause
any pain or febrile reaction.”

XXXI.--Case reported by Dr. Blin, of Dahomey.

“On March 5, 1906, native hospital attendant C., while gathering
vegetables in the hospital garden, was bitten in the right hand by a
_Cerastes_. The bite was inflicted in the tip of the index finger.
Ten minutes later a ligature was applied to the base of the finger
and another to the upper arm, and as soon as we saw the man, which
was after the lapse of about an hour, he was given an injection of 10
c.c. of antivenomous serum. The patient complained of feeling cold and
vomited. The axillary temperature was 36·1° C.; the pulse was weak,
irregular, and rapid. The finger and hand were swollen. A few minutes
later we gave a second injection of serum. Until evening (the accident
took place at 11 a.m.) the patient suffered from nausea, but sweating
set in, and at 7 o’clock the temperature had risen to 36·7° C. The
feeling of depression was much less. On the following day the symptoms
had disappeared, and forty-eight hours afterwards the patient returned
to duty.”

K.--Bitis arietans (Puff Adder).

XXXII.--Case reported by Dr. P. M. Travers, Chilubula Mission,
North-eastern Rhodesia.

“On Thursday, September 6, 1906, information was brought to me that a
child, aged 7 or 8, in inserting his hand into a mole’s hole had been
bitten by a _lifwafwa_ (’Death-Death,’ _i.e._, Puff Adder). I set off
in all haste on my bicycle. An accident obliged me to leave the road
when half-way, and, to complete the series of mishaps, I went to a
village with a similar name, a good half-hour distant from that where
the patient lived. The result was that by the time I arrived I should
say that about two hours had elapsed since the child had been bitten.
The snake had been killed, and was, indeed, a puff adder. It had bitten
the child in the middle finger of the right hand, and half the arm
was greatly swollen, and as hard as stone. As quickly as possible I
gave an injection of 10 c.c. of antivenomous serum, and then vainly
endeavoured to make the wound bleed. In a very short time the serum was
absorbed. On the following morning the child was still ill, with wild
eyes resembling those of an epileptic. He yawned continually, and did
not seem altogether conscious; the inflammation, however, had greatly
diminished. A few days later recovery was complete, but a large abscess
formed on the forearm, and the hand became necrosed. I was obliged to
amputate all the phalanges. The natives said the child was going to
die during the night. In my opinion the serum saved the child’s life,
and recovery would have been more rapid had I not been so late in
arriving.”

L.--Lachesis ferox (known as the _Grage_, in French Guiana).

XXXIII.--Case reported by Dr. Lhomme.

“In May, 1898, A., aged 48, a European convict undergoing sentence, was
admitted to the Penitentiary Infirmary, of Roches de Kouvous (French
Guiana), suffering from a poisonous bite.

“The man had been bitten while engaged in felling timber, at the place
called Passouva. The locality is one that is infested with snakes,
especially at the end of the wet season. Two venomous species in
particular are found there in considerable numbers, the rattle-snake
and another called the _Grage_ by the blacks, which appears to be a
_Lachesis_.

“The patient arrived at the Infirmary in the evening, about twelve
hours after the accident. We endeavoured to obtain precise details,
but, owing to special circumstances, A., who was alone, had been unable
to see what animal had bitten him. The clinical signs, however, pointed
to a venomous snake; inflammatory phenomena and pain set in soon after
the wound was inflicted, and in a very short time became acute.

“_Clinical Signs._--On examining the patient we found that the whole of
the right arm was swollen. The skin, which was of a dark red colour,
was acutely inflamed. The slightest touch or the least movement caused
the patient to cry out. The hand showed traces of the bite, in the
shape of two small red marks, each surrounded by a bluish areola. The
general condition was good. The thermometer, however, indicated a
slight rise of temperature, and the pulse seemed a little soft. The
urine on being examined on the day after the accident contained a small
quantity of albumin. Organs normal. General health before the accident
excellent. Nothing worth mentioning in the previous history.

“_Progress._--The conditions that we have just described disappeared
very quickly, once the treatment was applied. The pain soon ceased,
the temperature fell, and the patient was able to get a few hours
sleep. By the following day the inflammatory phenomena had noticeably
diminished. The œdema of the forearm and hand, however, persisted for
some time, though there was no formation of pus. On the third day after
the accident the albumin had completely disappeared from the urine.
Finally, after the lapse of a fortnight, the condition became normal,
and the convict, who had recovered the entire use of his arm, was able
to resume work.

“_Treatment._--On admission to the Infirmary, A. received a hypodermic
injection in the thorax of the contents of a bottle of antivenomous
serum. At the same time he was given tonics (alcoholised coffee). The
injured limb was placed in a hot phenic arm-bath. These baths were
continued on the following days, alternately with damp dressings. Milk
diet, and daily aperients.

“We saw the patient again more than a year after the accident; his
recovery had been complete; there was no loss of power in the arm
whatsoever, and he had never suffered from the nervous troubles
mentioned by some authors as a complication ensuing after a long
interval, and attributed by them to the antitoxic serum.”

XXXIV.--Case reported by M. Jean, Veterinary Surgeon of Artillery in
Martinique.

“C., a negro, aged 26, employed in the artillery quarters at the
Rivière d’Or, was bitten in the right leg by a snake measuring about 1
metre in length, which he declared was a _Trigonocephalus_. The patient
came to me twenty minutes after the accident. The marks of the bite
were clearly visible a hand’s breadth above the external malleolus.
The wounds were inflamed, and appeared as two small red spots 1·5 cm.
apart, from which a few drops of serum were exuding. I did not notice
any congestion. The patient, however, complained of a feeling of weight
in the leg, and supported himself upon the sound one. After making the
man lie down upon a bed, I applied a tight ligature above the bitten
part, and, with a penknife passed through a flame, I endeavoured to
incise the wounds. The instrument, however, was blunt and I obtained
but little blood.

“The treatment prescribed in Dr. Calmette’s directions was then
strictly followed. With the usual antiseptic precautions, I made
several hypodermic injections of the solution of hypochlorite of
calcium round the bite, and injected the dose of serum indicated in two
places in the abdominal wall. The patient was then vigorously rubbed
and covered with woollen blankets. He was made to take two cups of a
strong infusion of black coffee. Since he could not be induced to go
to hospital, he was carried half an hour later to his home, where he
placed himself in the hands of a ‘dresser.’

“According to information furnished by Captain Martin, who lived on
the spot and was able to follow the course of the case, the patient
remained throughout the day in a state of profound prostration, and had
several attacks of syncope. The injured limb was greatly swollen, and
the swelling, which extended to above the knee, produced a mechanical
difficulty in using the joint, leading to a belief that paralysis was
setting in. During the first five days the condition of the patient was
so alarming as to cause a fatal issue to be apprehended. By degrees
these symptoms diminished, until they disappeared about the fifth day.

“On the twentieth day, C. returned to his work. I saw him again a
month later, when he was in perfect health; his leg had returned to
its normal size, and all that remained were two small fibrous nodules
showing where the bite had been inflicted.”

XXXV.--Case reported by Dr. Gries, Fort-de-France, Martinique.

“On June 21, 1896, a young black, who had just been bitten in the
foot by a _Bothrops_ of large size, was brought to the Fort-de-France
Hospital. The entire limb was swollen and benumbed.

“Two hours after the accident I gave an injection of 10 c.c. of serum
in the abdomen, and the patient was taken back to his family. I saw
him again ten days later, and found that he was quite cured. His
friends stated that recovery had taken place much more quickly than
could have been hoped after so serious a bite, and without the usual
complications.”

XXXVI.--Case reported by Dr. Gries, Fort-de-France, Martinique.

“About 7 a.m., on November 25, 1896, G., aged 23, a fusilier belonging
to the disciplinary battalion, was bitten by a _Bothrops_ at Fort
Desaix under the following circumstances. One of his comrades had just
caught the snake, and was holding its head down on the ground by means
of a forked stick applied to the neck. G. passed a running noose round
the reptile’s neck, but, his comrade having withdrawn the fork too
soon, the snake had time to dart at him and bite him in left thumb. At
the moment when he was bitten the man was squatting, but he quickly
stood up, carrying with him the snake, which remained for a few seconds
suspended from the thumb by its fangs, and did not let go until its
victim had struck it on the head with his fist. G. immediately ran
to one of his officers, who applied a tight ligature to the base of
his thumb, and sent him off to the hospital, where he arrived on foot
and quite out of breath, ten or twelve minutes after the accident. He
was at once given a hypodermic injection of 10 c.c. of antivenomous
serum in the left flank; the thumb was washed with a 1 in 60 solution
of hypochlorite of calcium, after which the ligature was removed. A
few moments later, thinking the case a serious one, I caused a second
injection of 10 c.c. of serum to be given in the right flank.

“Immediately after being bitten the patient experienced complete loss
of sensation in the limb, as far as the middle of the arm. About 9 a.m.
he complained of acute shooting pains in the hand. At 11 o’clock the
limb was still benumbed, but by degrees sensation returned. Profuse
sweating.

“On November 26 sensation was restored in the whole limb; no
inflammatory phenomena. The patient was perfectly well.

“The _Bothrops_ on being brought to the hospital measured 1 metre 47
cm. in length.”

XXXVII.--Case reported by Dr. Lavigne, Colonial-Surgeon at
Fort-de-France.

“At 7 a.m. on January 19, 1897, G., aged 22, was going along a footpath
near Trouvaillant, when he was bitten in the left external malleolus by
a _Trigonocephalus_ which was rutting (a circumstance which, according
to the natives, aggravates the character of the bite).

“After killing one of the reptiles (the other having escaped), the
young man made his way to the detachment of gendarmery stationed close
by. The officer in command applied a ligature to the upper part of
the leg, cupped the man a few times, and sent information to us at
the Military Hospital. On reaching the spot at 9.15 we found, on the
postero-inferior surface of the left external malleolus, two small
wounds resembling those caused by the bite of a snake. The leg was
swollen and painful, and the patient could hardly put his foot to the
ground.

“At 9.30, after taking the usual antiseptic precautions, we gave
an injection of Calmette’s antivenomous serum, from a bottle dated
December 26, 1896. Not having any hypochlorite of calcium at our
disposal, we washed the wound with a 1 in 60 solution of hyposulphite
of soda, and applied a dressing of carbolic gauze. An hour later the
patient was taken to Saint Pierre in a carriage. Temperature 37·2° C.
No vomiting, or tetanic phenomena. In the afternoon the pain was less
acute, and the œdema seemed to have diminished a little. Mercurial
ointment rubbed in.

“Four days later the patient, being cured without having had the least
rise of temperature, proceeded to the country.

“This case is interesting, since a single dose of antivenomous serum
(20 grammes), injected two hours and a half after the accident,
sufficed to cure a young man bitten by a _Trigonocephalus_ measuring 1
metre 20 cm. in length.”

M.--Crotalus horridus.

XXXVIII.--Case recorded by Dr. P. Renaux, of Piriapolis, Uruguay (_La
Tribuna popular_, Piriapolis, December 14, 1898).

Silverita, aged 20, bitten in the ankle by a _Crotalus_, on December
7, 1898. Symptoms of serious intoxication. Treated with a dose of
antivenomous serum, injected half in the right flank, half in the left.
Recovery.

II.--A FEW NOTES AND OBSERVATIONS RELATING TO DOMESTIC ANIMALS
BITTEN BY POISONOUS SNAKES AND TREATED WITH SERUM.

A.--Naja haje.

XXXIX.--Case reported by Dr. Maclaud, of Konakry, French Guinea.

“A hound belonging to the Governor of Konakry was bitten in the ear
by a black _Naja_. A similar accident happened last year, and the
animal died on the fifth day. In the present case, serious phenomena
had already manifested themselves: depression, convulsions, and great
swelling of the entire head and anterior portion of the trunk. A dose
of 10 c.c. was injected at three different points: in the flank,
neck, and cellular tissue of the injured ear. Improvement was almost
immediate. On the following day the animal recovered its appetite, and
two days later was completely cured.”

XL.--Case reported by Dr. Marotte, of Konakry.

“At 10 a.m. on November 1, 1898, a large dog (a German brach), weighing
33 kilogrammes, was running about in some tall grass. It returned
to its master, looking unhappy, with its eyelids swollen. Thinking
that his dog had been bitten by a _Naja_, a snake which swarms round
Konakry, he took it to the hospital. The animal was unable to cover
the distance, which was only 300 metres; it was dragged along, but
collapsed, and had to be carried. Its head was swollen, it panted, and
its breathing was rapid and irregular; there was profuse salivation.
On the inner face of the right ear the marks of the two fangs of the
reptile were distinctly visible. A hypodermic injection of 10 c.c.
of antivenomous serum was immediately given in the right flank: this
was at 10.10 a.m. At 11 o’clock the symptoms appeared to become less
acute; the animal was easier, and its breathing became less rapid and
more regular. At 1 o’clock the animal succeeded in getting on to its
feet; the œdema had somewhat diminished, and it was able to half open
its eyes. At 6 o’clock the dog was taken back to its master’s house; it
seemed just as lively as though nothing had happened.

“On the following morning there was still a small amount of œdema in
the eyelids, but the appearance of the head had become normal.”

B.--Pelias berus (Common Viper).

XLI.--Case reported by M. de Maupas, of Challay, by Trôô.

“About 1 p.m., on July 30, 1898, a fairly large pointer was brought
to me, bitten in the right paw. On shaving off the hair the marks of
the two fangs of the snake were clearly visible. The wound had bled
a little, and the injured limb was painful and swollen. I ligatured
the paw above the joint, and injected a bottle of antivenomous serum,
which had been in my possession since September 6, 1897. The effect
was very rapid; after a quarter of an hour the dog reopened its eyes,
which until then had been half closed. Towards 5 o’clock I removed the
ligature. On the next day but one the swelling had almost disappeared,
and the dog took its food of its own accord; it ran about and seemed
lively.”

XLII.--Case reported by M. de Villiers, Mayor of Villiers-le-Duc,
Côte-d’Or.

“About 2 p.m., on May 23, 1898, the widow Veillard, of Villiers-le-Duc,
while driving her herd of cows to pasture among the brushwood, saw a
viper which she killed, and then, a few moments later, three others
in succession, which she likewise killed. Madame Veillard thought of
leaving this place, which seemed to her to be too much infested, when
one of her cows, which was quietly feeding, swerved violently and
dashed off through the scrub. With the help of her dog she succeeded in
recovering the cow, which appeared uneasy, ceased to feed, and had a
swollen muzzle. Madame Veillard then decided to return to the village.

“Towards 6 p.m., that is to say about three hours after the accident,
I was sent for. The head and tongue of the cow were swollen, there
was foam on the mouth, and the animal had difficulty in breathing. I
injected a dose of antivenomous serum, from our first-aid station,
beneath the skin of the shoulder, and gave a second injection a few
moments later. The cow was then led back to her shed.

“At 9 p.m. she was quiet. The swelling did not increase, and the cow,
which had previously refused all food, ate a handful of hay.

“On the following morning there was nothing to be seen beyond a little
swelling in the neck. The animal fed as usual, and gave her normal
quantity of milk.”

XLIII.--Case reported by M. P. Rat, engineer, of
Saint-Rambert-en-Bugey, Ain.

“About 2 p.m. on Sunday, September 7, 1902, while I was out shooting,
my bitch was bitten in the lower lip by a very large viper. Since I was
a long way from home, I was unable to give the injections until 6 p.m.,
by which time the poor beast was in a pitiable condition. Her head was
as large as a saucepan; she had no strength left, trembled, and was
unable to stand. I injected 15 c.c. of serum in the left flank. This
was all that I did.

“At 7 o’clock on the Monday morning the bitch ate and drank a little.
She began to walk about, and by the evening had completely recovered.
There was nothing but a very little swelling left.”

C.--Cerastes.

XLIV.--Case reported by Dr. Boyé, of Kissidougou, French Soudan.

“At Kan-Kau, on December 19, 1896, a cow belonging to the post, which
had been bitten by a snake at 8 a.m., seemed about to die. The snake,
which was killed by the herdsman, was a _Cerastes_ (Horned Viper).

“On going to the cattle-shed I found the animal on her side and
panting, with the limbs completely relaxed. A thick foam was dropping
from the half-open mouth, and asphyxia seemed imminent. The cow had
been bitten in the teats, which were enormously swollen; the œdema
extended over the whole of the belly and inner face of the thighs. Two
doses of serum were injected, one at the base of the teats, the other
in the subcutaneous tissue of the flank.

“On the following morning the œdema had diminished, and the breathing
was much easier; the animal seemed to be conscious of what was passing
around it.

“Forty-eight hours later the cow was able to walk and went out to
graze, having apparently entirely recovered from the accident.”

III.--NOTE ON THE COLLECTION OF VENOM AND THE TREATMENT OF BITES
FROM POISONOUS SNAKES IN THE FRENCH SETTLEMENTS IN INDIA.

By Dr. PAUL GOUZIEN.

Principal Medical Officer of Colonial Troops.

From the time of our arrival in India, in February, 1901, we turned our
attention to ensuring the regular collection of snake-venoms, with a
view to satisfying the desire for them that had been expressed by our
friend Professor Calmette, Director of the Pasteur Institute at Lille.

To gain this end, the moral and financial support of the Administration
was indispensable, and this did not fail us. Acting on our suggestion,
as formulated by letter on May 25, 1901, Governor Rodier, on June 11,
issued an order by the terms of which a sum of 200 rupees was placed
at the disposal of the Chief of the Sanitary Service, “with a view
to encourage the catching of poisonous snakes, and to assist the
collection of snake-venom by the granting of bounties to natives.”

On the issue of this order, we drew up instructions for the collection
of venom, which we caused to be distributed to all posts in the Colony.
At the same time an appeal in the vernacular was posted up in each of
our sanitary institutions, inviting the Hindus to commence the campaign
forthwith. The notice placarded on the door of the Pondicherry Hospital
ran as follows:--

“Public Notice.

“For the public good the Governor requests the population to capture
poisonous snakes in all places where they are found; to take them alive
if possible; and to bring them to the Hospital without removing their
fangs.

“One rupee will immediately be paid for each snake brought in.

“Those who read this notice are requested to communicate it to their
acquaintances.”

* * * * *

The Indian snake-charmers at once responded to this appeal, and the
harvest of snakes was soon abundant. The first provision of 200
rupees, allotted to us by the Administration in June, 1901, had to
be successively renewed in May and October, 1902. Since then, on the
proposition of our successor, Dr. Camail, this sum of 200 rupees has
been included in the local budget, thus definitively sanctioning the
principle of the collection of venom in our Indian Settlements.

The venom forwarded by us to France has been exclusively derived
from the cobra, or _Naja tripudians_. Other venomous serpents are
found in the French Settlements in India, especially the species of
_Hydrophis_, or sea-snakes; but the cobra is by far the commonest
species, and our trading stations teem with it. Yanaon is infested by
it at all seasons, but especially at the time when the Godavari is
in flood; the reptiles then make their way towards spots spared by
the inundation, and the natives frequently kill them in their houses.
Thus M. Mariapregassam, the Sanitary Officer in charge of the the
Medical Service of this dependency, was in a position to procure for
us, at the very commencement of our operations, important doses of
venom: it should be added that he acquitted himself of this task with
a perseverance and devotion worthy of the fullest recognition. Of the
653 cobras captured between August 1, 1901, and February 23, 1903, 229,
or more than one-third, were furnished by Yanaon. Moreover, the cost
price of the cobra fell in proportion to its numbers, and Yanaon paid
for its snakes on the average at the rate of 33 centimes apiece; while
at Chandarnagar and Pondicherry the snake-charmers frequently received
1 rupee (1 franc 67 centimes) per reptile, though it is true that even
this was an extremely poor remuneration, when we consider the risk of
the calling.

Again, owing to the limited amount of our grants, we were obliged to
restrict our expenditure, regulating the purchase-price of the snakes
according to the quantity of venom collected. Thus at Pondicherry,
having observed that each cobra yielded on an average twenty drops of
venom, we fixed the value of two drops at one _fanon_ (one-eighth of a
rupee), never more. In this way it was decidedly to the snake-charmer’s
interest to bring us fresh snakes, and not such as had been previously
deprived of their venom.

In spite of this new regulation, snakes continued to pour into the
hospital, and several were repeatedly brought to us at the same time;
in October and November, 1902, the figure 9 appears three times in our
statistics.

The combined results of the snake-harvest at our five settlements,
from August 1, 1901, to February 23, 1903, are shown in the following
table:--

Average
weight Average Average
Quantity of dry price price
Number Sum of venom venom of the of 1 gramme
of cobras expended collected per cobra cobra of venom

653 R. 446 242 0·37 R. 0.68 R. 1.84
grammes gramme (1.13 fr.) (3.07 fr.)

On an average, therefore, nearly three cobras are necessary to furnish
1 gramme of dry venom, since freshly collected venom weighs more,
owing to the proportion of water contained in it, which is greater
than half the total weight. Thus the quantity of fresh venom extracted
from an average cobra may be estimated at about 80 centigrammes. It
may be added that the product of the glands differs considerably in
appearance, according as it is derived from a dead or living snake.
In the former case it takes the form of extremely small, glistening
lamellæ, of a golden-yellow colour, similar in appearance, when in
bulk, to iodoform. Venom extracted from the living snake, on the other
hand, is of an amber-brown colour, and forms much larger lamellæ, which
are translucent and slightly elongate, resembling particles of gum
arabic. When the product is impure and mixed with a small quantity of
blood, it has a dull appearance, and is of a dark, dirty brown, almost
black colour.

At the Pondicherry Hospital venom is collected in the following
manner;[168] The snake is brought by the snake-charmer in a _chatty_, a
kind of earthern pot, covered with a rag, or half a calabash. Ensconced
at the bottom of this receptacle, the reptile has a difficulty in
making up its mind to emerge, which it does only after having been
stirred up several times. Once it is outside the charmer forces the
cobra to uncoil, and, while the animal is moving slowly along, fastens
it to the ground by placing the end of a bamboo on its neck, quite
close to the head. The Indian then cautiously seizes the head of the
cobra with his forefinger and thumb, and, with a rapid movement, throws
it into a jar prepared for the purpose, containing a few tampons of
absorbent wool impregnated with chloroform. As soon as the snake is
inside, an assistant quickly slips a metal plate over the opening of
the jar and presses his hand firmly down upon it. In a few minutes
the animal is dead; it is then taken out of the jar and its mouth is
swabbed out; next, the fangs having been raised by means of a probe, a
saucer is placed between the jaws, and, by pressure exerted upon the
poison-glands laterally and from behind forwards, the venom is made to
spurt out. The fresh product obtained in this way is of a very pale
yellow colour, and viscid. It is protected from the air and light until
completely desiccated; then, when it is in sufficient quantity and
distributed in flakes round the sides of the saucer, like the colours
on a palette, it is cautiously detached with a spatula, taking care to
protect the eyes against risk from flying particles of venom. After
being placed in well-corked bottles, the product is despatched to
France.

In spite of the precautions observed in the course of these
proceedings, and although the venom has not been extracted until after
the death of the animal, some regrettable accidents have taken place,
as we shall show further on.

Cases of bites from poisonous snakes appear but seldom in the
statistics of our settlements in India, and, contrary to what is
the case in the neighbouring English possessions, hardly any deaths
are _officially_ recognised in the annual returns as being due to
this cause. It is true that the death statistics are very badly
authenticated, and that the natives frequently conceal the real cause
of death.

We have been informed by Dr. Cordier, Surgeon-Major of the Sepoy Corps,
that, during a previous tour of duty in Bengal, he had successfully
treated two cases of cobra-bite with Calmette’s serum.

At the end of 1901 the following note was forwarded to us by Dr.
Paramananda Mariadassou, Physician to the Karikal Hospital:--

“Case I.--In the month of November, 1901, a woman of robust habit was
brought about midnight to the Karikal Hospital, in a semi-comatose
condition. Her husband stated that an hour before, while lying on a
mat stretched on the ground, she felt herself bitten in the shoulder
when in the act of placing her head on the pillow. With a start of
surprise she half rose and then lay down again. It was only on being
bitten for the third time that she made up her mind to seek for the
cause; passing her hand beneath the pillow in the darkness she touched
the body of a snake and cried out. Directly afterwards she pointed out
to her husband, who had at once hastened to her, the snake coiled up
against the wall; the man killed the reptile and burnt it on the spot.
According to him the snake was about a metre in length, and as thick as
all five fingers put together. The woman had barely time to tell her
husband what had happened, for she speedily became unconscious, and was
in this condition when brought to the hospital.

“On admission the following symptoms were observed: The patient did not
reply to questions put to her, the eyelids remained closed, and the
teeth clenched. On the right shoulder, a little on the inner side of
the deltoid prominence, two or three punctures were distinguishable,
marked by a small spot of coagulated blood. The respiration was normal,
but the pulse was feeble and thready. When a pledget impregnated with
ammonia was held under her nose the woman reacted, but immediately
relapsed into the soporose condition.

“Two doses of antivenomous serum were at once injected, one in each
flank: the patient seemed scarcely to feel the insertion of the needle.
The wound on the shoulder was then washed with a fresh solution of
hypochlorite of calcium, 1 in 60, and six injections, each of 1 gramme,
of the same solution were given round the wound. The latter was covered
with a pad of cotton-wool saturated with the solution, and two more
doses of serum were injected into the flanks. As the result of this
treatment, which altogether took nearly half an hour, the woman began
to unclench her teeth, and to respond to her name. She was made to
swallow a few mouthfuls of very hot black coffee. A little later she
resisted when a fresh injection of serum was about to be given her.
After having taken a second cup of coffee she sat up, opened her eyes,
and recognised those about her. She immediately asked to go home,
but was detained for some time longer. After being carried from the
operating table to a bed, she was wrapped in a blanket; a few minutes
later profuse perspiration set in, and the patient felt so well that
she was allowed to go.

“On the following day the husband came to thank us, and stated that his
wife had quite recovered, and that, while she had been unable to sleep
for the remainder of the night, it was rather from fear caused by what
had happened than in consequence of the pain.”

Case II.--We feel it our duty to relate in detail the following case,
having regard to the peculiar circumstances under which it took place.

Coupin, the son of Ponnin, aged 25, living at Carouvadicoupom, near
Pondicherry, is a snake-charmer, and one of those who regularly supply
us with venom. In the course of July, 1902, this man pointed out to us
a shrub[169] growing in one of the alleys of the hospital, to which he
attributed so marvellous a power against the bites of poisonous snakes,
that he offered to make a cobra bite him in our presence, little as
we showed any desire to witness such an exhibition. We allowed him to
talk, not wishing to encourage such an act of bravado.

However, on July 23 he returned to the charge, and, as we were leaving
the hospital accompanied by our colleagues, he showed us a cobra
which he had just caught, and declared himself ready to carry out the
proposed experiment there and then. In the face of so much confidence
and _sang-froid_, and, apart from this, being interested in learning
the justification for the reputation for immunity possessed by Hindu
snake-charmers, we thought we ought not to oppose this voluntary test.

Coupin then turned out from the chatty in which it was imprisoned a
medium-sized cobra, and amused himself for a few moments by teasing
it. Irritated by this sport, the snake reared itself up, hissed, and
struck at its aggressor several times, as though it would bite him;
but, at each dart, Coupin stopped it with his hand and gaze, and the
snake remained fascinated, with open mouth, hesitating to drive home
its fangs. At one moment the snake even crawled up to the native’s
outstretched hand, and appeared to lick it: it was evident that the
animal’s only intention was to defend itself, not to attack.

Coupin, however, was bent on getting bitten, and, by dint of exciting
the snake, the latter became so exasperated that, with hood dilated, it
struck at the snake-charmer’s right hand and drove in its fangs. The
man quietly raised his arm, to allow it to be clearly seen that the
cobra had a firm hold; then, forcing the animal to let go, he came to
us to prove that he was really bitten. There were two bleeding spots, 6
millimetres apart, in the centre of the fourth intermetacarpal space of
the right hand. The time was exactly 4.40 p.m.

The snake, which was immediately killed, was still able to yield twelve
drops of venom, when lateral pressure was applied to its glands.

Coupin walked towards a shrub of the kind mentioned above, which he
had planted that very morning in the courtyard of the hospital,[170]
plucked some leaves from it and began to chew them, making rather a
wry face, for he said that they were very bitter. He then seemed to
meditate for a few moments before the shrub. We asked him whether he
was afraid, but he stoutly denied it, declaring that this was not his
first experience, and that indeed he had been bitten by cobras so
often that he could not remember the first occasion. We endeavoured to
discover whether he was not rendered immune, as Indian snake-charmers
are reputed to be, by inoculating themselves subcutaneously with
increasing doses of venom, according to a principle to a certain extent
analagous to that on which the preparation of antivenomous serum
is based. He, however, assured us that he knew nothing about such
practices, and that the properties of the plant in question had always
sufficed to cure him without other treatment. Such was his confidence
in his specific that, before the cobra was killed, he suggested to our
hospital-warder that he should allow himself to be bitten in his turn,
in order to render the experiment still more conclusive, adding that
his own assistant would be the subject at the next demonstration.

Nevertheless, a slight œdema began to appear round the bite. The
injured man seemed to be suffering a little, but the pain did not
extend above the wrist; a slight trembling appeared in the other arm.
From time to time Coupin gently massaged the affected limb with his
left hand from above downwards, in order, he said, to lessen the pain,
and perhaps also with a view to checking the diffusion of the venom. A
slight perspiration broke out over the body; the pulse was regular, 92,
twenty minutes after the bite.

Towards 6.15, or about an hour and a half after the experiment, the
man, refusing an injection of serum, prepared to go home, but we
insisted that he should remain at the hospital for at least two hours
longer, so as to enable us to watch his condition. He consented to
this, and asked for something to eat. At this time the back of the hand
was somewhat more swollen, but Coupin seemed to be little disturbed by
it; he even declared that the swelling would increase still further on
the following day, and that, in two or three days, he would make an
incision in order to let out the impure blood collected at the spot;
also that the trouble was now localised, and would not extend higher.
He merely complained of acute thirst, and of a certain difficulty in
swallowing, which was due, he declared, to the extreme bitterness of
the leaves that he had just masticated. Temperature 36·8° C.; pulse
36. After the brief reaction at the outset, there was a certain amount
of hypothermia, but the general condition seemed satisfactory, and
the man remained perfectly calm. We therefore left him under the
supervision of the resident student and the male attendants, giving
orders that we should be sent for immediately in case of any serious
symptoms arising.

At 7.15 we received a note from the student to the effect that Coupin
had vomited, that his pulse was small, there was difficulty in
breathing, and that he had just received an injection of antivenomous
serum. We hastened to the hospital, where we were speedily joined by
Drs. Cordier and Lhomme.

On our arrival we found Coupin in a rather prostrate condition. The
pupils were fixed, he was foaming slightly at the mouth, respiration
was regular, the pulse was strong and quite rhythmical at 96; the man
was somewhat chilly. The patient was unable to speak, but had not lost
consciousness, for, when we asked him how he was, he indicated by signs
that he felt very ill. We subsequently learnt, from the student on
duty, that towards 6.45 the condition of the patient became suddenly
worse, after his companion had administered to him some medicine, the
nature of which we have been unable to discover; on swallowing this
drug Coupin was seized with vomiting, and became collapsed. We thought
it more likely, however, that this was a mere coincidence, rather than
the result of a poison adding its effects to those produced by the bite
of the snake.

While waiting for our arrival a ligature had been applied to the
injured arm, and near the bite there had been made two deep incisions,
from which some dark blood escaped. At the same time the patient
received hypodermically a first injection of 10 c.c. of Dr. Calmette’s
antivenomous serum, and two injections of ether and caffeine. As the
result of this treatment we found a marked increase in pulse-rate.
After a subcutaneous injection of 500 grammes of artificial serum,
there appeared to be a further distinct improvement until about 8.45
(four hours after the bite). From this moment, however, the patient
gradually sank. A second dose of antivenomous serum was injected
beneath the skin,[171] and, since the respiratory movements gradually
became slower, artificial respiration by Sylvester’s method was
resorted to, while the tongue was rhythmically drawn forward. From
time to time these proceedings were interrupted for a few moments, in
order to observe the condition of the respiration; at the base of the
thorax and in the flanks abrupt, jerky, tetaniform undulations were
observable, but there was no free respiratory movement. The abdominal
aorta, the pulsations of which were visible behind the navel, raising
the anterior wall of the abdomen, was somewhat misleading, simulating
the rhythmical oscillations of the abdominal respiratory type. The
heart, however, continued to beat regularly, without any appreciable
weakness. The radial pulse persisted, although weak and slow: rate 48.

The patient was kept alive by repeated injections of ether and
artificial serum (1¼ litres in three doses). About 8.30 there appeared
to be a slight improvement; the patient was warmer, and showed some
degree of sensation in the region of the bite. On pinching the
vasculo-nervous bundle in the left axilla reflex movements were
produced in the fingers, which closed convulsively. The pulse, which
had momentarily disappeared in the radial artery, could again be felt,
weak but regular. At the same time, when the epigastric region was
examined, a few faint respiratory movements were just perceptible.
A third injection of antivenomous serum was given and artificial
respiration was continued.

This factitious amelioration, however, was not maintained, and after
a few scarcely visible movements of the thorax the end soon came. The
eyes were fixed and insensible, the pupils slightly dilated; no sweats,
no urine passed. The body slowly grew cold; the pulse disappeared from
the femoral and carotid arteries, and diminished in the aorta. The
contractions of the heart were once or twice irregular, and its beats
became weaker and gradually The reflexes had disappeared. There were
still a few slight muscular contractions near the base of the chest,
and the patient quietly passed away at 11.5 p.m., as the result of the
progressive arrest of the heart’s action, respiration itself having
virtually disappeared two hours before the heart had ceased to beat.

Case III.--A week after this sad occurrence, another snake-charmer,
Kingilien by name, aged 25, was bitten in the first phalanx of the
right forefinger, when taking hold of a cobra in the courtyard of
the Pondicherry Hospital. Refusing an injection of antivenomous
serum, the man ran off as fast as he could go, after having a simple
ligature applied to his wrist. Scarcely had he reached his dwelling,
when he fell into a deep coma, in which condition he was carried to
Cottacoupom, to the abode of one Souraire Kramani, a kind of sorcerer,
who administered to him a certain medicament in a betel leaf. After
having vomited a large quantity of bile he was taken home. At this
time, according to the summary investigation that we caused to be made,
the patient was unable to utter a single word; he could only open his
mouth with difficulty, and his eyelids remained closed. Kingilien,
who had partially regained consciousness, seemed to be suffering
from continuous attacks of vertigo; his head, if pushed to one side,
drooped, and the man was incapable of voluntary movement. Respiration
was fairly easy, swallowing painful. The entire hand was greatly
swollen; poultices of leaves were applied to it, after a few incisions
had been made with a knife in the back of the hand, in order to reduce
the congestion. The arm was rubbed from above downwards with the very
bitter leaves of the _Vëmbou_, or mango-tree, and prayers were recited.
This is all the information that I have been able to obtain with
reference to this man, who, after a prolonged convalescence, is said to
have recovered (?).

Case IV.--One Latchoumanin, aged 25, also a snake-charmer, of
Caradicoupom, was bitten at the Hospital at 10 a.m., on August 2,
while handling a cobra. The bite was situated in the second joint of
the right thumb. After it had bitten the man, ten drops of venom were
extracted from the reptile’s glands.

A ligature was immediately applied, and the wound was made to bleed
by hard squeezing. Refusing all other treatment, especially injection
of serum, although we repeatedly urged it, the man made off home with
all speed, but on arrival failed to find the specific on which he
was relying. All that was then done was to recite a few prayers over
him, and a Brahmin priest was called to bless him. About 11.30, after
acute suffering, Latchoumanin sank into a comatose condition. At 12.30
respiration became stertorous, and the patient succumbed at 2 p.m.,
four hours after being bitten. Just as the medical officer, deputed by
us, reached the dying man, two chatties containing live snakes were
deposited at his bedside, to ward off ill-luck!

* * * * *

On the whole, the evidence collected in the last two cases is as
confused as it is incomplete, and we can scarcely say how much we
regret the obstinacy of these unfortunate victims in refusing to submit
to our treatment, for the serum would undoubtedly have produced its
maximum effect in them, since it would have been possible to make use
of it in good time. These disastrous occurrences, however, will not
cure natives of their exclusive reliance upon empirical practices;
and as regards the inhabitants of the Tamil country, that is to say,
Southern India, it may be foreseen that for a long time to come they
will continue to remain refractory to the serotherapic treatment,
submission to which the English have had less difficulty in securing
from the natives of Bengal, whose intellectual development undoubtedly
stands on a higher plane.

INDEX.

d’Abbadie, M., on inoculation, 238.

_Acalyptophis_, 133.

_Acanthophis_, 96.

“ _antarcticus_ (death adder), 96.

“ “ “ “ bite dangerous, 100.

_Acanthopterygii_, 290, 301, 304.

_Acanthurus_, 301.

“ _luridus_, 301.

Adder, 25, 26. _See also Vipera berus._

Africa, poisonous snakes in, 57-81.

“ “ “ geographical distribution of genera (tables), 143, 144.

“ (Central), witch doctors of, snake-bite remedies, 237.

“ (East), Vatuas’ method of inoculation, 239.

Agglutinins of venoms, 202.

_Aipysurus_, 140.

“ _annulatus_, 140.

“ _australis_, 140.

“ _lævis_, 140.

“ _eydouxii_, 140.

Albuminoid of snake-venom produces hæmorrhages, 162.

Albumins of venom devoid of toxic power, 164.

Albumose of snake-venom attacks nerve-cell of respiratory centres,
162.

Albumoses of venoms of _Colubridæ_, 162.

“ “ “ method of separation, 162.

“ _See also_ Proto-albumoses, Hetero-albumoses.

Alcatifa, extraction of venom from, for inoculation, 239.

Alcock, researches of, on glands of snakes, 147.

Alexins, 198, 209.

“ characteristics of, 207.

“ fixation of, 210, 211.

“ of normal serum, fixation by cobra-venom, 211.

“ neutralisation of, 212.

Alkaloids in venom, 160.

Alps, and mountains of Central Europe, _Salamandra atra_ found in,
313.

Amboceptors, 198, 210.

“ fixation of, 208, 220.

America, snakes in, geographical distribution of genera of (table),
146.

“ venomous snakes in, 100-131.

America, (Central), _Batrachus tau_ found on shores of, 302.

“ (North), musical toad found in, 318.

“ (South), witch doctors of, snake-bite remedies, 237.

“ (Tropical and Sub-tropical), _Latrodectus mactans_ found in, 275.

Ammonia, injection of, only temporary antidote against snake-venom,
261.

_Ancistrodon_, 49, 109, 110.

“ venom of, precipitation of anticoagulant substance in, 195.

“ _acutus_, 49.

“ _bilineatus_, 111.

“ _blomhoffii_, 50.

“ _contortrix_, 111.

“ _himalayanus_, 50.

“ _hypnale_, 51.

“ _intermedius_, 50.

“ _piscivorus_, 110.

“ _rhodostoma_, 51.

Anderson, relation of escape from _Naja haje_, 60.

_Anemone scultata_, 269.

Aniline colours, action of, diminishes toxicity of venoms, 167.

Animals, venomous, definition of, 1.

Arachnolysin, poison from _Latrodectus_ prepared by, 276.

_Araneida_ (spiders), 274.

Armstrong, H., chemical analysis of cobra-venom, 159.

Arrows, poisoned by Hottentots with venom of _Bitis arietans_, 72.

Arthropods, poisonous species of, 274.

Asia, poisonous snakes inhabiting, 30, 57.

“ “ “ “ geographical distribution of genera (tables), 142, 143.

Asp, 27, 28. _See also Vipera aspis_.

_Aspidelaps_, 64.

“ _lubricus_, 64.

“ _scutatus_, 64.

_Atheris_, 78.

“ _ceratophorus_, 78.

“ _chlorechis_, 78.

“ _squamiger_, 78.

Atlantic (Tropical), _Acanthurus_ found in, 301.

“ “ _Muræna moringa_ found in, 309.

_Atractaspis_, 78.

“ _aterrima_, 80.

“ _bibronii_, 80.

“ _congica_, 79.

“ _corpulenta_, 80.

“ _dahomeyensis_, 80.

“ _hildebrandtii_, 79.

“ _irregularis_, 79.

“ _leucomelas_, 81.

“ _microlepidota_, 81.

“ _micropholis_, 81.

“ _rostrata_, 80.

Australia, health authorities’ notices against venomous reptiles, 100.

“ mortality from snake-bite in, 100, 261.

“ poisonous snakes of, 81-100.

“ snakes of, almost all confined to sub-family _Elapinæ_, 5.

Bacteriolytic action of venoms, 206.

“ “ “ how differing from that of rat-serum, 208.

Bailey, action of venom on brain, 185.

Batrachians, 312.

_Batrachiidæ_, 302.

_Batrachus grunniens_, 302.

“ _tau_, 302.

Bavay on the spitting snake, 63.

Bee-sting, remedies for, 286.

Bees, venom of, 282.

Bertrand, researches of, 147.

Bertrand and Phisalix, experiments on immunity of hedgehog to venom,
226.

“ “ preparation of toad-venom, 319.

Bettencourt, R., venom antitoxin treatment of yellow fever, 184.

Bibron and Duméril on coloration of snakes, 16.

“ “ _Naja_ worship in Egypt, 61.

Bile, destructive effect on cobra-venom, 215.

Birds, symptoms after inoculation with lethal doses of venom, 172.

_Bitis_, 69.

“ _arietans_ (puff adder), 69.

“ “ “ “ bite from, 350.

“ “ “ “ venom used for poisoning arrows by Hottentots, 72.

“ _atropos_, 72.

“ _caudalis_, 73.

“ _cornuta_, 73.

“ _gabonica_, 73.

“ “ does not attack man, 74.

“ _inornata_, 72.

“ _peringueyi_, 72.

Black snake, 88. _See also Pseudechis porphyriacus._

Blin, bite from _Cerastes_, 349.

Blindness following bite of viper, 178.

Blood, anticoagulant action of venom on, mechanism of, 195.

“ coagulability, action of venom of _Lachesis lanceolatus_ on, 191.

“ “ destroyed by venoms of _Colubridæ_, 179, 188, 189, 191, 192, 193.

“ “ “ “ certain species of _Crotalinæ_, 191, 192, 193.

“ “ uncertain action of venom of Vipera berus on, in certain animals,
189, 190.

“ coagulation of, connected with action of venoms of _Viperidæ_ on
nervous system, 185, 186.

“ “ produced by venoms of _Viperidæ_, 179, 188, 189.

“ not coagulated after death caused by venoms of _Colubridæ_, 171,
188, 189.

“ of hedgehog toxic before heating, antitoxic afterwards, 226.

“ of scorpion antitoxic, 279.

Blood, toxicity of, in reptiles, 217.

“ “ “ confers partial immunity to venom, 218, 219.

“ “ “ destroyed by heating, 218.

“ “ in venomous snakes, 217.

Blood-corpuscles, red, agglutination by venoms, 202.

“ “ dissolution only effected by combination of venom with
blood-serum or lecithin, 197.

“ “ dissolved by snake-serums, 219, 220.

“ “ effects of venom upon, 196.

“ “ resistance to large doses of venom, 199, 200, 201.

“ “ “ “ “ “ explanation, 200, 201.

“ “ washing of, important before presentation to action of venom,
196, 197.

“ unaltered under action of simultaneous doses of venom and serum,
220.

“ white, effects of venom on, 203.

Bombay, laboratory for production of antivenomous serum at, 248, 252.

Bonaparte, Lucien, chemistry of venom of vipers, 160.

_Bothrops_, bites from, 353, 354.

Bottard on venomous fishes, 288.

_Boulengerina_, 58.

“ _stormsi_, 58.

_Brachyaspis_, 95.

“ _curta_, 95.

Brain, comparative action of venoms of _Colubridæ_ and _Viperidæ_ on,
185, 186.

“ substance of, fixation of venom on, 186.

Brazil, _Thalassophryne maculosa_ found on shores of, 303.

Brehm, on _Crotalus confluentus_, 125.

“ the daboia (_Vipera russellii_), 46.

“ _Echis carinatus_ (efa, viper of the pyramids), 76, 77.

“ reverence paid by Hindus to _Naja_, 38.

Broad-headed snake, 94. _See also Hoplocephalus variegatus._

Briot, A., experiments with weever-venom, 298, 299.

“ poison of _Scolopendra_ prepared by, 280.

Bromized water, saturated, modifies or destroys venoms, 164.

Brown snake, 87. _See also Diemenia textilis._

Brunton, Sir Lauder, on harmless ingestion of venom exceeding lethal
dose, 214.

_Bufo calamita_ (natter-jack), 318.

“ _musicus_ (musical toad), 318.

“ _viridis_ (green toad), 318.

“ _vulgaris_ (common toad), 318.

Bufotalin, 319, 320.

“ first active principle of toad-venom, and cardiac poison, 319, 320.

Bufotenin, 320.

“ second active principle of toad-venom, and neurotoxic poison, 320.

_Bungarus_, 30.

“ venom of, active hæmolysing power possessed by, 199.

“ _cæruleus_ (common krait), bite, cure of, 337.

“ “ “ “ venom of, dose lethal for different animals, 174.

“ _candidus_, 32.

_Bungarus candidus_, resemblance to _Lycodon aulicus_, 33.

“ _fasciatus_, 31, 32.

_Buprestidæ_, food for larvæ of _Cerceris bupresticida_, 285.

Bushmaster, or surucucu, 112. _See also Lachesis mutus._

_Calamaridæ_, species of _Callophis_ feed only upon, 42.

_Callionymus_, 301.

“ _belennus_, 301.

“ _lacertus_, 301.

“ _lyra_, 300-301.

“ _vulsus_, 301.

_Callophis_, 40.

“ feeds only on snakes belonging to _Calamaridæ_, 42.

“ _bibronii_, 41.

“ _gracilis_, 41.

“ _maclellandi_, 41.

“ _maculiceps_, 41.

“ _trimaculatus_, 41.

Calmette’s serum, cobra-bites treated with, 363-5. _See also_ Serum,
antivenomous.

Calvados, _Callionymus lyra_ common on coast of, 301.

_Cantharis_ (blister-beetles), 281.

Cantor, on venom of _Naja bungarus_, 39.

“ vindictiveness of _Naja bungarus_, 39.

Captivity, poisonous snakes kept in, 61, 62, 125, 156, 223.

Carawalla. _See Ancistrodon hypnale._

Cardiac poison of toad-venom (bufotalin), 319, 320.

Caribbean Sea, _Scorpæna grandicornis_ found in, 293.

Carpi and Morgenroth, lecithide of bee-venom prepared by, 285.

Carrière, experiments on ingestion of venom, 214.

Cascavella (_Crotalus terrificus_), 124.

Cato, army of, patronage of snake-charmers by, 228.

_Causus_, 67.

“ _defilipii_, 67.

“ _lichtensteinii_, 68.

“ _resimus_, 67.

“ _rhombeatus_, 67.

Cells, dissolution of. _See_ Cytolytic action.

_Cerastes_, 47, 75.

“ bites from, 348-350.

“ “ cured, 358.

“ secretion of, 150.

“ venom of, fatal to barefooted pedestrians, 76.

“ _cornutus_, 47, 75.

“ _vipera_, 75.

_Cerceris bupresticida_, 285.

Ceylon, snake-charmers of, 229.

Chameleons succumb rapidly to snake-poisoning, 172.

Chelicera (fang of spider), 274.

Chemical reactions exhibited by venoms, 162.

Chemical substances modifying or destroying venoms, 164.

Chemistry of snake-venoms, 159.

Cherry and Martin on antagonism between toxins and antitoxins, 253.

_Chilomycterus_, 307.

“ _orbicularis_, 307.

“ _tigrinus_, 307.

China and Japan, _Lophius setigerus_ found in seas of, 304.

Chloride of gold, antidote to venom before absorption, 261, 263.

“ “ solution, modifies or destroys venom, 164.

“ lime solution, modifies or destroys venom, 164.

Cholesterin, antidote to lecithin, 198.

Chromic acid, antidote to venom before absorption, 260.

“ “ solution, modifies or destroys venoms, 164.

Clamouse, on bites from European vipers, 343.

Clot Bey on Egyptian snake-charmers, 228-229.

Clothing protective against dangerous effects of snake-bite, 170.

Cobra, bite of, clinical symptoms, 169.

“ “ “ “ exhibit rapid general intoxication, 169.

“ “ treated with Calmette’s serum, 363.

“ extraction of venom from, method, 153.

“ Egyptian (_Naja haje_ or _haie_), 59.

“ method of carrying after capture, 21.

“ snake-charmers’ skill with, 229.

“ venom of, 149.

“ “ alkaloids in, 160.

“ “ chemical analysis, 159.

“ “ comparison of toxicity by means of intra-cerebral injections, 186.

“ “ destructive action of bile on, 215.

“ “ dissolution of trypanosomes by, 207.

“ “ dose lethal for different animals in twenty-four hours, 174.

“ “ fixation on nervous elements, 186.

“ “ local effects on serous membranes slight, 179.

“ “ potency of antineurotoxic antivenomous serum against, 250, 251,
252.

“ “ vaccination against, 242, 244, 245.

Cobra-di-Capello, 33. _See also Naja tripudians._

“ “ spectacled, used by Hindu snake-charmer, 229.

_Cœlenterates_, poisonous species of, 269.

_Cœlopeltis_, 22.

“ _moilensis_, 23.

“ _monspessulana_, 23.

Cold, intense, toxicity of venom not diminished by, 166.

Colombia, herons of, probably immune to snake-venom, 227.

“ “ hunt young snakes for food, 226.

Coloration of snakes, 15, 16.

“ “ subject to biological laws of mimicry, 15, 16.

_Colubridæ_, 3, 30, 57, 82, 100, 101-109. _See also Acanthophis_,
_Aspidelaps_, _Boulengerina_, _Brachyaspis_, _Dendraspis_,
_Denisonia_, _Diemenia_, _Elapechis_, _Elapognathus_, _Furina_,
_Glyphodon_, _Homorelaps_, _Hoplocephalus_, _Micropechis_,
_Notechis_, _Ogmodon_, _Opisthoglypha_, _Proteroglypha_,
_Pseudechis_, _Pseudelaps_, _Rhinhoplocephalus_, _Rhynchelaps_,
_Sepedon_, _Tropidechis_, _Walterinnesia_.

_Colubridæ_ (sub-family _Elapinæ_). _See also Bungarus_, _Naja_,
_Hemibungarus_, _Callophis_, _Doliophis_.

“ resemblance to harmless snakes, 3.

“ species of, bite rapidly produces general intoxication, 168.

“ venoms of, absorption by digestive tract often without ill-effect,
180, 181.

“ “ “ “ “ “ “ cause, 181.

“ “ action on nervous centres profound, 185.

“ “ affinity of scorpion poison to, 278.

“ “ albumoses of, 162.

“ “ destroy coagulability of blood, 179, 188, 189.

“ “ dialyse slowly, 161.

“ “ lethal effects on mammals, 170.

“ “ minimum doses lethal for guinea-pig in twenty-four hours, 173.

“ “ precipitation of anticoagulant substance in, 195.

“ “ recovery rapid after non-lethal doses, 177.

“ “ resistant to heat, 161.

“ “ richness in neurotoxin, 249.

Common rattle-snake, 125. _See also Crotalus durissus._

Congestin, poison from _Anemone scultata_, 271.

Conjunctivitis caused by discharge into eyes of venom of spitting
snake, 63, 64.

Copperhead, 90. _See also Denisonia superba._

Coral-snake, 104.

“ immunity from bite of, 238.

“ venomous nature of, 108.

“ _See also Elaps corallinus._

Coral or harlequin snake, 106. _See Elaps fulvius._

Cordier, D., cobra-bites treated with Calmette’s serum, 363.

Cotes, E. C., on extraction of venom by charmers, 234.

_Cottus_, 289, 290, 292.

“ poison-apparatus of, 293.

_Crabronidæ_, 285.

“ stings of females of, toxic to other insects, nearly harmless to
man, 285.

_Crotalinæ_ (_Viperidæ_), 101, 109.

“ characteristics of, 6.

“ venoms of certain species of, non-coagulant, 191, 192, 193.

“ _See Ancistrodon_; _Lachesis_.

_Crotalus_ (rattle-snake), 110, 122.

“ comparative toxicity of organs, 220.

“ eggs of, rich in poison, 220.

“ poison glands of, 148.

“ venom of, alkaloids in, 160.

“ “ comparison of toxicity by means of intra-cerebral injections, 186.

“ “ ingestion causing death, 180.

“ “ weak hæmolysing power possessed by, 199.

“ _adamanteus_, venom of, dose lethal for rabbit, 175.

“ _cerastes_ (horned rattle-snake), 129.

“ _confluentus_ (Pacific or mottled rattle-snake), 124.

“ “ “ “ “ habits, 125.

“ “ devoured by pigs, 125.

_Crotalus confluentus_, secretion of, 150.

“ _durissus_ (common rattle-snake), 125.

“ _horridus_, 127.

“ “ bites from, 355.

“ _lepidus_, 129.

“ _mitchelli_, 127.

“ _polystictus_, 129.

“ _scutulatus_ (Texas rattle-snake), 124.

“ _terrificus_ (dog-faced rattle-snake or cascavella), 124.

“ _tigris_, 127.

“ _triseriatus_, 129.

_Cryptobranchus japonicus_ (great Japanese salamander), 313-315, 317.

“ “ venom of, 317.

“ “ “ action similar to that of viperine venoms, 317.

_Curados de Culebras_, immunity produced by inoculation by, 235-237.

Cytolytic action of venoms, 206.

Daboia. _See Vipera russellii._

Deafness following bite of viper, 178.

Death adder, 96. _See also Acanthophis antarcticus._

Delezenne, establishment of existence of kinase in venoms, 204.

“ on the kinasic properties of venoms, 204, 213.

_Dendraspis_, 65.

“ _angusticeps_, 66.

“ _antinorii_, 66.

“ _jamesonii_, 66.

“ _viridis_, 66.

_Denisonia_, 88.

“ _carpentariæ_, 92.

“ _coronata_, 89.

“ _coronoides_, 89.

“ _dæmelii_, 90.

“ _flagellum_, 91.

“ _frenata_, 90.

“ _frontalis_, 91.

“ _gouldii_, 91.

“ _maculata_, 91.

“ _melanura_, 92.

“ _muelleri_, 90.

“ _nigrescens_, 92.

“ _nigrostriata_, 92.

“ _pallidiceps_, 92.

“ _par_, 92.

“ _punctata_, 91.

“ _ramsayi_, 90.

“ _signata_, 90.

“ _superba_ (the copperhead), 89.

“ _suta_, 90.

“ _woodfordii_, 93.

Dialysis, results of, in experiments with venoms of _Colubridæ_ and
_Viperidæ_, 161.

Diastases, action upon venoms, 214.

Diastasic actions of venoms, 212.

_Diemenia_, 86.

“ _modesta_, 87.

“ _nuchalis_, 87.

“ _olivacea_, 87.

“ _psammophis_, 87.

“ _textilis_ (brown snake), 87.

“ “ “ “ bite dangerous, 100.

“ _torquata_, 87.

Digestion of snakes aided by venoms, 213, 214.

Digestive tract, absorption of venoms of _Colubridæ_ often without
ill-effect on, 180, 181.

“ “ “ “ “ “ “ cause, 181.

_Diodon_, 305.

_Dipsadomorphinæ_, sub-family of _Opisthoglypha_, 3.

“ geographical distribution, 4.

_Dipsas_, teeth of, 8.

_Distira_, fresh-water genus of _Hydrophiinæ_, 5, 136.

“ _cyanocincta_, 137.

“ _jerdonii_, 137.

“ _ornata_, 136.

“ _subcincta_, 137.

Dog, minimal dose of cobra-venom lethal for, 174.

Dog-faced rattle-snake, 124. _See also Crotalus terrificus._

_Doliophis_, 42.

“ _bilineatus_, 43.

“ _bivirgatus_, 42.

“ _intestinalis_, 42.

“ _philippinus_, 43.

Domestic animals, treatment of poisonous bites in, 265.

Duck-billed platypus (_Ornithorhynchus paradoxus_ or _O. anatinus_),
323.

Duméril and Bibron, on coloration of snakes, 16.

“ “ _Naja worship_ in Egypt, 61.

Dutch Indies, poisonous snakes inhabiting, 30-57.

Dyer, venom antitoxin treatment of yellow fever, 184.

Eau de Javel, antidote to venom before absorption, 263.

“ “ in treatment of wasp- or bee-stings, 286.

Echidnin, chemistry of, 160.

_Echinoidea_ (sea-urchins), 273.

_Echinoderms_, poisonous species of, 273.

_Echis_, 48, 76.

“ _carinatus_ (_efa_, viper of the pyramids), 48, 76.

“ “ bite from, 347.

“ “ dreaded by Egyptians, 77.

“ “ venom rapid in action, 49.

“ _coloratus_, 77.

_Efa_ (_Echis carinatus_), 48, 76. _See also Echis carinatus._

Eggs of bees, venom contained in, 284.

“ fowls, artificial intoxication by venom, effect on embryo, 214.

“ _Crotalus_ rich in poison, 220.

Egypt, laboratory researches in, 149, 150.

“ snake-charmers of, 228-229.

Egyptians, dread of _Echis carinata_ (_Efa_) shown by, 77.

“ “ and pursuit of _Naja haje_ among, 60.

Ehrlich, theory of lateral chains, 208, 220.

_Elachistodontinæ_, sub-family of _Opisthoglypha_, 3.

“ geographical distribution, 4.

_Elapechis_, 58.

“ _boulengeri_, 59.

“ _decosteri_, 59.

“ _hessii_, 59.

“ _guentheri_, 58.

“ _niger_, 58, 59.

“ _sundevallii_, 59.

_Elapinæ_, sub-family of _Colubridæ_, 30.

“ geographical distribution, 5.

_Elapognathus_, 97.

“ _minor_, 97.

_Elaps_, 101, 108.

“ _ancoralis_, 108.

“ _annellatus_, 103.

“ _anomalus_, 103.

“ _buckleyi_, 103.

“ _corallinus_ (coral snake), 104. _See also_ Coral-snake.

“ _decoratus_, 104.

“ _dissoleucus_, 106.

“ _dumerilii_, 104.

“ _elegans_, 103.

“ _euryxanthus_ (Sonoran coral-snake), 102.

“ _filiformis_, 107.

“ _fraseri_, 107.

“ _frontalis_, 106.

“ _fulvius_ (harlequin or coral-snake), 106.

“ _gravenhorstii_, 102.

“ _hemprichii_, 104.

“ _heterochilus_, 102.

“ _heterozonus_, 103.

“ _langsdorffii_, 103.

“ _lemniscatus_, 107.

“ _marcgravii_, 106.

“ _mentalis_, 107.

“ _mipartitus_, 107.

“ _narduccii_, 108.

“ _psyches_, 106.

“ _spixii_, 106.

_Elaps surinamensis_, 102.

“ _tschudii_, 104.

Electricity passed through solution of venom in form of continuous
electrolytic current destroys toxicity, 165. _See also_ High
frequency currents.

Embryo, anomalies in development consequent on introduction of venom
into eggs of fowl, 214.

_Enhydrina_, 139.

“ venom of, fixation on nervous elements, 186.

“ _bengalensis_ (syn. _E. valakadien_), 139.

“ _valakadien_ (syn. _E. bengalensis_), 139.

“ “ venom of, dose lethal for different animals, 174.

_Enhydris_, 138.

“ _curtus_, 138.

“ “ venom of, dose lethal for rat, 174.

_Entomophaga_, 286.

Eosin, photodynamic action of, diminishes toxicity of venoms, 167.

_Epeira_, 276.

Erythrosin, photodynamic action of, diminishes toxicity of venoms,
167.

Europe, poisonous snakes inhabiting, 22-29.

“ “ geographical distribution of genera (tables), 142.

“ (Central). _See_ Alps.

“ _Triton cristatus_ and _T. marmoratus_ found in, 313.

Ewing, action of venom on brain, 185.

Facial bones, special arrangements of, characteristic of poisonous
snakes, 6.

Fasting, prolonged, snake-venom shows greatest activity after, 176.

Faust, S., salamandrine prepared by, 316.

Fayrer, Sir J., fatal results of experimental ingestion of venoms,
180.

“ “ on the daboia (_Vipera russellii_), 47.

“ “ habits of the krait (_Bungarus candidus_), 33.

“ “ harmless ingestion of venom exceeding lethal dose, 214.

“ “ _Naja bungarus_, 39.

Feeding, artificial, in laboratories for collection of venom, 157.

“ “ of poisonous snakes, 17, 18.

Fer-de-lance (_Lachesis lanceolatus_), 112, 113, 114.

Féré, Ch., experiments on development of embryo after introduction of
venom into fowl’s egg, 214.

Fishes succumb rapidly to snake-venom, 172.

“ venomous, 288.

“ “ poison-apparatus of, 289.

Flexner and Noguchi, on action of snake-serum on red corpuscles, 219.

“ “ cytolytic action of venoms, 206.

“ “ investigations on toxicity of snakes’ organs, 220.

Food, abstinence from, by snakes, 149.

Fowls killed by causing them to ingest venom, 180.

Fox, W. A., bite from _Sepedon hæmachates_, 337.

France, mortality from snake-bite in, 3.

Fraser, on destructive action of bile on cobra-venom, 215.

Frog-serum, antidote to poison of pedicellariæ, 274.

Frogs succumb slowly to snake-poisoning, 172.

_Furina_, 98.

“ _bimaculata_, 99.

“ _calonota_, 99.

“ _occipitalis_, 99.

Gaboon viper, 73. _See also Bitis gabonica._

Gangrene, produced by venom of _Viperidæ_, 177.

Gautier, Armand, chemical constituents of venom, 160.

Geographical distribution of poisonous snakes in Africa, 143, 144.

“ “ “ “ America, 146.

“ “ “ “ Asia, 142, 143.

“ “ “ “ Europe, 142.

“ “ “ “ Oceania, 145.

Geracki, collection of venom, 156.

Gibbs, Wolcott, chemical constituents of venom, 160.

Glands (acid and alkaline), poison-organs of the hymenoptera, 282.

“ secretion of venom from, 147.

Glandular secretions of persons and animals bitten by venomous
snakes, toxic, 181.

Glycerine, means of preservation of concentrated solution of venom,
166.

_Glyphodon_, 83.

“ _tristis_, 84.

_Gobiidæ_, 300.

Gouzien, Paul, collection of venom from poisonous snakes in French
settlements in India, 359.

“ “ on collection of venom, 156.

Grage (_Lachesis atrox_), immunity from bite of, 238.

Grass-snakes, parotid glands of, 147.

“ “ withstand large doses of venom, 172.

Gressin on poisoning from weever-stings, 299.

de Gries on bites from _Bothrops_, 353, 354.

Ground rattle-snake, 120. _See also Sistrurus miliarius._

Grunting batrachus. _See Batrachus grunniens._

Guiana, witch-doctors of, snake-bite remedies, 237, 238.

Guinea-pig, minimal doses of various venoms lethal for, 173, 174, 175.

“ vaccination against cobra-venom, 242.

Hæmolysins of venom, resistance to heat, 202.

Hæmolysis, failure of, under exposure of red corpuscles to large
doses of venom, 199, 200, 201.

“ in venoms, comparative study of, 196.

“ power of, possessed by various venoms, 199.

Hæmorrhages produced by albuminoid of snake-venom, 162.

“ visceral, complicating recovery from bites of _Viperidæ_, 177, 178.

Hæmorrhagin in venoms, 187.

“ local effects of, not prevented by antineurotoxic serum, 251.

“ predominance in venom of _Viperidæ_, 249.

Hæmorrhagin, present in some species of _Viperidæ_, 249.

“ sensitive to heat, 249.

_Hamadryas elaps_, 37. _See also Naja bungarus._

Harlequin or coral snake, 106. _See also Elaps fulvius._

Heart, action of venom on, 184.

Heat, comparative effect on venoms of _Colubridæ_, _Hydrophiidæ_ and
_Viperidæ_, 161.

“ hæmorrhagin sensitive to, 249.

“ resistance of hæmolysins of venoms to, 202.

“ sole agent in attenuating venom submitted to alternating high
frequency currents, 165.

Heating destroys toxicity of blood of reptiles, 218.

Hedgehog, immunity of, to venom of _Vipera berus_, 226.

“ “ “ “ proved experimentally, 226.

“ blood of, toxic before heating, antitoxic afterwards, 226.

_Heloderma horridum_, 321.

“ “ saliva sometimes toxic, sometimes harmless, 323.

“ “ venom of, 321, 322.

_Hemibungarus_, 39.

“ _calligaster_, 40.

“ _collaris_, 40.

“ _japonicus_, 40.

“ _nigrescens_, 40.

Henri, V., poison from pedicellariæ prepared by, 273.

Herons of Colombia hunt young snakes for food, 227.

“ “ probable immunity to snake-venom, 226, 227.

Hetero-albumoses, active principle of snake-venom, 164.

“ separation from snake-venom, 162, 163.

_Heterometrus maurus_, venom of, 279.

“ “ “ effect upon sparrows, 279.

High frequency currents, alternating, attenuate venom only by thermic
action, 165.

Hill, Patrick, on duck-billed platypus, 324.

Hindus, worship bestowed on _Naja_ by, 38.

Holbrook on _Crotalus confluentus_, 125.

_Holocanthus_, 305.

“ _imperator_, 305.

_Homalopsinæ_, sub-family of _Opisthoglypha_, 3.

“ geographical distribution, 4.

“ aquatic, 4.

_Homorelaps_, 57.

_Hoplocephalus_, 93.

“ _bitorquatus_, 94.

“ _bungaroides_ (syn. _H. variegatus_, broad-headed snake), 94.

“ _curtus_ (_Notechis scutatus_, tiger-snake), 95.

“ “ “ “ “ bite dangerous, 100.

“ “ “ “ “ secretion of, 149.

“ _stephensii_, 94.

Horned rattle-snake, 129. _See also Crotalus cerastes._

Horse, bleeding, aseptically, after vaccination to obtain
antivenomous serum, 245, 246.

“ immunisation to venom, difficulties attending, 244, 245.

Horse, minimal dose of venom lethal for, 176.

“ polyvalent serum prepared from, 251.

“ red corpuscles of, reasons for choice of, for exposure to action of
venom, 196, 197.

“ vaccination of, against cobra-venom, 244, 245.

Horse-serum must be added to venom to dissolve washed red corpuscles,
197.

Hottentots, venom of _Bitis arietans_ employed for poisoning arrows
by, 72.

_Hydrelaps_, 134.

_Hydrophiidæ_ (sea-snakes), 100.

“ bite from, cure, 338.

“ “ rapidly produces general intoxication, 168.

“ venoms of, resistant to heat, 161.

_Hydrophiinæ_ (sea-snakes), 4, 131.

“ “ habitat and geographical distribution, 4, 5.

“ “ habits of, 131.

_Hydrophis_ (sea-snakes), 134.

“ “ venom from, 360.

“ _cærulescens_, 135.

“ _cantoris_, 135.

“ _elegans_, 135.

“ _fasciatus_, 136.

“ _gracilis_, 135.

“ _leptodira_, 136.

“ _nigrocinctus_, 135.

“ _obscurus_ (syn. _H. stricticollis_), 136.

“ _spiralis_, 135.

_Hydrus_, 132.

Hymenoptera, 281.

“ poison-glands of, 281, 282.

Hypochloride of calcium solution modifies or destroys venoms, 164.

Hypochlorite of lime, antidote to venom before absorption, 261, 263.

“ “ remedy for wasp- or bee-sting, 286.

Hypochlorites, alkaline, antidotes to venom before absorption, 261.

Hypoleucocytosis, accompanying snake-bite, in lethal cases, 211, 212.

“ following fatal dose of venom, 216.

Immunity to venom, active, incontestably possible, 240.

“ “ doubtful, by Vatuas’ method, 239.

“ “ hereditary, pretended, 238.

“ “ “ “ in India and Egypt, 240.

“ “ natural, 222.

“ “ partial, enjoyed by snakes due to diastasic substances in blood,
218, 219.

“ “ in lethal doses not conferred by ingestion of venom, 215.

India, French Settlements in, collection of venom and treatment of
bites from poisonous snakes in, 359.

“ legend relating to _Naja_ in, 37.

“ mortality from snake-bite in, 2, 38, 363.

“ “ “ “ excessive, due to snake-worship, 2.

“ “ “ _Naja_ bites, 38.

India, poisonous snakes inhabiting, 30-57.

“ snake-charmers in, 229-234.

“ “ “ remedies for bites, 237.

“ _Teuthis_ found in, 301.

Indian Ocean, _Chilomycterus orbiculari_s and _C. tigrinus_, 307.

“ “ _Naseus_ found in, 301.

“ “ _Plotosus_ found in, 308.

“ “ _Pterois_ found in, 296.

“ “ _Scorpæna diabolus_ found in, 293.

“ “ _Tetrodon stellatus_ found in, 306.

Inoculation, experimental, by Fraser, of Edinburgh, 235.

“ extraction of venom from alcatifa for, 239.

“ graduated, by French viper-catchers, 234.

“ immunity incontestable from, 240.

“ subcutaneous, productive of immunity, 234.

Insects, venomous species of, 281.

Invertebrata easily killed by venom inoculation, 173.

Jacolot, on Mexicans’ method of immunisation, 255-257.

Japan, _Cryptobranchus japonicus_ found in, 315.

“ _Prionurus_ found in, 301.

“ _Tetrodon rubripes_ found on shores of, 306.

“ “ “ _See also_ China and Japan.

Jararacussu (_Lachesis lanceolatus_), 112, 113, 114.

Jean, bite from _Trigonocephalus_, 352.

Jugglers called in to expel _efas_ (_echis carinatus_) from Egyptian
houses, 77.

_Julus_, 280.

Kanthack, A. A., on chemical constituents of venom, 160.

Kasauli, laboratory for production of antivenomous serum at, 248, 252.

_Katipo_ (_Latrodectus scelio_), 275.

Kayalof, Mlle., poison from pedicellariæ prepared by, 273.

Kidney, action of venom on, 183.

Kinase in snake-venoms, 204.

Kinasic properties of venom, how produced, 213.

“ “ “ _See also_ Diastasic actions.

King cobra. _See Naja bungarus._

Kipling, Rudyard, account of battle between mongoose and cobra, 223.

Kobert, poison from _Latrodectus_ and _Epeira_ prepared by, 276.

Krait, 30. _See also Bungarus._

Krefft, Gerard, on snakes of Australia, 81, 82.

Kyes, lecithide from scorpion-venom, 278.

“ on relation of toxins to antitoxins, 254, 255, 257.

“ the production of lecithides, 197, 199.

Labaria (_Lachesis atrox_), 114.

Labial glands, upper, venomous secretions, 147.

Laboratories for preparation of antivenomous serum, 248, 252.

de Lacerda, on diastatic actions of venoms, 212.

“ _Elaps_, 108.

“ harmless ingestion of venom exceeding lethal dose, 214.

_Lacertidæ_, 321.

_Lachesis_, 51, 109, 111.

“ bite of, clinical symptoms, 169.

“ “ “ primarily local, violent, 169.

“ classification of species, 52.

“ venom of, absorption by digestive system, cause of acute
inflammation of gastric mucous membrane, 180.

“ “ rich in kinase, 204.

“ _alternatus_, 115.

“ _ammodytoides_, 117.

“ _anamallensis_, 56.

“ _atrox_ (grage), immunity from bite of, 238.

“ “ (labaria), 114.

“ _aurifer_, 119.

“ _bicolor_, 119.

“ _bilineatus_, 118.

“ _borneensis_, 57.

“ _brachystoma_, 118.

“ _cantoris_, 53.

“ _castelnaudi_, 117.

“ _ferox_ (grage), bites from, cure, 351.

“ _flavomaculatus_, 55.

“ _flavoviridis_, 53.

“ _godmani_, 118.

“ _gramineus_, 55.

“ “ venom of, dose lethal for rabbit, 175.

“ _jerdonii_, 54.

“ _lanceolatus_ (fer-de-lance, or jararacussu), 112.

“ “ description and habits, 113, 114.

“ “ mortality from bite of, 113.

“ “ secretion of, 150.

“ “ venom of, 325.

“ “ “ coagulant action on blood, 191.

“ “ “ “ “ diminishes when heated, 191.

“ _lansbergii_, 118.

“ _lateralis_, 119.

“ _luteus_, 54.

“ _macrolepis_, 56.

“ _microphthalmus_, 114.

“ _monticola_, 52.

“ _mucrosquamatus_, 54.

“ _mutus_ (bushmaster or surucucu), 112.

“ _neuwiedii_ (urutù), 115.

“ _nigroviridis_, 119.

“ _nummifer_, 117.

“ _okinavensis_, 52.

“ _pictus_, 115.

“ _pulcher_, 114.

“ _puniceus_, 56.

_Lachesis purpureomaculatus_, 54.

“ _schlegelii_, 119.

“ _strigatus_, 53.

“ _sumatranus_, 56.

“ _trigonocephalus_, 56.

“ _undulatus_, 118.

“ _wagleri_, 57.

“ _xanthogrammus_, 117.

Lamb, G., on action of venom on brain, 185.

“ on coagulant action of venom of _Vipera russellii_, 191.

Landouzy, Prof., on serum therapeutics, 240.

Lannoy, on diastasic actions of venoms, 212, 213.

“ proteolytic action of venoms, 204.

“ researches of, on glands of snakes, 147.

Lapeyre, on bites from European vipers, 346.

_Latrodectus_, 276.

“ _erebus_, 276.

“ _mactans_, 275.

“ _malmignattus_, 275.

Lavigne, bite from _Trigonocephalus_, 354.

de Lavison, R., on _Lachesis lanceolatus_, 113.

Lecithides, production of, 191, 197, 198, 199, 254, 258.

“ “ from bee-venom, 285.

“ “ “ scorpion-venom, 278.

Lecithin, added to venom to dissolve washed red corpuscles, 197.

“ cholesterin antidote to, 198.

“ combination with snake-venom, 254.

Leipothymia following inoculation of venom of _Synanceia brachio_,
292.

Le Naour, on the spitting snake, 63.

Leucocytes, protective _rôle_ against snake-poisoning, 216.

Leucolysin, mode of producing, 203.

Lewin, experiments on immunity of hedgehog to venom, 226.

Leydig, researches of, 147.

Lhomme, bite from _Lachesis ferox_, 351.

“ collection of venom, 156.

Light, destructive effect of, on venom in solution, 165.

Liver, action of venom on, 182.

Livingstone, mention of _Naja haje_ by, 60.

Lizards, 321-323.

“ only one species venomous, 322.

“ succumb rapidly to snake-poisoning, 172.

_Lophius_, 304.

“ _piscatorius_, 301.

“ _setigerus_, 303-304.

Lucan, passage from, quoted, on immunity of Psylli, 240.

Lumière, A., and Nicolas, J., on effect of intense cold on venom, 166.

Lungs, action of venom on, 184.

_Lycodon aulicus_, resemblance of _Bungarus candidus_ to, 33.

Maclaud, bite from _Naja haje_, 356.

Madsen, Th., and Noguchi, H., on ratio between dose of venom and time
elapsing till death, 177.

Mal on Hindu snake-charmers, 229.

Malaysia, poisonous snakes of, 81.

_Malmignatte_, 275.

Mammals, action of _Colubrine_ venom on, symptoms and course, 171.

“ “ “ “ _post-mortem_ findings, 171.

“ “ _Viperine_ venoms on, symptoms and course, 171.

“ “ “ “ _post-mortem_ findings, 171.

Man, minimal dose of venom lethal for, 176.

“ not attacked by _Bitis gabonica_ (Gaboon viper), 74.

Mano de sapo root, eaten by Mexicans during immunisation treatment,
236.

Maoris’ fear of _Katipo_, 275.

Marchand, on bites from European vipers, 339.

Mariadassou, P., serum treatment, 363-371.

Mariapregassam, collection of venom, 361.

Marotte, on _Naja haje_ bite, 356.

Martin, C. J., chemical constituents of venom, 160.

“ “ experiments on _Pseudechis_, 162.

“ “ “ with rats proving harmlessness of ingestion of venom of
_Pseudechis_, 181.

“ “ on venom of _Ornithorhynchus_, 324.

“ “ and Cherry, on antagonism between toxins and antitoxins, 253.

“ “ and Smith, MacGarvie, on local and general effects of albumoses
derived from snake-venom, 163.

Martinique, mortality from bite of fer-de-lance in, 113.

Massasanga, 120. _See also Sistrurus catenatus._

de Maupas on _Pelias berus_ bite, 357.

Mediterranean Sea, _Muræna helena_ found in, 309.

“ “ _Scorpæna porcus_ found in, 294.

Medulla, substance of, fixation of venom on, 186.

_Meloë_ (oil-beetles), 281.

Mexico, inoculation of natives in, successful, 235-237.

_Micropechis_, 93.

“ _elapoides_, 93.

“ _ikaheka_, 93.

Milk from mother bitten by poisonous snake causing death of young,
181, 214.

Mimicry, biological laws of, coloration of snakes subject to, 15, 16.

Mitchell, S. Weir, on chemical constituents of venom, 160.

“ “ fatal results of experimental ingestion of venoms, 180.

“ “ harmless ingestion of venom exceeding lethal dose, 214.

Moindrot, H., bites from European vipers, 345.

Molluscs, poisonous species of, 286.

Mongoose, battles with hamadryads and cobras, 223, 224.

“ “ victory mainly due to natural agility, 225.

“ immunity to snake-venom, 223.

“ “ “ not absolute, 225.

“ “ “ proved by injections, 224, 225.

_Monotremata. See Ornithorhynchus paradoxus_ or _O. anatinus_.

Mons on bite from horned viper, 349.

Morgenroth, on combination of venom with lecithin, 254.

“ reconstitution of toxins, 257.

“ and Carpi, lecithide of bee-venom prepared by, 285.

Mortality from bite of _Naja_ in India, 38.

“ “ _Vipera berus_ (common viper or adder), 27.

“ “ poisonous snake-bite; localities:-- Australia, 100, 261. France,
3. India, 2, 38, 363. Martinique, 113.

Mottled Rattle-snake 124, 125. _See also Crotalus confluentus._

Moudon, on bite from _Cerastes_, 348.

Moult of snake’s skin, 16, 20.

“ venom shows greatest activity after, 176.

Mouse, experiments on, demonstrating neutralisation of venom by
antitoxin, 254.

Mucous membranes, acute inflammation produced by deposit of venoms
on, 180.

_Muræna_, 309.

“ poison apparatus in buccal teeth, 288.

“ “ “ of, 309, 310.

“ _helena_, 309.

“ _moringa_, 309.

_Murænidæ_, 307, 309.

_Murex brandaris_, 286.

“ _trunculus_, 286.

Murison, Lieutenant C. C., on bite from _Echis carinata_, 347.

Muscles, striated, action of venoms on, 184.

Muscular apparatus of head of poisonous snakes, 11, 12, 13.

Myriopods, venomous species of, 280.

_Naja_ (cobra), 33, 59.

“ habits of species of, 37.

“ legend relating to marks on its neck, 37.

“ mortality from bite of, in India, 38.

“ poison-glands of, 148.

“ venom of, active hæmolysing power possessed by, 199.

“ worship bestowed on, by Hindus, 38.

“ _anchietæ_, 62.

“ _bungarus_ (_Ophiophagus_ or _Hamadryas elaps_, king cobra or
hamadryad), 37, 38.

“ “ action of venom, 39.

“ “ feeds on other snakes, 38.

“ “ killed by mongoose, 223.

“ “ method of procuring food, 38, 39.

“ “ vindictiveness of, 39.

“ _flava_, 61.

“ _goldii_, 62.

“ _haje_ or _haie_ (Egyptian cobra), 59.

“ “ bites from, 356.

_Naja haje_, danger extreme from its boldness in pursuit of victims,
60.

“ “ dreaded and hunted down in Egypt, 60.

“ “ employed by Egyptian snake-charmers, 61.

“ “ secretion of, 149.

“ “ “ tables, 150.

“ “ worshipped among ancient Egyptians, 61.

“ _melanoleuca_, 62.

“ _nigricollis_, 62.

“ _samarensis_, 36.

“ _tripudians_ (Cobra-di-capello), 33-36.

“ “ collection of venom from, 156, 360.

“ “ marks produced on skin by bite of, 10.

“ “ muscular apparatus of head of, 11, 13.

“ “ poison-gland of, 11, 13.

“ “ var. _cæca_, 35.

“ “ “ _fasciata_, 35.

“ “ “ _miolepsis_, 36.

“ “ “ _sputatrix_, 35.

“ “ “ _typica_, 34.

_Naseus_, 301.

Natter-jack, 318.

Neurotoxic and hæmolytic actions of venoms, parallelism between, 255.

Neurotoxin, 191, 195.

“ essential active substance in venoms, 187, 250.

“ highly resistant to heat, 249.

“ of scorpion-poison, 278.

“ of toad-venom (bufotenin), 320.

“ potency of antineurotoxic serum against, 250, 251.

“ predominance in venom of _Colubridæ_, 249.

“ present in venoms of some species of _Viperidæ_, 249.

Neuwied on _Elaps_, 108.

New Caledonia, terrestrial poisonous snakes unknown in, 100.

New Guinea, poisonous snakes of, 81-100.

New Zealand, _Katipo_ found in, 275.

“ no poisonous snakes in, 100.

Nicolas, J., and Lumière, A., on effect of intense cold on venom, 166.

Noc, on action of different venoms, 190, 191.

“ bacteriolytic property of venom, with respect to different
micro-organisms, 207, 208, 209.

“ hæmolytic powers of venoms, 196.

“ study of venom of _Ornithorhynchus_, 324.

Noguchi, H., on action of aniline colours on venom, 167.

“ failure of hæmolysis under large doses of venom, 200, 201.

“ and Flexner, cytolytic action of venoms, 206.

“ “ “ investigations on toxicity of snakes’ organs, 220.

“ “ “ on action of snake-serums on red corpuscles, 219.

“ “ Madsen, Th., on ratio between dose of venom and time elapsing
till death, 177.

Normandy, coast of, _Cottus_ abundant on, 292.

_Notechis_, 95.

“ _scutatus_ (syn. _Hoplocephalus curtus_, tiger-snake), 95.

“ “ “ “ “ bite dangerous, 100.

“ “ venom of, dose lethal for rabbit, 175.

Oceania, geographical distribution of genera of poisonous snakes
(tables), 145.

Octopods, poisonous juice exuded by, a means of overpowering prey,
287.

_Ogmodon_, 82.

“ _vitianus_, 82.

Oil beetles, 281. _See also Meloë._

_Ophiogeni_ in Egypt, 228-229.

_Ophiophagus_, 37. _See also Naja bungarus._

Ophthalmia, purulent, produced by snake-venom experimentally, 180.

“ “ “ venom of species of _Sepedon_, 180.

_Opisthoglypha_, group of _Colubridæ_, 3.

“ sub-families of, 3. _See also Homalopsinæ_, _Dipsadomorphinæ_,
_Elachistodontinæ_.

“ “ slightly poisonous and not dangerous to man, 4.

_Ornithorhynchus paradoxus_, or _O. anatinus_ (duck-billed platypus),
323.

“ “ “ “ “ venom of, 324, 325.

“ “ “ “ “ action similar to venoms of _Viperidæ_, 324.

“ “ “ “ “ toxicity very slight, 325.

Pacific Ocean (Equatorial), _Pterois_ found in, 296.

“ “ (Tropical), _Scorpæna diabolus_ found in, 293.

“ “ “ _Synanceia brachio_ most commonly found in, 291.

“ rattle-snake, 124, 125. _See also Crotalus confluentus._

Pain, severe, after bite of species of _Viperidæ_, 169.

“ slight from bite of cobra, 169.

Panama, _Thalassophryne reticulata_ found on shores of, 303.

Pancreatic juice, addition to venom produces kinasic power, 213.

Paris, brown _Pelobates_ found near, 318.

Parotid glands, venomous secretions, 147.

Pasteur Institute (Lille), poisonous snakes in captivity at, 72.

“ “ “ preparation of antivenomous serum at, 245-248.

“ “ “ rattle-snakes in captivity at, 125.

“ “ “ work and experiments at, 189, 190, 191, 204, 214, 223, 224,
244-248, 267.

Paterne, D., bites from European vipers, 341.

Peal, H. W., on bite from _Hydrophiidæ_ (sea-snakes), 338.

Pedicellariæ (organs of the _Echinoidea_), poison prepared from, 273.

_Pediculati_, 303.

Pedlar on chemical constituents of venom, 160.

_Pelias berus_ (common viper), bite from, 339.

“ “ “ “ “ cure, 357.

_Pelobates fuscus_ (brown _Pelobates_), 318.

Pelor, 293, 296.

_Percidæ_, 304.

Peritoneum, hæmorrhagic injections of, produced by venoms of
_Viperidæ_, 179, 180.

Permanganate of potash, antidote to venom before absorption, 260.

“ “ solution, modifies or destroys venoms, 164.

Philadelphia, laboratory for production of antivenomous serum at,
248, 252.

Philippine Islands, poisonous snakes inhabiting, 30-57.

Phisalix, experiments of, on venom with alternating currents of high
frequency, 165.

“ on effects of emanations of radium on venom, 166.

“ variations in local effects of venoms, 176.

“ venom of _Cryptobranchus japonicus_, 317.

“ poison from bee-venom prepared by, 283.

“ researches of, on glands of snakes, 147.

“ and Bertrand, experiments on immunity of hedgehog to venom, 226.

“ “ “ preparation of toad-venom, 319.

_Phoorsa. See Echis carinatus._

Phrynolysin, 320.

“ extracted from skins of toads, 320.

Physiology of experimental poisoning, 170.

_Physostomi_, 307.

Pig, destruction of vipers and rattle-snakes by, 125, 222, 226.

“ immunity to snake-venom due to defence provided by adipose tissue,
222.

“ serum, devoid of antitoxic substance, 222.

Pigeons, vaccination against rattle-snake-venom, 241.

“ killed by causing them to ingest venom, 180.

Pinto, Col. S., on immunity to inoculation, 238, 239.

_Platurus_, 140.

“ _colubrinus_, 141.

“ _laticaudatus_, 141.

“ _muelleri_, 141.

“ _schistorhynchus_, 141.

_Plectognathi_ (family _Gymnodontes_), 305.

Pliny on salamanders, 312.

“ treatment of poisonous snake-bites, 259.

_Plotosus_, 308.

“ _lineatus_, 308.

“ “ poison-apparatus of, 308.

Plutarch on snake-charmers, 228.

Poison-apparatus of _Cottus_, 293.

“ _Muræna_, 309, 310.

“ _Plotosus lineatus_, 308.

“ _Scorpæna_, 294.

“ snakes, 8.

“ _Synanceia_, 291.

“ _Trachinus_ (weevers), 297, 298, 299.

“ venomous fishes, 289.

Poison-fang, 8.

“ action of, 148.

“ of _Proteroglypha_ grooved, 4,

“ _Viperidæ_ canaliculate, 5.

Poison-gland of Hymenoptera, 281, 282.

Poison-gland of non-venomous snakes, 217.

“ venomous snakes, 10, 11, 12, 13.

_Polistes_, 285.

_Pompilus_, 285.

Pondicherry, collection of venom at, 156-158.

“ Hospital, collection of venom, method, 362.

“ public notice in, _re_ capture of poisonous snakes, 360.

Prairie rattle-snake, 120. _See also Sistrurus catenatus._

Pravaz syringe, injection of serum with, 263.

Precipitins of venoms, 202.

_Prionurus_, 301.

Pröscher on extraction of phrynolysin from skins of toads, 320.

Proteids, extraction from snake-venom, 163.

Proteolytic action of venoms, 204.

“ “ “ extent and limitations, 205.

_Proteroglypha_ (group of _Colubridæ_), 4.

“ bite rapidly produces general intoxication, 168.

“ poison-fangs of, grooved, 4.

“ sub-families of, 4. _See also Hydrophiinæ_; _Elapinæ_.

Proto-albumoses, active principle of snake-venom, 164.

“ separation from snake-venom, 162, 163.

_Pseudechis_, 87.

“ venom of, experiments on, 162.

“ “ ingestion by rats harmless, 181.

“ _australis_, 88.

“ _cupreus_, 88.

“ _darwiniensis_, 88.

“ _ferox_, 88.

“ _microlepidotus_, 88.

“ _papuanus_, 88.

“ _porphyriacus_ (black snake), 88.

“ “ “ “ bite dangerous, 100.

“ “ “ “ secretion of, 149.

“ _scutellatus_, 88.

_Pseudelaps_, 84.

“ _diadema_, 85.

“ _harriettæ_, So.

“ _krefftii_, 85.

“ _muelleri_, 84.

“ _squamulosus_, 84.

“ _sutherlandi_, 86.

“ _warro_, 86.

_Pseudocerastes persicus_, 47.

Psylli, Egyptian charmers and healers, 228-229.

“ Roman charmers and healers, 228.

“ “ “ “ “ Lucan on, 240.

_Pterois_, 293, 295-296.

Puff adder, 69. _See also Bitis arietans._

Putrefaction, rapid, following death from snake-bite, 211, 212.

Pyramids, viper of (_Echis carinatus_), 76.

Queensland, mortality from snake-bite slight in, 100.

Rabbit, experiments on, demonstrating neutralisation of venom by
antitoxin, 255.

“ minimal doses of various venoms lethal for, 173, 174, 175.

“ vaccination against cobra-venom, 243.

_Rascasse_, 296.

Rat, P., on common viper’s bite, 358.

“ ingestion of venom of _Pseudechis_ harmless to, 181.

“ minimal doses of various venoms lethal for, 174.

Rat-serum, bacteriolytic action of venom not comparable to, 208.

Rattle-snake, common, 125. _See also Crotalus durissus._

“ dog-faced, 124. _See also Crotalus terrificus._

“ ground, 120. _See also Sistrurus miliarius._

“ horned, 129. _See also Crotalus cerastes._

“ Pacific, or mottled, 124. _See also Crotalus confluentus._

“ prairie, 120. _See also Sistrurus catenatus._

“ Texas, 124. _See also Crotalus scutulatus._

“ venom, vaccination of pigeons against, 241.

Red Sea, _Naseus_ found in, 301.

Reichert on chemical constituents of venom, 160.

Renaux, P., on bites from _Crotalus horridus_, 355.

Rennie, Major S. J., case of bite of _Bungarus cæruleus_, 337.

Reptiles, toxicity of blood in, 217.

Respiratory centres, nerve-cell of, attacked by albumose of
snake-venom, 162.

_Rhinhoplocephalus_, 95.

“ _bicolor_, 95.

_Rhynchelaps_, 97.

“ _australis_, 98.

“ _bertholdi_, 97.

“ _fasciolatus_, 98.

“ _semifasciatus_, 98.

Richards on fatal results of experimental ingestion of venoms, 180.

Richet, C., congestin from _Anemone scultata_ prepared by, 270.

“ thalassin, from _Anemone scultata_ prepared by, 269.

Ringhals slang, 63. _See also Sepedon hæmachates._

River-jack viper, 73. _See also Bitis gabonica._

Rogers, Major L., experiments on action of venom on nervous centres,
186.

“ “ researches of, on glands of snakes, 147.

Romans, snake-charmers’ customs among, 228.

“ “ “ “ Lucan on, 240.

Roudot, Natalis, on Hindu snake-charmers, 229.

Russell, on the venom of _daboia_ (_Vipera russellii_), 46.

Sachs, on relation of toxins to antitoxins, 254.

Salamandarin, 316. _See also_ Salamandrine.

Salamander, Japanese, 317. _See also Cryptobranchus japonicus._

“ venom of, closely analogous to that of toad, 321.

“ “ potency exaggerated by the ancients, 312.

Salamanders and toads most dreaded by ancients, 312.

_Salamandra atra_ (black salamander), 313.

“ _maculosa_ (spotted salamander), 313, 314.

Salamandridine prepared from venom of salamanders, 317.

Salamandrine, prepared from venom of salamanders, 317.

Saliva of _Heloderma horridum_ sometimes toxic, sometimes harmless,
323.

“ venomous, of non-poisonous snakes, 214.

Sangis, name of snake-charmers of Bengal, 229.

São-Paulo (Brazil), laboratory for production of antivenomous serum
at, 248, 252.

Scales, arrangement of, on heads of poisonous snakes, 14, 15.

_Scolopendra_, 280.

_Scolopendridæ_, bite of, 281.

_Scorpæna_, 288, 289, 293.

“ poison-apparatus of, 294.

“ _diabolus_, 293.

“ _grandicornis_, 293.

“ _porcus_, 294.

_Scorpio occitanus_, 277, 278.

Scorpion, blood of, antitoxic, 279.

“ manner of stinging, 277.

“ poison, 278.

“ “ affinities with that of _Colubridæ_, 278.

“ “ neurotoxin of, 278.

_Scorpionidea_ (scorpions), 276.

Sea-snakes, 131. See also Hydrophiinæ.

“ (_Hydrophis_), venom from, 360.

_Sepedon hæmachates_ (spitting snake or ringhals slang), 63.

“ “ bite of, cure, 337.

“ “ venom of, purulent ophthalmia discharged by spitting, 63, 64.

“ “ “ “ “ caused by projection of, 62, 180.

Serous membranes, local effects on, of cobra-venom, slight, 179.

“ “ “ “ venoms of _Viperidæ_, severe, 179.

Serph, collection of venom. 156.

_Serranus_, 304.

“ _ouatabili_, 304.

Serum, antivenomous, antineurotoxic, 250, 251.

“ “ “ potency against cobra-venom, 250, 251, 252.

“ “ in treatment of bites of poisonous snakes, 326.

“ “ “ yellow fever, 184.

“ “ method for measuring power of, 256, 257.

“ “ “ “ “ _in vitro_, 202.

“ “ neutralisation of snake-venom by, 253-258.

“ “ “ “ “ experiments showing necessary proportions to effect, 254,
255.

“ “ polyvalent, 251.

“ “ “ prepared from horse, 251.

“ “ preparation of, 246.

“ “ “ test-solutions, 217.

“ “ “ at Pasteur Institute, Lille, 245-248.

“ “ “ special laboratories, 248, 252.

Serum, antivenomous, preventive power tested by intravenous
injection, 246.

“ “ rules respecting proportions of quantity to be administered, 266,
267, 268.

“ “ specificity of, 248.

“ Calmette’s, in treatment of cobra-bites, 363, 364, 365.

“ therapeutics, antivenomous, 241-252.

“ “ “ technique of, 262-265.

“ _See also_ Snake serum.

Serums, specific against coagulant venoms, 192.

Sewall on vaccination of pigeons against rattle-snake venom, 241.

_Siluridæ_, 307, 308.

_Silurus glanis_, 308.

_Sistrurus_, 110, 120.

“ _catenatus_ (prairie rattle-snake, or massasanga), 120.

“ _miliarius_ (ground rattle-snake), 120.

“ _ravus_, 120.

Skin, marks produced on, by bites of different species of snakes
(venomous and non-venomous), 10.

Smell, loss of, following bite of viper, 178.

Smith, MacGarvie, researches of, 149.

“ “ on chemical constituents of venom, 160.

“ “ and Martin, C. J., on local and general effects of albumoses
derived from snake-venoms, 163.

Snake-bite, death from, rapid putrefaction following, 211, 212.

“ hypoleucocytosis accompanying, in lethal cases, 211, 212.

“ mortality from, 2, 3, 38, 57, 100, 261, 363.

“ non-lethal, suppuration following, 212.

“ poisonous, treatment in domestic animals, 265.

“ “ “ men and animals, 259.

“ “ “ _See also_ Serum therapeutics, antivenomous.

Snake-charmers, 228.

“ deaths from bites, 234.

“ Egyptian, 228-229.

“ “ employment of _Naja haje_ for performances, 61.

“ Indian, 229-234.

“ Libyan, 228.

“ Roman, 228.

“ safety in skill, 234.

Snake-serum combined with snake-venom does not destroy red
corpuscles, 220.

“ dissolution of red corpuscles by, 219.

Snake-venom, action on heart, 184.

“ “ kidney, 183.

“ “ liver, 182.

“ “ lungs, 184.

“ “ nervous centres, 185.

“ “ spleen, 183.

“ “ striated muscles, 184.

“ activity greatest after prolonged fasting and after moult, 176.

“ aids digestion of prey, 213, 214.

Snake-venom, antagonism between coagulant and anticoagulant kinds,
194.

“ antidotes to, before absorption, 260, 261.

“ artificial introduction into egg of fowl, effect on embryo, 214.

“ bacteriolytic action, 206.

“ “ substance in, peculiarities of, 207, 208.

“ chemical study of, 159.

“ collection of, 147, 152-158.

“ “ in French Settlements in India, 359.

“ combination with lecithin, 254.

“ combined with snake-serum does not dissolve red corpuscles, 220.

“ complex effects on tissues, 215.

“ complexity of means of defence against, 215.

“ cytolytic action, 206.

“ diastasic action of, 212.

“ dried, 149.

“ effects of, in non-lethal doses, 177.

“ extraction of, by Hindus, 233.

“ “ from _Alcatifa_, for inoculation, 239.

“ freshly collected, 149.

“ hypoleucocytosis following fatal dose, 216.

“ immunity to, 222.

“ “ from inoculation, 234-235.

“ “ of herons to, probable, 226, 227.

“ ingestion of, fails to secure immunity to lethal dose, 214, 215.

“ “ harmless, 214.

“ lethal to snakes of other species, 219.

“ neutralisation by antitoxin, 253-258.

“ “ injection of antitoxic serum, second step in treatment after
bite, 262.

“ no strict ratio between dose inoculated and time elapsing till
death, 177.

“ parallelism between neurotoxic and hæmolytic action, 255.

“ prevention of absorption first step in treatment after bite, 262.

“ produces acute inflammation of mucous membrane, 180.

“ protective _rôle_ of leucocytes against, 216.

“ proteolytic action, 204.

“ reconstitution, method of, 257, 258.

“ secretion of, 147-152.

“ temperature lowered after fatal dose, 216.

“ toxic conditions of, 151.

“ vaccination against, 241.

“ variations in local effects of, 176.

Snakes, coloration of, 15, 16.

“ “ subject to biological laws of mimicry, 15, 16.

“ cranial skeleton of, 6.

“ dentition of, 6.

“ moulting of skin, 16, 20.

“ non-poisonous, arrangement of scales on head of, 14.

“ “ poison-glands in, 217.

“ “ venomous saliva of, 214.

Snakes, non-poisonous, withstand large doses of venom, 172.

“ poisonous, all species carnivorous, 17.

“ “ arrangement of scales on head of, 15.

“ “ artificial feeding of, 17, 18.

“ “ bite of, danger diminished by clothing or other means of
protection, 170.

“ “ blood of, toxicity, 217.

“ “ characterised by special arrangement of facial bones, 6.

“ “ deaths from, in Queensland, 100.

“ “ devoured by herons, 227.

“ “ different species should not be placed in same cage, 219.

“ “ difficult to distinguish from non-venomous, 2.

“ “ digestion aided by venom, 213, 214.

“ “ dread of destruction of, cause of excessive mortality from
snake-bite in India, 2.

“ “ geographical distribution of, 2, 3.

“ “ habits of, 17.

“ “ health authorities’ notices respecting, in Australia, 100.

“ “ kept in captivity, 61, 72, 125, 156, 223.

“ “ method of capture, 20, 21.

“ “ “ striking and seizing prey, 17.

“ “ muscular apparatus of head of, 11, 12, 13.

“ “ of Africa, 57-81.

“ “ Asia, Dutch Indies and Philippine Islands, 30-57.

“ “ Australia, 81-100.

“ “ Europe, 22-29.

“ “ Malaysia, 81.

“ “ New Guinea, 81-100.

“ “ South Sea Islands, 81-100.

“ “ Sunda Islands, 81.

“ “ poison-apparatus of, 8.

“ “ poison-fangs of, 8.

“ “ poison-glands of, 10, 11, 12, 13.

“ “ succumb to venom of other species, 173.

“ “ teeth of, difference in arrangement and dimensions of various
species, 9.

“ “ treatment of bites from, in French Settlements in India, 359.

“ “ unaffected by enormous doses of their own venom, 172.

“ “ unknown in New Caledonia, 100.

“ “ "New Zealand, 100.

“ “ victory of mongooses over, in combat, due mainly to natural
agility, 225.

“ worship of, 2.

“ “ extant in India, 2.

_Solenoglypha_, 109.

“ bite produces important local disorders, 168.

“ marks produced on skin by bite of one of, 10.

Sonoran coral-snake, 102. _See also Elaps euryxanthus._

South Sea Islands, poisonous snakes of, 81-100.

Sparrows, effect of venom of _Heterometrus maurus_ on, 279.

_Sphærechinus granularis_, poison from pedicellariæ, 273.

Spinal cord, comparative actions of venoms of _Colubridæ_ and
_Viperidæ_ on, 185, 186.

Spiders. _See Araneida._

Spitting snake, 63. _See also Sepedon hæmachates._

Spleen, action of venom on, 183.

Sponge-divers, malady of, 272.

_Squamipinnes_, 304.

Stings (wasp- or bee-), treatment for, 286.

Stomach, acute inflammation of gastric mucous membrane produced by
ingestion of venoms of _Viperidæ_, 180.

_Strongylocentrotus lividus_, poison from pedicellariæ of, 273.

Strychnine, injection of, of no value as antidote against
snake-venom, 261.

Sunda Islands, poisonous snakes of, 81.

Superstitions, native methods of inoculation full of, 239-240.

Suppuration following non-lethal snake-bites, 212.

Surucucu or bushmaster, 112. _See also Lachesis mutus._

Sutherland, Surgeon-Captain, bite from _Echis carinatus_, 348.

Sydney, laboratory for production of antivenomous serum at, 248, 252.

_Synanceia_, 288, 289, 290.

“ poison-apparatus of, 291.

“ _brachio_, 291.

Syncope, following inoculation of venom of _Synanceia brachio_, 292.

_Teleostei_, 290, 305, 307.

Temperature, effect of, on venoms, 161.

_Tetrodon_, 290, 305.

“ _rubripes_, 306.

“ _stellatus_, 306.

_Teuthididæ_, 301.

_Teuthis_, 301.

Texas rattle-snake, 124. _See also Crotalus scutulatus._

Thalassin, poison from _Anemone scultata_, 270.

_Thalassophis_, 133.

_Thalassophryne_, 288, 303.

“ _maculosa_, 303.

“ _reticulata_, 302-303.

Thuau on bites from European vipers, 342.

Tidswell, F., on venom of _Ornithorhynchus_, 324.

Tiger-snake, 95. _See also Notechis scutatus_.

Toad, common, 318.

“ green, 318.

“ musical, 318.

“ and frog, distinctions between, 318.

“ “ salamander, much dreaded by ancients, 312.

“ venom of, 318, 319.

“ “ active principles of, 319, 320.

“ “ closely analogous to that of salamander, 321.

“ “ preparation, 319.

“ “ exaggerated by the ancients, 312.

_Trachinidæ_, 297.

_Trachinus_ (weever), 288, 289, 297.

_Trachinus_ (weever) poison-apparatus of, 297, 298, 299.

“ _araneus_, 297.

“ _draco_, 297.

“ _radiatus_, 297.

“ _vipera_, 297.

Travers, P. M., on bite from _Bitis arietans_, 350.

Trichloride of iodine modifies or destroys venoms, 164.

_Triglidæ_, 290.

_Trigonocephalus_, bites from, 352, 355.

_Trimeresurus gramineus_, 55. _See also Lachesis gramineus._

“ _riukianus_, 53. _See also Lachesis flavoviridis._

_Triodon_, 305.

_Triton cristatus_, 313.

“ _marmoratus_, 313, 314.

_Tropidechis_, 94.

“ _carinatus_, 94.

_Tropidonotus matrix_ (grass-snake), venogen of, 151.

Trypanosomes, dissolution by cobra-venom, 207.

Tubriwallahs, snake-charmers of Bengal, 229.

Tunis, snake-charmers of, 228.

Tuxpan, natives of, inoculation methods, 235-237.

Urodela, salamanders belong to order of, 312.

_Urutù_, 115. _See also Lachesis neuwiedii._

Vaccination against cobra-venom, 242.

“ “ snake-venom, 241.

Van Denburgh, J., observations on _Heloderma horridum_, 323.

Vatuas, method of inoculation of, 239.

Venomous secretion, histology, 151.

de Villiers, on common viper’s bite, 357.

Viper, common, of Europe. See _Vipera berus_.

“ horned, bite from, 349.

“ inoculation of professional catchers of, in France, 234.

_Vipera_, 43.

“ zoological characters of, 23, 24.

“ _ammodytes_, 29, 69.

“ _aspis_ (asp, or red viper), 27, 28.

“ “ bite from, cure, 339.

“ “ poison-cells, 151.

“ berus (common viper, or adder), 25, 26.

“ “ devoured by hedgehogs, 222, 226.

“ “ mortality from bite, 27.

“ “ venom of, chemical constituency, 149, 160.

“ “ “ immunity of hedgehog to, 226.

“ “ “ uncertain coagulant action on blood, 189, 190.

“ _latastii_, 28, 69.

“ _lebetina_, 44, 69.

_Vipera raddii_, 44.

“ _renardi_, 44.

“ _russellii_ (_daboia_, or Russell’s viper), 45, 40.

“ “ muscular apparatus of head of, 11, 12.

“ “ poison-gland of, 11, 12.

“ “ protection against, adopted by natives, 46.

“ “ venom of, coagulant action on blood, diminished when heated, 191.

“ “ “ extremely potent, 46.

“ “ “ dose lethal for rabbit, 175.

“ “ “ ingestion causing death, 180.

“ _superciliaris_, 69.

“ _ursinii_, 24, 25, 44.

_Viperidæ_, 5, 43, 66.

“ bites of, local gangrene resulting from, 177.

“ characteristics of, 5.

“ geographical distribution, 6.

“ poison-fangs canaliculate, 5.

“ species of, bite produces grave local disorders, 168.

“ sub-families of, 6. _See also Viperinæ, Crotalinæ._

“ venoms of, absorption by digestive tract sets up acute inflammation
of gastric mucous membrane, 180.

“ “ action on nervous centres weak, 185, 186.

“ “ comparison of coagulant action on blood of various species, 190.

“ “ easily destroyed by heat, 161.

“ “ hæmolysing power, weak, 199.

“ “ lethal effects on mammals, 171.

“ “ neurotoxin present in those of some species, 249.

“ “ non-dialytic, 161.

“ “ produce coagulation of blood, 179, 188, 189.

“ “ “ hæmorrhagic injections of peritoneum, 179, 180.

“ “ recovery after non-lethal doses, slow, 177.

“ “ “ “ “ followed by loss of sight, smell, or hearing, 178.

“ “ recovery after non-lethal doses complicated by visceral
hæmorrhages, 177, 178.

“ “ resemblance in action of that of Japanese salamander to, 317.

“ “ “ “ “ _Ornithorhynchus_ to, 324.

“ “ richness in hæmorrhagin, 249.

Viperin, chemistry of, 130.

_Viperinæ_, 43, 66, 101. _See also Atheris_, _Atractaspis_, _Bitis_,
_Causus_, _Cerastes_, _Echis_, _Pseudocerastes_, _Vipera_.

“ characteristics of, 6.

Viscera, hæmorrhages from, complicating recovery from bites of
_Viperidæ_, 177, 178.

“ hyperæmia of, caused by fatal bite of species of _Colubridæ_, 171.

Wall, chemical constituents of venom, 160.

Waller, fatal instance of rapid poisoning from bite of _Naja haje_,
60.

_Walterinnesia_, 64.

_Walterinnesia ægyptia_, 65.

Wasp, sting of, death from, 283.

“ “ remedies for, 286.

Weevers, 297. _See also Trachinus._

“ stings of, 298, 299.

Wehrmann, on diastasic actions of venoms, 212, 213.

“ experiments on ingestion of venom, 214.

Wertheimer, Austrian naturalist, fatally bitten by coral snake, 108.

Witch-doctors, remedies of, 237, 238, 239.

Wolfenden, Norris, chemical constituents of venom, 160.

Wright, O. B., observations on _Heloderma horridum_, 323.

Yellow fever, treatment by antitoxin of venom, 184.

Zervos, Dr. S., malady of sponge-divers, 272.

FOOTNOTES:

[1] As regards the distinctive characters of these various snakes, and
of the majority of those that we shall describe in this book, we have
followed the statements in the “Catalogue of the Snakes in the British
Museum (Natural History),” vol. iii., by George Albert Boulenger,
F.R.S. (London: Printed by order of the Trustees, 1896.)

[2] _Acad. de médecine_, March 19, 1889.

[3] _Erpétologie générale_, t. vii.

[4] “Le serpent cracheur de la côte occidentale d’Afrique,” _Société
Zool. de France_, 1895, p. 210. Bavay thinks that the Spitting Snake
is a _Naja haje_, but the description that he gives of the head of
the reptile, which was sent to him by Le Naour, certainly agrees with
the characters of _Sepedon_. Moreover, I have satisfied myself that
the many specimens of _Naja haje_ that I have kept in captivity in my
laboratory never possessed the faculty of spitting their poison to a
distance.

[5] “The Snakes of Australia,” Sydney, 1869.

[6] L. Lannoy, “Thèse de doctorat ès sciences,” Paris, 1903, No. 1,138,
série A, 454.

[7] “Snake Commission Report,” 1874.

[8] _Bulletin de l’Académie de Médecine_, t. x., 1883, p. 947.

[9] _Zeitschrift für Biologie_, xxiii.

[10] Kühne and Chittenden, “Ueber Albumosen,” _Zeitschrift für
Biologie_, 1884.

[11] _Comptes rendus de la Société de Biologie_, 29 février, 1896.

[12] _Annales de l’Institut Pasteur_, 1896, p. 489.

[13] _Province médicale_, 21 Septembre, 1901.

[14] Rockefeller Institute for Medical Research, New York, 1906.

[15] _Proc. Roy. Soc._, London, lxxiv., 1904, pp. 108-109.

[16] _Ibid._, pp. 104-108.

[17] “Communication de l’Institut Sérothérapique de l’État danois,”
tome i., Copenhagen, 1906.

[18] _Indian Annals_, July, 1868.

[19] _Medical News_, Philadelphia, 1884.

[20] “Zur Pathologie des Schlangenbisses,” _Forschungen der Medicin_,
Berlin, 1890.

[21] _Annales de l’Institut Pasteur_, t. xii., 1898, p. 369.

[22] _Thèse Bordeaux_, 1902.

[23] _Virchow’s Archiv für Pathologie, Anatomie, und Physiologie_, Band
179, 1905.

[24] Société de Médecine et de Chirurgie de São Paulo (Brazil), June
15, 1904.

[25] _Medical Record_, September 15, 1900.

[26] _Lancet_, January 2, August 20, October 22, 1904, and September
23, 1905.

[27] _Proceedings of the Royal Society_, vol. lxxi., 1903.

[28] “The Constitution of Snake-venom and Snake-sera,” _University of
Pennsylvania Medical Bulletin_, vol. xv., 1902, p. 345.

[29] Fontana, “On Poisons,” translated by J. Skinner: London, 1787.

[30] _Smithsonian Reports_, 1854.

[31] _Smithsonian Contributions to Knowledge_, 1860.

[32] _Medical Times and Gazette_, vol. ii., 1873.

[33] “On the Physiological Action of the Venom of the Australian Black
Snake,” _Proceedings of the Royal Society of New South Wales_, July,
1895.

[34] _Indian Medical Gazette_, December, 1901.

[35] _Comptes rendus de la Société de Biologie_, November 4, 1899.

[36] _Ibid._, October 28, 1899.

[37] _Annales de l’Institut Pasteur_, June, 1904.

[38] At the Serum-therapic Laboratory of São Paulo (Brazil), Dr.
Vital, Brazil, is at the present time preparing serum specific against
_Lachesis_-venom.

[39] _Medical Times and Gazette_, vol. ii., 1873.

[40] “The Thanatophidia of India.” Churchill, London, 1872.

[41] “On the Physiological Action of the Venom of the Australian Black
Snake,” _Proceedings of the Royal Society of New South Wales_, July 3,
1895.

[42] _Archives biologiques_, 1897 and 1898; _Comptes rendus de la
Société de Biologie_, October 28, 1899.

[43] _Comptes rendus de la Société de Biologie_, October 28, 1899;
November 4, 1899; July 26, 1902.

[44] _Annales de l’Institut Pasteur_, June, 1904.

[45] _Journal of Pathology and Bacteriology_, 1899-1900.

[46] _Journal of Experimental Medicine_, March 17, 1902; _University of
Pennsylvania Medical Bulletin_, November, 1902.

[47] _Comptes rendus de l’Académie des Sciences_, June 16, 1902.

[48] _Comptes rendus de la Société de Biologie_, No. 27, 1902.

[49] _Berliner klinische Wochenschrift_, Nos. 38, 39, 1902; Nos. 2-4,
1903; Nos. 42-43, 1903.

[50] _Annales de l’Institut Pasteur_, 1904, p. 387.

[51] _Journal of Experimental Medicine_, 1905, No. 2, pp. 191-222.

[52] _Lancet_, April 2, 1904, pp. 916-921.

[53] “The Constitution of Snake-venoms and Snake-sera,” _University of
Pennsylvania Medical Bulletin_, vol. xv., November, 1902, p. 345.

[54] _Comptes rendus de l’Académie des Sciences_, August 11, 1902.

[55] _Annales de l’Institut Pasteur_, June, 1904.

[56] “Sur l’action protéolytique des venins,” _Comptes rendus de
l’Académie des Sciences_, September, 1902, and _Thèse Paris_, No.
1,138, 1903.

[57] “On the Plurality of Cytolysins in Snake-venom,” _University of
Pennsylvania Medical Bulletin_, vol. xvi., 1903, p. 163.

[58] _Ann. Soc. Méd. de Gand_, 1905, fasc. 3.

[59] _Annales de l’Institut Pasteur_, April, 1905.

[60] _Annales de l’Institut Pasteur_, 1898.

[61] _Thèse Paris_, No. 1138, 1903.

[62] _Comptes rendus de l’Académie des Sciences_, August 11, 1902.

[63] _Comptes rendus de la Société de Biologie_, January 11, 1896.

[64] Wehrmann, _Annales de l’Institut Pasteur_, 1897 and 1898.

[65] Carrière, “Sur le sort des toxines et des antitoxines dans le tube
digestif,” _ibid._, 1898, p. 435.

[66] _British Medical Journal_, 1895 and 1897.

[67] Chatenay, “Les réactions leucocytaires vis-à-vis de certaines
toxines,” _Thèse Paris_, 1894.

[68] Flexner and Noguchi, “Snake-venom in Relation to Hæmolysis,
Bacteriolysis, and Toxicity,” _Journal of Experimental Medicine_, vol.
vi., March 17, 1902.

[69] “Trattado del veneno della vipera,” 1787.

[70] _Archiv für mikroskopische Anatomie_, Bd. ix., 1873.

[71] _Morphologisches Jahrbuch_, Bd. viii., 1883.

[72] _Comptes rendus de la Société de Biologie_, January 20, 1894.

[73] _Archives de Physiologie_, 1894.

[74] _Comptes rendus de l’Académie des Sciences_, Paris, January 22,
1894.

[75] _Comptes rendus de la Société de Biologie_, January 13, 1894.

[76] _Annales de l’Institut Pasteur_, 1897.

[77] _Archives italiennes de Biologie_, 1888 and 1889.

[78] _Archives de Physiologie_, 1894.

[79] _Comptes rendus de la Société de Biologie_, July 25, 1903.

[80] _Journal of Pathology and Bacteriology_, May, 1903.

[81] _Journal of Pathology and Bacteriology_, 1900, p. 273.

[82] _Comptes rendus de la Société de Biologie_, July 1, 1905.

[83] “The Jungle Book,” by Rudyard Kipling. London: Macmillan and Co.,
Ltd. Reprint of 1905, pp. 183, 184.

[84] _Deutsche medicinische Wochenschrift_, 1898.

[85] _Comptes rendus de la Société de Biologie_, 1895, p. 639, and
1899, p. 77; _Bulletin du Muséum d’Histoire naturelle_, 1895, t. i., p.
294, t. ii., p. 100.

[86] “Aperçu général sur l’Egypte.” Paris, 1840.

[87] Brehm’s “Thierleben”; French edition, “Les Reptiles,” p. 480.

[88] _Maclure’s Magazine_, April, 1894.

[89] _British Medical Journal_, August 17, 1895.

[90] _Archives de médecine navale_, 1867, p. 390.

[91] _Revue scientifique_, 1892, p. 254.

[92] _Comptes rendus de l’Académie des Sciences_, February 24, 1896.

[93] “The Pharsalia of Lucan, translated into blank verse by Edward
Ridley, Q.C., sometime Fellow of All Souls’ College, Oxford.” (London:
Longmans, Green and Co., 1896). Book ix., p. 296, lines 1,046 to 1,065.

[94] _Journal of Physiology_, vol. viii., 1887, p. 203.

[95] “Les Vipères de France,” p. 136 (1889).

[96] _Annales de l’Institut Pasteur_, 1892, p. 181.

[97] _Comptes rendus de l’Académie des Sciences_, t. 118, February,
1894, p. 356, March, 1894, p. 720; _Comptes rendus de la Société de
Biologie_, February, 1894, pp. 111, 120; _Archives de Physiologie_,
July, 1894; _Annales de l’Institut Pasteur_, May, 1894, p. 275, April,
1895, p. 225.

[98] _British Medical Journal_, June 15, 1895.

[99] _Cf._ papers by George Lamb, _Scientific Memoirs by Officers of
the Medical and Sanitary Departments of the Government of India_,
New Series, Nos. 1, 3, 4, 5, 7, 10, 16; L. Rogers, _Proceedings of
the Royal Society of London_, vol. lxxii., and _Lancet_, February 6,
1904; C. J. Martin, _Intercolonial Medical Journal of Australasia_,
August 20, 1897, April 20, 1898; Dr. Hunter, _Lancet_, January 2,
1904; Dr. Tidswell, _Australasian Medical Gazette_, April 21, 1902; A.
Calmette, _Comptes rendus de l’Académie des Sciences_, May 2, 1904; Dr.
Vital Brazil, “Contribution a l’étude de l’intoxication ophidienne”
(separately published pamphlet), Paris, 1905; G. Bill, _Intercolonial
Medical Journal of Australasia_, July 20, 1902.

[100] _Annales de l’Institut Pasteur_, 1895, No. 4.

[101] “The Nature of the Antagonism between Toxins and Antitoxins,”
_Proceedings of the Royal Society of London_, vol. lxiii., 1898, p. 420.

[102] Calmette, _Comptes rendus de l’Académie des Sciences_, 1902, No.
24; Preston Kyes, _Berliner klinische Wochenschrift_, 1904, No. 19.

[103] _Berliner klinische Wochenschrift_, 1905, No. 50.

[104] _Comptes rendus de l’Académie des Sciences_, Paris, September,
1881.

[105] “Le venin de la vipère,” Paris, 1889.

[106] _Transactions of the Third Intercolonial Congress_, 1892, p. 152.

[107] “Les morsures de vipères chez les animaux,” _Recueil de médecine
vétérinaire d’Alfort_, May 15, 1897.

[108] _Comptes rendus de la Société de Biologie_, December 13, 1902;
June 6, July 25, 1903; February 20, 1904.

[109] _Semaine médicale_, June 24, 1903.

[110] _Comptes rendus de la Société de Biologie_, May 19, 1906.

[111] “El Latrodectus formidabilis de Chile,” by Fredérico Puga-Borne,
Santiago, 1892; and “Biologia Centrali-Americana,” Arachnida, vol. ii.,
pl. 35.

[112] Blackwell, “Experiments and Observations on the Poison of
Araneida,” _Transactions of the Linnean Society of London_, 1855, p.
31. See also “Insect Life” (U.S. Department of Agriculture, 1889), vol.
i., parts 7, 8, 9 and 10, and vol. ii., part 5.

[113] “Beiträge zur Kenntniss der Giftspinnen.” Stuttgart, 1901.

[114] “Zur Kenntniss des Kreuzspinnengiftes,” _Hofm. Beiträge_, ii., p.
125, 1902.

[115] Joyeux-Laffuie, “Appareil venimeux et venin de scorpion” (Thesis
for the degree of Doctor of Science), Paris, 1883; and _Comptes rendus
de l’Académie des Sciences_, November 6, 1882.

[116] “Ueber die Giftwirkung des Nordafrikanischen Skorpiones,”
_Zeitschrift für Biologie_, Bd. xii., p. 170, 1876.

[117] _Comptes rendus de la Société de Biologie_, 1885, p. 574.

[118] _Berliner klinische Wochenschrift_, 1903, Nos. 42, 43.

[119] _Annales de l’Institut Pasteur_, 1895, p. 232.

[120] _Proceedings of the Royal Society_, vol. xlii., 1887, p. 17.

[121] “L’immunité dans les maladies infectieuses,” Paris, 1901.

[122] _Comptes rendus de la Société de Biologie_, November 15, 1904.

[123] “La scolopendre et sa piqure,” _Thèse Paris_, 1887.

[124] “Appareil venimeux et venin de la scolopendre,” _Thèse
Montpellier_, 1885.

[125] “Lehrbuch der Anatomie der Wirbellosen Tiere,” 1848.

[126] _Arch für anat. Wissensch._, 1859.

[127] _Comptes rendus de l’Acad. des Sciences_, 1884.

[128] “Appareil glandulaire des hyménoptères,” Paris, 1894.

[129] _Comptes rendus de l’Académie des Sciences_, 1898.

[130] _Annales sc. Anat. Zoologie_, 8^e série, t. x., 1898.

[131] _Comptes rendus de l’Académie des Sciences_, July 25, 1890.

[132] _Comptes rendus de l’Académie des Sciences_, July 24, 1905.

[133] _Berliner klinische Wochenschrift_, 1906, No. 44.

[134] _Comptes rendus de l’Académie de Médecine_, t. liii., 1905, p.
498.

[135] “Traité de zoologie médicale,” t. ii. (Paris).

[136] _Comptes rendus de la Société de Biologie_, January 17, 1908.

[137] _Comptes rendus de la Société de Biologie_, February 25, 1905.

[138] “Les poissons venimeux,” _Thèse Paris_, 1889.

[139] “Poissons venimeux et poissons vénéneux,” _Archives de
Physiologie_, May, 1872; _Archives de médecine navale_, February, 1865,
and January, 1881.

[140] “Poissons venimeux et poissons vénéneux,” _Thèse Paris_, 1899.

[141] “Les poissons vénéneux,” Paris, 1900.

[142] “Sédentarité des poissons venimeux,” _Comptes rendus de la
Société de Biologie_, 1895, p. 86.

[143] _Comptes rendus de la Société de Biologie_, 1904, p. 666.

[144] _Thèse Paris_, 1884.

[145] _Bulletin du Muséum d’histoire naturelle_, 1899.

[146] “Giftfische und Fischgifte,” _Vorträge im Rostocker
Fischerverein_, 1902, and _Die medizinische Wochenschrift_, 1902.

[147] _Comptes rendus de la Société de Biologie_, October 25 and
November 8, 1902, and June 21, 1904; _Journal de Physiologie_, March,
1903.

[148] Brehm (Sauvage’s translation), “Les Merveilles de la
Nature--Reptiles et Batraciens” (Paris, 1885).

[149] Hoppe-Seyler’s “Med.-chem. Untersuchungen,” Berlin, 1866.

[150] _Comptes rendus de l’Académie des Sciences_, April 1, 1889, and
January 29, 1890.

[151] _Ibid._, 1890.

[152] “Beitrage zur Kenntniss des Salamandarins und
Salamanderalkaloïde,” _Archiv. f. experimentale Pathologie und
Pharmakologie_, Bd. xli., 1898, p. 219, and Bd. xliii., 1900, p. 84.

[153] _Comptes rendus de la Société de Biologie_, 1897, pp. 723, 823.

[154] _Comptes rendus de l’Académie des Sciences_, April 21, 1851, and
May, 1852.

[155] _Journal de Thérapeutique_, 1877, p. 929.

[156] _Comptes rendus de l’Académie des Sciences_, February 25, 1884.

[157] _Archives de Physiologie_, 1893, p. 511.

[158] _Archiv für mikroskopische Anatomie_, Bd. ii., 1889, p. 57.

[159] “Zur Kenntniss des Krotengiftes,” _Hofm. Beiträge_, Bd. i., 1901,
p. 575.

[160] “Ueber Bufonin und Bufotalin,” Leipzig, 1902; and _Archiv für
experimentale Pathologie und Pharmakologie_, December, 1902.

[161] “Rapports des venins avec la biologie générale,” _Revue générale
des Sciences_, December 30, 1903.

[162] _Comptes rendus de l’Académie des Sciences_, December 14, 1903.

[163] H. Coupin, _La Nature_, September 19, 1903.

[164] “On the _Ornithorhynchus paradoxus_, its Venomous Spur and
General Structure,” _Trans. Linn. Soc._, 1822, p. 622.

[165] “Observations on the Femoral Gland of Ornithorhynchus and its
Secretion;” _Proc. Linn. Soc. New South Wales_, vol. ix., July, 1894.

[166] “Note sur la sécrétion venimeuse de l’_Ornithorhynchus
paradoxus_,” _Comptés rendus de la Société de Biologie_, March 12, 1904.

[167] “On the Effects of Wounds Inflicted by the Spurs of the
_Platypus_,” _Proceedings of the Royal Society of Tasmania_, 1876.

[168] The photographs, by which this note was accompanied, are
reproduced in Chapter IV. of this volume, pp. 155, 157, 158.

[169] _Polygala telophioides_, Will.

[170] We subsequently learnt that he had informed his friends of his
intention, but had not said a word about it to his wife.

[171] The thick and cloudy appearance of the contents of the bottles
made us hesitate to have recourse to intravenous injection.

*** End of this LibraryBlog Digital Book "Venoms - Venomous Animals and Antivenomous Serum-therapeutics" ***

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