Transcriber's Notes:
When italics were used in the original book, the corresponding text has
been surrounded by _underscores_. The oe ligature has been replaced by
the letters oe. Greek letters have been replaced by their names and
surrounded by square brackets (i.e. [alpha]). The male and female
symbols have been replaced by [M] and [F] respectively. Upside-down V
and Y have been represented as [V] and [Y] respectively. Ditto marks
have been replaced by the text they represent.
Some presumed printer's errors have been corrected. In particular,
punctuation has been normalized and entries in the Index were altered to
match the main text.
THE SNAKES OF EUROPE
------------------------------------------------------------------------
UNIFORM WITH THIS VOLUME
THE LIFE OF CRUSTACEA
BRITISH FRESHWATER FISHES
THE OX AND ITS KINDRED
THE LIFE OF THE MOLLUSCA
------------------------------------------------------------------------
THE
SNAKES OF EUROPE
BY
G. A. BOULENGER
LL.D., D.SC., PH.D., F.R.S., F.Z.S.
WITH FOURTEEN PLATES AND FORTY-TWO FIGURES IN THE TEXT
METHUEN & CO. LTD.
36 ESSEX STREET W.C.
LONDON
------------------------------------------------------------------------
_First Published in 1913_
------------------------------------------------------------------------
PREFACE
There is no work in the English language dealing with the Reptiles of
Europe. I have therefore endeavoured to supply this desideratum, so far
as the Snakes are concerned, by drawing up in a concise form an account
of what is known of their characters, their distribution, and their
life-histories. Professor Sordelli, of Milan, having kindly acceded to
my request to reproduce some of the beautiful figures drawn by him for
the work published in collaboration with the late Professor Jan under
the title of "Iconographie Générale des Ophidiens," I have been able to
supplement my descriptions with illustrations which leave nothing to be
desired from the point of view of accuracy. A few drawings have been
made specially for this book by Mr. J. Green. I have further to
acknowledge the permission given by the Trustees of the British Museum,
the India Office, and the Zoological Society, to reproduce a few figures
from previous publications of which I am the author.
In order to render this little book more useful, the account of the
Snakes of Europe has been preceded by an Introduction summarizing what
is known of Snakes generally.
I have purposely avoided overburdening a work of this kind, which aims
at concision, with bibliographical references and synonymic lists. I am
sure my readers will be thankful for being spared this display of
erudition. Whenever I have had to compile, and to trespass on ground
that is not my own, I have been careful to draw only from the writings
of the most trustworthy authorities. The descriptions of the species are
based on the collection in the British Museum, which has been
considerably increased since the publication of the Catalogue of Snakes
(1893-1896). I have also had access to Monsieur F. Lataste's rich
private collection, now under my care, and Dr. R. Gestro has kindly
entrusted to me for study the collection of Italian Snakes in the Genoa
Museum. I am indebted to Dr. L. W. Sambon for the chapter on Parasites,
which he has written at my request.
To all who have helped me I beg to tender my hearty thanks.
G. A. B.
CONTENTS
INTRODUCTION
CHAPTER PAGE
I. Definition and Classification 1
II. External Characters--Integument 8
III. Coloration 29
IV. Skeleton 40
V. Dentition 53
VI. Poison Apparatus--Different Kinds of Poisons 62
VII. Nervous System-Sense Organs 73
VIII. Viscera 77
IX. Organs of Reproduction; Pairing; Oviposition; Development 82
X. Habits 91
XI. Parasites 107
XII. Distribution 118
XIII. Snakes in Relation to Man 133
SYSTEMATIC ACCOUNT OF THE SNAKES
OF EUROPE
First Family: TYPHLOPIDÆ
Genus TYPHLOPS, Schneider 144
1. Typhlops vermicularis, Merrem--The Greek Blind-Snake 144
Second Family: BOIDÆ
Genus ERYX, Daudin 147
2. Eryx jaculus, Linnæus--The Javelin Sand-Boa 147
Third Family: COLUBRIDÆ
Genus TROPIDONOTUS, Kuhl 152
3. Tropidonotus natrix, Linnæus--The Grass-Snake,
or Ring-Snake 152
4. Tropidonotus tessellatus, Laurenti--The Tessellated
Water-Snake 160
5. Tropidonotus viperinus, Latreille--The Viperine
Water-Snake 165
Genus ZAMENIS, Wagler 170
6. Zamenis gemonensis, Laurenti--The European Whip-Snake 170
7. Zamenis dahlii, Fitzinger--Dahl's Whip-Snake 177
8. Zamenis hippocrepis, Linnæus--The Horseshoe Whip-Snake 179
Genus COLUBER, Linnæus 181
9. Coluber quatuorlineatus, Lacepède--Aldrovandi's Snake 182
10. Coluber dione, Pallas--The Dione Snake 185
11. Coluber longissimus, Laurenti--The Æsculapian Snake 187
12. Coluber leopardinus, Bonaparte--The Leopard Snake 191
13. Coluber scalaris, Schinz--The Ladder Snake 194
Genus CORONELLA, Laurenti 196
14. Coronella austriaca, Laurenti--The Smooth Snake 197
15. Coronella girondica, Daudin--The Southern Smooth Snake 202
Genus CONTIA, Baird and Girard 205
16. Contia modesta, Martin--The Dwarf Snake 205
Genus COELOPELTIS, Wagler 207
17. Coelopeltis monspessulana, Hermann--The Montpellier Snake 208
Genus MACROPROTODON, Guichenot 212
18. Macroprotodon cucullatus, I. Geoffroy--The False
Smooth Snake 213
Genus TARBOPHIS, Fleischmann 216
19. Tarbophis fallax, Fleischmann--The Cat-Snake 217
20. Tarbophis iberus, Eichwald--The Caucasian Cat-Snake 219
Fourth Family: VIPERIDÆ
Genus VIPERA, Laurenti 221
21. Vipera ursinii, Bonaparte--Orsini's Viper 221
22. Vipera renardi, Christoph--Renard's Viper 227
23. Vipera berus, Linnæus--The Northern Viper, or Adder 230
24. Vipera aspis, Linnæus--The Asp Viper 239
25. Vipera latastii, Bosca--Lataste's Viper 247
26. Vipera ammodytes, Linnæus--The Sand-Viper, or
Long-Nosed Viper 249
27. Vipera lebetina, Linnæus--The Blunt-Nosed Viper, or Kufi 257
Genus ANCISTRODON, Palisot de Beauvois 261
28. Ancistrodon halys, Pallas--Pallas's Pit-Viper 262
Index 265
LIST OF PLATES
PLATE FACING PAGE
I. Typhlops vermicularis, Eryx jaculus 144
II. Tropidonotus natrix and Vars. cettii and persa 152
III. Tropidonotus tessellatus, T. viperinus and
var. aurolineatus 160
IV. Zamenis gemonensis and vars. persica and
viridiflavus 170
V. Zamenis gemonensis, var. caspius, Z. dahlii,
Z. hippocrepis 176
VI. Coluber quatuorlineatus and var. sauromates,
C. dione 182
VII. Coluber longissimus, C. leopardinus and
var. quadrilineatus 188
VIII. Coluber scalaris 194
IX. Coronella austriaca 196
X. Coronella girondica, Contia modesta 202
XI. Coelopeltis monspessulana, Macroprotodon
cucullatus, Tarbophis iberus, T. fallax 208
XII. Vipera ursinii, V. renardi, V. berus 220
XIII. Vipera aspis, V. latastii 240
XIV. Vipera lebetina, V. ammodytes, Ancistrodon halys 250
------------------------------------------------------------------------
THE SNAKES OF EUROPE
INTRODUCTION
CHAPTER I
DEFINITION AND CLASSIFICATION
Snakes, _Ophidia_--regarded by some authorities as an order of the class
_Reptilia_, by the author as a sub-order of the order _Squamata_, which
includes besides the Lizards, _Lacertilia_, the Chameleons,
_Rhiptoglossa_, and the extinct _Dolichosauria_ and _Mosasauria_--may be
defined as greatly elongate scaly Reptiles without limbs, or with mere
vestiges of the hind pair, without movable eyelids, without ear-opening,
with elongate, deeply forked tongue retractile into a basal sheath, with
transverse vent and paired copulatory organs, and with the two halves of
the lower jaw independently movable, connected at the symphysis by an
elastic ligament.
The latter character alone distinguishes them from all Lizards, but no
single Lizard possesses all the others in combination.
In their most highly developed form these Reptiles are adapted for rapid
reptation and for swallowing prey much exceeding their own calibre;
hence the bones of the skull, on which a prehensile function devolves,
are loosely attached to the cranium by ligamentous elastic tissue, or
articulated in such a manner as to permit a wide buccal expansion;
whilst the absence of a sternum and the mobile attachment of the ribs
allow a corresponding dilatation of the body as the prey descends into
the digestive canal.
The fatal venom which many of these Reptiles possess has so impressed
the mind of men, even the scientific, that for a long time snakes were
primarily divided into poisonous and non-poisonous, a classification in
which the more important characters, derived from the general structure,
and especially from the skull, were subordinated to the physiological.
Such a system was far from reflecting natural relationships. Besides, as
our knowledge progressed, drawing a distinction between poisonous and
harmless snakes became more and more difficult, so many snakes
previously regarded as harmless proving to be poisonous in various
degrees--at least enough to paralyze the small prey on which they
subsist, if not to be of serious danger to man.
In the division into families, as followed in this work, the presence or
absence of a poison organ is left out of consideration. Further, in this
as in many other groups of the animal kingdom, external characters do
not furnish trustworthy indications for higher divisions, and the
definitions of the families are therefore based exclusively on
osteological characters. For those who wish to name snakes with
facility, the key which concludes the chapter on External Characters
will, however, remedy this defect, and suffice for the identification of
all the European species without any reference to their anatomy. Many
attempts have been made to furnish an easy criterion for the distinction
of harmless from poisonous snakes, but the characters hitherto suggested
with this object can only be applied successfully to the small number of
representatives in a limited area. Thus, in Southern Australia it might
be stated that all snakes showing the regular nine large shields on the
upper surface of the head are dangerous to man, whilst those with small
shields or scales are harmless; but in most parts of Europe this
criterion would have to be reversed. In some countries the shape of the
pupil might be used for the purpose, in others the size of the ventral
shields, or the presence or absence of a loreal shield, between the
nasal and the preocular, and so on. But when we have to deal with the
snakes of the whole world, about 2,000 species, of which nearly
one-third are poisonous to a greater or less degree, every attempt at a
definition of the two categories without regard to the dentition breaks
down. Only those who have made a study of the snakes of the world can
make a guess from the general appearance as to an unknown form being
poisonous or not, and even they may sometimes feel embarrassed, unless
the dentition be examined; the mistakes which have occasionally been
made by some experienced herpetologists are proof sufficient of the
fallacy of external characters for this purpose.
The Ophidia are divided into nine families, the first, third, seventh,
and ninth of which have representatives in Europe:
I. No transverse (ectopterygoid) bone; pterygoid not extending to
quadrate or mandible; no supratemporal; nasals in contact with
prefrontals; coronoid present; vestiges of pelvis.
Maxillary loosely attached to lower surface of cranium, toothed; lower
jaw edentulous; a single pelvic bone
1. TYPHLOPIDÆ.
Maxillary bordering mouth, forming a suture with premaxillary,
prefrontal, and frontal, toothless; pubis and ischium present, latter
forming a symphysis
2. GLAUCONIIDÆ.
II. Transverse bone present; both jaws toothed.
_A._ Coronoid present; nasals in contact with prefrontals.
1. Vestiges of pelvis; supratemporal present.
Supratemporal large, suspending quadrate
3. BOIDÆ.
(Subfamilies: _Pythoninæ_, _Boinæ_.)
Supratemporal small, intercalated in the cranial wall
4. ILYSIIDÆ.
2. No vestiges of pelvis; supratemporal absent
5. UROPELTIDÆ.
_B._ Coronoid absent; supratemporal present.
1. Maxillary horizontal; pterygoids reaching quadrate or mandible.
Nasals in contact with prefrontals
6. XENOPELTIDÆ.
Nasals not in contact with prefrontals
7. COLUBRIDÆ.
Three series: A. _Aglypha_ (subfamilies: _Acrochordinæ_, _Colubrinæ_,
_Dasypeltinæ_); B. _Opisthoglypha_ (_Homalopsinæ_, _Dipsadomorphinæ_,
_Elachistodontinæ_); C. _Proteroglypha_ (_Hydrophiinæ_, _Elapinæ_).
2. Maxillary horizontal, converging posteriorly towards palatine;
pterygoid not reaching quadrate or mandible
8. AMBLYCEPHALIDÆ.
3. Maxillary vertically erectile perpendicularly to transverse bone;
pterygoid reaching quadrate or mandible
9. VIPERIDÆ.
(Subfamilies: _Viperinæ_, _Crotalinæ_.)
The technical terms employed in the above synopsis will be found
explained and illustrated by figures in the chapter on the Skeleton.
No serial arrangement can express the affinities of the various groups
as conceived by the classificator; a diagram therefore follows to show
the author's views as to their interrelationships, and possibly their
phylogeny. Leaving aside the Typhlopidæ and Glauconiidæ, which should be
regarded as burrowing types independently derived from some Ophidian
form less specialized than any with which we are at present acquainted,
and probably without direct relationship to the Lizards, the family
Boidæ, and more especially the Pythons, claim the position of ancestral
group, from which all other snakes may have been derived.
Viperidæ Amblycephalidæ
| |
Colubridæ opisthoglyphæ Colubridæ proteroglyphæ |
| | |
+---------------------------+-----+--------------+
|
Uropeltidæ |
| |
Ilysiidæ Xenopeltidæ Colubridæ aglyphæ
| | |
+------------+--------------+
|
Boidæ
Further remarks on this subject in the chapter on Dentition.
It is to be regretted that paleontology cannot help us at present as
concerns the lines of evolution, the comparatively few fossil Ophidians
known, from the Lower Eocene upwards, the remains of which can be
identified with some measure of certainty, being either non-poisonous
types (_Boidæ_, _Ilysiidæ_, _Palæophiidæ_, _Colubridæ_) or _Viperidæ_
(Viperines from the Miocene of France and Germany, Crotalines from the
Miocene of North America). The vertebræ from the Puerco Eocene of
America, on the limit between the Cretaceous and Eocene periods,
described as the oldest snake remains, _Helagras_, Cope, are stated to
approach the Lacertilian type.
Whether the vertebræ named _Symoliophis_, Sauvage, from the chalk of
France, and _Coniophis_, Marsh, from the Laramie Cretaceous of North
America, are Ophidian, as claimed by their describers, or
Dolichosaurian, cannot be decided without further material.