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THE STORY OF REPTILE LIFE

THE FRINGED GECKO (See p. 80).

THE STORY OF

REPTILE LIFE

BY W. P. PY CRAFT
F.Z.S., A\L.S., &c.

AUTHOR OF " THE STORY OF BIRD
LIFE," "THE STORY OF FISH LIFE"

1905

LONDON: GEORGE NEWNES, LTD.
SOUTHAMPTON STREET, STRAND

" »;• » /• ' BlOLOGt

••---• — :;••.%." ur;

TAe rights of translation and of reproduction are reserved.

PREFACE.

AMONG the higher animals at least, probably
none are so generally and so universally disliked
and mistrusted as the Eeptiles. Tradition has
done much to inculcate this antipathy ; and the
natural dread inspired by such as the snakes,
has provided justification for its perpetuation.

If, however, it be true that " a fellow feeling
makes us wondrous kind,7' then, surely, many of
those who now regard the Eeptiles as nature's
outlaws, should be induced to reconsider their
harsh verdict ; since, as it is the purpose of this
little book to show, like ourselves, these creatures
are also called upon to battle with nature for a
hold on life.

In the preparation of these pages I have
received much kindly help from Dr A. Smith
Woodward, F.E.S., of the British Museum of
Natural History ; and from Mr G-. A. Boulenger,
F.E.S., also of the Museum. For the most
valuable assistance which they have giyen me I
am grateful.

Those who may wish to pursue their enquiries
into the story of Eeptile Life yet further, will
find a mine of information in Dr A. Smith Wood-
ward's "Palaeontology of Vertebrates," and Dr
Gadow's volume on " Eeptiles " in the Cambridge
Natural History.

W. P. PYCRAFT.

LONDON, 1905.

'-.52884

CONTENTS.

CHAP. PAGE

INTRODUCTION 9

I. "BEAKED" LIZARDS 11

II. TORTOISES AND TURTLES ... o 19

III. CROCODILES o 46

IV. GECKOS, LIZARDS, AND CHAMELEONS . . 72
Y. SNAKES 106

VI. DOMESTIC LIFE 130

VII. REPTILIAN LIVERIES . 146

VIII. FLYING-DRAGONS 165

IX. EARTH DRAGONS 175

X. DRAGONS OF THE DEEP . 193

LIST OF ILLUSTRATIONS.

PAGE

The Fringed Gecko (p. 80) . . Frontispiece

FIG. 1 — The Tuatera Lizard (Sphenodon punctatum) 1 3
,, 2 — The upper portion of the Shell — Carapace

— of a Tortoise 21

„ 3— The Skeleton of a Turtle ... 24

,, 4 — The Big-headed Tortoise ... 30

,, 5 — Armadillo rolled up .... 32

,, 6 — Outline restoration of an extinct Crocodile 52

,, 7 — Legs of different Species of Lizards . 93

,, 8— The Flying-lizard (Draco volans) . . 101

, , 9 — Outline drawing of Chameleons ( Chameleon) 1 03

,, 10 — Head of a Poisonous Snake dissected . 125

,, 11 — The Frilled-lizard (Chlamydosaurus kingi) 158
,, 12 — Outline restoration of an extinct Flying-
dragon (Pteranodori) . . . .173

,, 13 — Outline restoration of the Skull of an
extinct Mammal-like Reptile Cyno-
gnathus . . . . . .177

,, 14 — Restoration of Land -dragon . . . 185
,, 15 — Outline restoration of an extinct gigantic

Land -dragon . . . . .188

,, 16 — Outline restoration of an extinct long-
necked Sea-dragon .... 195

,, 17 — Outline restoration of an extinct Fish-
lizard 199

„ 18— A. Left-arm of Crocodile, etc. . . 203

THE STORY OF EEPTILE LIFE.

INTEODUCTIOK

THE story of Eeptile Life is largely the story of
a people, if we may so use the word, whose glory
has departed. Just as in the study of the human
race we are able to follow the histories of nations,
their rise, glorious zenith, and decadence; so
with the Keptile folk we may trace a similar
course of evolution. The survivors of to-day
are but a remnant ; a feeble tribe, spurned and
despised. Time was when they were the domi-
nant forms of life upon the earth, so that we
speak of the " Age of Eeptiles " : for millions of
years — from the Permian to the end of the
Jurassic era — they held sway, but were at last
outnumbered and overpowered by the present
reigning type of animal life — the mammalia.
But their defeat is without ignominy, since, as
we shall show later, their conquerors are at the
same time their descendants. Similarly, the
Eeptiles are the descendants of the race which
they in turn displaced.

Lowly in origin, and restricted in influence,
these creatures nevertheless rapidly came to the
fore ; they spread themselves over the face of
the earth, and took possession of the waters

10 THE STORY OF REPTILE LIFE.

thereof, and of the heavens above, many exceed-
ing in stature all creatures that have ever lived
either before or since. Waxing numerous they
branched out into many tribes, each carving a
way for itself. What the members of these
several tribes were like, and how they have
overcome their enemies ; what weapons they
have employed ; what subterfuges they have re-
sorted to ; how they have conducted themselves
as parents ; and what their pedigrees disclose, is
to be the theme of the following chapters.

But before w^e proceed further, it is essential
that a clear idea should be formed of what con-
stitutes a reptile. Save among experienced
naturalists, only the very vaguest notions appear
to exist on this head. Generally, a group of
animals totally distinct is included in the popular
idea of the class reptiles. These alien forms are
the frogs and toads, newts and salamanders.
Now between the reptile and the creatures just
referred to there is a very wide difference. Both
agree in being "cold-blooded," in having a back-
bone, and four limbs adapted for walking : but
they differ fundamentally in that the young of
the frog-tribe — certain peculiar exceptions apart
— when they leave the egg do so in the form
of "larvae." That is to say they differ from
their parents in that they are obliged to live in
water and to breathe by means of gills like the
fishes. Later, these gills disappear and breathing
by lungs is substituted. But in this adult stage
they still differ from the reptile in that the skin
is naked, and richly supplied with glands for the
purpose of keeping the skin moist — hence the

"BEAKED LIZARDS." 11

" sliminess " which makes these creatures so
objectionable to many. Among the reptiles the
young leave the egg in the form of the parent —
that is to say, they never pass through a gill-
breathing stage. Further, the body is invested
in a scaly covering, and the skull moves upon
the backbone by means of a single bony knob,
instead of two such knobs, or " condyles " as
they are called, as in the frog and its allies.
Other characters there are whereby these two
groups — the Reptiles and the " Amphibia" —
may be distinguished, but we do not intend to
discuss them here. They are of too technical a
character for this little book.

CHAPTER I.

"BEAKED LIZARDS."

AFTER the elimination of the alien tribes re-
ferred to in our Introduction, we have left four
large groups, the Crocodiles, the Tortoises and
Turtles, the Lizards, and the Snakes, and lastly,
a fifth, represented only by a single species, the
Tuatera lizard of New Zealand. This creature,
with certain fossil forms, constitutes the order
Rhynchocephalia, or beaked " lizards."

Though but remnants of a fallen race, as we
have just remarked, these four groups are so
distinct one from another that it will be neces-
sary to tell the story of their rise and evolution
in as many separate chapters.

12 THE STORY OF REPTILE LIFE.

The distinctions which enable us so easily to
discern the reptile from the amphibian, are
based upon observations made upon living ani-
mals. A study, however, of the skeletons of the
two groups would have led to practically the
same results. But supposing there had been no
survivors either of the Amphibia or the Eeptiles,
then the dividing line would have been very
difficult to draw ; for though the skeleton of
any of the modern Amphibia differs conspicuously
from that of any reptile now living, the same is
by no means true of the more primitive types of
these two groups. Indeed, even at the present
day the greatest experts are not agreed as to the
class to which certain very ancient fossils belong.
One places them with the Amphibia, regarding
them as members of the group known as " Laby-
rinthodonts," another with the Keptiles. These
creatures, it is not surprising to learn, are ances-
tral types from which have probably sprung the
living reptiles of to-day. Other and allied forms
of the problematical types probably gave rise
to some of the fossil species — the "Dragons"
of the later chapters of this book. Be this as it
may, belonging to the same geological era — the
Permian — remains have been found of an un-
doubted reptile, known as Palseohatteria, which
is represented to-day by an actual living de-
scendant, the " Tuatera " of New Zealand. This
"living fossil," as it has been called, is thus one
of the most remarkable of existing reptiles, and
forms in itself a quite distinct group, the fifth,
to which reference has just been made. With
an ancestry traceable for millions of years, this

.2 3

•a «

«

•§ g

O ^H

14 THE STORY OF REPTILE LIFE.

wonderful creature, according to human stand-
ards, is one of the very bluest blood. Yet,
measured by the cold and impartial standards of
scientific criticism, it ranks among the lowest
instead of the highest of the Eeptile people.
The proud position of precedence is given to the
much less ancient house of the Crocodiles, these
having risen highest in the scale of evolution.

Whether, as some hold, the Tuatera, or
Hatteria as it is also called, represents the stock
from whence our reptiles of to-day have been
derived, or whether it and its ancestor the
Palseohatteria are offshoots derived, in common
with the remaining living species, from the
problematical reptiles, is a point which we
do not propose to discuss here. Those who
would examine the evidence on this matter
will find much information ready to hand in
Dr Gadow's book, to which reference has
already been made.

Whether the Tuatera is rightly regarded or
not as the representative of the ancestral stock
from which the existing reptiles are derived, it
is probably the most primitive of all living
species of this class. On this account, then, it
is fitting that it should be described, at least
briefly, in this opening chapter ; for many of its
peculiarities appear again, with modifications, in
other groups.

Although the Tuatera is generally referred to
as a lizard, it is really nothing of the kind. It
is no more permissible to speak of it as a lizard,
than it would be to call it a tortoise or a croco-
dile. It stands by itself in a group apart from

"BEAKED LIZARDS." 15

all its contemporaries. The evidence on which
this decision is based is of too technical a char-
acter for discussion here : we need only say that
it rests upon the structure of the skeleton, and
of certain internal characters related to the
organs of generation.

Of the skeletal structures which appear again
in other groups, sometimes strangely modified,
we may mention one or two of the more im-
portant. The ribs, for example, in the Tuatera
are remarkable for the presence of curious hook-
like processes which project backwards from the
middle of the upper portion of each rib, to
overlap the rib next behind it. These " uncinate "
processes occur elsewhere only among the Croco-
diles and the birds. Behind the breastbone are
found numerous rod-like bones embedded in the
muscles of the belly. These are commonly known
as the " abdominal ribs " ; they occur again in the
Crocodiles and the ancient " Labyrinthodonts "
and " fish-lizards," and it is probable that from
the fusion of similar bones the singular shield
on the belly of the Tortoise has been derived.
The teeth are quite remarkable. Numerous and
irregular in size, they occur not only along the
edges of the jaws, but also on the bones of the
palate. These teeth are not renewed when worn
out as in most other reptiles, but fusing with the
edges of the jaws gradually wear away till, in
very old individuals, the jaws become toothless.
It is on this account that the name beaked
lizards has been bestowed. Large males attain
a length of about two feet and a half. Both
sexes are alike save only in that the males have

16 THE STORY OF REPTILE LIFE.

a larger head and a stronger nuchal crest. Of a
dark olive green, with small spots of white on
the sides, the general appearance of the animal
is sober enough. It is enlivened, however, by a
row of pointed and slightly erectile spines along
the ridge of the back and extending on to the
tail. The under surface is clothed in moderately
large scales, whilst those on the sides are so small
as to give a granular appearance. The eye is
large and has a vertical pupil. The tail is thick
and compressed, and like that of many lizards, and
at least one species of mammal — a mouse, which
occurs in the island of Cyprus — is easily shed.
This is an ingenious device which enables the
owner to escape when seized by this organ.
Among the lizards at least, when threatened,
the tail is temptingly paraded, when, as soon
as it is grasped, the creature makes a dash for
liberty, the tail becoming detached with the
slightest shock. The lost appendage is speedily
renewed, and with it a new chance of escape
from unpleasantly close encounters is gained.
A similar regeneration does not, however, appear
to take place with the mouse in question.

But perhaps more than on any other account
the Tuatera is celebrated for the presence of
a third eye seated in the middle of the roof
of the skull. It should be mentioned, however,
that this organ is now quite f unctionless and has
shrunk to quite insignificant proportions. It
is connected by a long stalk with what is known
as the pineal gland, an outgrowth of the " primary
fore-brain." Coming to the surface through a
special aperture in the skull, between the parietal

"BEAKED LIZARDS." 17

bones — hence the name parietal eye — it is
covered by a horny scale. At one time this
eye was undoubtedly functional. But whether
it served some peculiar need in the days of long
ago, a need which has now ceased to exist, or
whether it merely supplemented the normal
lateral eyes which were then less perfect than
now, no man can tell.

Perchance it is a survival of pre-reptilian days,
that is to say of some larval condition, before the
lateral eyes were developed.

The discovery of this eye is quite a modern
achievement; and immediately the fact of its
existence became known a vigorous search was
instituted by anatomists the world over, with
the result that a similar, but yet more vestigial
eye was found in many other living reptiles, and
in a large number of extinct forms. In many
of the latter, indeed, this eye seems to have been
of considerable size. This is especially the case
in the old fish lizards, Ichthyosaurus. Besides the
reptiles, however, the amphibia and fishes also
show traces of this organ.

The Tuatera is, alas, verging on extinction.
Bush-fires, wild-pigs, dogs and cats, and reptile-
eating Maories and the advancement of civilisa-
tion have swept the Tuatera from the mainland
of New Zealand, so that to-day it is to be found
only in a few uninhabited islands. Here it dwells
in the seclusion of a burrow which it digs for
itself, and into which a hasty retreat is beaten
on the slightest sign of danger. The Tuatera
is a sociable animal, sharing its burrow with
various kinds of Petrels, though, be it noted,
B

18 THE STORY OF REPTILE LIFE.

members of its own species are summarily evicted
should they presume to attempt a lodgement.

The birds, by a mutual arrangement, occupy
the left, and the Tuatera the right side of the
chamber. It is interesting to note that whilst
the dark burrow serves all the purposes of a
nursery for the bird, which incubates its eggs,
it is unsuitable for this purpose for the pro-
prietors of the burrow, who, owing to their
more phlegmatic temperament are compelled to
seek the aid of the sun to bring their young
into being. The hatching time covers a rela-
tively enormous period — thirteen months, and is
rendered further remarkable by the fact that the
development of the embryo is, for a time, during
the winter months, suspended so that the embryo
may be said to hybernate within the egg.

Somewhat lazy in their movements as a rule,
crawling at a slow pace and dragging the body
and tail along the ground, when animated
by the excitement of the chase they lift the
whole trunk off the ground, and move with
some speed. This is kept up, however, only for
a few yards, when they grow weary and stop.
During the greater part of the day they sleep ;
and are fond of lying in the water, being able
to remain submerged for hours without breathing.
They feed only upon other animals, and these
they will take only when alive and moving
about. During the night, and especially during
the pairing season, they are said to croak or
grunt.

CHAPTEE II.

TORTOISES AND TURTLES.

FAMILIARITY certainly blinds our eyes to muck
that is wonderful in Nature. Perhaps in no-
instance is this more true than in the case of
the -creatures which form the subject of the
present chapter. To the world generally the
Tortoise is regarded as a somewhat uninteresting
creature, the type of sluggishness and the source
of the familiar ornamental commodity known as
"tortoise-shell," whilst its cousin the Turtle
has acquired undying fame on account of the
excellent soup it affords when boiled ! Yet, if
we look but a little below the surface, really as
well as metaphorically, we shall discover that
these "ugly ducklings" occupy a really unique
position in the animal kingdom.

This isolated position these creatures owe to
the remarkable coat of mail which they have
developed as a protection against their enemies.
This armour, in the typical tortoise, takes the
form of an inflexible shell investing the trunk,
but leaving the head, tail, and limbs free. These,
when danger threatens, can be drawn into the
front and hinder apertures of the shell so that,
being also armoured, a practically invulnerable
mass is presented to the enemy.

Critically examined, this shell is found to be
composed of an outer layer of horny plates or
shields, superimposed upon a closely fitting series.

19

20 THE STORY OF REPTILE LIFE.

of bony plates, which, like the horny covering
shields, are also symmetrically disposed.

Generally, in armour-clad animals where the
protecting covering is made up of horny shields
covering bony plates, the horny outer layer
exactly corresponds to the bony plate beneath
it. This is not the case with the tortoises and
turtles, or, to use a more comprehensive term,
embracing all the members of this order, the
Chelonians.

In the specimen from which this figure was
drawn, the horny shields in question were removed
from one side of the carapace, as this shell is
called, so that their relationship one to another
and to the bony elements beneath them, can be
readily made out. If the exposed portion of the
underlying bony shell be examined two sets of
patterns can be made out on its surface. One is
formed by shallow grooves, which represent the
impress of the edges of the horny shields, the
other by a series of curiously ziz-zag lines. These
represent the sutures or rough jagged edges of
distinct bones, which have a very remarkable
history, inasmuch as one set — those which may
be seen running down the middle of the back —
are formed by table-like expansions of what are
known as the " spines " of the vertebrae, or back-
bone, and therefore belong to the skeleton ; whilst
the remainder, those which take the form of bands,
running at right angles to the backbone, and those
which form the margin of the shell, are derived
from bones originally embedded in the skin. They
are this, and something more.

Since the day when they formed nodules of

TORTOISES AND TURTLES.

21

bono embedded in skin, many and strange
changes have taken place. The order of these
changes none can tell, only the result thereof
is ours, and this, without exaggeration, may
be called startling. When we come to take

FIG 2. —The upper portion of the shell— carapace— of a tortoise, to show
the form and position of the horny plates and underlying bones.
The horny plates are indicated on the right hand side, the impres-
sion of their edges made upon the underlying bones is shown by
dots on the left side. The bones are shown by jagged lines.

an inventory of the structures pertaining to
the outside of these creatures — structures which,
without previous experience, we might expect
to find, since they are found in other reptiles —
one of the first things to be missed would be

"22 THE STORY OF REPTILE LIFE.

the skin, and the next the thick layer of muscles
underlying this. Both are wanting in the trunk
of the Tortoises ! When we come to look deeper
into this anomalous state of things we find that
the bands of bone which we have just described
as running at right angles to the long axis of the
skeleton, that is to say the bands of bone running
from side to side, have a strangely complex
history. Originally, as we have said, nodules of
bone embedded in skin, they have, with the
wasting of the underlying muscles, come to lie
at first directly upon the ribs, and later, fusing
therewith, have ultimately replaced even these
almost completely. So much so, that all that re-
mains to-day, of what appear to be complete ribs,
is the head thereof, or the portion which joins
the backbone and the tip, or that portion which
supports the little bones which form the margin
of the shell. This we know, because in the very
young tortoise comp]ete ribs are present, but as
development proceeds, all save the two ends
become absorbed and replaced by the bones, origin-
ally, as we have said, belonging to the skin.
Exactly how this is done requires an intimate
knowledge of the changes which may take place
in the tissues of animals, and these we cannot
attempt to deal with here. Those who would
verify these statements must consult more
technical works than this little book, and
bring with them at the same time the results
of a scientific training.

The history of the breastplate of the tortoise
is no less strange. Like the shell this is made
up, externally, of symmetrically arranged plates

TORTOISES AND TURTLES. 23

of horn, covering equally symmetrically arranged
bony elements. There is no skin, save that
represented by the horny shields, and no inter-
mediate layer of flesh. The bony elements repre-
sent in part the bones of the shoulder girdle of
other animals, and in part the peculiar " abdominal
ribs " which we have already mentioned as a
notable feature in the Tuatera " lizard." There
is apparently nothing equivalent to the breast-
bone of other reptiles to be found in the Tortoises.

The development of the shell has been accom-
panied by many other and profound changes in
the form of the skeleton. Thus, the backbone,
between the base of the neck and the base of the
tail, has become virtually suppressed, its originally
separate elements being greatly reduced, and
immovably fused one with another. The reduc-
tion of the spine to its present almost vestigial
condition has been a long process. The decline
was inevitable directly the bony shell had acquired
rigidity enough to prevent the movement of the
backbone. As soon as this stage was reached a
new order of things became established, and the
material of the superseded spine became available
for absorption and reincorporation into the newly
developing structures. This is the fate of all
useless organs in Nature ; they are broken up,
like old buildings, to contribute to the growth
of new ones.

Yet another remarkable feature is the position
of the limb-girdles. In all other animals the
shoulder-blades lie on the outside of the foremost
ribs ; but in the Chelonians these bones are placed
on the inside of the ribs, i.e. within the shell.

24: THE STORY OF REPTILE LIFE.

Similarly the haunch-bones which support the
hind-limbs, in other animals lie behind the last
rib, and near the surface of the body, in the
Chelonians they lie, like the shoulder-blades,
within the shell. The anomalous position of

FIG. 3. — The skeleton of a turtle, viewed from the inside, after the
removal of the breastplate. Note the position of the shoulder and
hip girdles, lying beneath the ribs instead of above them.

these bones, however, is only a feature of adult
life. In very young tortoises, where the develop-
ment of the shell has only just begun, the shoulder-
blades lie a little in front of the first rib, whilst the
hip-bones are to be found just behind the last
rib. But the broadening of the ribs caused by
the excessive development of the external bony
shields gradually creeps over the shoulder-
blades in front, and the hip-bones behind, so that

TORTOISES AND TURTLES. 25

at last they came to lie, as we see, entirely
within the shell.

It is interesting to note that some few tor-
toises seem to have found that the inflexible
bony shell, such as we have just described,
needed yet further modification to make it a
thoroughly trustworthy fortress against attack.
This need has been met by developing a hinge
either across the carapace, or across the plastron
or breast shield. By this means one or other or
both of the apertures of the shell can be closed
completely as by a portcullis. The hinged
carapace, be it noted, is found only in these
species belonging to the genus Cinyxis, found in
tropical Africa, whilst the hinged plastron has
been independently acquired by several different
tortoises in widely different parts of the world.
Thus the little Spider-tortoise of Madagascar has
the plastron so hinged that the front portion can
be drawn up, so as to completely close the mouth
of the shell. The Iberian tortoise of Spain and
Morocco closes the hinder aperture of the shell
in a similar manner. In this species, however,
the hinge does not appear till comparatively late
in life, and is best developed in females. Some
six species of the genus Testudo, found in India,
Madagascar, and S. China, can also .close this end
of the shell by raising the hinder half of the
plastron. But the N. American species of the
genus Cistudo have made a decided improvement
on the mechanism adopted by the foregoing,
inasmuch as these can raise both ends of the
plastron, so that when the head, legs and tail
are drawn in, and the "oak is sported," the

26 THE STORY OF REPTILE LIFE.

hungry enemy must either pass on to other
game, or sit down and endeavour to take his
prize by siege ! As these creatures are able to
live for long periods without food, siege tactics
-are not likely to succeed.

Before we leave the subject of the shell we
must briefly comment on the remarkable cara-
pace and plastron of the rare Leathery Turtle
{Dermochelys) of the West Atlantic and Indian
Oceans — the largest of all living Chelonians. x

Like that of the Tortoises we have already
examined, the shell is of dermal origin. That is
to say, it is made up of bony growths developed
in the outer skin ; but here the resemblance ceases.
For whereas in the Tortoises and Turtles gener-
ally these bony plates are symmetrically disposed,
and, in the carapace sink down on to and become
inseparably fused with the skeleton, in the
Leathery Turtle they take the form of innumer-
able small plates* interlocked one with another
to form a mosaic. The carapace of this turtle
is furthermore peculiar in that it remains per-
manently distinct from the skeleton, so that,
when removed the ribs and vertebrae are re-
vealed, muscle-covered, as distinct as in other
reptiles. The horny shields which cover the
shell generally in other Chelonians are here con-
spicuous by their absence; instead, the shell is
•covered with a smooth, leathery skin — hence the
name, " Leathery Turtle."

The fundamental differences between the shell
of the Leathery Turtle and that of other Chelo-
nians has an important bearing upon the ques-
tion of the origin of the two groups. The

TORTOISES AND TURTLES. 27

mosaic-like plates of the carapace of the former
resemble the plates of the bony armour of the
crocodiles, and are probably derived from a
primitive armature of this kind. If this be so,
then the bony plates of other Chelonians must
be regarded as a later development, the origin of
which is yet to be discovered. This is the view
most generally favoured at the present time, and
accordingly, we must look upon the Leathery
Turtle as the sole survivor of a primitive and
independent group.

Parallels are always interesting, and it is
seldom that they cannot be found in the animal
world, however remarkable the instance we may
have to match.

Thus, though the shell of the Tortoise has no
counterpart among the living reptiles, we find a
very close resemblance thereto in the shell of cer-
tain gigantic and extinct mammals — the S. Ameri-
can Armadillos, known as Glyptodonts. These
creatures were encased, like the Chelonia, in a
bony shell, which in some forms is as much as five
feet long, and an inch in thickness. The struc-
ture of this shell resembled that of the Leathery
Turtle, in that it was made up of a series of
small bones closely interlocked to form a mosaic,
but different therefrom in that each of these
bony plates was covered by a horny shield. As
in the Chelonia, the separate bones of the verte-
bral column were welded together to form a tube.
The limb-girdles, however, did not occupy the
anomalous position which they held in the
Chelonia, inasmuch as they bore the same rela-
tion to the skeleton as in other animals.

28 THE STORY OF REPTILE LIFE.

In the structure of the skull several points
are to be observed whereby the Chelonia differ
from other reptiles. With these, in detail, we
have no concern here ; for our purpose it is
enough to notice, firstly, that teeth are con-
spicuous by their absence. Their work is per-
formed by horny sheaths which encase the jaws
as in birds. That the ancestral Chelonia had
teeth is very probable, and doubtless some day
this fact will be established by the discovery of
a fossil skull with teeth implanted in the jaws.
In one other point the Chelonia and the birds
agree — though this of course by no means im-
plies relationship — and this is in the form of the
lower jaw, which, instead of being made up of
two separate halves, is fused into a single bone.

The breathing of the Chelonia has acquired
certain peculiarities, inasmuch as, on account of
the rigid walls of the shell, expansion of the
chest cavity by the movement of the ribs and
abdomen has become impossible. The lungs,
which are complicated, spongy structures, are
filled and emptied partly by the movement of
the neck and limbs, which by their movement
act as pistons, and partly by the action of the
tongue bones, which are of great size. By these,
when the neck is stretched out, the throat is
alternately inflated and emptied by air drawn in
through the nostrils. The deflation of the throat
causes the air to be forced down the windpipe,
the valves of the nostrils preventing its escape
by any other way.

In every great group of animals we find that
the struggle for existence has caused a gradual

TORTOISES AND TURTLES. 29

dispersal of the members thereof, compelling
them to seek a livelihood in an environment
quite different to that of the centre from which
they started. Thus we get an exchange con-
stantly taking place between the inhabitants of
the sea and those of the land. We find the crab
deserting his natural element to climb palm-trees
for cocoa nuts, and mammals which have adopted
the life of fishes. Such an exchange, however,
can only take place under certain conditions — the
emigrants must adapt themselves to the require-
ments of their environment ; and this brings
about a more or less complete transformation of
the body.

Among the Chelonia we have many instances
of this. Originally terrestrial, some have adopted
a fresh water habitat, others have taken to the
sea. The modification which these aquatic forms
have undergone are sufficiently well marked to-
render them easily distinguishable from their
stay-at-home relatives. Hence we get Land Tor-
toises, Water Tortoises, and Turtles.

What the ancestral Tortoise may have been
like we do not know, but its descendants do not-
appear to have found any great necessity to
change their form after once the general archi-
tecture of the body had been determined on.
This much is to be gathered from the fact that
the fossil remains of these creatures, which occur
in remote geological formations — the earliest
known Chelonian occurring in the Upper Keuper
of Wiirtemberg — -differ but little from the same
parts of the skeleton of its nearest modern repre-
sentative. It is only in minor characters, divid-

30 THE STORY OF REPTILE LIFE.

ing the larger or smaller groups of species one
from another, that modifications occur among the
living Chelonia.

This conservatism is really very remarkable
when we reflect that they were already an
ancient group long before we have any record of
the advent of the birds upon the earth. It
seems difficult to realise that the conditions of
life through such enormous periods of time can
have affected them so little.

Fig. 4.— The big-headed tortoise. This creature is remarkable for the
large size of the head and the extraordinary flatness of the shell.

In the history of the past, many animals have
sought protection for the body by encasing it in
armour-plate. It would seem, however, that such
protection either ends in bringing about the
extermination of the species by which it has
been adopted, or in being discarded by later
generations. The Chelonia afford an exception
to this rule. Judging by the conditions of life
which obtain to-day, it is not easy to see why
this should be so, inasmuch as the Tortoises and
Turtles do not appear to be beset by any more
formidable enemies than their unprotected rep-
tilian neighbours. The key to the mystery may

TORTOISES AND TURTLES. 31

perhaps rest in their slowness of motion. Their
unarmoured neighbours escape by flight, a way-
which is impossible to these sluggish creatures.

Land-tortoises may be readily distinguished
by their feet. The toes are very short, with no
trace of webs between them, and the hind-feet at
least are club-footed. The peculiar form of these
feet is the outcome of adaptation to the support
of the remarkably heavy and inflexible body.
To the weight and immobility of the trunk we
may attribute the fact that the creatures are
confined to the earth. Tree-climbing to them is
an impossibility. They may delve below the
surface, but they cannot rise above it. But this
by the way.

The outer surface of the legs is covered with
little horny scales, covering, in many cases, bony
nodules, so that when drawn into the shell the
mouth and hinder apertures thereof are effectually
protected against attack. In some cases, as we
have already remarked, these apertures are closed
by raising the ends of the breast-plate.

Comparisons are said to be odious. Applied
to human affairs this is often true. In natural
history it is otherwise. Let us then contrast the
method of barricading practised by the Tortoise
with that of the remarkable South American
mammal, the Armadillo. This animal, like the
Tortoise, is encased in bony armour covered with
horny plates. The great back-shield differs from
that of the Tortoise among other things in its
great flexibility, so that, having no breast-plate,
the animal can curl itself up into a ball, leaving
but a single aperture, which is closed by the tail

32 THE STORY OF REPTILE LIFE.

and head-shield. How wonderfully this is done
can be seen in the accompanying illustration.

Of the Land Tortoises, one of the most familiar,
at least in Great Britain, is the " Greek Tortoise "

Fig. 5. — Armadillo rolled up.

(Testudo iberia), this being the species commonly
offered for sale on barrows in the streets, from
whence it finds its way into our gardens, and
also, not seldom, our houses, being imported into
the latter under the mistaken idea that it will
kill the "black beetles."

TORTOISES AND TURTLES. 33

The home of the Tortoise is 1ST. Africa and S. W.
Asia. It also occurs in Southern Andalucia,
breeding in the sandy pine forests of the
Marismas, near the mouth of the G-uadalquiver.

There are three claimants, it should be men-
tioned, to the title of " Greek " Tortoise. The
second, Testudo Grceca, is a close ally of T. iberia,
and occurs in the northern half of the Balkan
Peninsula, Asia Minor, Syria, Italy, and the
Islands of the Mediterranean.

The third is the genuine Greek Tortoise,
Testudo marginata, since it is restricted to Greece
proper, and is the only land tortoise which is
found there.

These three species are very much alike in
habits, and are exclusively vegetable feeders.
They are very fond of basking in the sun, and
extremely averse to getting wet, retreating to
some sheltered place on the fall of the first few
drops of rain. On the approach of winter they
bury themselves in a hole in the ground, or in a
heap of decaying leaves and there hybernate till
spring.

The " Gopher " Tortoise of the South-eastern
States of North America is a particularly interest-
ing species on account of its curious habit of
living in a burrow. The burrow, at its mouth,
is only sufficiently wide to admit the body of the
animal, and runs slightly downwards to a length
of about four feet. The whole passage may be
as much as two yards long, and gradually widens
from the mouth inwards, terminating in a spacious
chamber lined with branches of fir trees. Each
burrow is inhabited by a pair of tortoises. When
C

34 THE STORY OF REPTILE LIFE.

the dew is on the grass, or after rain, they
emerge to feed upon the grass, succulent vege-
tables, or fruit, varying this with gum which
exudes from trees, especially the gum of the
pine. This species is easily captured by the
simple expedient of digging a hole in front of
the entrance to the burrow, so that the animal
when leaving its house immediately falls into the
pit.

Beauty of form the Tortoise has not, but the
coloration of the horny plates of the back, in
some species, is certainly striking. This is
especially true of a small group known as
" elegant " tortoises. The majority belong to
S. Africa ; but perhaps the most beautiful of all
is the "starred" tortoise (Testudo elegans) of
India and Ceylon.

All the members of this group are conspicuous
for their extremely convex carapace. The horny
covering shields are either black with bright yellow
lines radiating from the centre of each, or yellow
with black radiating lines. The effect of this
black-and-gold scheme of coloration is, in many
species, heightened by the elevation of the scales
into prominent bosses.

It might be imagined that such a plan of
coloration would render the wearer extremely
conspicuous. As a matter of fact, the reverse is
the case ; for it has been shown that these tor-
toises are very difficult to distinguish from the
rocky ground of the grass jungles in which they
live.

According to an old Sanskrit legend, the world
is supported on the back of a gigantic elephant,

TORTOISES AND TURTLES. 35

whose feet are planted on the back of a still
more gigantic tortoise. What the tortoise took
its stand upon the legend does not so much as
hint at ! This old legend, like so many legends,
has a central particle of solid truth, inasmach as
large species of tortoise occur both in Europe
and North America, as far back as the Eocene,
one species, indeed, from the Siwalik Hills of
India having a carapace nearly six feet long.

These ancient giants have long since ceased to
exist on the continents either of the Old or New
World. They were, says Dr Gunther, "unable to
survive the changes of climate in the northern
latitudes, or to coexist with the large carnivora,
and especially with man, in the more congenial
south. But there were two spots on the earth's
surface where they continued to flourish to
within a century or two of our time — viz. Mada-
gascar and the neighbouring islands of the
Western Indian Ocean, and the Galapagos
Archipelago in the easternmost part of the
Pacific."

They do not appear to have lived in Mada-
gascar within historic times, having probably
been cleared off from the inhabited parts of the
island at the time when the first Europeans
landed. But their skeletons occur in consider-
able numbers throughout the island.

In the islands north of Madagascar, however,
these creatures dwelt in absolute security for
ages, none of these islands, save the Comoro
group, being inhabited either by man or large
mammalia. As a consequence, with absolute
freedom from enemies, they had nothing to do

36 THE STORY OF REPTILE LIFE.

but to eat, to multiply, to grow in stature, and
possess the land. Thus, not only the larger
islands of the Aldabra group — the Seychelles,
Keunion, Mauritius, and Rodriguez — but also
the smaller islands became peopled in incredible
numbers.

The discovery of these island fastnesses by
Europeans speedily brought about the downfall
of these harmless creatures. Their vast numbers
melted like the snow. Proving more wholesome
and more toothsome food than turtle, every
passing ship stopped to bear away as many as
she could carry. Later, a still further drain
upon their ranks was imposed by the settlement
of naval and military forces, until speedily the
supply became exhausted. Recourse was then
had to importation from neighbouring islands,
and we gather from the reports of the French
India Company that in 1759 four small vessels
were accordingly employed in bringing tortoises
from Rodriguez to Mauritius. One vessel carried
a cargo of no less than 6000, and altogether more
than 30,000 were imported into Mauritius in less
than eighteen months !

As a result the dawn of the nineteenth century
witnessed the practical extinction of these wretched
creatures on all the islands save the south island
of the Aldabran atoll. Here a few stragglers
still possibly remain, thanks to the rugged char-
acter of the land.

Of the tortoises of the Galapagos Islands much
the same story must be told. At the beginning
of the sixteenth century immense numbers
existed in these islands. Now only three, Abing-

TORTOISES AND TURTLES. 37

don, Albemarle, and Duncan Island harbour a
few survivors.

Such is the lamentable history of these helpless
victims, as collected with infinite pains by Dr
Gunther some five years since.

Isolated by the submergence of the lower
land, these tortoises were prevented from inter-
breeding and the swamping effect of intercrossing,
so that in time each group of islands, and in the
case of the Galapagos, almost every island came
to possess its own peculiar species.

Of the many species of these Galapagos tor-
toises which have been described, two only can
be mentioned here. The first, and perhaps the
most interesting of all, is Daudin's Tortoise,
Testudo daudini, from the south island of Aldabra.
A specimen recently in the collection of the Hon.
Walter Eothschild was the largest living tortoise
known. The length of its shell was 55 inches,
or 67^- over the curve, and the weight 560 Ibs.
The species known as Testudo abingdoni is peculiar
on account of the thinness of its shell, which is
extremely delicate. A curious feature about the
carapace of these Galapagos tortoises, or at least
of the majority of the species, is the great size
of the opening of the front of the shell, which
presents a cave-like appearance, very different
from the narrow crescentic aperture of the typical
tortoise.

Water is hard to find in the islands where
these tortoise live, and travellers have often
found relief for their parching thirst in the fluid
contained in the pericardium or membrane sur-
rounding the heart. The naturalist Baur relates

38 THE STORY OF REPTILE LIFE.

an instance where lie and his five companions,
when thus suffering, found relief by killing one
of the species known as Testudo vicinia, a native
of Albemarle Island. They found no less than
five cups of clear fluid in this receptacle. Simi-
larly Darwin relates in his "Voyage of the
Beagle " how that the contents of the bladder
are also, under pressure, greedily drunk. The
taste of the fluid is said to be bitter, whilst that
of the pericardium is tasteless.

The difference between the fresh- water or pond
Tortoises and Terrapins and their cousins of the
dry land are generally by no means such as would
strike one at first sight. So closely do they
resemble one another, indeed, that some surprise
might naturally be expressed that such different
environments should have effected so little change.
The only difference between the land and aquatic
forms appears to be in the form of the feet, the
aquatic species having webbed feet, which may
even become paddle-shaped. A more careful
examination of one of these pond-tortoises would,
however, reveal modifications which are obviously
special adaptations to their peculiar mode of life.
Besides the change in the form of the feet to
facilitate movement through the water, special
breathing organs have been developed to permit
of prolonged submersion. Thus in certain " soft-
shelled " tortoises of the sub-order Trionychoidea,
the mucous membrane of the throat is beset with
thread-like processes richly supplied with blood.
These act like the gills of fishes, fresh water
being constantly taken in through the mouth
and passed over the delicate blood-filled pro-

TORTOISES AND TURTLES. 39

cesses which exchange the carbon dioxide of
the blood for oxygen. But there is this differ-
ence between the breathing of the tortoise and
that of the fish. In the former the vitiated
water is expelled through the mouth, in the
fish through one or more slits at the sides of
the throat. The water breathing of these tor-
toises is supplementary to that of the lungs,
and is effected in a perfectly rhythmical manner
some sixteen times per minute, by the move-
ment of the hyoid or tongue bones. Other
water tortoises, such as the European Pond-
Tortoise (Emys orbicular is), and the Sculptured
Terrapin of North America (Clemmys insculpata),
have developed accessory breathing organs in
the shape of thin-walled bladders which open
into the hinder end of the gut. The inside of
these bladders is richly ^supplied with blood-
vessels which are bathed by a constant exchange
of fresh water, the bladder being incessantly
filled and emptied through the vent. If one
of these tortoises is suddenly taken out of the
water the contents of these vessels will be
instantly squirted out. Although this habit is
well known, the source of the water is gener-
ally misunderstood, inasmuch as it is usually
supposed to be the urine from the bladder.

Yet another extremely interesting modification
which the pond-tortoises have undergone is that
displayed by a large number of species forming
the sub-order Pleurodira. These all have ex-
tremely long necks, and on this account ap-
parently are unable to retract them so as to
the head within the shell. Instead, they

40 THE STORY OF REPTILE LIFE.

curve the neck round to the right or left bring-
ing it and the head under the eaves of the
"carapace," hence the name side-necked tor-
toises. Of course in this way the whole of one
side of the head and face is exposed. In most
land-tortoises this would be a grave danger, but
apparently in the aquatic regions the need for
such effective protection is less urgent.

When, probably owing to overcrowding, some
of the more adventurous tortoises essayed to
make a living by the margins of pools and
shelving banks of streams, and eventually in
the water itself, they apparently found it ex-
pedient to exchange a vegetable for an animal
diet, inasmuch as the water-tortoises of to-day
are almost entirely carnivorous. To the car-
nivorous habits we may trace further peculiarities
in the development of new traits of character
called forth by the very different nature of the
food. Preying on other living creatures, often
more active and highly organised than them-
selves, their only chance of success is, not
seldom, by cunning.

An admirable instance of this is furnished by
the Snapping Turtle or " Snapper " (Chelydra
serpentina), one of the largest of the pond-
tortoises. Fishes are decoyed within striking
distance by the artful display of two temptingly
worm-like filaments protruding from the tip of
the tongue, the rest of the animal being con-
cealed in the mud. The consequences of touching
these are far more serious than treading on the
tail of the Irishman's coat! Larger prey this
diabolical monster captures by stealthily ap-

TORTOISES AND TURTLES. 41

preaching under the disguise of an old rotten
log. This disguise is afforded by the fresh water
algse which grows luxuriantly on its shell, and
on the mud which settles there.

The Snapper measures more than three feet
from the snout to the tip of the tail, and has a
geographical range extending from the Canadian
Lakes, east of the Rockies, through the United
States to Central America. It is held in whole-
some fear, even by man himself, on account of
the severe bites which it is capable of inflicting,
and is besides cordially hated for the destruction
it causes amongst food-fishes and water-fowl.

For this destruction, however, the Snapper
pays a heavy toll, inasmuch as young Snappers
are caught in considerable numbers by his arch-
enemy man, for table purposes. Their capture
is effected by a hook baited with pieces of fish ;
but the tackle used must be of the strongest, for
a hooked Snapper is not taken without a struggle.
Only the young are esteemed, the adults being
uneatable owing to the strong odour of musk
which pervades the flesh.

The "Alligator Turtle" (Macroclemmys tem-
mincki), a very near relative of the Snapper,
and very like it in size and appearance, is even
more ferocious, perhaps we should say courageous.
When danger threatens, instead of retreating
within its shell it assumes a defiant attitude.
Eaising itself on its legs, with open mouth, it
throws itself upon its assailant with great spirit,
shooting out the head as far as the long neck
will allow, and at the same time throwing the
body forwards, often with such impetus as to

42 THE STORY OF REPTILE LIFE.

bring it to the ground should the object aimed j
at be missed. The strength of the jaw is sur- j
prising. One of these creatures has been known
to bite a piece clean out of an inch plank.

The cunning of the disguise of the Snapper
is equalled only by one other pond-tortoise — the
" Mata-mata " (Chelys fimbriata). The back of
the shell in this animal, as in the Snapper,
bears a close resemblance to an old sunken log,
but the guise has been acquired by somewhat
different means, large conical bosses, divided
from one another by deep valleys, giving the
appearance of rough bark, and thus taking the
place of the algae on the shell of the Snapper.

Like the Snapper, the Mata-mata has assumed
a disguise in order to increase the effectiveness
of a lure by which unwary fishes and other prey
may be brought within reach of the mouth. The
lure in the present case takes the form, not of
brightly-coloured filaments from the tongue, but
of ragged-looking flaps of skin projecting from
the head and neck. The ear-flaps and the flaps
of skin on the throat are kept in constant motion,
and thereby attract the attention of passing fishes
and other curious creatures which, drawing closer
and closer, are at length brought near enough to
the mouth to be suddenly engulfed by the inrush
of water down the throat of the artfully concealed
monster.

The Mata-mata is a native of the rivers of
Guiana and Northern Brazil, and is perhaps the
most bizarre-looking of all its tribe. It is a really
big tortoise, attaining a length of more than three
feet when fully adult.

TORTOISES AND TUETLES. 43

From the pond-tortoises we pass, by a very
natural transition, to the Marine Turtles. In
them we see the final results of adaptation to
jin aquatic life. Whilst the general form of
juhe body has undergone little or no change,
phe limbs have become completely transformed
iinto swimming paddles. In the fore-limbs the
J3xtent of the changes is extremely marked,
^either in the fore nor the hind limbs are
iligits any longer to be distinguished; in ac-
bordance with their new functions in both limbs
ohey are enclosed within a common skin, so
fthat the once walking limbs have now become
< • paddles," superficially bearing the strongest
resemblance to the paddles of the old fish
[lizards — the Plesiosaurs and Ichthyosaurs, to
)e described later — the Penguins among the
Ipirds; or the Whale tribe among the Mam-
|nals. In all these cases, just as in the turtles,
bhe paddles have been evolved by the modifica-
tion of limbs originally used in quite other ways.
[Another point of interest with regard to the
paddles of the turtles is, that whilst those of
Ihe fore-limbs were of great length, the hinder
|)air were extremely short. The explanation of
[his, of course, is obvious — the long paddles were
lised as propellers, the short ones as rudders.
IChe same applies also to the ancient Ichthyo-
laurs, and to the modern whales. In the latter,
Indeed, the hind-paddles have disappeared al-
|ogether, the work of steering being undertaken
>y the tail. In some other cases, to be discussed
'S we proceed, we shall find this arrangement
xactly reversed — the hind-limbs developing at

44 THE STORY OF REPTILE LIFE.

the expense of the fore, so that these became id
time reduced to the merest vestiges.

Ill-fitted as they are for a life ashore, yet the
females, at any rate, are obliged to sojourn here
awhile, at least once a year, when they come tq
deposit their eggs. Other aquatic reptiles, such
as the ancient Plesiosauria and Ichthyosauria.;
seem to have avoided this necessity by retaining!
the eggs within the body until they hatched — j
that is to say, they were viviparus.

Gigantic as some of the tortoises have become, I
they are surpassed by their sea-dwelling cousin*
the turtles, the species known as the Leathery!
Turtle, sometimes weighing as much as a ton.j
This animal, however, is like other giant forms,
verging on extinction. We shall see indeed as]
we proceed how often Nirvana has been achieved!
by the reptile-people through the gateway oil
over-growth.

The Green-turtle or " edible-Turtle " (CMonA
my das), and the Hawks-bill Turtle (Chelone imbril
cata), in so far as the general shape of the body!
and paddles is concerned, are extremely like the!
Leathery Turtle just described, yet, as has been!
pointed out earlier in this chapter, they are only!
in a very remote degree related — their similarity!
is due to what is called " convergence of de-
velopment," and not to community of descent.
It is this same convergence, this adaptation to
environment, which has produced the community
of likeness, which has been pointed out between
such widely different forms as the turtle, the fish-
lizards, and the whales.

The Green-turtle is the species which plays

TORTOISES AND TURTLES. 45

<o conspicuous a part in our great public feasts.
The home of this creature is in the Atlantic,
[ndian and Pacific Oceans, and throughout this
rast area it roamed at one time in abundance,
though the numbers are now greatly reduced.
I Large specimens attain a weight of more than
|uhree hundredweight.

It is from the horny shields of the Hawks-
bill Turtle, of tropical and sub-tropical seas, that
ibhe world's supply of tortoise-shell is obtained.
jThe removal of these shields is in many cases
accompanied by the most revolting barbarity.
The miserable victim is held over a fire till
the heat makes the coveted horny plate part
j from the bony shell, after which the poor beast
I is allowed to escape to the sea — there to die a
I lingering death. This end is not, however,
believed in by the brutes who inflict this
torture. They believe that once in the sea a
new set of plates will be developed, and thus
a crop will be assured for future harvests.
Such is the practice of the Singalhese. The
natives of Celebes are more humane. Their
prisoner is killed by blows on the head, and
the body immersed in boiling water, with the
desired result.

Shields are rarely thick enough to use for
commercial purposes as they leave the body.
Accordingly several are welded together by
being heated in oil or boiled. Even the
shavings can be melted and moulded into large
pieces.

Other species of turtles there are, but con-
siderations of space not only forbids their

46 THE STORY OF REPTILE LIFE.

mention, but compels us to omit much that
we would have said about the species which we
have selected for discussion.

CHAPTER IE.

CROCODILES.

FEROCIOUS and repulsive in appearance, the
Crocodiles of to-day nevertheless are a most
interesting and highly important group. To
them belongs the distinction of being at once the
largest as well as the most highly organised
of all the Irving Reptiles.

Their origin is still a mystery. The earliest
known members of the group carry us back to
the Liassic period ; but previous to this there
had existed in the still older Keuper formations
crocodilian forms which, though more primitive
in structure in some respects, were yet too
specialised in others to render it possible to
regard them as the ancestors of the Crocodiles
of the Lias and their living descendants. That
the Crocodiles, in a wide sense, — that is, includ-
ing the very early forms of the Keuper forma-
tions— are related on the one hand to the
remarkable Tuatera Lizard (Hatteria), and on
the other to the still more remarkable and
extinct Dinosaurs, there can be no doubt.
More remotely the group appears to be related
to the Tortoises and the extinct Plesiosauria,
the long-necked fish-lizards of the Trias and Lias.

CROCODILES. 47

Though in general appearance Crocodiles look
very much like gigantic lizards, yet a closer
examination will show that this resemblance is.
rather accidental than due to a community of
descent. The peculiar lizard-like form we must
regard as the common inheritance of all the
reptiles; and variations on this are the result
of modification in adaptation to environment.

Among living Crocodiles and their direct
ancestors, the rough outline of this primitive
form have been more or less faithfully pre-
served, and this because they have escaped
extreme specialisation in any one direction.
Though aquatic in habits, yet, like the Newts
among the Amphibia, the land has never been
entirely forsaken. Among living Crocodiles the
shore is the repository for the eggs, and to
the shore they resort for the daily sun-bath.
Further, they are frequently compelled to travel
overland in search of water when the streams
which give them harbour dry up. That their ex
tinct ancestors, and the yet older forms which
preceded them, led similar lives, is almost certain.
Indeed evidence is forthcoming which makes this
conclusion irresistible.

If, superficially, the changes which the environ-
ment has effected are not great, yet direct adapta-
tions to environment can be easily discovered.
Externally the most obvious are the webbed
feet, the bony armour, and the enormous tail,
which is used as a propeller ; and after these
the position of the eyes and nostrils. Internally
modifications of the skull and of the soft part of
the palate have taken place, which enable the

48 THE STORY OF REPTILE LIFE.

animal to drag its prey under water, and yet
save itself from drowning by the inrush of water
into the open mouth. In other words, it must
drown its prey without drowning itself. To do
this the hinder margin of the tongue is raised into
a transverse fold, which is met by a similar fold
hanging from the back of the roof of the mouth, and
known as the velum palatinum. When the edges
of these two folds meet, the mouth cavity is com-
pletely shut off from the throat, and consequently
from the entrance to the gullet and windpipe.

If we turn to the skull we shall find that besides
this peculiar modification of the soft parts of the
mouth, other and very considerable changes have
taken place in the form and arrangement of those
bones of the palate which are concerned in the
formation of the respiratory passages. As
result of these changes the creature is enabled to
lie submerged and open-mouthed, in wait for
his prey, the while breathing as freely as if on
land. To understand the nature and extent oi
this peculiar modification, a brief sketch of the
method of conveying the air to the windpipe
and lungs in reptiles, unmodified in this respect,
will be helpful. In them the nasal passages,
traced from the snout backwards, open into tho
roof of the mouth near the middle of the palate,
the air passing from thence to the aperture of the
windpipe at the back of the throat or pharynx^
Now in the Crocodiles these passages are con^
tinued backwards to the extreme hinder end of the
skull, so that the air is conveyed from the nasal
passages backwards directly into the pharynx,
which, as we have already seen, is, by a special

CROCODILES. 49

arrangement of folds produced by the tongue
and the velum palatinum, completely shut off
from the mouth. Thus, though the mouth may
be filled with water, the animal can breathe with
impunity, by simply thrusting the tip of the snout
above the water, which would not be possible if
the posterior apertures of the nostrils opened in
their usual place.

This peculiar arrangement, be it noted, is not
an institution of yesterday, but the result of a
slow series of changes, which took ages of geo-
logical time to accomplish. The remains of the
ancient Crocodiles of the Jurassic period show
that in them the change had already begun.
From thence onwards to the Cretaceous, the
completion of this important passage was slowly
pushed forwards to its final accomplishment.

The position of the external nostrils, to which
reference has been made, is obviously the result
of a more perfect adaptation to aquatic life. If
a living specimen be examined it will be noticed
that these apertures are seated at the extreme tip
of the snout, and directly raised above its surface.
They can be closed at will, so as to exclude the
water, when the animal is completely submerged,
whilst from their peculiar position they enable
the animal to breathe, so long as they can obtain
air, even while the rest of the body is below the
surface, and the mouth open, since the water
is excluded from the air passage at the back of
the throat by the mechanism just described.

The old Jurassic Crocodiles have revealed yet
other important facts which throw light upon the
course of the evolution of their descendants,
D

50 THE STORY OF REPTILE LIFE.

Perhaps the most important of these facts is that
which concerns the relative lengths of the fore
and hind limbs. In the fossil forms in question
the hind-limbs are conspicuously the longest ;
and this continues to hold good until Tertiary
times, since when the differences have greatly
diminished. From this we may gather that
among the earlier members of the family the
hind legs played a more important part in
swimming than now. Gradually, however, this
work became thrown upon the tail, and in pro-
portion as it took up the work of the legs the
latter diminished, according to the law of the
substitution of organs. That is to say, the tail
developed at the expense of the legs.

The fore-limb reveals a still more startling
piece of evidence concerning the past history of
the group. This time we glean our information
not from the remains of bygone days, but from the
developing embryo of living Crocodiles. Herein
we find that the small bones or phalanges of the
fourth or fifth fingers are more numerous than
in the adult. Thus, in the fourth finger we find
seven, and in the fifth finger six phalanges in place
of four. Before development is complete these
additional phalanges have disappeared. To the
initiated the discovery of these little temporary
bones threw a ray of light upon the gloom which
enshrouded the early origin of the Crocodiles,
using the word in its widest sense, and not merely
to include the former, which had lived from the
Jurassic onwards. They showed that the stock
from which this illustrious house derives its origin
was probably of more strictly aquatic habits than

CROCODILES. 51

was hitherto supposed. And for this reason*
Strictly aquatic animals, which use their limbs
in swimming, have commonly adopted the plan
of increasing the length of the hand and foot by
adding to the number of these little phalangeal
or finger bones, as witness the old Fish Lizards,
the Turtle, arid the Whales among the mammals.
The inference is, then, that the temporary pre-
sence of similar additional bones in the hand
of the developing Crocodile is a reminiscence of
an ancient swimming organ long since obsolete.
That it was never completely paddle-shaped, as
is the turtle or whale, we may be sure, inasmuch
as both these are too highly specialised ever to
be reduced again to the normal hand or foot from
which they were derived. That the inference
will some day be abundantly proved by the dis-
covery of some " new " fossil, we may predict
with tolerable safety.

Whether these long-handed ancestors were
really more aquatic in their habits, or simply
used the limbs more than the tail in swimming,
we cannot of course say. But we have positive
evidence to show that a very near ally of the
living Crocodiles actually did exchange the am-
phibious for a purely aquatic life.

The creature in question (Geosaurus suevicus)
has long been known from fragments obtained
from the Jurassic, but the intensely specialised
iharacter of the animal has only recently
(1892) come to light through the researches
of Dr Fraas, a German naturalist. He has
shown us that it resembles its contemporaries
of the Jurassic in that the hind-limbs are

52

THE STORY OF REPTILE LIFE.

longer than the fore. Here, however, resem-
blance, both to fossil and recent crocodiles ceases,
inasmuch as the lizard-like form is completely
transformed by adaptation to an exclusively
aquatic, and probably marine life. This adapta-
tion has produced a remarkable but superficial
likeness to its contemporary the Ichthyosaurus.
The fore-limbs were paddle-shaped, whilst the
hind-limbs were of considerable length, and ter-
minated in a broad, webbed foot. They probably

FIG. 6.— Outline Restoration of an extinct Crocodile specially adapted
for an exclusively marine life.

performed the work of locomotion, whilst the
tail, of great length, and terminating in a broad
fin, served as a rudder. The paddle-shaped fore-
limbs were probably used only as balancers.

That these limbs are the result of specialisation
for the purpose of swimming there can be no
doubt, and it is equally certain that this peculiar
transfiguration can only have taken place after
they had ceased to be used as supports for the
body on dry land. The development of the
paddle-shaped fore-limb has resulted in many
profound structural changes in which only the
four fingers have escaped. Thus the upper arm
bone, or humerus, lost its characteristic shape,

CROCODILES. 53

and became modified to form a broad, much-
compressed cylinder, whilst the fore-arm and
wrist are still more strikingly changed. In the
former, instead of a pair of moderately long
and stout rods, we find a pair of greatly ex-
panded plates ; whilst the latter, instead of being
made up of a series of small bones, is represented
only by one large and one small quadrangular
plate. The thumb has undergone the same
flattening process, the first joint or metacarpal
bone forming a broad semilinear plate instead of
a slender rod ; the second joint or first phalanx
being similarly modified, but in a less marked
degree. The four fingers have undergone little
or no change. During life the whole of this
limb was completely invested by the skin, like a
hand which is thrust into a fingerless glove.
The accompanying illustration will show at a
glance, not only what this transformed hand
looked like, but how great a change it has
undergone when compared with the limb of a
modern crocodile.

The hind-limb, though less profoundly changed,
is yet conspicuously modified. The thigh-bone
is relatively of enormous length, being as long
as the shank and foot combined. The latter has
retained only a vestige of the fifth toe, whilst
the bones of the first or great toe have, like the
thumb, become greatly flattened. They differ,
however, from those of the thumb in that their
length greatly exceeds their breadth. During
life this limb appears to have served the purpose
of a long oar.

The body of the Crocodiles, like that of other

54 THE STORY OF REPTILE LIFE.

Eeptiles, is completely invested in a covering of
horny scales ; and underlying these, in certain
parts of the body, is an armour-plating of bone.
The more important features of these scales, and
of the bony armour, we propose now to briefly
outline.

If these scales be carefully examined, there
will be found in the centre of each of those of
the sides, belly, and tail, and especially those of
the lower jaw, a little dot or pit. At this spot
the scale is soft, and at the bottom of the pit,
careful dissection would show the delicately
sensitive terminations of a nerve. On the lower
jaw instead of a pit we find little wart-like
prominences, also provided with sensory nerves.
Through these delicately constructed channels
the body is kept in touch with the outer world.

The bony armour is made up of a series of
closely interlocked square plates, each plate
corresponding in size to the horny scale above
it, and having a peculiar honey-combed appear-
ance on the outer surface. In the majority of
living Crocodiles this armour is confined to the
upper surface. A large cluster occurs in the
neck, and behind this follows a huge shield in-
vesting the whole of the back. Only in the
Caimans (p. 69) do we find similar bony plates
on the belly.

Why this armour was originally assumed, and
why it is still retained, we can only guess.
Probably it was developed as a protection against
collision with rock and tree-trunks in time of
flood. There seems some foundation for this view
inasmuch as the fossil species .Metriorhynchus

CROCODILES 55

and Dakosaurus were quite defenceless, and these
are known to have been marine forms, and there-
fore removed from dangers of this kind. Noto-
suchus of the Cretaceous was also defenceless, and
apparently a swamp-dweller. The one or two
species of armoured marine crocodiles must be
regarded as originally river crocodiles which had
not had time to lose their armour before extinc-
tion overtook them. A form known as Teleo-
saurus, of the Lower Oolite, had dorsal and
ventral armour.

Long descriptions of the internal organs would
be out of place here, but a few brief comments
on one or two which will serve to bring out the
differences between the Crocodiles and other
Reptiles should certainly be acceptable.

The organs of sense are well developed. The
eyes, in addition to an upper and lower eyelid,
are provided with a peculiar sheet of membrane
which can be drawn across the eyeball. This is
known as the nictitating membrane, and is ex-
ceedingly thin and transparent. Its movements
carry over the eye a watery fluid secreted by a
special gland, and thus its surface is kept con-
stantly moistened. When under water this cur-
tain is drawn over the eye as a protection, its
transparency being so great as to leave vision
unimpaired.

The position of the eyes and nostrils are
directly connected with the habits of the animal.
Both are placed on the top of the head, pro-
jecting considerably from the surface. This
arrangement allows the animal when in the
water to breathe and see at the same time whilst

56 THE STORY OF REPTILE LIFE.

the body is submerged. In this way prey can
be approached unsuspected.

The external ear, too, has been directly modi-
fied in accordance with the peculiar habits of the
animal. Its aperture lies in a deep recess over-
hung by a flap of skin provided with muscles,
which by their contraction close the aperture
and prevent the inrush of water. Like the eyes
and nostrils, the aperture of the ear is on the
surface of the skull, so that hearing as well as
sight and smell is possible when the animal is
submerged.

The tongue is large, and fixed to the floor of
the mouth, so that it can be raised, but not pro-
truded as in lizards. Its surface is covered with
numerous tiny wart-like processes, which form
the centres of touch and taste. The peculiar
fleshy fold which runs across the back of the
tongue, and the part it plays in the breathing of
the creature when in the water, we have already
described (p. 48).

The lungs have attained a high degree of per-
fection, and resemble those of birds. They differ,
however, both from those of the birds and those
of the tortoises in that, instead of being attached
to the roof of the chest cavity, they are quite
free.

The stomach and heart demand a passing
notice, inasmuch as both these organs are more
highly developed than in other reptiles.

The stomach seems peculiarly small, when we
remember that these huge creatures can swallow
very large animals, man himself sometimes fall-
ing a victim. Large prey is, however, not

CROCODILES. 57

swallowed whole, but torn to pieces by the
powerful jaws and teeth, aided by violent and
sudden wrenches of the body from side to side.
Thus, in a very short space of time the carcase
is broken up and swallowed piecemeal. Having
regard to the carnivorous diet, the structure of
the stomach is peculiar, inasmuch as its walls are
thick and fleshy as is the gizzard of a grain-
eating bird, which it furthermore resembles in
that the inner walls of this gizzard are hardened.
This stomach, however, differs from that of birds
in that of the two compartments, of which it is
composed, the first forms the gizzard-like portion,
whilst the second and much smaller has glandular
walls secreting digestive fluids. In birds the

flandular lies in front of the muscular portion,
a flesh-eating birds the walls of the stomach
are thin, and one would have expected to find
the same conditions obtain in the case of the
Crocodile. If the stomach is small, the capacity
of the gullet is considerable, and it is in this
ante-chamber to dissolution that the prey is
stored, being gradually thrust backwards as
digestion proceeds.

The heart differs from that of all other Reptiles,
and agrees with that of the higher animals —
birds and mammals — in that it is divided into
four chambers, though the separation of the
arterial and venous blood is not as complete as
in the bird or mammal.

Finally, we may remark that the Crocodiles
differ from all other Eeptiles, as well as from the
Birds, in that the chest containing the heart and
lungs is, as in the mammals, shut off from the

58 THE STORY OF REPTILE LIFE.

abdominal cavity containing the rest of the
viscera by a muscular partition : though this, it
is to be remembered, is of a different origin
from the mammalian partition known as the
diaphragm.

The more perfect condition of the lungs and
heart, and the separation of the chest from the
abdominal cavity are points of exceeding interest,
foreshadowing the still more perfect conditions
of the organs in the more highly organised
birds and mammals, which at the time when
the earliest Crocodiles flourished had not yet
made their appearance on the earth.

So far, perhaps, it may be objected, this
chapter has savoured more of the museum and
dissecting room than of living Crocodiles.
Although this is, in a measure, true, yet it is
contended that the facts which we have been
discussing are just those which will enable us to
appreciate the more fully the various phases
which make up the life-history of these animals.
In studying these creatures in their wild state,
or even in Zoological Gardens, these somewhat
technical details fall into their proper places,
and losing whatever appearance of pedantry
which paraded by themselves they may appear
to possess, will be regarded as so many keys
unlocking as many separate mysteries, and
thereby giving us an insight into the great
mystery of all — how the Crocodile came to be.

To see the Crocodile — using this term in a
wide sense to include all living species of the
group — in a wild state we must travel beyond
the confines of Europe, though earlier in the

CROCODILES. 59

world's history they occurred here. Indeed, re-
mains of several kinds of Crocodiles, long since
extinct, occur in different geological formations
of the British Islands, finally becoming extinct
during Tertiary times. To-day, we meet with
these Eeptiles only in the tropical and sub-
tropical regions of America, Africa, Asia, and
Australia.

To the observer watching these animals for the
first time, whether at large or in captivity, the
first thing probably to attract his attention
would be their remarkable resemblance to a log
of wood, a resemblance heightened by their
absolute stillness. This likeness is obviously
advantageous to the Crocodile, especially when
lying in wait for prey in the water. Thereby
they pass for what they seem to animals coming
to drink, which in consequence approach unsus-
pecting to quench their thirst, and are then
seized by the nose, dragged down into the water,
and held there till drowned. Once the jaws
have closed on a victim they rarely lose their
grip. Man himself does not escape. In India
a long roll of victims has to be recorded every
year, and these are chiefly women who come to
the river for water or to wash clothes therein.
Men have been known to regain their freedom
from this terrible foe by digging their fingers
into the creature's eyes. The opportunity to do
this, however, but seldom occurs, and probably
even then may lose it in their terror. Strangely
enough, in some places, though Crocodiles swarm,
man is never attacked. Possibly because other
prey is plentiful.

60 THE STORY OF REPTILE LIFE.

Swamps and pools, and the banks of rivers
.are the common haunts of Crocodiles, though
some frequent estuaries, and from thence stray
far out to sea.

How these creatures have slowly adapted
themselves to their environment we have already
seen. We may therefore now pass on to de-
scribe the different types of Crocodiles, and the
characteristic features and habits of some of the
more important species.

Whether the Crocodiles of to-day should be
regarded as representing but a single group, or
divided into two separate families, is a moot
point with naturalists. Those who hold the
latter view consider the Gharial of the rivers of
western India and Arakan, and the False Gharial
of Malaysia as representatives of a distinct
family, the direct descendants of the long-
snouted crocodiles of the Cretaceous, whilst the
Alligators, Caimans and Crocodiles they regard
as descendants of a short-snouted type of the
older Jurassic period.

The Gharial and False Gharial are to be
distinguished externally by the length of the
snout and slenderness of the teeth. There are
besides certain distinguishing features to be
found in the skeleton, but into these we need
not enter.

But little is known of the habits of the Gharial
although in its native rivers it is common enough.
The remarkably long snout of the species, and
the peculiar slenderness of the teeth are pro-
bably adaptations to facilitate the capture of its
prey, which appear to consist almost entirely of

CROCODILES. 61

fish. It is interesting to note in this connection,,
that the Gangetic dolphin (one of the mammalia),
which lives in the same rivers, has a similarly
elongated snout and teeth of the same slender
type. As this creature is also a fish-eater, the
elongated beak is probably also the result of
adaptation to the same end. A full grown
Gharial may attain a length of twenty feet or
even more, though this length is far exceeded
by a closely allied species — Rhamphosuchius cros-
sidem — long since extinct, which attained a length
of fifty feet. The tip of the snout in the Gharial
is greatly expanded, and in the male this ex-
panded portion is surmounted by a hollow hump
on the top of which the nostrils are placed
Apparently this hump comes within the category
of sexual ornaments, for when the nostrils are
closed it can be inflated like a bag. Feeding
only on fish, this species rarely attacks man,
and it is probably on this account that it is.
held sacred by the Hindus in many parts of
India. Cases are on record, however, which
show that large individuals, at least, will occasion
ally select human victims ; but such instances,
appear to be rare.

Crocodiles may be distinguished from Alligators-
by the fact that, in the former the fourth tooth
of the lower jaw fits into a notch in the upper
jaw ; whilst in the Alligators this tooth fits into-
a pit instead. In very old Alligators this tooth
often perforates the bone and is visible on the
surface of the upper jaw.

The geographical range of the true Crocodiles,
is extremely wide, since they are found in Africa,

62 THE STORY OF REPTILE LIFE.

S. Asia, Malaysia, Australia, and America. Three
groups may be distinguished according to the
shape of the head. In the first the head is
long and narrow, recalling that of the Gharials ;
the second is intermediate in type between the
first and third, which last has the muzzle very
short and broad like that of the alligator, from
which, however, it may readily be distinguished
by the peculiar notch in the upper jaw for the
reception of the fourth tooth.

One of the best-known of the Crocodiles is the
Marsh Crocodile (Crocodilus palustis\ known in
India as the " Mugger." This species inhabits
the rivers and marshes of India and Ceylon,
extending eastwards through Burma and Malacca
into the Malay archipelago.

In India it is held in veneration by the
Hindus, and is kept in a state of semi-
domestication, attended by fakirs. Mr A. L.
Adams has given a graphic account in his
"Wanderings of a Naturalist in India," of a
visit to a celebrated crocodile pond or " mugger-
peer " at Karachi. This pond, some three hun-
dred yards in circumference, and studded with
small islands, was the home of hundreds of these
scaly creatures of all sizes and ages. Visitors
being expected by the fakirs who have charge
of this pond and its inmates to pay for their
entertainment by providing a feast for the scaly
monsters, Mr Adams had a goat slaughtered,
"during which operation," he says, "the brutes
seemed to rouse themselves as if preparing for
a, rush. Then our guide, taking piece after piece
of the flesh, dashed it on the bank, uttering a

CROCODILES. 63

low, growling sound, at which the whole tank
became in motion, and Crocodiles, of whose
existence we had been before ignorant, splashed
through the shallow water, struggling which
would seize the prize." The largest of these
crocodiles, said to be over two hundred years
old, lived by himself in a long narrow tank.
By way of further distinction the fakirs had
painted his forehead red ; and they and the
natives who worship in the neighbouring temples
showed him great veneration, making a salaam
whenever he showed himself above water.

According to Sir J. Emerson Tennent, the
Marsh Crocodile is an arrant coward, hastening
to conceal himself on the approach of man. On
one occasion one of these Crocodiles which was
overtaken in the jungle by a gentleman on
horse-back, fled to the nearest shallow pool,
and thrusting its head into the mud till it
covered up its eyes, "remained motionless, in
profound confidence of perfect concealment/'
The same habit of covering the eyes and leav-
ing the body exposed, it will be remembered,
is also a characteristic of the ostrich, thereby
bringing upon itself much ridicule. As a matter
of fact, however, this habit of hiding the head
is not so foolish as it appears. The bodies of
these and many other creatures which also adopt
this habit, harmonize so perfectly with their
surroundings that, but for the brightness of
the eyes, they would often pass undiscovered.
By hiding the head, not only are the eyes
effectually concealed, but the outline of the
body is most effectually disguised, inasmuch as

64 THE STORY OF REPTILE LIFE.

it harmonizes the more completely with its sur-
roundings. It is quite possible that the narrator
of this episode may have passed several crocodiles
thus concealed, they having had warning of his
approach before he discovered them.

That a crocodile should be susceptible to
tickling seems hardly likely. Yet this is a
fact. Sir Emerson Tennent gives an instance
which came under his own observation. " One
morning . . . we came suddenly upon a croco-
dile asleep under some bushes . . . several
hundred yards from the water. The terror of
the poor wretch was extreme when it awoke
and found itself surrounded. ... It started to
its feet and turned round in a circle, hissing
and clanking its bony jaws, with its ugly green
eyes fixed upon us. On being struck with a
stick, it lay perfectly quiet and apparently dead.
Presently it looked cunningly round and made
a rush towards the water, but on a second blow
it lay again motionless and feigning death. We
tried to rouse it, but without effect . . . nothing-
would induce it to move till, accidentally, my
son, then a boy of twelve years old, tickled it
gently under the arm, and in an instant it drew
the limb close to its side, and turned to avoid
a repetition of the experiment. Again it was
touched under the other arm, and the same
emotion was exhibited, the great monster twist-
ing about like an infant to avoid being tickled."

During times of great drought, they, like the
African mud-fish Protopterus, bury themselves
in the mud and remain in a state of torpor till
released by the return of the rains. Occasion-

CROCODILES. 65

ally, however, instead of burying themselves,
they appear to migrate in a body in search of
water, numbers falling by the way, either by
accident, or at the hands of natives whom they
encounter.

The largest and most formidable of all the
crocodiles is the Estuarine Crocodile (Crocodilus
porosus). It resembles in general appearance
the foregoing species, but may be distinguished
therefrom by the more elongate snout. Further-
more, it differs from the Indian Marsh Crocodile
and from all other species, by the presence of
a long ridge running forward from each eye
towards the snout. Specimens of over twenty
feet are fairly common, and one instance is on
record of a specimen which had attained the
enormous length of thirty -three feet. Frequent-
ing the tidal portions of rivers, it is not surprising
to find that this species frequently descends to
the sea. This fact accounts for its wide geo-
graphical distribution, which extends from the
Gulf of Bengal to Southern China, across the
Malay Peninsula to Australia. Its ferocity
makes it at once detested and feared. In India
the natives of Dacca, at the mouth of the Bay
of Bengal, make the hunting of this beast a
profession. An account of one of these hunts,
published in a native paper, tells how a boy
was carried off by a man-eater of this species.
The hunter having been summoned, he moored
his canoe near the scene of the tragedy, knowing
that having recently made a successful raid the
brute would hover near the spot in the hope of
obtaining fresh victims. In a short time the
E

66 THE STORY OF REPTILE LIFE.

quarry was descried, when the hunter, and h.'s
assistant, hid themselves in the canoe whilst
the hunter's son, a boy, entered the water and
commenced to splash about. At once the croco-
dile made for him, but the boy quickly beat
a retreat, and the monster coming up at the
exact spot where his intended victim had been,
was struck by a couple of harpoons. After a
long chase, the wounded crocodile was at last
secured and despatched with an axe. When
opened the stomach was found to contain several
gold and silver ornaments — gruesome relics of
former victims.

Perhaps one of the best-known species is the
Crocodile of the Nile (Crocodilus niloticus). It
is only slightly inferior in size to the Indian
Crocodile just described, and is nearly as danger-
ous. The steamboat and the modern rifle have
practically effected the extinction of this species
in Egypt, though in the upper reaches of the
Nile it is still abundant, and still exists in
Palestine. From thence it extends southwards
to the Cape, and northwards to Senegal. It
also occurs in some numbers in Madagascar.
Like others of its tribe this species has a habit
of lying half-asleep on sand-banks, with its
mouth wide open. At such times, the Nile
Crocodile invites, or at least permits, the en-
trance between his huge jaws of numbers of
Egyptian Plovers (Plumanus cegyptius\ who fear-
lessly enter this formidable cavern for the pur-
pose of clearing the mouth of insects which may
have intruded, attracted by the moisture of the
tongue.

CROCODILES. 67

The boldness and ferocity of this species is
well illustrated by the account narrated by a
correspondent of the Times, of an incident
which occurred during a journey to Mashona-
land. One evening while crossing the Tokui
River on horseback a man named Williams was
seized by the leg by a crocodile and dragged
from his horse into the stream. He was, how-
ever, immediately released and succeeded in
swimming to a small island. But a comrade
who rode in to his assistance fared almost as-
badly, for another crocodile sprang up between
him and his horse's neck, then slipped back, and
in doing so, made with its claws a dreadful
wound in his side, and in the horse's neck.
Williams ultimately died of his wounds. It is
said, indeed, that more people are killed by
crocodiles than by any other of the wild beasts
of Africa.

In Madagascar this crocodile digs long sub-
terranean passages of from thirty to forty feet
in length, the passage opening below the level
of the water, and rising gently terminates in
a chamber large enough to allow of the creature
to turn its huge body round. To admit air, the
roof of this chamber is pierced by numerous
holes. Into these lairs the crocodile retires to
devour his prey, or to escape danger. In this
last endeavour, however, they often fail, for
natives, guided by the air-holes, dig them out
from above.

Known as Ohampsa by the ancient Egyptians,
this crocodile was held by them in great rever-
ence, numbers being kept and tended with the

68 THE STORY OF REPTILE LIFE.

greatest care by the priests. They bedecked
these hideous creatures with ornaments, hanging
rings and precious stones from the fleshy flap
protecting the ears, and encircling the fore-feet
with bracelets. Thus adorned they were pre-
sented to the people for veneration. A crocodile
among these ancient people, was one of the symbols
of Typhon, the brother of Osiris, who was con-
sidered the author of all evil. One of these
deities was a man with a crocodile head, named
Sarek. When these creatures died, their bodies
were embalmed, and hundreds of these mummi-
fied bodies exist till to-day. Embryos, as well
as adults, seem to have shared this distinc-
tion.

One other crocodile must find mention here.
This is the Long-snouted Crocodile (C. cata-
phmctus) of W. Africa. In the peculiar length
and slenderness of its snout this species closely
resembles the Grharials. It is interesting to note
that it preys on fish, frogs, aquatic reptiles, and
wading birds, which it approaches by stealth.
Shy and timid in its habits, this species is pro-
secuted by the natives for the sake of its flesh,
which, in spite of its musky flavour, is much
esteemed. This appreciation for crocodile flesh
is widespread ; the natives of other regions where
crocodiles of some sort or another abound, are
equally fond of it. This species is abundant in
the fresh water of the interior, and thrives in the
salt-water lagoons of the Guinea Coast ; and in
the delta of the Camerons it may be seen lying
on the sandbanks bordering the mangrove
swamps, from which it darts with amazing

CROCODILES. 69

celerity on the slightest alarm. A fully adult
example measures about eighteen feet.

The slenclerness of the jaws seem, as in the
Gharial, to be correlated with the feeding habits.
Neither the one nor the other appears, except
rarely, to attack large prey. This seems to
support the view that the short-snouted forms
have acquired this characteristic by adaptation to
the requirements for the capture of powerful
prey, such as the large mammalia.

With the Caimans and Alligators we may close
this chapter. Closely allied, they are to be
distinguished from the Crocodiles by the fact
that the fourth lower tooth is received into a
socket in the upper jaw instead of a notch.

Alligators appear to have been common in
Europe in past ages, for their remains occur in
the pluviatile deposits of the Upper Chalk, and
they survived until the Pliocene age. Possibly
their extinction was due to climatic changes,
for at this time the tropical types of vegetation
seem to have begun their retreat southwards in
the European regions, and this may have been
followed by a similar retreat on the part of the
animals dependent thereon. At the present day
but two species of Alligators are known. One of
these, strangely enough, occurs in the rivers of
China, the other in the Southern States of North
America.

The American species (Alligator mississippiensis)
seems to have fallen on evil days. They are being
slain by the thousand for the sake of their hide ;
and settlers wage unrelenting war on them for the
ravages they make upon their pigs. As a con-

70 THE STORY OF REPTILE LIFE.

sequence of this persecution, it is interesting to
note that as their numbers diminish in Florida
the Mocassin snakes increase ; whilst in Louisiana,
where they are also rapidly decreasing, the musk-
rats are at the same time increasing and doing
much damage by their burrowing.

In the spring and early summer months, and
more especially during cloudy days or in the
evening, alligators make much noise, croaking
like a bull-frog, but louder. On the approach
of winter they retire to holes in the ground, and,
passing into a state of torpor, remain till awak-
ened by the spring. TV'hilst in this state of
helplessness they are eagerly sought for and
disinterred by negroes who esteem the tail a
great delicacy.

The Caimans number five species, and are
distinguished from the Alligators, among other
things, by the armour-plating of scutes along the
under surface of the body.

The traveller-naturalist Bates found the
Caimans in myriads in the waters of the Upper
Amazon. " It is scarcely exaggerating/' writes
Bates, " to say that the waters of the Tolimoens
are as well stocked with large alligators in the
dry season as a ditch in England is in summer
with tadpoles."

Caimans never attack man when on his guard,
I)ut they seem to know when this may be done
with impunity. Bates gives several instances in
support of this view. While staying at Caicara
a large trading canoe arrived, manned by an
Indian crew. These fellows, during the first two
days after their arrival, spent the time, as was

CROCODILES. 71

their custom, in drunkenness and debauchery
ashore. Whilst in this muddled condition, one
of them during the hottest part of the day took it
into his head to go alone to the river to bathe.
" He was seen only by the Juiz de Paz, a feeble
old man who was lying in his hammock, in the
open verandah at the rear of his house, on the
top of the bank, and who shouted to the besotted
Indian to beware of the alligator. Before he
could repeat his warning the man stumbled, and
a pair of gaping jaws, appearing suddenly above
the surface, seized him round the waist and drew
him under water. A cry of agony, ' Ai Jesus '
was the last sign made by the wretched victim.
The village was aroused : the young men . . .
seized their harpoons and hurried down to the
bank, but of course it was too late ; a winding
track of blood on the surface of the water was all
that could be seen. They embarked, however,
in montarias, determined on vengeance ; the
monster was traced, and when, after a short
lapse of time, he came up to breathe — -one leg of
the man sticking out from his jaws — was
despatched with bitter curses." On another
occasion a boy, whilst bathing, wa£ seized by
the thigh and carried under water : a cry
was raised which reached the lad's father, who,
rushing down to the bank, plunged in after
the monster and its victim. "It seems," says
Bates, " almost incredible that a man could over-
take and master the large Caiman in his own
element ; but such was the case in this instance,
for the animal was reached and forced to release
his booty by the man's thrusting his thumb into

72 THE STORY OF REPTILE LIFE.

his eye. The lad showed us the marks of the
alligator's teeth in his thigh."

CHAPTEE IV

GECKOS, LIZARDS, AND CHAMELEONS

THE creatures which form the subject of the
present chapter are those which, with the Snakes
to be considered presently, make up the sub-
class Squamata. This sub-class is divided into
two orders — Lacertilia or Lizards in a wide
sense, and Ophidia, or Snakes. The Lacertilia
are again divided into three sub-orders — Geckos,
Lizards proper, and Chamseleons. The total
number of species comprising these sub-orders
amounts to more than 1800.

The exact origin of the forms which belong
to this sub-class is unknown, but they are pro-
bably descendants of the ancient group to which we
have already referred, and of which the remark-
able Tuatera Lizard is the sole representative. No
fossils are known which carry us beyond the
Juranic. Attaining their greatest develop-
ment within the Tertiary period, they appear,
says Dr Gadow, " to have a future before them,
being apparently still on the increase in number
and species, but certainly not in size."

Their manifold variety in shape, size, and
structure give them a quite peculiar interest,
inasmuch as their several variations are generally
directly traceable to adaptation to their environ-

GECKOS, LIZARDS, AND CHAMELEONS. 73

ment. Between the typical lizard and the
crocodile there is an undoubtedly superficial
resemblance, so much so that the former is often
described as crocodile-like, whilst the latter is as
often referred to as lizard-like. The likeness,
however, is purely superficial, and confined to
the general contour of the body.

Any one who will take the trouble to compare
the skeletons of the two groups, or the organs of
circulation or respiration, for example, will see
at once how widely they are separated. Conse-
quently, no further comparison between the two
need be made here. If, however, the differences
which distinguish the Lizards from the Crocodiles
are many and wide, this is by no means the case
between the Lizards and the Snakes, inasmuch as
many Lizards have come to assume a snake-like
form through the loss of their limbs, concerning
which loss we shall have much to say later on in
this chapter. Nevertheless, a little discrimination
will enable even the uninitiated to tell the limb-
less lizard from the snake. In the first place, the
two halves of the lower jaw in the lizard will be
found to be closely united, and the ear is usually
visible externally. In the snake the two halves
of the lower jaw are connected only by a liga-
ment, and there is no external aperture to the
ear. Furthermore, the lizards, with few excep-
tions, have movable eyelids, the snakes never.

As a rule, the body of the lizard is covered
with overlapping scales, but in some forms these
become reduced to mere tubercles, whilst in
others they are underlain by bony scutes recalling
those on the back of the crocodiles. These scales

74 THE STORY OF REPTILE LIFE.

are shed periodically, generally in the form of
large flakes, but in certain instances they are
cast off in one piece, e.g. the Slow-worm (Anguis).
Skin-glands, as in the birds, are conspicuous by
their absence. The nearest approach to these
organs are certain pores in the anal and femoral
regions. Each of these pores perforates a scale,
and leads into a tubular invagination, or infolding,
which is lined with what are known as epidermal
cells, the breaking up of which produces a
yellowish debris, and by filling up the tube,
eventually appears at the surface in the shape of
.a little cone. Their use is unknown.

The teeth present some interesting variations
in the nature of their attachment to the jaws.
Thus in some forms they become immovably
fixed, or ankylosed, by their bases with the
inside of the jaw, when the dentition is said to
pleurodent; in others, they are as firmly fixed
to the cutting edges of the jaws, forming then
an acrodent dentition. When the teeth are
lodged in sockets, as happens in the Crocodiles,
the dentition is described as thecodent.

Most Lizards, like the Tuatera, are remarkable
for their ability to part company with their tails
.at a moment's notice. When threatened, this
organ, in many species, is temptingly raised as
if to invite or perhaps challenge the enemy to
seize it. If this be done it immediately breaks
off, leaving its owner to make good his escape
before his would-be captor has had time to
recover from his surprise. But these tail-less
lizards have no need to adopt the stratagem of
the fox in the fable, to persuade their fellows to

GECKOS, LIZARDS, AND CHAMELEONS 75

undergo a similar amputation, for in a very short
time a new tail is developed. This, however, is
never so perfectly developed as the original
organ. In the first place, distinct vertebrae are
replaced by a simple fibrous rod ; and in the
second, the scales clothing the outer surface are
rarely of the same regular arrangement as those
of the stump or of the last portion. Sometimes,
however, the more primitive ancestral arrange-
ment of scales is reverted to, at others the
arrangement is true to type, as in the Common
Lizard and Slow-worm, for example. It is
interesting to remark that though the bony
skeleton of the regenerated organ is not replaced,
the muscles of the new growth do not differ
greatly from those of the old stump. The tail
of the "Monitor" Lizards (Faranus) differs from
that of their allies in that, instead of being fragile
and easily detachable, it is, on the contrary, of
unusual strength. Of great length and slender-
ness, it appears to be used as a whip, inflicting
blows of considerable severity.

Another peculiarity of the Lizard-tribe is the
possession of what are known as "fat bodies."
These are organs of unknown function, found in
both sexes, extending from the inguinal region
forwards along the belly immediately beneath
the skin. They are largest during the spring-
time, and consist of a mass of connective tissue
permeated with fat, which gives them a yellowish-
white colour. Later in the year they become
greatly reduced in size, forming grey or reddish
flaps richly supplied with blood-vessels.

In the great number of the species, and their

76 THE STORY OF REPTILE LIFE.

extremely specialised condition, the Lizards
among Reptiles occupy the place of the Passeres
among Birds.

Of the senses the best developed is sight, and
after this hearing. The majority of species are
carnivorous, the larger kinds feeding on small
mammals, birds, and the members of their own
tribe ; the smaller kinds mainly upon insects,
worms, and so forth : a few are exclusively herbi-
vorous. Some species of lizards never drink,
others do so by lapping movements of the tongue,
which varies greatly both in its length, shape,
and power of movement.

Lizards are found over the whole globe, save
only polar and sub-polar regions. They may be
found in the most arid deserts, as well as the
most fertile spots, and extend their range verti-
cally to the regions of perpetual snow. But
whilst the colder regions afford little more than
a bare existence, the tropics and sub-tropical
regions produce food in abundance. Consequently
it is here that the greatest wealth in point of
numbers, size, shape, and coloration is met
with. These are the regions wherein the group
has attained its maximum development. Escape
from the extremes of climate appears to be
necessary in all cases, since in tropical climates,
during the hottest months of the year, when
drought prevails, the bulk of the species fall into
a state of torpor; whilst in the colder regions
the species hybernate, remaining dormant for
many months.

The evolution of the Lizard tribe has been
marked, as we have already hinted, by a very

GECKOS, LIZARDS, AND CHAMELEONS. 77

conspicuous diversity in the matter of adapta-
tion to environment, and for the capture of
food. Adaptations which are expressed in
structural modifications, sometimes of a very
profound character. In all this they differ
conspicuously from the Crocodiles and Tortoises,
which are peculiar, rather on account of the
uniformity they display in their organisation.

In the matter of the capture of food a few
examples will suffice. In the case of Lizards
which feed upon living animals the prey is
seized, generally, by a snapping motion of the
jaws, and passed whole down the throat, nob
torn in pieces, as with the Crocodiles. Adapta-
tions indeed for tearing prey are conspicuous
by their absence. Some of the former, however,
seize their victims by a lightning thrust of the
tongue, and among these the Chamseleons come
easily first. In these creatures the tongue
attains a great length. Covered with a sticky
secretion, this organ is expelled with a dart-
like motion and unerring accuracy, so that a
fly can be taken at a distance of five or six
inches from the tip of the creature's snout.
Only in two species of lizards belonging to
the genus Heloderma is the prey killed by
poison. This is injected, as in the case of
Snakes, by means of grooved teeth, which
convey the deadly secretion from the large
glands in which it is formed, but whilst in
the snakes the poison is transmitted through
certain teeth in the upper jaw, in these lizards
it is conveyed through certain teeth in the
lower jaw. The herbivorous lizards of the

78 THE STORY OF REPTILE LIKE.

genus Iguana have the edges of the teeth
finely serrated, in which particular they bear
a close resemblance to the teeth of the Giant
Dinosaurs, which has been named on this account
Iguanodons.

In the curious Galapagos lizards, Conolophus
and Amblr/rhynchuS) the teeth are trilobate in
form, a character apparently directly connected
with the creature's herbivorous diet.

When the tongue is ndt used for the capture
of food, it appears either to become degenerate,
or to become modified into an organ of touch,
forked at the top, very sensitive, and capable of
being protruded or withdrawn with great rapidity.

With this brief survey we must pass on to
consider the peculiar characteristics of the in-
dividual groups which form the subject of the
chapter, and the part they play in the economy
of nature.

One of the oldest groups of the Lizard tribe is
that represented by the Geckos. Of almost world-
wide distribution, and numbering nearly 300 dis-
tinct species, considerable differences in habitat,
as might have been expected, are met with. Many
have become peculiarly modified to enable them
to climb, and these are the most generally known
forms. Their strange shape and weird move-
ments have long attracted the attention of man-
kind, among whom they, have, in many cases,
engendered feelings of dread and animosity, which
are totally undeserved. They are believed in some
countries to be capable of emitting venom from
their toes, and poisoning whatsoever they crawl
over, whilst one species at least is credited with

GECKOS, LIZARDS, AND CHAMELEONS 79

the power of indenting steel with the teeth ! In
Egypt so intense is the dread in which the lobe-
footed species is held, that it is known as the
"father of leprosy."

The Geckos are plump in shape, mostly
sombrely coloured, and flat-headed. The skin is
mostly covered with small granular tubercles,
but regularly arranged scales are rarely present,,
save in the under-surface. Two genera, however,
have the upper surface of the body also invested
in scales, and both these are desert-dwelling
types. The skin is shed in flakes and eaten.
The eyes are remarkable in that they are
not protected by movable eyelids, but by a
transparent shield, of the shape of a watch-
glass, which is generally regarded as a modified
nictitating membrane. Behind this the eye
moves freely. The eyelids are reduced to
fringes encircling this peculiar cover. This
" window " appears to be kept clean by the
tongue, which can be protruded for some con-
siderable distance. In response to the more or
less nocturnal habits of the creature the pupil of
the eye contracts into a vertical slit, as in the
eyes of cats, for example.

The tail presents many variations of form.
Generally cylindrical, and tapering to a point,
it is in some forms leaf -like, as in the fimbriated
Gecko ( Uroplates-fimbriatus) for example ; or pro-
vided with lobes, as in the Fringed-Gecko
(Ptychozoum homalocephalum) • but in many desert
forms the tail is long, slender, and laterally com-
pressed. In some species it is more or less
prehensile.

80 THE STORY OF REPTILE LIFE.

One of the most remarkable features of this
sub-family is the peculiar modification which the
foot of the climbing species has undergone.
Herein the under-surface of the toes has de-
veloped a series of plates, which serve as
adhesive pads, wherewith the animal is en-
abled to climb, not only trees, and the
smooth faces of rocks, but even the polished
vertical surface of a window-pane ; or, stranger
still, to run along the ceiling with the ease
and security of a fly. The pressure of the
foot causes the plates to spread out, and
driving out the air between the plates, to form
a vacuum. Long claws, more or less perfectly
retractile, complete the armament of this re-
markable organ. Dr Gadow remarks, anent the
wonderful climbing powers of these creatures :
"Those which take up their abode inside a
house become almost domesticated. They are
strange sights when hunting for flies running
up and down the papered walls ; but we fairly
gasp when they come to the upper corner,
calmly bend over, and with the next jerk
slide along the whitewashed ceiling. We are
accustomed to flies performing such feats, but
at animals five inches long, supple and fat, we
are inclined to draw the line. However, that
is the way of the Geckos, and — be it confessed
— the more we ponder over the mechanism of
their fingers and toes, the less we comprehend
how such little vacua can support or suspend
such heavy creatures from a dry and often
porous surface."

Yet another remarkable feature of the climbing

GECKOS, LIZARDS, AND CHAMELEONS 81

Geckos is the extraordinary development of that
portion of the inner ear, known as the endolym-
phatie sac. In all animals this is concerned with
the work of keeping the body informed of its
position by the movement of certain hard bodies
suspended in fluid, over delicate nerve-endings.
In the Geckos in question this sac leaves the head,
and becomes stowed away in the shape of a large
pair of bags behind the ear, or on the sides of
the neck.

Nearly all the Geckos appear to possess a
voice, which in some species resembles the
word " Gecko " — hence the name by which these
creatures are known. A South African desert
species is said to congregate at times in such
numbeus, and to produce such a din, as to
make existence in the neighbourhood intoler-
able. The males are larger than the females.

The smaller Geckos feed chiefly on insects,
but the larger forms will take anything that
they can manage to overpower; the smaller
species of lizards, mice, young rats, and even bats,
having been recorded among their victims.

Of the climbing species the most remarkable
are the Fringed and Fimbriated Geckos. The
former, Ptychozoum homalocephalum, a native of
the Malay Islands and Archipelago, has developed
curious membranous expansions of skin which
extend down each side of the body, limbs, and
tail. By their means the animal is said to be
enabled to take flying leaps, the membranes
acting as a parachute.

It does not seem to be definitely known that
this interpretation of the use of these folds is
F

82 THE STORY OF REPTILE LIFE.

correct. More probably they are only part of a
general protective disguise, the folds being applied
to the surface of the trees so as to effectually
blend the body with its surroundings, and thus
bring about invisibility. The plausibility of this
view will impress every one who has had an oppor-
tunity of watching the Fimbriated Gecko (Uro-
vlates fimbrialus) now living (1903) in the Gardens
of the Zoological Society in London. The remark-
able way in which this extraordinary creature
harmonises with the branch on which it rests, is
one of the first things that rivets the attention.
This harmony is partly due to the coloration of
the animal, which is of a dark grey, almost black,
but relieved by large, irregular blotches of lichen
colour; and partly to the presence of a short
ragged fringe which extends along on each side
of the body as far as the base of the tail, where
it is replaced by broad lobes. When the animal
is at rest the body is pressed flat against the
bough, so that the fringe along the flanks, and
the lobes of the tail completely obscure the
general outline. To make the disguise more
complete the hind legs are placed in what one
might be pardoned for calling an unnatural
position. Thus the right leg will be directed
forwards, the left stretched backwards in a
straight line parallel with the tail. Even in
confinement, exposed in a glass case with pur-
posely unsuitable background, and within a foot
of the observer, this creature is almost invisible.
Indeed, but for its remarkable eye, it is probable
that its presence would be discovered only by
the merest accident. This, the most conspicuous

GECKOS, LIZARDS, AND CHAMELEONS. 83-

feature of the body, is large, of a bright golden
colour, relieved by curious crescentic lines of
bright chestnut, ranged on either side of the
pupil, which is vertical — possibly in accordance
with nocturnal habits. The horns of the crescents
are directed inwards, and the crescents them-
selves are three or four in number, one lying
within the other, by fine semilunar bars of red.
It is known to the natives by a name which
signifies "the beast that leaps at the chest,"
and they believe that if any one approaches the
tree on which one of these curious creatures is
lying it will leap out on to his chest, and cling
there so firmly that it can only be removed by
shaving away the skin !

In these two species we have the highest point
of specialisation for an arboreal life which has
been attained in the group.

Let us now turn to the modifications which
have taken place through adaptation to a
desert-dwelling habitat. The best instance is
that furnished by the Persian Seratosdncus
scincus, a denizen of the desert. The digits,
in place of the adhesive lamella, have their
under surface granular, and fringed with
lamellae, resembling those which form the ad-
hesive disc of climbing species. In this desert
form the lamellae serve for running over loose
sand. Furthermore, the body differs from
that of climbing species in that it is clothed
with scales. On the upper surface of the tail
these scales give place to large nail-like plates.
Their use is remarkable, inasmuch as they can be
rubbed one upon another to produce a shrill

84 THE STORY OF REPTILE LIFE.

cricket-like noise, intended apparently as a decoy
for grasshoppers, on which the wily performers
largely feed. Stridulating organs of this kind
are rare among vertebrates.

From the Geckos we must pass now to the
Lizards proper, which in numbers surpass all
other orders of Reptiles, since, up to the present
time, more than 1500 distinct species have been
described. The general form of the body we
have already indicated (p. 79), consequently
we are free to proceed to discuss the various
modifications which have taken place therein as
a result of the struggle for existence. These
take the form of adaptations to various and often
widely different modes of life. In this connection
it is a point of some significance and extreme
interest to remark that the degree of modification
varies to a surprising extent, even among rep-
tiles living amid precisely similar surroundings ;
some of these creatures undergoing profound
changes, obviously directly adapted to their
peculiar habitat, whilst others apparently succeed
in holding their own without suffering any very
obvious transformation.

The common English Lizards Lacerta mvipara
and Lacerta agilis, and the Giant monitors serve
as admirable examples of the ground-dwelling
forms which have succeeded in holding their
own without undergoing any conspicuous modi-
fication of form. Both the English species are
heath dwellers, the vivaparous lizard exhibiting
a preference for moist places, and occasionally
taking to the water, being a good swimmer.
The monitors are to be met with in Africa,

GECKOS, LIZARDS, AND CHAMELEONS. 85

Southern Asia, and Australia, and although they
vary greatly both in size and habitat, some being
semi-aquatic, they have yet, as we have just
remarked, escaped conspicuous modification of
form. As with the English species, there is
nothing remarkable about the shape or covering of
the body, the limbs are well developed, and bear
the normal number of digits, five on each foot.

The life history of the largest of these crea-
tures, Faranus salvator, which attains a length of
seven feet, is extremely interesting viewed in
this light. Its range is considerable, extending
from Nepal to Ceylon, Cape York, and Southern
China, including the Malay Islands and Philip-
pines. Mr Annandale, who studied this species
in Lower Siam, describes it as equally at home on
land, in the water, or among the branches of
trees. In the water it swims beneath the surface
folding the legs close to the body, and using the
tail both as oar and rudder.

Among the branches of the trees these great
lizards find an abundance of food. In the states
where the Siamese practise tree-burial, these
monitors are said to eat the flesh of the corpses.
Another which he met with had seized a flying
squirrel. Specimens which he captured on the
ground proved when dissected to have been
feeding on tortoises, others on dung beetles. Eggs
appear to be a delicacy much appreciated by the
monitors. These are taken up with great care,
and passed unbroken into the gullet lest their
contents should escape. Here they are said to
be crushed by the contractions of the muscles of
the gullet.

•86 THE STORY OF REPTILE LIFE.

Among the natives, by the way, both the flesh
and eggs of the different species of monitor are
highly esteemed as food. In Burma, the wretched
victim, if not wanted at once, suffers the most
barbarous treatment. The fore-feet are turned
•over the back, the toes are broken and the
sinews drawn out and tied in a knot, thus ren-
dering escape impossible. In India, they are put
to a very droll use by thieves. If they desire
to scale a wall too high to climb, they procure
one of these lizards, tie a rope round its body,
and placing it against the wall, which is of mud,
release their prisoner, which at once makes for
the top and jumps over to the other side bearing
the rope with it. Up this the man swarms, the
weight of the creature, aided by the vigorous
hold which it takes of the ground, keeping the
line fast ! !

Though essentially ground-dwellers, the life
led by the lizards we have just described is un-
attended, as we have already remarked, by any
peculiar modification of form. Adaptation is
conspicuous by its absence. Hence the versatility
displayed. Quite otherwise, however, is it with
the ground-dwellers which we are now to examine.

These forms, in order that they may maintain
their existence, have been compelled to undergo
certain more or less striking structural modi-
fications. In some cases these are obviously
adaptations to the peculiar requirements of the
creature's environment ; in others the interpreta-
tion is by no means so easy.

Among the more interesting of these changes
we may notice the development of thorny spines

GECKOS, LIZARDS, AND CHAMELEONS. 87

on the skin of species that frequent arid, sandy
localities. In the " Horned Toad " (Phrynosoma),
for example, of the western half of the United
States and Central America, the horny scales
have become transformed into a bristling armour
of sharp-pointed spines of varying size. The
larger of these spines closely resemble the dried
husks of seeds and thus afford protection to the
animal by causing it to harmonise with its sur-
roundings. These rather forbidding looking
creatures are fond of basking in the broiling
sun, and in the afternoon, when the sand is
heated to fever heat, they begin to retire for
the night. This they do within a very short
space of time, by moving the body slowly for-
wards in such a way that certain peculiar scales
arranged like a fringe along the sides of the
body turn the sand up over the back after the
fashion of a plough. Soon only the head remains
visible, and this looks like a little cluster of dry
thorns. To prevent the sand getting into the
nostrils the latter are provided with special
closing valves. About a dozen species of horned
toads are known, the largest of which is about
eight inches in length.

Strangely enough, another spine-covered lizard
occurs in Australia, and is known as the Moloch
Lizard (Moloch horridus). But little appears to
be known about this animal save that it feeds
upon ants. The spines embossing the skin appear
to be extremely hygroscopic. This fact was dis-
covered by Dr Willes who, placing a live speci-
men in a shallow dish of water, remarked that
the water was immediately sucked up as by

88 THE STORY OF REPTILE LIFE.

blotting paper. The similarity between the
moloch and horned "toads," it is to be re-
marked, is the result, not of blood relationship,
but of adaptation to a similar environment.
Such parallels are not rare in Nature, and may
occur whenever like structures are acted upon
in like manner. Yet another spine-clad lizard
is found in South and Tropical Africa and in
Madagascar. Known as girclled-tailed lizards,
and attaining a length of fifteen inches, it differs
from the spiny forms just described in many
respects. In the first place, the horny spines
are backed by bony nodules so that the creature
is invested in a complete armour. In the second,
the spines are more symmetrical in form and
arrangement, constituting, in the back, a broad
shield composed of a number of transverse bands.
The spines on the base of the head, the neck,
and around the tail are very large. The spines
of the moloch lizard and of the horned " toads "
appear to serve as a disguise rather than as
offensive-defensive armour. Concerning the use
of the spines of the girdled-tailed lizards we have
no definite information. But we have yet another
group of armoured lizards to which reference must
be made — the Thorny-Tailed Lizards ( Uromastix)
— and in these the armour is defensive. Desert-
dwellers, like the forms just described, these
creatures diifer conspicuously therefrom, in that
the head and trunk are quite smooth, being
clothed only in small scales. The tail, however,
is armed with strong spines which appear to have
been developed in conjunction with the peculiar
liabit of these creatures of living in burrows.

GECKOS, LIZARDS, AND CHAMELEONS. 89

These they enter head-first, and leave the tail to
block the entrance thereto. These lizards are
purely vegetable feeders, and have a wide distribu-
tion, occurring in North Africa, Arabia, Syria,
Persia, and North- Western India.

There is nothing about the general appearance
of Uromastix, to which reference has just been
made, that would lead one to suppose that it was
a burrowing animal. The same is true of several
other lizards. Thus the members of another
genus — Liolepis — of this family, Agamidse, live
in holes in the ground, which may run vertically
downwards for as much as two feet before there
is a bend in their course. Each burrow is in-
habited by a pair of lizards. The same absence
of any peculiar modification is true of the remark-
able Conoloplms of the Galapagos Islands. This
is possibly due to the fact that burrowing is only
an incident in the life-history of these species ;
that is to say, existence does not depend on their
ability to burrow. With many other species,
however, it would appear to be otherwise. Thus
the eyes in many sand-burrowing lizards are pro
tected by a transparent disc of skin on the lower
eyelid, so that this can be drawn over the eye
and yet leave the sight unimpaired. In the
genus Ophiops, of North Africa and India, the
lower eyelid and its window-pane is permanently
fused with the upper lid so that the eye is shielded
as in the G-eckos, though it will be remembered
in this case the protection was afforded by a
different means.

A considerable number of lizards, however,
belonging to widely different families have

DO THE STORY OF REPTILE LIFE.

undergone very marked changes in adaptation
to burrowing habits, resulting, in extreme cases,
not only in the loss of the limbs, but of the limb
girdles. In these cases the length of the body
becomes enormously lengthened and snake-like.
So much, indeed, do they resemble snakes, that
only after some experience can the one be dis-
tinguished from the other. One of the most
interesting features about the loss of the limbs
is that every possible gradation from fully
functional limbs to mere vestiges thereof may
be found. Nowhere is this gradation in the
reduction of the limbs so well seen as in the
Skink family.

The Skinks, it should be remarked, are a very
numerous family, numbering several hundred
species, and distributed nearly all over the world.
Australia may perhaps be regarded as their head-
quarters, but they occur also in some numbers in
Africa and the Oriental region, and, sparingly,
in Europe and North and South America.
Dwellers in sandy regions, they seek safety
from pursuit not in precipitate flight, but by
burrowing, which they do with the ease and
rapidity of moles, in some cases penetrating to
a depth of several feet in a surprisingly short
space of time. They, and the burrowing forms
of other lizards, however, differ conspicuously
from the moles, and similarly modified types
of the mammalia, in that the burrowing habit
has resulted, in the most extreme cases, in the
total loss of the limbs; whilst in the mam-
malian forms in question the burrowing habit
has resulted in the development of digging-limbs

GECKOS, LIZARDS, AND CHAMELEONS. 91

of surprising power. The burrowing lizards,
strangely enough, resemble instead the non-
burrowing snakes.

The most typical skink, perhaps, is the species
known as the Common Skink (Scincus officinalis),
a thick-set, short-tailed lizard clothed in peculiarly
large, smooth, overlapping scales resembling those
of fishes, and forming an admirable covering for
burrowing purposes. The limbs in this species
are short but well developed and possess the
normal number of toes. It is a small animal,
not exceeding four inches in length, and in the
olden time was much esteemed in medicine,
being regarded as a cure for every ill that flesh
is heir to. Even to-day it is greatly esteemed,
both for its healing powers — which are imaginary
— and as an article of food, by the Arabs. Con-
trasting conspicuously with this species, stands
the Australian Stump-tailed Lizard (Trachysaurus
rugosus\ inasmuch as the body of this animal,
which is about fourteen inches long, is clothed
in a dense armour of bony nodules encased in
horny scales, that give the body the appearance
of a pine cone. Living in a region widely remote
from that of the Common Skink, it may well be
that the conditions of life demand a more durable
armour; be this as may be, we know nothing
at present which will account for the wide differ-
ences in the covering of the two species. Its
chief food consists in worms and insects, varied
by fruit and vegetables. Both the present and
the foregoing species possess four limbs bearing
the normal number of toes.

Let us turn now to the other members of the

92 THE STORY OF REPTILE LIFE.

family in whom reduction of the limbs is a more
or less conspicuous feature. Within the limits of
two genera, as may be seen in the accompanying
illustration, examples may be found showing
every gradation in the reduction of the toes
from the full complement of five to their com-
plete disappearance, and with them of the limb
itself which is represented only by a tiny stump.
The " bronze lizards," which furnish four of the
five examples, are natives of the Mediterranean
countries and South- West Asia. All appear to
be more or less surface burrowers hiding under
stones or pieces of bark. Some resort to damp
places in search of food, but all seek dry and
sandy spots whereon they may expose themselves
to the full glare of the sun. One species of
skink, by the way, occurring at Tunis and
Algeria, and belonging to the genus Euprepes,
is remarkable in that it leads a semi-aquatic life ;
spending much of its time on the floating leaves
of the Water-lily (Nymphea alba), seeking safety
when alarmed by diving. Its normal element,
however, is the sand, and by night it retires
under stones.

A considerable number of surface-burrowing
forms, other than Skinks, members of widely
different families, are known to science. In
some of these only the hind-limbs are repre-
sented, and these often only in the males.
They take the shape of fin-like flaps of skin,
which, in the case of the " scale-footed " lizards,
belonging to the family Pygopodidce, are found
on dissection to contain a degenerate five-toed
foot. Generally, the limb-girdles in these legless

GECKOS, LIZARDS, AND CHAMELEONS. 93

lizards are wanting, or reduced to the merest
vestiges. The common British "slow-worm"
(Anguis fragilis), and the curious " glass-snakes "
(Pseudopus) represent other members whose limbs
have completely disappeared. The latter are
extremely interesting on account of the manner
in which they kill their prey. This they do
either after the fashion of poisonous snakes, by
rapidly curling the body around the victim so as.

FIG. 7.— Lees of different species of lizards belonging to the Skink
tribe show the gradual evolution of the limbless condition.

to crush it to death, or by shaking it till stunned.
At least, when seized "by man, the glass-snakes
do not attempt to bite, though armed with
powerful jaws. Instead, they instantly encircle
the hand or arm by coiling the body around it,
and then besmearing it with excrement which is
said to be peculiarly offensive on account of its.
powerful smell.

The snake-like form of the lizards which we
have just described has been slowly acquired, in

94 THE STORY OF REPTILE LIFE.

consequence of a change in its habits, the precise
nature of which it is not easy to understand.
The transformation seems to be due to adapta-
tion to life in a sandy habitat, where escape from
enemies is made by burrowing, and prey of a
sluggish disposition or helpless character is to be
captured without chase, and without the effort
of climbing. By a perfectly natural transition
we are led to the consideration of some yet
more curious forms, highly specialised in some
respects, degenerate in others. These are the
amphisbsenas.

Only one species, belonging to the genus
Chirotes, possesses limbs, and these are repre-
sented by vestiges of the fore-limbs. For the
rest, the amphisbsenas are entirely limbless, and
resemble worms rather than lizards. This
peculiarity is traceable to the fact that they lead
an entirely subterranean life, and have in con-
sequence lost all external evidence of both eyes
and ears. With the glass-snakes and the other
surface-dwelling forms burrowing is a secondary
feature in the life-history of the animal, and has
in consequence involved certain minor modifica-
tions only — the protection of the eyes by a trans-
parent window formed by the lower eyelid,
closely-fitting scales, and the absence of limbs.
Bearing in mind the fact that the moles, and
other quite unrelated mammalian burrowing
forms, have developed specially powerful arid
peculiarly modified limbs, it seems strange that
the lizards should have acquired equal skill as
burrowers by suppressing the limbs and adopting
the model of the lowly earth-worm. But the

GECKOS, LIZARDS, AND CHAMELEONS. 95

amphisbsenas have become still further modified,
for the body, in place of a covering of overlap-
ping scales, is invested only in a soft skin, form-
ing a series of worm-like rings, each of which,
however, is cut up into a series of little squares — -
the vestiges of scales. Burrowing like earth-
worms, eyes, even if protected from injury, like
those of the glass-snake and "blind- worms," for
instance, would be not only useless but a source
of danger, and consequently have disappeared.
These remarkable creatures exhibit a decided
preference for ant-heaps and mounds of decaying
vegetable matter. Their method of progression,
is peculiar, inasmuch as they are able to move
either backwards or forwards with equal ease,
Only the lack of scales on the body renders such
a form of locomotion possible. The common
mole, it will be remembered, has peculiarly
nodified hair, which also allows of similar
forward or backward movements. The facility
with which the amphisbaenas move in either
direction, as well as the difficulty of distinguish-
ing the head from the tail, has led to the belief
in some parts of the world that these creatures
possess two heads. They feed on worms and in-
sects, and in rare cases, apparently, on snakes.
Tropical America,, the southern parts of the
United States, and Africa furnish the bulk of the
species; four, however, occur in the Mediter-
ranean countries.

Although most lizards are expert swimmers,
aquatic forms are rare, and only one species is-
entirely marine. This is the remarkable Iguanoid
(Amblyrhynchus cristatus) — the Galapagos Sea.

96 THE STORY OF KEPTILE LIFE.

Lizard. This remarkable creature, as its name
implies, a native of the Galapagos Islands, has
been vividly described by Darwin in his " Voyage
of the Beagle." It lives, he tells us, exclusively
on rocky sea beaches, never venturing for more
than a few yards inland. Its whole sustenance
is obtained from the sea, its food consisting of a
peculiar kind of sea-weed which grows on the
bottom of the sea at some distance from the land.
Like herbivorous mammals, this lizard appears
to be gregarious, and to set out for its feeding
ground in herds of considerable numbers. When
swimming, the legs are pressed closely to the
sides of the body, progression being effected by
a serpentine movement of the body and tail. It
is noteworthy that this creature has undergone
comparatively little change in form, in spite of
its markedly aquatic habits. The most noticeable
modifications are an incipient web between the
toes, and the flattening of the tail from side to side.
The peculiar habits of the animal will account
for the fact that, although more aquatic than
terrestrial, yet its original terrestrial structural
features predominate. Darwin has shown that
it has an inherent dread of remaining at sea
longer than necessary. So much so, that it will
not even seek temporary safety in the sea when
threatened on shore. " Hence," says Darwin,
"it is easy to drive these lizards down to any
little point overhanging the sea, where they will
sooner allow a person to catch hold of their tails
than jump into the water. . . . Perhaps this
singular piece of apparent stupidity may be
accounted for by the circumstance that this

GECKOS, LIZARDS, AND CHAMELEONS. 97

reptile has no enemy whatever on shore, whereas
at sea it must often fall a prey to the numerous
sharks. Hence, probably, urged by a fixed and
hereditary instinct that the shore is its place of
safety, whatever the emergency may be, it there
takes refuge." Darwin describes the lizard as a
"hideous looking creature, of a dirty black
colour, stupid and sluggish in its movements.
The usual length of a full-grown one is about a
yard, but there are some even four feet long ; a
large one weighed about twenty pounds : on the
island of Albemarle they seem to grow to a greater
size than elsewhere."

The American Basilisk (Basiliscus americanus)
is another expert swimmer. It is an arboreal
lizard, preferring the branches of trees which
overhang the water, into which it plunges at the
slightest alarm. It swims by rapid strokes of the
fore-limbs, the long tail trailing behind. Both in
its method of swimming and in its habit of seek-
ing safety by taking refuge in the water, this
species stands in strange contrast with the
Galapagos Sea Lizard just described.

Many species of the large family of Iguanas
are more or less aquatic. The Water Monitor
(Faranus salvator), which ranges from India,
through the Malayan region of China and Aus
tralia, and attains a length of seven feet, is a strong
swimmer, occasionally entering salt water. The
Water Monitor, and probably other species of
the same genus, possesses one peculiarly interest-
ing adaptation to aquatic habits, in the shape of
a pair of large cavities within the snout leading
from the nostrils. When the latter are closed
G

98 THE STORY OF REPTILE LIFE.

these pouches serve as reservoirs of air. This
seems to be the only instance of an internal
structural modification due to adaptation to
aquatic habits. Professor V. Ball, writing of the
Indian Monitor (V. bengalensis\ which he met
with in the Nicobars, describes an attempt to
capture a specimen which he did not wish to
injure. " As I was pressing him into a corner he
made a rush into the water, but returned, appar-
ently not liking the surf. Just as I thought he
could not escape, he made a sudden dart into the
water, dived through the surf, and disappeared."
Lizards are essentially creeping animals, but
some run with great swiftness. One species
which has not yet apparently received any-
English name (Phrynocephalus inter scapularis), is
said by Dr G-adow to run so fast that scarcely
anything but its shadow is seen. During this
time, it is to be noted, the tail is rolled upwards,
and not trailed as in crawling. It is a sand-
burrowing species, and occurs in Transcaspia. But
instances of extreme agility displayed by lizards
could be found in plenty. Accordingly space
can be found here only for such cases as call for
special comment. Most lizards, in running, do
so upon all four legs ; a few species, however,
serve to form exceptions to this rule of a
somewhat remarkable character, inasmuch as
for short distances at least, they do so upon
the hind legs only. This curious trait was
first brought to the notice of the scientific
world by Mr Saville Kent, who described its
occurrence in the remarkable Frilled - lizard
(Chlamydosaurus) King of North- Western Australia.

GECKOS, LIZARDS, AND CHAMELEONS. 99

Since then several other Australian lizards, many
of the American Teguexius, and Old - World
Monitors have also been shown to adopt, for
short distances, the same method of escape.
It has been contended that this habit has been
directly inherited from those extinct giants,
the Dinosaurs (chap, ix.), but of course this view
cannot be seriously entertained.

Although the number of different kinds of
lizards which have their abode in the tree-tops
is legion, there can be no donbt but that this
habitat is not to be regarded as their ancestral
home. They are, as their structure shows,
essentially terrestrial animals. Furthermore, it
is interesting to notice that, with the vast
majority of species, no special adaptation to
an arboreal mode of life has taken place.
Strangely enough, the struggle for existence
seems to have prevented specialisation in this
direction in all save a few exceptional cases.
The majority of these tree-dwelling species
seem, on the contrary, to be exceptionally
versatile. Climbing with ease, leaping with
marvellous precision, and escaping pursuit,
when necessary, by daring plunges into the
rivers, and thus avoiding capture, by swimming
to a place of safety.

The Common Iguana (Iguana tuberculata) may
serve as a case in point. This species inhabits
the forests of South and Central America, choos-
ing those trees which border and overhang creeks
and rivers. When alarmed, no matter what the
height of the tree, they jump boldly down into
the water below.

100 THE STORY OF REPTILE LIFE.

Travellers navigating the narrow and un-
frequented creeks in the mosquito country run
some considerable danger of meeting sudden
death from these plunges, inasmuch as Dr
Gadow assures us, on the authority of Napier
Bell, that the voyager in this region "often
encounters quite a shower of falling Iguanas,
and runs some risk of getting his neck broken."
This will readily be believed when it is known that
full-grown specimens may measure as much as six
feet long, and attain a weight of 30 Ibs.

Arboreal and aquatic, these creatures are also
burrowers, digging deep holes in the sloping sides
of banks; yet neither climbing, swimming, nor
digging have involved any special structural
modifications. Many lizards not only climb with
remarkable ease and rapidity, but are also expert
leapers. The Carolina A.nolis (Anolis Carolinensis),
and the Green Gecko (Phelesuma) for example,
leap from leaf to leaf like tree frogs. It will be re-
membered that another of the Geckos (Ptijchozcwm
hornalocephalum), was described, in the early part
of this chapter, as enjoying the reputation of leap-
ing powers of a high order, mainly, it would
seem, on account of the presence of large folds
of skin on each side of the body, which were
regarded as serving the purpose of a parachute,
affording the necessary support when in mid-air.
On the whole, however, these folds appear rather
to serve as masks, enabling the creature more
effectively to harmonise with its surroundings.

Only in one small group amongst the Eeptilia
have structural modifications, which unquestion-
ably subserve the practice of leaping, taken place,

GECKOS, LIZARDS, AND CHAMELEONS. jM

and these are of a quite unique character. The
creatures so modified are the " Flying Dragons "
of the Indo-Malayan countries.

About twenty species of this remarkable genus
are known. All, as may be supposed, are arboreal,

FIG. 8. —The Flying Lizard (Draco volans). The " flight " is performed
by means of the parachute formed by skin stretched over the pro-
truding ribs.

and, like the Anolis, move about the trees in a
succession of leaps, but, unlike this species, are
supported in mid-air by a relatively enormous
pair of " wings." These are formed of folds of
skin stretched between the hindmost ribs of the
body, which for this purpose are drawn out so

TO 2 TKF, STOTvY 0V REPTILE LIFE.

as to project far beyond the body wall in the
form of long slender rods. At the will of the
animal these "wings" can be folded up like a
fan. The ribs which take part in the formation
of this strange organ are these known as " float-
ing-ribs " — they are those whose ends are uncon-
nected with the breastbone. Possibly in the
ancestral form, these ribs were unusually long,
and tended to broaden the body, thus by increas-
ing the surface and rendering leaping more safe
and easy. In course of succeeding generations
selection took place, favouring those with longest
ribs, until ultimately the Flying-Lizard of to-day
came into being.

One would have imagined that the " flights "
of this lizard would be extensive, but so far the
evidence seems to show that this is not the case.

The Flying-Lizards and the Chamseleons, now
to be described, stand alone among the lizard tribe
for the profound specialisation which they have
undergone in adaptation to an arboreal life.

The Chamseleons have long since acquired fame
for their remarkable power of changing colour,
the which we shall discuss later. But the peculiarly
interesting structural changes which have taken
place in the skeleton are by no means so familiar.
To enter into details concerning this is no part
of the province of the present little work, suffice
it here to draw attention to the external character
only. One of the first things which must attract
the attention of the observer in watching these
strangely sluggish creatures is the feet. In both
fore and hind limbs the toes are not only remark-
.ably short, but arranged in a perfectly unique

GECKOS, LIZARDS, AND CHAMELEONS. 103

manner. No longer pointing directly forwards,
they are bound together, as it were, into bundles.
Of these, on the hand three are turned towards

FIG. 9. — Outline drawing of Chamseleons (Chameleon), to show the
remarkable tongue, eye, feet, and prehensile tail. From life.

the inside of the leg, and two towards the out-
side ; in the foot two turn inwards, and three
outwards. That is to say, the inner bundles are

104 THE STORY OF REPTILE LIFE.

opposed to the outer, just as the thumb is opposed
to the finger in the human hand, so that the
Chamseleons grasp a bough much as we grasp a
stick ; the difference being that the thumb and
first finger on the hand, and the great and second
and third toes on the foot are bound up together.
This makes a most perfect grasping, but a most
indifferent walking organ. In other words, it has
become highly specialised to perform a special
function. The tail is also peculiar, and like that
of many other arboreal creatures, is prehensile, and
used as a fifth limb. It differs, furthermore, from
that of most other lizards, in that it is not capable
of being renewed should it become accidentally
broken off.

The eyes are no less remarkable than the feet.
Unusually prominent, they are closely encased
by the eyelids, the apertures of which are reduced
to a mere pinhole and have a very limited power
of movement. Thus the eyeball, closely invested
by the lids, moves loosely in the socket, that of
the right side being moved quite independently
of its fellow of the opposite side. Up and down,
forward and backward, in the most grotesque
manner, after the fashion of a search-light, they
are kept constantly at work.

The skin is also peculiar, inasmuch as it is
scaleless and covered instead, with warty granules.

Concerning the ancestors of this group, and
the steps by which it has reached its present
extraordinary form, we know nothing. As we
have already hinted, the Chamseleons, like the
Geckos, are regarded by zoologists as forming a
group by themselves quite distinct from the true

GECKOS, LIZARDS, AND CHAMELEONS. 105

lizards. This distinction, in the case of the
Chamseleons, is made on account of the peculiar
structure of the tongue and certain skeletal
characters, of which the peculiar form of the feet
is not the least important.

The home of the Chamaeleons is Africa and
Madagascar, and the neighbouring islands. One
species, however, occurs in Europe — Andalucia.
Two are found in the island of Socotra, a third in
Southern Arabia, and one in India and Ceylon.

In size they vary greatly, the smallest species,
which occur in Madagascar and tropical Africa,
not exceeding three inches in length, while the
largest, Chamceleon parsoni, of Madagascar, attains
a length of two feet !

Adaptation to environment, so strikingly illus-
trated by the Chamaeleons, not seldom causes
animals not in the least related to assume a
strong superficial resemblance. Sometimes this
resemblance affects the whole body, at others
only certain parts are affected ; but in nearly all
cases a close examination will bring out the real
affinities of animals which are suspected of having
fallen under the spell of " convergent evolution."

The two following instances are excellent
examples of convergent evolution.

The genus Anolis, which is represented by
more than one hundred species, is a near ally of
the Iguanas, being indeed a member of the same
family. But it has the curious adhesive pads
found elsewhere only on the toes of the Geckos,
which are a totally distinct group, belonging, as
has just been remarked, to a different sub-order.
The members of the genus in question, like the

106 THE STORY OF REPTILE LIFE.

Geckos, are arboreal. In this case, however,
there is no possibility of mistaking any member
of the genus Anolis for a Gecko, for though the
feet have come to acquire a similar form, the rest
of the body is unmistakably lizard-like.

The second case of convergent evolution, that
of an arboreal lizard, Lyriocephalus scutatus, which
represents a genus in itself, is a much more
striking instance. The animal in question has
come to bear a remarkably strong resemblance
to a Chamseleon. The likeness, however, is con-
fined to the general shape of the body, the feet
being lizard-like and not in the least resembling
the peculiarly modified feet of the Chamseleon.

CHAPTER V.

SNAKES.

FROM the point of view of evolution the Snakes
are an extremely interesting group. Their near
relationship to the lizards we have already re-
ferred to ; indeed the differences between the
two groups are comparatively slight, consisting
chiefly in the structural modification of the jaws,
characters which are intimately connected with
the peculiar habits of feeding which characterise
the snake-tribe.

The invariable absence of limbs in the Snakes
constitutes one of the most obvious and striking
features which these creatures possess, and it is
this character alone by which they are popularly

SNAKES. 107

distinguished from the lizards. Those, however,
who rely on this character do so on the assump-
tion that all limbless reptiles are snakes, and
consequently unhesitatingly refer such forms as
the common English Slow- worm (Anguis fragilis),
the Glass-snakes (Pseudopus gracilis), and other
limbless lizards to the members of the Snake
family. Since, then, the typical lizard and the
typical snake can be so readily distinguished,
what are the characters by which the excep-
tional limbless types of the one may be distin-
guished from the invariably limbless forms of
the other group ?

The limbless lizard will be found to have a
distinct external ear in the shape of a more or
less well-marked pit lying behind the eye, whilst
the two halves of the lower jaw are firmly united
in front, and the bones of the upper jaw are
firmly fixed to the skull. Further, the tongue
in these degenerate forms is never withdrawn
into a sheath, and the scales of the belly are
not markedly different from those of the back.

In the Snake, an external ear is never present,
the halves of the lower jaw are connected in
front only by an elastic band, whilst those of the
upper jaw are freely movable on the skull. The
tongue is always withdrawn, when not in use, into
a sheath, and the scales of the belly are generally
very markedly different from those of the back,
inasmuch as, with certain rare exceptions, they
form a series of broad transverse bands lying one
behind the other. These differences are largely
connected with the peculiar habits of the snakes,
and this significance will be dealt with presently.

108 THE STORY OF REPTILE LIFE.

It must not be supposed, however, that these are
the only features which serve to distinguish the
snakes. Some others we shall discuss as we
proceed, but the majority are of too technical a
nature to claim mention here.

Having briefly indicated the superficial differ-
ences between the lizard and the snake, we may
proceed to rapidly survey the more important
structural features of the latter.

The covering of the body is invariably fur-
nished by scales, and these are never supple-
mented by bony plates or nodules. Symmetrically
arranged on the head, in the form of shields,
these scales afford useful characters for the
purposes of classification. Those of the body
are small in size, save only those along the under
surface, which take the form of narrow bands or
shields ranged in a consecutive series at right
angles to the long axis of the trunk. They play
an important part in locomotion.

At least once a year, generally much more
frequently, the horny outer layer of the skin
is shed, and this is done in such a way that
not only is it turned completely inside out, but
the exact shape of its late owner is preserved,
even the peculiar " watch-glass " over the eye
being undisturbed. These diaphanous snakes
may often be picked up where snakes are
common. Only in the Sea-snakes is the skin
shed in flakes.

If, by any mischance, the skin is not shed,
death inevitably follows ; the old envelope be-
coming so tough and hard as to form an unyield-
ing shell, preventing not only the further growth,

SNAKES. 109

but also the breathing of the animal. This casting
of the skin, furthermore, is accomplished in a very
remarkable manner, inasmuch as it is forced off
by the formation on the inner skin of a layer of
very fine hairs, which serve the purpose of releas-
ing the old skin by their rigidity of position.
Strangely enough, a precisely similar mechanism
is adopted by the Crustacea for ridding them-
pelves of the old shell when this has become too
small. These hairs are known as casting hairs.
Having performed their primary purpose, they
are retained for purely decorative ends, becoming
transformed into the curious, and often micro-
scopic, stripes, ridges, or spikes which ornament
the edges of the scales in the snakes and other
reptiles which change the skin after this fashion,
and the carapace of the Crustacea.

The eye is peculiar in that, like the Gecko
and certain burrowing lizards it has no eyelids.
Instead, it is covered by a horny shield, which
may be compared to a watch glass. This shield,
as in the case of the Gecko, is probably formed
by the transformation of the nictitating mem-
brane. The snake, however, differs from the
Gecko in that the eye, behind its shield, is
immovable.

The nostrils are situated at the end of the
snout. The sense of smell appears to be well
developed, some snakes indeed, as in the common
English Grass-snake (Tropidonotus natrix), hunting
its prey by smell rather than by sight and
sound.

The tongue is long, slender, forked at the top,
and very sensitive, serving entirely as a delicate

110 THE STORY OF REPTILE LIFE.

organ of touch, and not as is so commonly sup-
posed, as stinging or poison-injecting organ. But
to this point we shall return. It is furthermore
peculiar in that, when at rest, it is withdrawn
into a sheath.

The skeleton is remarkable for the enormous
number of the ribs, and of the bones which make
up the vertebral column, in some spines as many
as three hundred being present. Furthermore,
these vertebrae articulate with one another by
quite peculiar attachments, which, while adding
considerably to the strength of the backbone,
allow only of side to side movements between
individual vertebrae. The ribs commence with
the vertebra next behind that supporting the
head, that is to say, with the axis vertebra, and
extend backwards to within a short distance of
the end of the body. They are long, and readily
movable, and take the place of feet in loco-
motion. Limb girdles and breastbone are con-
spicuous by their absence. Only in a few cases
are vestiges of limbs to be found, and these
always represent the hinder pair.

Teeth are borne not only by the jaws, but
by the palatine and pterygoid bones, which form
the roof of the palate as well. They are lodged
in shallow pits, and for greater security become
fused with their respective supporting bones.
Shaped like curved needles, with the points
directed towards the throat, these teeth are quite
useless for tearing purposes, and serve only as
obstacles to prevent the escape of food from the
mouth, inasmuch as this can pass in readily-
enough, but any backward movement thereof is

SNAKES. Ill

at once arrested, being caught on the needle
points. Thus it is that snakes are obliged to
swallow their prey whole. Broken teeth have
no terrors for snakes, since provision is made
by Nature for a constant renewal of those which
are lost.

The lungs of snakes are peculiar in that owing
to the great elongation of the body cavity, the
left lung is much smaller than the right. The
latter is, furthermore, remarkable in that it
consists only of an exceedingly thin-walled bag,
only the anterior portion of which is used for
respiratory purposes, the hinder end serving
merely as a reservoir of air.

Having now considered the principal charac-
teristics of snakes, we may proceed to enquire
into the factors which have given these creatures
their peculiar features. Probably the most im-
portant influence at work has been the method
of securing prey. Originally, like the lizards,
four-footed, they seem to have been essentially
hunters on the ground, taking their prey by
stealth. This led, as in the case of many lizards,
to the loss of the limbs and the enormous elonga-
tion of the body. Simultaneously with the dis-
appearance of the limbs they developed new
organs of locomotion, pressing the ribs into this-
service. The fact that every rib in the body,
save only the very hindmost, takes part in this
exercise, shows that this peculiar adaptation must
have taken place quite early in the history of
the group, before the ribs of the neck vertebrae
became reduced to the dimensions which they
present in the majority of other forms. The

112 THE STORY OF REPTILE LIFE.

crocodiles alone among modern reptiles, have
preserved a complete series of free ribs in this
region. The part which these ribs play in loco-
motion is briefly as follows. The free ends of
each pair of ribs are attached to the ends of
one of the broad shields which we have remarked
running down the under surface of the body.
When the creature walks the ribs are moved
forward, one pair at a time, and in doing so, they
move the horny shield to which these free ends
are attached, so that its hinder edge projects
downwards from the body and catches hold of
whatsoever inequalities in the ground there may
be. These inequalities serve as levers by which
the body is thrust forwards. As a further aid
to progress the body is thrown into a series of
undulations in a horizontal plane, but never
vertical, as is sometimes erroneously represented
in pictures.

Mention has been made of limbs. These occur
only as the merest vestiges, representing the
hind-limbs, in certain archaic burrowing snakes
and in the giants among the snakes, the Pythons
and Boas. Externally, they are to be found in
the shape of a pair of claw-like spurs half-
concealed between the scales, at the wider end
of the body. Dissection reveals further vestiges
in the shape of the remains of thigh bones and
hip-girdles. All trace of the fore-limbs, their
girdles, and of the sternum, has absolutely
vanished. The remnants of these once functional
limbs are very precious links to the student of
evolution, for they prove beyond doubt the fact
that the modern snake has descended from limb-

SNAKES. 113

bearing ancestors. Why the hind-limbs have
persisted so long after the disappearance of the
fore-limbs is a point which cannot be answered.

The peculiarly specialized condition of the
body leaves but little room for further modifica-
tion for the purpose of locomotion. Hence it is
that we find more uniformity in the body than
among the lizards. Yet, in spite of specialisation,
snakes hold their own among the trees, on the
ground, or burrowing beneath its surface, or in
the water. Tree-snakes sometimes have the
shields of the under surface of the body more
or less markedly keeled so as to afford a safer
hold, and further have a prehensile tail.

Keels of this kind are especially well developed
in the Tree-Snakes of the genus Dendrophis, natives
of South-Eastern Asia and Australia. These have
the ventral scales armed with a pair of suture-
like keels notched on each side. Therewith they
are enabled to glide up the branches of trees in
an almost straight line, instead of having to adopt
an undulating motion. These snakes attain a
length of six feet. Certain new- world tree-snakes
of the genus Leptophis, when frightened or shaken
out of a tree, coil up the body like a watch-spring,
and let themselves drop from considerable heights.
Alighting upon the ground on the spiral they
escape without injury. Having a very slender
body and a long whip-like tail, they are extremely
graceful in form, attaining a length of six feet.
They feed upon small reptiles, birds, and their
eggs.

The burrowing snakes, like the burrowing
lizards, show gradations of adaptation to this
H

114 THE STORY OF REPTILE LIFE.

peculiar mode of life. Some have undergone
but little change, waylaying their unsuspecting
prey, by covering themselves with earth, so
as to leave only the head exposed. Others, and
these are represented by four closely allied
families, have undergone still further specialisa-
tion, the eyes in at least three families being
reduced to mere vestiges.

In one family, the Shield-Snakes (Uropeltidce)
of Ceylon and Southern India, the tail terminates
in a large shield, giving the body an obliquely
truncated appearance. The use of this peculiar
shield is unknown. They burrow in the soft
earth often to a depth of several feet, and rarely
appear above ground, and then only apparently
during the rainy season. They appear to live
solely on earth-worms.

The Cylinder Snakes (Eysiedce) of Ceylon and
South-Eastern Asia, Tropical South America,
like the Boas, to which they show some affinity,
retain traces of the hind-limbs in the shape of
claw-like spurs hidden among the scales. The
most conspicuous member of this family is very
beautifully coloured, and on this head we shall
have more to say later (p. 161). Like their allies,
the Shield-Tailed Snakes, just referred to, these
snakes burrow deeply, and feed on earthworms
and insects. The Coral Snake, however, appears
to be a partial exception to this rule, since it is
not so confirmed a burrower as the remaining
members of the family.

The Blind Snakes, representing the families
Typhodise and G-laucinidse, are particularly
interesting forms. Degraded to a worm-like

SNAKES. 115

form by their burrowing habits, yet the species
included in the first-named family retain traces
enough of their former glories to show that
they are, to quote Dr Gadow, "undoubtedly
the last living descendants of formerly cosmo-
politan, rather archaic snakes." Even to-day
they have a wide distribution, occurring in
tropical and sub-tropical countries. The mouth
is exceedingly small, placed in the under surface
of the head, and the jaws are capable only of
the smallest dilatation. The tail, which is very
short, ends in a horny spine.

The forms which make up the family Glauconidse
are interesting inasmuch as, though greatly de-
generate, the pelvic girdle and hind-limbs show
less reduction than in any other snakes, all the
elements of the girdle being represented, as
well as vestiges of femora or thigh bones. The
blind snakes feed on ants and millepedes.

Just as some animals are omnivorous, whilst
others have become adapted to, or specialised for,
one kind of food, so others are omnimotile, if we
may use such an expression ; and now in one
direction, now in another, become pledged to
one form of locomotion only ; or, as we say, are
" specialised." We have already had many
instances of this, and the snakes furnish no
exception to the rule, though from their gener-
ally specialised conditions, further modifications
are neither striking nor profound.

Instances of snakes which climb, crawl, and
swim, with equal ease, have already been
quoted ; so also have others, in which the body
has become adapted for one kind of locomotion

116 THE STORY OF EEPTILE LIFE.

only, as in the case of the strictly subterranean
snakes. The result of an exclusively aquatic life
may now, therefore, fittingly be considered.

As might be expected, such a mode of life is
approached by many gradations. The Common
Ringed Snake, for example (Tropidonotus natrix\
of Great Britain, divides its time, more or less,
between the land and the water. Common in
woods, heaths and hedges, it is especially abundant
near water. Its chief food is frogs, but it preys
also on mice, voles, young birds, eggs, and fish.
When swimming, which it does with the greatest
ease, the head and neck are raised above the
surface of the water, a fact which shows that no
special adaptation has taken place in response to
the environment. The Giant Anaconda (Eunectes
murinus) of the tropical forests of the Guianas,
Brazil, and North-Eastern Peru, is still more
aquatic, spending the greater part of its time in
the water. Attaining a length of over thirty
feet, this enormous reptile, however, is more
versatile than the Ringed Snake, inasmuch as
it is frequently found on shore basking on the
burning sand, coiled up among the rocks, or
stealthily hiding among the trees. The traveller-
naturalist Bate several times encountered these
enormous reptiles, and describes them as especially
numerous and much detested in the country near
Santarem, where it periodically visits the farm-
yards, carrying off poultry, young calves, and
whatever else it can lay hold of. Even man is
sometimes attacked. As an instance, he quotes
the case of a lad who was suddenly encircled in
the terrible coils of one of these monsters at Ega.

SNAKES. 117

"The father and his son," he says, " went ... . .a
few miles up the Teffe to gather wild fruit ; land-
ing on a sloping sandy shore, where the boy was
left to mind the canoe whilst the man entered the
forest. The beaches of the Teffe form groves of
wild guava and myrtle trees, and during most
months of the year are partly overflown by the
river. Whilst the boy was playing in the water
under the shade of the trees a huge reptile of
this species stealthily wound its coils around
him, unperceived, until it was too late to escape.
His cries quickly brought the father to the rescue,
who rushed quickly forward, and seizing the
Anaconda boldly by the head, tore his jaws
asunder." When in the trees it will often dart
down its head from a considerable height to seize
a passing peccary or other animal. In the water
it lurks in quiet pools, or floats down with the
current, but like the Grass Snake, keeps its head
well above the surface.

The Javan Wart Snake (Acroch&rdus javanicus),
may be taken as the representative of a family
which is almost if not absolutely aquatic, frequent-
ing rivers or estuaries, with brackish water, and
occurring far out to sea. From these, it is but a
step to strictly marine snakes. These are repre-
sented by more than sixty species, occurring in
the Indian and Western South Pacific Oceans.
They are found, says M. Boulenger, "in abundance
in the Persian Gulf, along the coasts of India,
Burma, and the Malay Archipelago, to North
Australia and New Caledonia." The coast-
frequenting species ascend rivers. Between
these marine forms which penetrate up the

118 THE STORY OF REPTILE LIFE.

rivers, and the fresh-water forms which occasion-
ally wander out to sea, there is this difference,
that whilst the latter show only a slight modifi-
cation in the shape of a somewhat compressed
"body, the marine forms have acquired an eel-like
form, the tail being flattened into an oar-shaped
organ.

That these marine forms, which are believed
never to leave the water, have been derived from
several distinct fresh- water types is an extremely
interesting point, especially in view of the fact
that, though unrelated, all have acquired the
same peculiarly modified body. Here we see again
the principle of convergent evolution at work —
that is to say, the effect of a similar environment
acting on similar structures. Just as the burrow-
ing lizards and the burrowing snakes have come
to resemble one another in the same way.
Further, we have to remark a resemblance of
another kind between these marine snakes, inas-
much as certain harmless kinds have come to
bear so close a resemblance to poisonous species
in their coloration that they can only be dis-
tinguished after careful discrimination. On this
point we shall have something to say when dis-
cussing the phenomena of mimicry.

Comment has frequently been made through-
out these pages on the fact that, while certain
animals have preserved a remarkable versatility
of locomotion, or the ability to subsist upon a
varied diet, others have, by what we may call
a process of concentration, acquired a peculiar
facility in one direction only in the matter of
movement, or a special adaptability for subsist-

SNAKES. 119

ence on one kind of food. But, at the same time,
in gaining these ends they have done so by a com-
plete surrender of freedom in other directions.
The development of perfection in one direction has
been at the expense of efficiency in every other.
In other words, it has led to specialisation. In
many cases this specialisation may be traced to
the pursuit of food. A pursuit dictated possibly
by congenital preference, sometimes by force of
circumstances. In others the interpretation is
to be sought elsewhere.

The peculiar form of the body of the snake
is, in part, probably to be attributed to its
singular feeding habits. In the case of the
blind burrowing forms this interpretation seems
certainly to be well founded, but whether the
pursuit of their peculiar food is the result of an
ancestral preference, or of force of circumstances
cannot of course be known. It is legitimate
speculation to suppose that the earliest snakes
were small creatures, living upon insects and the
smaller members of their own class. These being
easily procurable without the effort of pursuit,
the limbs became less and less needful, and con-
sequently gradually atrophied. Later, in the
absence of severe competition and abundant
food, the carnivorous species were evolved, ulti-
mately developing into the giant forms of to-day
— which, by the way, are not so large as certain
extinct species.

The foregoing remarks will probably gain an
additional interest if a brief survey is given of
the different methods adopted by snakes for pro-
curing their prey ; and of the peculiar, and indeed

120 THE STORY OF REPTILE LIFE.

remarkable structural modifications which they
have undergone for the purpose of swallowing
their victims.

Since it is the practice, in all save a few ex-
ceptional cases, among the snakes to swallow
their prey whole — and this prey is generally of
large size, the circumference of the victim being
much greater than that of the captor — the bones
of the jaws have acquired an unusual elasticity
of movement. This has been attained by substi-
tuting elastic ligaments for the usual inflexible
joints between the different bones which make
up the jaws. When the food is seized, the
process of swallowing is not, like that of other
animals, performed by forcing the prey down the
mouth and into the body, but rather, the creature
seems to draw itself over its prey and slowly to
envelop it. The sternum and shoulder girdle
being absent the ribs are free to expand to any
extent, and hence the region of the chest offers
no restrictions to the size of the morsel
swallowed.

The work of swallowing appears to be a purely
mechanical one, a fact which sometimes leads to
" regrettable events." A case in point occurred
some eleven years since (October 1892), in the
gardens of the Zoological Society of London.
Mr A. D. Bartlett relates how, on the evening of
that fatal day, two pigeons were placed in the
cage containing two fine specimens of Boa con-
strictors, one of the birds being immediately
seized, the keeper left the house. Eeturning
next morning he found that one of the snakes
had disappeared. A glance at the remaining

SNAKES. 121

snake showed that, from its enormously dis-
tended body, it must have swallowed its com-
panion, which was about nine feet in length.
Unable to curl itself round, it was stretched
nearly full length along the floor of the cage, its
body distended to bursting point, and its scales
no longer forming a faultlessly overlapping series,
but stretched wide apart like so many small
islands. Within eight-and-twenty days not only
had the gigantic meal been digested, but another
pigeon introduced into the den was immediately
swallowed !

" This peculiar case," says Dr Gadow, " is not
one of ordinary cannibalism : it is rather an un-
intentional accident. When two snakes happen
to get hold of the same animal . . . and begin
to swallow it, the action of swallowing becomes
almost mechanical, the snakes continuing to push
their jaws over their prey ... so long as they
feel something in the mouth. After the original
prey has been mastered, it is the turn of the
opposite snake's head, and if the weaker snake
does not give way it is swallowed by its stronger
mate."

Some snakes kill their prey before swallowing
it ; others swallow it alive. The Common Grass
Snake (Tropidonotus natrix), for example, swallows
its prey after the latter fashion. Fishes and
frogs form its commonest victims. The former
are seized by the belly and borne to land ; the
latter, if seized by one hind leg, is gradually
swallowed without more ado, the other three
limbs being pushed forward towards the head.
If seized by the middle, the hapless victim is

122 THE STORY OF REPTILE LIFE.

turned and swallowed head foremost, and for
some time afterwards may be seen wriggling
within the body of the captor.

Contrary to what might be expected, the un-
fortunate victims do not seem to suffer much
injury during their passage to oblivion, for on
rare occasions — and they are very rare — the
captive is returned unhurt to the light of day.
Dr Gadow gives an instance of one such restora-
tion : " One very tame snake," he says, " had
swallowed a frog on my table when a friend
•entered the room. The snake was frightened,
jumped on to the ground, striking it with its
full belly, and thereby hurting the frog, which
squeaked loudly ; whereupon the snake reversed
its mechanism and the frog hopped away, none
the worse for its terrible experience."

Those snakes which kill their prey before
swallowing, do so by one of two methods — by
crushing, or by poison.

Perhaps the best known of the crushing or
constricting snakes are those of the Python tribe,
which contain within their ranks the largest of
living snakes. Between sixty and seventy species
are known, of which the "Anaconda" of the
tropical forests of South America is the largest,
though the Indian Pythons, Python molurus and
Python reticulatus, run it very close, attaining a
length of thirty feet. These enormous creatures
can crush a tiger or an ox with comparative
case, though the tales of such bulky animals
being swallowed afterwards cannot be credited.
The prey is apparently seized by a sudden spring
and immediately encircled by coil after coil of

SNAKES. 123

the lithe and powerful body, which being drawn
tighter and tighter, soon reduces the victim to a
crushed and mangled corpse of the shape of a
sausage. By means of these constrictions the
necessary shape for convenient swallowing is
obtained.

The Burmese have a quaint legend about the
Eeticulated Python (Python reticulatus) which
has been done into English by Mason in his book
on "Burma . . . and its Productions." "Ac-
cording to an old Karen legend," he says, " all
the poisonous serpents derive their virulence
from the Python, which, though innocuous now,
was originally the only one that was venomous.
In these days he was perfectly white, but having
seduced away a man's wife, Aunt Eu (Eve), he
made her, while she was in his den, weave figures
on his skin in the forms which are now seen.
At that time, if he bit the footstep of a man in
the road, such was the virulence of his poison
that the man died, how far soever that man
might have passed from the bitten track. The
Python had not, however, ocular demonstration
of the fact, so he said to the crow : ' Crow, go
and see whether people die or not when I bite
the foot-track/ So the crow went to the neigh-
bourhood of a Karen cabin, and found the people,
as is their custom at funerals, laughing, singing,
dancing, jumping, and beating drums. He there-
fore returned to the python, and told him that,
so far from his effort producing death, on the
contrary they produced joy. The python was
so angry when he heard this, that he ascended a
tree and spit up all his venom, but other creeping

124 THE STORY OF REPTILE LIFE.

things came and swallowed it, and people die of
their malignancy to this day. The tree, there-
fore, from which the python spat up his venom
became deadly, and its juice is used to this day
for the purpose of poisoning arrows. The python
made the other creatures promise not to bite
without provocation. The cobra said : ' If there
be transgression so as to dazzle my eyes to make
my tears fall seven times in one day, I will bite/
So said the tiger (whose bite the Karens esteem
as virulent as a serpent's) and others, and they
were allowed to retain their poison. But the
water-snake and the frog said they would bite
with or without cause as they liked. So the
python drove them into the water, where their
poison melted away and their bite became
harmless."

Concerning poisonous snakes we may remark
that these are not, as was at one time believed,
a group of closely related forms, opposable, as a
group, to the non-poisonous snakes. On the
contrary, a more complete knowledge of their
anatomy shows that these poisonous, together
with certain non-poisonous forms, represent one
of two distinct branches of a common, non-
poisonous stock, the members of each branch
having independently acquired their deadly
powers.

It is popularly supposed that the venom of the
snake is concealed in the curiously long forked
tongue, which is always so much in evidence in
the snakes. As in the similar organ of the
lizard, this is, as a matter of fact, perfectly harm-
less, and used only as an organ of touch. The

SNAKES.

125

poisonous weapons of these creatures are to be
found in a pair of specially modified teeth in the
upper jaw, and a corresponding pair of poison
bags or glands. These teeth in some forms are
marked by a deep furrow in front ; in others,
the edges of the furrow meet to form a channel
open only at the point of the tooth. At the
base of each tooth is the bag of poison, so placed
that the opening of the mouth causes the poison
fang — which has been lying folded back towards

FIG. 10.— Head of a poisonous snake dissected to show the poison gland
and fang through which the venom is conducted. — After GADOW.

the throat — to press upon the bag and force out
of it into the groove, or tube of the tooth, a
small but deadly quantity of venom, which is
introduced into the body of the snake's victim
as the fang buries itself in the flesh thereof.

The poison bag is formed by a modification of
either of certain salivary glands known as the
upper labial gland, or of the gland answering
to the parotid gland. The fact that two different
glands have been utilised for the same purpose,
coupled with the fact that the bones bearing the
fangs differ remarkably in size, is strong evidence

126 THE STORY OF REPTILE LIFE.

in favour of the view of the independent origin
of the poisonous snakes.

The snakes of the genus Doliophis, allies of the
Cobras, are remarkable for the enormous size of
the poison bags, which extend far beyond the
head, along each side of the body, terminating
in club-shaped thickenings. Owing to their great
size the heart has been shifted further backwards
than in any other snake.

The virulence of snake-poisons, and the
symptoms which follow its injection, differ con-
siderably.

Of the first named is the much dreaded " Krait"
(Bungarus corulens), which is said to cause more
deaths in India than any other snake. It lives
chiefly on rats, lizards, and other snakes. Scarcely
less formidable is the "Hamadryad" or King-
Cobra, which attains a length of twelve feet, enor-
mous for a poisonous snake. Ranging from India
to South China and the Philippines, it is held in
detestation everywhere on account of its size and
poisonous properties.

The African cobras have a remarkable habit
of squirting the poison from the mouth when
threatened, and are said to be able to throw
several feet. The object of such waste is not
easy to understand, since unless the venom
reaches a raw surface, or is injected into the flesh
by the teeth, it is powerless.

Foremost among venomous snakes stand the
Vipers and Pit-vipers, inasmuch as it is among
these forms that the poison apparatus has reached
its highest perfection. To attain this, certain of
the jaw-bones have undergone considerable modi-

SNAKES. 12T

fication. Thus the maxillary, in other poisonous
snakes a longish bone, firmly fixed, and lodging
the fangs and sometimes smaller teeth behind,
is in the vipers reduced to a columnar shape and
shifted forwards so as to lie in the front of the
jaw. Into the lower end of this bone the long
poison tooth is fixed ; above, it is slung on to the
neighbouring bones so as to move as by a hinge.
By this means, when the mouth is closed the
fang is drawn backwards so that its point looks
towards the throat, but as soon as the jaws
open the point is forced forwards so as to-
be in the best possible position for its deadly
work.

As is generally the case among poisonous
snakes, a series of reserve teeth are to be found
packed away behind the functional fang. Every
gradation is represented, from the nearly finished
tooth to the merest germ.

The Viper family has succeeded in many
spheres — ground-dwelling, arboreal, semi-aquatic,
and burrowing types being represented.

Pages might be written on this group, but we
must select for the present purpose one or two
of the most conspicuously dangerous types.
Such are the "Daboia" (Fipera russelli) and the
Pit-vipers.

The " Daboia" has been described as one of
the scourges of India, and is equally terrible in
Ceylon, Burma, and Siam. What the " Daboia "
is to India, the " Fer-de-Lance " (Lachesis lanceo-
latus) — one of the Pit- vipers — is to America,
since it occurs in abundance in the sugar-planta-
tions, and exacts therefrom a heavy toll on those

128 THE STORY OF REPTILE LIFE.

who labour there. The experiment of importing
the mongoose to wage war against this terrible
creature proved a failure ; even this redoubtable
little warrior retreating before its venom and
seeking safer prey. The Pit-vipers are so-called
from the presence of a pit between the nostril
and the eye, supplied by branches of the
trigeminal nerve. Apparently sensory, the
function of the pit is unknown. Some sixty
species of Pit-vipers are known, and of these
probably the most remarkable are the dreaded
Rattle-snakes.

We might remark that the only poisonous snake
in Great Britain belongs to the Viper family.
Fipera berus^ the Common European Viper. This
snake exhibits a preference for heaths, moors, and
woods. Brambles, clumps of nettles, and heaps
of stones are also favoured spots affording safe
cover. Mice form its principal food.

The bite of the Common Viper, though attended
with great pain, is rarely fatal. The bitten limb
soon swells and becomes discoloured. Very
shortly after the deposit of the venom the victim
is overcome by great prostration, vomiting, and
cold perspiration, and experiences some difficulty
in breathing. In from twelve to twenty-four
hours the severity of the symptoms begins to
abate, but recovery may not take place for some
days later, and then is rapid. Death, however,
may occur from depression or the secondary
effects of the wound. The remedy is to apply
a ligature and bandages above the wound, then
to open the latter still further with a clean knife
and pour in Condy's fluid or bleaching powder.

SNAKES. 129

Internally, before the arrival of the doctor, small
doses of alcohol may be given.

The Common Viper may generally be distin-
guished from the Grass-snake by reason of the
diamond-shaped pattern which runs down the
back and the ^-shaped bar on the head. The
females are larger than the males.

Certain mammals and birds are immune by
nature against snake-bites : such are the Hedge-
hog, the Pig ; and the Secretary-bird, Honey-
buzzard, and Stork.

It should be remembered, in justice to these
dreaded and much abused creatures, that their
poisonous properties are directed mainly to the
capture of food. Man falls but too often a
victim to their virulence because he threatens
their safety, or invades their dominions.

One of the most remarkable adaptations for
feeding to be found among the Yertebrata is that
of the Egg-eating Snake (Dasypeltis scabra) of
tropical and South Africa. The jaws are
almost toothless, since large teeth would pro-
bably break the egg-shell and so waste the
contents. The egg is accordingly swallowed
whole, and, having passed the head, forms a
huge swelling immediately behind. After a few
slight contortions the swelling suddenly col-
lapses, and later the shell and its inner lining,
neatly rolled up, are ejected from the mouth,
like the indigestible pellets of birds of prey.
Dissection of the creature shows that the teeth
of the jaws have been replaced by teeth in the
throat formed by downwardly directed spines
from the vertebral column, which, piercing the
I

130 THE STORY OF EEPTILE LIFE.

gullet, play the part of true teeth. By breaking
the egg far down the gullet, none of its precious
contents are wasted.

The food of this species appears to consist
chiefly of birds' eggs. Though even when full-
grown and scarcely exceeding a length of two feet
and a half, it is quite able to swallow an ordinary
hen's egg.

CHAPTER VI.

DOMESTIC LIFE.

DOMESTICITY is not a strong point with the
Reptile people. Amorous outbursts displayed
in the choice of mates, and here and there proofs
of some slight regard for their offspring, are all
that can at present be recorded in their favour
on this head. In all this they stand in strong
contrast to their poor but distant relations the
Frogs and Toads and their kind on the one hand,
and their aristocratic cousins the Birds on the
other. Indeed, in all that pertains to the
emotions of this character they are almost fish-
like. Laggards in love, they are still more
apathetic as parents.

In so far as the affections are concerned, the
Eeptile is seen at its best, or worst, according to
the traditions of its tribe, when seeking a mate.
The advances appear always to be made by the
males, and to vary greatly in the way in which
they are made. Where rivals are many, some
endeavour to succeed by wiles and blandish-

DOMESTIC LIFE. 131

ment ; others employ violence, the several suitors
fighting viciously among themselves for the
coveted prize.

But little appears to be known concerning
the methods of courtship prevalent among the
Tortoise tribe. The writer was therefore the
more fortunate in witnessing a little love passage
between two painted Terrapins (Chrysemys picta)
in the Eeptile House at the Zoological Society's
Gardens in London, the date, to be quite precise,
being the 21st of July 1901. The unusual
activity of a male of this species was the first
thing to attract attention to his movements,
which appeared to be excited by some strange
stimulus. Watched more closely, he was found
to be dodging a female of his own species, and
making most frantic efforts to swim round so as
to directly oppose her path. This done, he
closed up, and immediately commenced to beat a
lively tattoo with his long finger-nails upon her
devoted head and eyes, the movements being so
rapid that nothing more than a blurred image of
the nails was visible. As soon as she escaped
these peculiar attentions, he set about circum-
venting her again, and again succeeded, and this
was repeated, not once, but many times during
my stay there.

Dumb for the rest of the year, some at least
appear to find a voice during this time of court-
ship. Thus the giant Tortoise of the Galapagos
(Testudo nigra), at this period only, utters a hoarse
bellowing sound, which can be heard at a distance
of more than a hundred yards. His mate is at all
times voiceless, like the far-famed Cicada.

132 THE STORY OF REPTILE LIFE.

Among the Crocodiles fierce battles are appar-
ently commonly fought by the males for the pos-
session of some coveted female ; whilst displays
and caperings of a most ludicrous kind, accom-
panied by loud bello wings, intended for the eye and
ear of his mate alone, appear to take place after
the conqueror has driven off his rivals. Thus the
Alligator has been described as endeavouring to
ingratiate himself in the eyes of his chosen one
by splashing and roaring in the midst of a
lagoon, twirling round on the surface of the
water with head and tail lifted up, and the body
swollen out with air to bursting point. During
this time, too, it should be mentioned, these
creatures emit a strong odour of musk, which is
secreted by glands situated in the lower jaw.

Among the lizards, as with the birds, the males
are often brilliantly coloured, whilst their mates
are comparatively dull. The difference between
the sexes, however, is by no means as frequent
as among the birds. There seems to be evidence
to show that this beauty is the result of sexual
selection. That is to say, the females choose as
mates those which are more brightly coloured than
their rivals, or at least those which combine
beauty of colour with aptitude for display.
Darwin, dealing with this subject, reminds us
that in the genus Sitana, the males alone are
furnished with a large throat pouch, which can
be folded up like a fan, and is coloured blue,
black, and red; but these splendid colours are
exhibited only during the pairing season. In
the female this pouch is wanting. Coloured
pouches of this kind are common among the

DOMESTIC LIFE. 133

reptiles and probably serve in all cases the
same purpose.

In many species of lizards the males during
the breeding season become very pugnacious, and
rivals never meet without a conflict. In Anolis
carolinensis, for example, when two males meet
they face one another, bob the head up and
down two or three times, expand the throat
pouch, lash their tails from side to side, and
then, worked up to the requisite pitch of fury,
rush at one another, rolling over and over, and
holding firmly with the teeth. The conflict

fenerally ends in one of the combatants losing
is tail, which is eaten by the victor !

Dr Gadow, on the authority of Mr Annandale,
describes as follows the courtship of the lizard
(Calotes emma) of the Malay Peninsula. "The
males are very pugnacious and change colour
as they fight. At the time of courtship a curious
performance is gone through by the male, the
female remaining concealed in the foliage hard
by. He chooses some convenient station, such
as a banana leaf or the top of a fence, and
advances slowly towards the female. His colour
is then pale yellowish flesh colour, 'with a con-
spicuous dark spot on each of the gular pouches,
which are extended to their utmost. He stands
upright, raising the fore part of the body as high
as possible, and nodding his head solemnly up
and down. As he does so, the mouth is rapidly
repeatedly opened and shut, but no sound is
emitted. When he is driven away, caught or
killed, the dark spot disappears entirely from
the neck."

134 THE STORY OF KEPTILE LIFE.

With the Chamaeleons ornament in this direc-
tion can no further go ; at least it would almost
seem so. Only in a few species, however, do we
meet with these marked sexual differences. The
most conspicuous instance is that furnished by
Chameleon bifurcus of Madagascar. Herein the
snout of the male is armed with two enormous
bony projections resembling horns. Only a
rudiment of these is present in the female. In
Owen's Chamseleon (Chameleon oweni), from the
west coast of Africa, the male bears three such
"horns," two of which project from the forehead
and the third from the snout ; but the female is
weaponless. These curious projections appear to
be comprised of fibrous tissue in the young
animal, and to become bony later in life. Pro-
bably during a still earlier phase in the history
of their development, they were quite flexible
in character, as in the case of a similar appendage
in one of the lizards (Ceratopliora stoddartii). This
suggests that originally the "horn" may have
been of still softer tissue, erectile during excite-
ment. From this it passed to a permanently
rigid structure which now, late in life, becomes
bony. At the present day, at least with the
Chamseleons, these appendages appear to be used
as weapons of offence by the males when fighting
for the possession of mates. As in the case of
horns in the mammalia, there seems to be a
tendency for these structures to be transmitted
to the females, and probably, in the course of
ages, they will, in this sex, come to assume very
nearly the proportions of those of the males,
though it is improbable they will ever be quite

DOMESTIC LIFE. 135

as large since they do not come under the
influence of selection.

The snakes, like the lizards, afford instances
of sexual differences in colour, but there seems
to be no evidence that these creatures fight for
their mates, and hence perhaps the absence of
all weapons save poison, and this is only associated
with the capture of food or the slaughter of
foes.

On the whole, there is far less activity and
intensity of feeling displayed by the reptiles in
their choice of a mate than is the case with the
birds, as those who may have read the Story of
Bird-life will probably have remarked.

Similarly, in the care they display for their
offspring, the reptiles are far behind the birds.
With the latter, it may be remarked, the young
are produced from eggs only after a long period
of incubation, but in many reptiles the eggs are
often retained within the body during the whole
process of their development, so that the young
are ready to leave the shell immediately after
the egg is deposited, or are even born free.
It is of importance to note that whilst in some
reptiles the internal development pf the egg is
normal, in others it occurs only when for some
reason laying is retarded. In this, probably, we
have the clue to the origin of the normal cases
of internal development.

When the development of the egg takes place
outside the body, incubation by the mother rarely
takes place. Instead, the eggs are buried in warm
earth or decaying vegetable matter and there
hatch out. It is probable that in those rare

136 THE STORY OF KEPTILE LIFE.

instances where incubation of the eggs is sup-
posed to obtain, the real object is protection,
inasmuch as no appreciable increase in tempera-
ture was traceable in the case of the Indian
Python (Python molurus), which, during the
summer of 1881 remained for almost six weeks
coiled around her eggs, fifteen in number, in the
gardens of the Zoological Society of London.

A receptacle for the eggs in the shape of a
nest appears never to be made, though the Nile
Monitor (Paramis nttoticus), is said to build itself
a nest among the bushes on the banks of streams,
especially those which dry up in summer. It
may happen, that further investigation will show
that this is used also for the eggs.

That the progress of embryonic development
may be arrested and suspended for a relatively
long period of time is probably a fact not
generally known. Thus the eggs of one of the
northern Pond-tortoises (Emys orUcularis), laid
in the autumn, do not hatch out till the follow-
ing spring, withstanding the severe winters of
North Germany and Russia, though only a few
inches below the surface. Similarly, in the
"Tuatera" (Sphenodon punctatus), the eggs are
laid from November to January or February —
the southern summer — and by August contain
nearly ripe embryos. These, however, do not
hatch out till the following February, or till
the embryos are some thirteen months old.
During a large part of this time they seem to
undergo a sort of summer sleep, or cestivation,
akin to the winter sleep, or hybernation, of the
tortoise embryo.

DOMESTIC LIFE. 137

The egg-shell among the reptiles varies greatly
in its texture, being of great hardness in some
forms, as in some tortoises and in crocodiles for
example, and soft and leathery or parchment-like
in others, as in most lizards and in snakes. In
these cases, where the shell is of sufficient density
to require this, the snout of the embryo is pro-
vided with a sharp conical " tooth " wherewith
the shell is cut, just as among the birds. In
colour the shell is white or yellowish, but with-
out markings as in birds, save in the Tuatera
lizard, the egg-shell of which may bear a zone
of reddish spots.

Eggs which have only a parchment-like shell,
be it noted, sometimes exhibit the strange feature
of growing after they have been laid. This
growth is due to the stretching of the shell by
the developing embryo, which in addition to
feeding on the contained food material, takes in
air and moisture through the shell.

The number of the eggs varies, among the
tortoises, for example, some species laying from
three to five, others as many as one hundred
and twenty. Among the birds, it may be
remembered, there are many species, which lay
but a single egg, and more in which the number
does not exceed three.

That the reptiles' eggs are invariably white
is to be explained by the fact that they are
never exposed, but laid either in holes of trees,
or burrows, or buried in the ground.

With many reptiles great care is displayed in
the disposal of the eggs. Thus the European
Pond-tortoise first prepares the ground by water-

138 THE STORY OF REPTILE LIFE.

ing it from the bladder and the peculiar anal
water sacs to which we have already referred.
Then it stiffens the tail and bores it a hole
with it, enlarging this by the aid of the hind
feet till it is about five inches deep. The eggs
are then laid at the bottom and distributed by
the feet. Then the soil is put in again and
beaten down flat, and the spot concealed by
scratching the surface a little with the claws.
This done, no further interest in the nest is
displayed.

The eggs of some species of tortoises, by the
way, are highly esteemed as food, or eagerly
sought for on account of the oil they yield.
The vast quantities that are destroyed by man
every year for this purpose is almost incredible.
The naturalist Bates, describing the scenes which
took place on the breeding ground of the " Arran-
Turtle" (Podocnemis expansa) of Tropical South
America some fifty years ago, gives us an idea
of the magnitude of this destruction. "The
turtles," he says, "lay their eggs by night,
leaving the water ... in vast crowds, and
crawling to the central and highest part of the
praia." They " excavate with their broad webbed
paws deep holes in the fine sand : the first comer,
in each case, making a pit about three feet deep,
laying its eggs (about one hundred and twenty
in number), and covering them with sand; the
next making its deposit at the top of its pre-
decessor, and so on until every pit is full. The
laying season over, which lasts about fifteen days,
the natives commence the work of collecting the
eggs. This is done in a very methodical manner.

DOMESTIC LIFE. 139

"Placards/7 says Bates, "were posted up on the
church doors at Ega, announcing that the excava-
tion on Shimuni would commence on the 17th of
October, and on Catesa ... on the 25th. We
set out on the 16th, and passed on the road . . .
a large number of people, men, women, and
children in canoes of all sizes, wending their way
as if to a great holiday gathering. By the
morning of the 17th, some four hundred people
were assembled on the borders of the sand-bank,
each family having erected a rude temporary shed
of poles and palm leaves to protect themselves
from the sun and rain. Large copper kettles
to prepare the oil, and hundreds of red earthen-
ware jars were scattered about on the sand. The
excavation of the taboleiro, collecting the eggs,
and purifying the oil, occupied four days. All
was done on a system established by the old
Portuguese governors, probably more than a
century ago. The commandante first took down
the names of all the masters of households, with
the number of persons each intended to employ
in digging; he then exacted a payment of one
hundred and forty reis (about fourpence) a head
towards defraying the expenses of sentinels. The
whole were then allowed to go to the taboleiro.
They ranged themselves round the circle, each
person armed with a paddle, to be used as a
spade, and all began simultaneously to dig, on
a signal being given — the roll of drums. . . .
It was an animating sight to behold the circle
of rival diggers throwing up clouds of sand in
their energetic labours and working gradually
towards the centre of the ring. ... By the end

140 THE STORY OF REPTILE LIFE.

of the second day the taboleiro was exhausted ;
large mounds of eggs, some of them four to five
feet in height, were then seen by the side of each
hut, the produce of the labours of the family."

"When no more eggs are to be found, the
mashing process begins. . . . The whole heap is
thrown into an empty canoe and mashed with
wooden prongs ; but sometimes naked Indians
and children jump into the mass and tread it
down, besmearing themselves with yolk and
making about as filthy a scene as can well be
imagined. This being finished, water is poured
into the canoe, and the fatty mass left for a
few hours to be heated by the sun, on which
the oil separates and rises to the surface. The
floating oil is afterwards skimmed off with long
spoons, made by tying large mussel-shells to the
end of rods, and purified over the fire in copper
kettles.

The destruction of turtle eggs every year
by these proceedings is enormous. At least
€000 jars, holding each three gallons, are ex-
ported annually from the Upper Amazons and
the Madeira to Para, where it is used for lighting,
frying fish, and other purposes. It may be
estimated that at least 2000 more jarfuls are
consumed by the inhabitants of the villages on
the river. Now it takes at least twelve basket-
fuls of eggs, or about 6000 by the wasteful
process followed, to make one jar of oil. The
total number of eggs annually destroyed amounts
therefore to 48,000,000, As each turtle lays
120, it follows that the offspring of 400,000
turtles is thus annihilated. A vast number,

DOMESTIC LIFE. 141

nevertheless, remain undetected, and these would
probably be sufficient to keep the turtle popula-
tion of the rivers up to the mark, if the people
did not follow the wasteful practice of lying in
wait for the newly-hatched young, and collecting
them by thousands for eating, their tender flesh
and the remains of the yolk in their entrails
being considered a great delicacy. The chief
natural enemies of the turtle are vultures and
alligators, which devour the newly-hatched young
as they descend in shoals to the water. These
must have destroyed an immensely greater num-
ber before European settlers began to appropriate
the eggs than they do now. It is almost doubt-
ful if this natural persecution did not act as
effectively in checking the increase of the turtle
as the artificial destruction now does. If we are
to believe the tradition of the Indians, however,
it had not this result, for they say that formerly
the waters teemed as thickly with turtles as the
air does now with mosquitoes. The universal
opinion of the settlers on the Upper Amazon is,
that the turtle has very greatly decreased in
numbers and is still annually deer easing. "

But this is a digression, though it is hoped
a pardonable one. Let us return to our subject
— the Care for the Young.

Among the Crocodiles, a veritable nest is built,
although in its simplest form this differs but little
from the hole dug by the majority of reptiles.
The Common Crocodile, for example (Crocodilus
niloticus), has been observed in Madagascar to
dig a hole in the sand of from eighteen inches
to two feet deep, so contrived that the bottom

142 THE STORY OF REPTILE LIFE.

of the nest is wider than the top, and has its
centre in the form of a mound. Thus, when
the eggs, some twenty to thirty in number, are
laid, they roll down the slope into the circular
trench. When the hole is filled up the mother
takes up her station on top when sleeping, and
thus betrays what she had taken so much pains
to conceal. In about twelve weeks the eggs are
hatched. The mother, when the time of hatching
is at hand, repairs to the nest to liberate her
young ones and conduct them to the water. The
reality of the mother's regard for her young was
proved by the naturalist Yoeltzkow, who built
a fence about a nest near hatching time. Several
times she returned and partly destroyed it during
the night, and each time it was replaced by a
stronger. At last the nest was found deserted,
and then it was discovered that the mother had
dug a hole beneath the fence through which her
offspring escaped.

It seems that the mother is warned of the
approaching escape from the shell by a peculiar
hiccough-like noise made by the young when she
returns for her nightly slumbers. Young birds,
it will be remembered, also signal their approach-
ing appearance by " cheeping " whilst within the
shell. Like the birds, the Crocodile breaks the
shell by means of an egg-tooth placed on the top
of the snout. The nest of the Alligator (Alli-
gator missisippiensis) is a much more portentous
structure, resembling that of the mound birds.
It is a large structure, built by the female, and
formed of dead leaves and twigs, together with
fine earth heaped up into a mound about three

DOMESTIC LIFE. 143

feet high, and as much as eight feet in diameter.
On the top of this mound, some eight inches
from the surface, some twenty to thirty white,
hard-shelled eggs are laid, and left to incubate
by the heat generated by the decaying vegetable
matter. As soon as the young escape from the
shell they make their way out of the nest and
run to the water without any aid or further care
from the parents. During the time that incuba-
tion is going on, however, the eggs appear to be
jealously guarded ; the mother digging a cave in
the river bank, immediately below the nest, and
there lies in wait for possible marauders.

Sea-snakes appear to guard their young for
some time after birth, inasmuch as the naturalist
Semper once found a large female coiled up
among the rocks, and between her folds were
at least twenty young, two feet in length.

That the Common British Viper accompanies
its young for some time appears to be very
probable, but the very prevalent belief that
they take refuge in the mother's throat when
threatened by danger, is wholly without founda-
tion in fact.

Among the lizards very little care appears to
be taken of the eggs, and of the young none
at all. Thus, for example, the Common English
Lizard (Lacerta vivipam) retains the eggs, some
six to twelve in number, within the body until
they are ripe, sometimes even the young escape
from the shell before leaving the body of the
parent. But once free they are left to their
fate. For some days they lie motionless among
the leaves or in crevices of the ground, being

144 THE STORY OF REPTILE LIFE.

nourished by the remains of the food yolk of
the egg. Not until this is absorbed do they
commence to feed, their first meal consisting of
aphides, and similar tiny creatures. At birth it
should be mentioned, they are less than an inch
in length.

We may pass now to a brief survey of another
side of reptile domestic life — their sociability.
Reptiles are far less frequently found dwelling
in colonies or living in large herds than birds
or mammals. Perhaps the most remarkable
instances are the great " warrens " of the Sand
Iguana of the Galapagos (Conolophus subcristatus),
and the enormous herds of an allied form living
on the same islands, Amblyrhynchus cristatus.
The former Darwin found to be so numerous
on James Island that "we could not for some
time find a spot free from their burrows on
which to pitch one single tent." The latter
are still abundant, and may be seen swarming
in masses of thousands on the rocks fringing the
sea. Similarly the Crocodilia and certain species
of sea-snakes consort together in enormous
numbers ; as also did the Tortoises of the
Galapagos a couple of centuries ago. These
huge crowds, however, are not gathered together
for mutual protection or love of their kind ; they
are simply the result of unchecked increase, there
being room and food enough for all, and no
enemies sufficiently powerful to keep down their
numbers.

In other cases, however, mutual advantage is
evidently the inciting cause to the gathering
together of large numbers of the same specie.

DOMESTIC LIFE. 145

Thus the Common British Grass-Snake (Tropi-
donotus natrix) and the Viper (Fipera lerus) on
the approach of winter seeks out some sheltered
hole in a bank, or under the roots of trees, and
in a state of torpor await the spring. Though
commonly they retire singly, they are not un-
frequently found huddled together in masses
of considerable numbers. With the Common
Rattle-snake (Crotalus horridus) of North America,
this custom of hybernation in large masses is
apparently the rule rather than the exception.
Assembling, it is said, in thousands from a radius
of twenty or thirty miles they meet, in the
ancestral den, to pass the winter in a state of
torpor, huddled together for the sake of warmth.
This "homing" instinct is, of course, of the
same nature as that which guides the swallow
back to its old nest, or the salmon back to the
same river, for nesting purposes.

Among the Crocodilia extremes of climate are
avoided in one of three ways — hybernation,
aestivation, and migration. Thus the Alligator
(A. missisippiensis) passes the cold season in a
state of torpor in holes in the ground; whilst
the Marsh Crocodile (C. palustris) of, India and
Ceylon passes periods of drought buried in the
mud, remaining there, in a torpid condition, till
the rains. The large Caiman (Caiman jacar) of
South America, apparently disapproving of this
waste of time, avoids unpleasant extremes by
migrating, retreating to the flooded forests in
the wet season, and returning to the rivers in
the dry season.

The Lizards and Tortoise-tribe also hybernate
K

146 THE STORY OF REPTILE LIFE.

when the winter is cold, but they do so singly
and not in colonies as in the foregoing instance.

CHAPTER VII.

REPTILIAN LIVERIES.

"THE existence of colour, as such," remarks
Professor Poulton, "is not necessarily of any
value to an organism." Colour is the incidental
result of chemical or physical structure which
causes certain light- waves to be absorbed ; or the
elements of the tissues may be so arranged that
the light is scattered, causing what are known as
interference colours, such as the metallic colours
of birds' feathers. The red colour of blood is an
instance of non-significant colour, since, hidden
away in the tissues of the body, its redness ceases
to exist, and only becomes apparent when drawn
from the animal. The often beautiful colours of
non-living bodies again serve as instances of non-
significant colour.

Nevertheless, the coloration of the vast bulk of
living animals is fraught with a deep significance,
and represents the results of a long process of
selection. From the wide range of variation
offered by the inevitable production of non-
significant colours, the innumerable patterns
which form the characteristic liveries of the
different species of animals have been formed.
Animals which, by their conspicuous coloration,
either drew upon themselves the attention of their

REPTILIAN LIVERIES. 14T

enemies, or advertised their presence to their prey,,
were gradually exterminated. In yet other cases,,
strangely enough, the development of strangely
contrasting colours proved of the greatest
benefit to the possessors, in consequence they
became yet more conspicuous, and survived on
account of this advantage over their more sombre;
relatives. It is by these means that the different
types of animal coloration of to-day have beeni
arrived at. The nature of these types, and the
part they play in the Story of Eeptile Life, we-
may now proceed to discuss.

The Eeptiles rank among the most gorgeously
coloured of animals, and the several types of
coloration which they display may be grouped
under three main heads : — Resemblance colours ;
Warning colours ; and the colours induced by
courtship.

Closely allied as the Eeptiles undoubtedly are.
to the birds, yet in the matter of coloration they
more nearly resemble the naked amphibia — the
much despised frogs, and toads and their allies.
Among the birds, seasonal changes and sexual
differences in coloration are common. Changes
according to season are almost unknown among-
the Eeptiles, and sexual differences are the excep-
tion, not the rule. With the birds, fleeting changes
of colour are restricted to naked areas of the
skin on the head and neck in some few species ;
and even then are rare, the colour being for the
most part fixed. The Eeptiles afford numerous
examples wherein the most rapid changes of
colour, all over the body, take place. The
interpretation of this is not far to seek ; it is due

148 THE STORY OF REPTILE LIFE.

chiefly to the very different nature of the covering
of the body. In the feathers of the bird, changes
of colour can take place only with extreme slow-
ness ; whereas, in the scaly skin of the Reptile,
or fish, or the smooth skin of the frog, a fleeting
play of colour is possible. It is brought
about in this wise. The horny outermost layer
of the skin is colourless; in the layer beneath
this are embedded iridescent cells with striated
surfaces. Below this, in the deepest layer of the
skin, cutis, are a large number of cells filled
with highly refractive granules, chiefly guanin-
crystals. These cause white colour by diffuse
reflection of direct light. Nearer the surface are
cells filled with oil-drops, and these give a yellow
colour. In the granular mass are embedded
numerous colour-bearing branching sacks or
chromatophores containing, for the most part,
blackish-brown or reddish pigment. The branches
of these sacks being contractile, the contained
granules of colour are drawn away from or
towards the surface of the skin, and thus,
combining with the stationary colour, effect a
corresponding change in the coloration of the
animal.

The marvellously .vivid hues which bedeck so
many Reptiles are all produced by a very limited
palette — black, red, yellow, and white, with the
combinations grey and brown. The white pig-
ment, as we have already remarked, is due to
guanin-crystals ; blue and green are structural or
optical colours. The former appears, at least in
birds, to be associated with a dark-coloured pig-
ment; the latter with a yellow pigment, in

REPTILIAN LIVERIES. 149

combination with a modification of the outer
horny and colourless layer of the epidermis.
The green colour of some tree snakes, however,
appears to be due to a pigment, inasmuch as Mr
Boulenger, one of our greatest authorities on
Eeptiles, observes that green tree-snakes give
the colour of the alcohol in which they are
preserved a green tinge.

Wholly white Eeptiles, it is interesting to
note, are unknown in an adult state, though it
must be remarked the newly-born chamseleon is
snow-white ; uniformly green, or blue, and black
are common. As a rule, however, the colours
are varied so as to produce a well-marked
pattern.

The " resemblance colours," to which reference
was made at the beginning of this chapter, are
so called because they enable the wearers to
conceal themselves, by reason of their likeness
to the general surroundings. By this means
they are enabled either to escape their enemies
or to approach their prey unobserved. Since
the same type of coloration is adopted to gain
two very different ends, we can only tell
whether the livery of any particular reptile is
assumed for protective or aggressive purposes
after a careful examination of each case. Thus,
the green tree-frog is obviously protectively
coloured, whilst the green tree-snake is to be
regarded as aggressively coloured. Incidentally,
of course, the aggressively coloured reptile is
also protectively coloured.

Though the real significance of the colours of
animals was not really grasped until within this

150 THE STORY OF REPTILE LIFE.

last few years, its meaning was vaguely realised
long since. As witness of this we quote the
following lines : —

•" The deadliest snakes are those which, twined 'mongst

flowers,

Blend their bright colouring with varied blossoms,
Their fierce eyes glittering like the spankled dewdrop ;
In all so like what nature has most harmless,
That sportive innocence, which dreads no danger,
Is poisoned unawares." — Old Play.

The absence of white coloration among
Keptiles is easily understood. Save amid snow,
such an investment would be extremely con-
spicuous, therefore the wearer would need either
to be sufficiently strong to bid defiance to all
enemies, or to be independent of colour for its
food. Amid snow a white dress might be essen-
tial, as among birds and mammals, but as
reptiles which live in regions where snow falls
hybernate during the winter months, no such
adaptation to their environment is needed.

The Lizards, Grass-snake, and Viper of the
British Islands are admirable examples of resem-
blance colours. Harmonizing perfectly with their
immediate surroundings, the lizards are to be
regarded as illustrating protective resemblance,
acquiring by their disguise escape from their
enemies the snakes. Whilst the latter from
their equally perfect covering illustrate aggres-
sive resemblance whereby they are enabled to
steal unawares upon their prey. It may be
objected that this theory of coloration proves
too much, inasmuch as, if the lizards are effec-
tually concealed, and with their other prey

REPTILIAN LIVERIES. 151

similarly protected, the snakes would starve.
As a matter of fact, in the first place, this
particular form of coloration, with both hunter
and hunted, is not absolutely perfect. In the
second, lizards have enemies other than snakes,
and snakes have prey other than lizards. The
protective coloration affords both a measure of
protection sufficiently great to ensure the sur-
vival of the device. Many times in the life of
an individual death must have been escaped
solely on account of this coloration; and so
with the snakes, conspicuously where their
chances of approaching prey unawares would be
infinitely small. The khaki uniform of our
soldiers does not prevent many from falling
victims to the more sharp-sighted of the enemy ;
but clad in red the mortality would be many
times as great.

Protective "resemblance colours" are of two
kinds among the Reptiles — those which are rela-
tively permanent and fixed, and those which are
variable and fleeting, though no sharp line can be
drawn between the two, inasmuch as, by reason
of the contractile powers of the chromatophores
under the stimulus of changes in the environ-
ment, even relatively permanent types of colora-
tion may change.

One of the best of all examples of permanent
protective coloration among the Eeptiles is
probably that of the Fimbriated Gecko ( Uroplatcs
fimbriatus) of Madagascar (see frontispiece).

The general colour of the body may be de-
scribed as that of a piece of bark, blotched irre-
gularly with patches of lichen-colour. Judging

152 THE STORY OF REPTILE LIFE.

from a specimen now (1903) living in the
Gardens of the Zoological Society, it would
seem, from the large size of the eyes, and its
custom of lying absolutely motionless along a
branch, that this creature is crepuscular in its
habits.

In a wild state, doubtless, the day is passed
stretched motionless along a bough, and abso-
lutely secure from detection. The resemblance
to the bough is still further enhanced partly by
the curious disposition of the limbs, which are
thrust out at odd angles from the body, and
partly owing to narrow fringes of skin, extend-
ing from the side of the lower jaw backwards to
the tail, where they suddenly expand into broad
folds. By this means the outline of the body is
obliterated passing insensibly into that of the
bough.

Contrasting in the strangest possible manner
with this is another Gecko (Phelesuma Madagas-
cariensis) also hailing from Madagascar. This
animal is of a rich, verdigris green, enlivened with
bright vermilion red spots in the middle of the
back, and a Y-shaped red bar on the crown of
the head. Little appears to be known about the
habits of this animal, but there can be no doubt
but that, unlike its relative, it hunts by day.
Its small eyes and green colour proclaim this.
These eyes, by the way, differ remarkably from
those of the species just described, inasmuch as
they are red in colour, and have a round pupil.
In the Fimbriated Gecko they are of a beautiful
golden yellow, streaked with vertical lines of
chestnut, and the pupil is vertical, by day appear-

REPTILIAN LIVERIES. 153

ing only as a barely perceptible slit. As the
shadows of evening grow the slit widens, till at
last the pupil becomes perfectly round.

Both these Geckos are instances of permanent,
protective coloration. Variable protective colora-
tion occurs in some Geckos and many Lizards,
but is apparently not met with among Snakes.
One of the best examples afforded by the Lizards
is that of the variable.

Calotis mystaceus, of Burma. Mr Mason
thus describes it : " The male ... is sometimes
a beauty. He may be often seen jerking his
head up and down, with the head, pouch, and
whole front of the body a glowing ultramarine
blue, contrasting beautifully with the reddish-
brown of the hinder part of the body and tail.
From the nose to the shoulders below the eye,
is a broad white band, which is interrupted by
those reddish-brown patches, in line with the
white band, before reaching the uniform reddish-
brown of the hinder part of the body. Occa-
sionally the white band below the eye assumes a
brownish colour, and the animal appears to have
a broad band down each side. He does not
always, however, appear in this xgay dress.
While I am writing, I see him coming down the
trunk of one of the trees in a very faded garment.
His skin suggests a bright calico after it has.
been washed, whose colours succumb to soap.
The blue is there, but it is no longer the bright
blue of yesterday. It has changed to a dull,
light indigo colour. He runs across the grass to
the foot of another tree, and stops on the bare
ground at its base, where for a minute or more

154 THE STORY OF REPTILE LIFE.

Tie bites with great energy at a struggling grass-
hopper, and while thus exercising himself the blue
fades out from his body altogether, and his whole
body takes the colour of the brown earth on which
he stands. After tarrying a minute or two he ran
up the other tree, and the dull light blue colour
seemed to return to him." Since the female of
this species is similarly coloured, it may be that
this naturally variable coloration has been in-
creased by sexual selection.

Equally vivid are the changes displayed by the
red Agama.

Agama sanguinolenta. Dr G-adow, on the
authority of a German naturalist, Zandes, thus
describes the many changes of colour displayed
by this lizard : " The usual garb is earthy brown
above, with somewhat darker and indistinct
markings. The under parts are whitish. Some-
times the creature changes to dirty white, at
other times into blackish or grey brown. Bluish-
red stripes may appear on the sides of the body ;
blue lines begin to show on the throat, and
alternately the whole belly, originally white,
may become ultramarine blue. When the general
tone happens to be sulphurous yellow, blue often
appears on the tail and limbs. Brick red appears
on four longitudinal rows of patches on the sides
of the body. Sometimes the whole animal assumes
.a vinous tinge, or it is at first greenish before
turning into blue. The change begins on the
tail and limbs, extends over the head, and at
length reaches the back. Eed appears in both
sexes, more frequently in the female ; blue almost
entirely in the male. Sunlight and warmth only

REPTILIAN LIVERIES. 155

intensify the colour." The change of fleeting
colours from behind forwards is interesting,
because Eimer has noticed that the change in
permanent pattern of many reptiles also takes
place from behind forwards.

It is the Chamseleon which is popularly supposed
to be the past master in the art of colour changes,
and certainly their reputation is justified. The
colour of the Common Chamseleon (Chamcdeon
vulgaris), Dr Gadow reminds us, is impossible to
describe, since the same specimen may appear
in half a dozen garbs in as many days. After
careful study for many months, when every
possible change and combination of colour seems
to have been exhausted, it will suddenly develop
a quite new combination. Individuals vary,
some change but slowly and seldom, others
frequently and rapidly. Some are much speckled,
others patched or streaked. In the dark they
appear generally to fade to a cream colour, but
this is not always the case; light focussed on
one side only, it is interesting to note, causes
that side to change in response, while the opposite
side of the body remains unchanged. Adaptation
to their immediate surroundings appear to take
place only to a modified extent, though, as a rule,
they appear to be brightest when amidst bright
green foliage.

Some animals have acquired the mantle of
protective coloration, not so much for the shelter
it affords as for the purpose of approaching their
prey unobserved, like wolves in sheep's clothing.
This device is known as "aggressive resem-
blance." It is practised, it will be remembered,

156 THE STORY OF REPTILE LIFE.

by the Mata-mata Tortoise (p. 42), the Croco-
diles and Alligators (p. 59), who, by their
resemblance to logs, are enabled to creep up to,
or be approached by, their prey without creating
suspicion. The Grass-snake and the Viper of
the British Islands, and the green tree-snakes,
and the sand-coloured desert forms are all in-
stances of aggressive resemblance. The giant
arboreal Boas and Anacondas have also to be
regarded under this head. Their enormous
bodies, if uniformly coloured, would be too con-
spicuous, consequently the surface is broken up,
in the case of the Boas (e.g. Python molurus) by a
net-work of black and yellow, and by the Ana-
condas by blotches of the same tints. Thus
the effect of strong light and shade, as of sun-
light breaking through a dense mass of leaves,
is produced. Instances of reptiles which resort
to what are known as adventitious colours for
protective or aggressive purposes are rare. The
Mata-mata, and a few other fresh- water Tortoises,
are cases in point.

Protective coloration, however, is sometimes
assumed for its own sake, and not for aggressive
purposes, as in the case of those snakes which
frequent rocky or desert places. But for their
harmony with their surroundings, they would be
in constant danger of being pounced upon by
snake-eating hawks and other enemies with a
liking for snake-flesh.

Certain lizards, and some snakes, have adopted
a system of what is known as "warning colora-
tion," whereby the creature, by exhibiting certain
conspicuously coloured areas, endeavours to make

REPTILIAN LIVERIES. 157

itself appear more formidable than it really is, or
save itself the trouble and expense of carrying
out its threat in those cases where the ability to
do this exists. That is to say, it adopts the
policy of " bluffing," which, as in human affairs,
is very often effective.

Among the lizards a very good instance is
furnished by the Moustached lizard (Phryno-
cephalus mystaceus). This is an inhabitant of
Transcaspia and Southern Russia, and when
threatened becomes violently excited, raises itself
upon its hind limbs, curls and uncurls its tail,
and opens its mouth to its widest extent ; with
the result that it assumes a quite fearsome
aspect. This effect is largely enhanced by the
fact that the corners of the mouth are provided
with flaps of skin, which, in excitement, swell up
into half-moon shaped plates, the inner surfaces
of w"hich pass gradually into the rosy lining of
the mouth, thereby causing it to appear much
larger than it really is.

The frilled-lizard, a native of Northern and
North-Western Australia, can assume an even
more formidable aspect when threatened by a
superior force. This is done by means of an
enormous frill encircling the head. This frill is
supported by the horns of the tongue-bones,
which are extraordinarily elongated, projecting
from the throat, on either side of the head, into
the frill like the ribs of an umbrella. When
brought to bay, the red-lined mouth, armed with
teeth, is opened to its fullest extent, and the
frill is spread so as to stand out like two huge
wings on either side of the head, with the result

REPTILIAN LIVERIES. 159

that a truly terrible aspect is assumed, calculated,
especially when backed by the very serviceable
looking teeth, to make most foes deliberate before
pressing attack further.

That signs other than colour are sometimes
adopted for warning purposes we have just seen
in the case of the frilled lizard. The deadly
Eattle-snakes (Crotalus) and the equally poison-
ous Cobra (Nqja\ are further cases in point.
Protective coloration has been adopted, as in
the foregoing instances, as a first-line of defence,
and when this is broken through, they fall back
upon the second — warning tactics. The device of
the rattle-snake is the production of peculiar
shrill sounds produced by a number of horny
"bells" loosely jointed and fitting closely one
into the other. These bells, which may be as
many as twelve in number, have a curious origin.
"The oldest terminal bell," says Dr Gadow, "is-
in reality the horny covering or tip of the tail,
and with each moult or shedding of the skin the
youngest bell becomes loose, but is held by the
new covering which has been developed in the
meantime. There is thus produced an ever-
increasing number of loosely joint ecj bells, but
every now and then most or all the bells break
off, probably when they are worn out, and a new
set is developed." The noise made by this rattle,
when the weather is dry is very considerable ;
so much so that in a room a vigorous snake can
make conversation almost impossible for half an
hour or more. During this time the rattle is
kept in such rapid vibrations that it shows only
as a blurred image. By this means possible

160 THE STORY OF REPTILE LIFE.

enemies are warned off, and thereby the snake is
saved the expenditure of poison which is used
only for the slaughter of victims for food, or the
purposes of self-defence when hard pressed.

The Cobras effect the same end by dilating
the neck. This is done through the agency of
the ribs in this region, which are raised so as to
expand the skin into a broad shield, sometimes
described as a "hood," and thereby giving a
terribly formidable appearance to the infuriated
animal. In some species the back of this shield
is adorned with a curious pattern described by
some as "spectacle pattern," by others as "eye-
like markings," and these are supposed to add to
the terrifying aspect. It is difficult to see, how-
ever, how this can be, since they are, from their
position, hidden from the view of the creature
for whose benefit the display is made.

In the foregoing cases the animals when at
rest are quite inconspicuously coloured, and in
no way court attention : but the North American
lizard known as the Gila-monster (Heloderma
suspectuin) behaves in a quite different manner.
About two feet long, and clad in what may be
likened to a " blazer " of black and orange
arranged in rings, this creature, though more
or less careful to conceal its very obtrusively
coloured carcase, makes no effort, when dis-
covered, to escape danger by flight. This
insolent confidence is apparently begotten by the
consciousness of power in the possession of
poison fangs. It is the only known poisonous
lizard. Like the poisonous snake, the death-
dealing fangs are grooved, and down these the

REPTILIAN LIVERIES. 161

poison, secreted by large glands, is conveyed
into the wound inflicted by the bite. It feeds
on worms, centipedes, frogs and lizards' eggs.
The frogs are paralysed by the poison, before
swallowing, as is the case with snakes. Though
not so powerful as that of many snakes, the bite
of the lizard has been known to produce death
in people whom they have bitten.

A precisely similar plan of warning coloration,
rings of black and red, or black and yellow, has
been adopted by certain South American snakes of
the genus Elaps, whilst the poisonous sea-snakes
of the genus Hydrophis and Enhydris, for example,
though less brilliant, have adopted a like device
— dark bands on a lighter ground. Hydrophis
obscura has black bars on a yellowish ground;
Enhydra bengalensis, black bars on a grey or
olive ground.

That this warning coloration is of use only
as a protection against their immediate enemies,
there can be no doubt. Indeed, Dr Alcock, F.R.S.,
of the India Museum, Calcutta, tells me that the
sea-eagles seize and devour these snakes with
impunity; so that the shore around the coast
of Malabar is strewn with the skeletons. This
means that the peculiar coloration can have no
significance for the eagles, which evidently find
this creature neither unpalatable nor dangerous.

Imitation is said to be the sincerest form of
flattery. Sometimes, however, a different motive
must be attributed to the imitators. In the cases
we are now about to consider, for example, certain
perfectly harmless snakes have adopted the livery
of the obnoxious species which have just been
L

162 THE STORY OF REPTILE LIFE.

described. These snakes live in the same regions
as the obnoxious forms, and thus it is easy to
see that, disguised as dangerous, they participate
in whatever advantages the obnoxious forms have
acquired, and in consequence, live in peace, in-
stead of perpetual molestation and persecution.
This assumption of the coloration of alien and
obnoxious forms is known as "Mimicry." Thus,
the deadly snakes of the genus Elaps, have
many imitators. The poisonous Elaps fulvius
of Guatemala is imitated by the harmless
Pliocerus equalis : Maps corallinus of Mexico by
the harmless Homalocranium semicindum-, whilst in
other parts of South America similar cases occur.
The poisonous water-snakes are likewise mimicked
by harmless forms.

Another interesting form of mimicry is that
wherein not so much the colours, as the actions
of the mimicked form are copied. A case in
point is that of the harmless and toothless Egg-
eating Snake (Dasypeltis\ which mimics the
poisonous Bug Adder (Clothos atropos). Both
are protectively coloured, but the harmless form
when alarmed, renders itself practically indis-
tinguishable from the poisonous, by flattening
out its head and darting forward with a hiss
as if to strike. It may well happen, of course,
that this disguise may cost the mimic its life,
and so completely defeat the object of the
mimicry. But this would only occur when the
subject to be terrified chanced to be a man,
who naturally kills at sight all venomous
reptiles he may come across, and it must be
remembered that the disguise of this snake is

REPTILIAN LIVERIES. 163

not an adaptation to defeat the wiles and higher
powers of discrimination of its arch-enemies.

The origin of the "warning colours" of
poisonous reptiles is probably a device lately
adopted and following on the success attained
by creatures which, unarmed, developed dis-
tasteful properties — rendering them unpalatable
to such animals as attempted to prey upon
them — and then advertised their unpalatability
by the display of conspicuous colours. This
device by no means assured absolute immunity,
since a certain percentage of these conspicuous
forms, constantly fell, and still fall, victims to
young and inexperienced animals who probably
seize them on account of their gaudy colours,
just as a child would do. Finding them unpala-
table they for ever after leave all animals so
coloured severely alone. The general truth of
this has been proved by experiment. Though
the subjects of the experiments die, only a small
percentage are sacrificed, whilst the vast body
of survivors have their safety assured. Dis-
tasteful ness in itself, without colour, is obviously
no protection since it makes no difference to the
distasteful animal whether it is tasted and re-
jected, or tasted and swallowed, whether it
die from injuries received, or whether it die
from ingestion; inasmuch as the taster is left
to go on repeating the experiment throughout
its life from inability to ' distinguish distasteful
from palatable forms.

For similar reasons, poisonous properties, in
themselves, are no protection — where protection
is required. If the poisonous animal be attacked

164 THE STORY OF REPTILE LIFE.

by a hungry animal, its superior in size, it will
succumb, and its death will fail to benefit its
surviving relatives inasmuch as the poison
renders the body neither unpalatable nor danger-
ous to the animal which eats it. Consequently
then, its poison is unrealized by the swallower, and
therefore could never have served as a deterrent
for future remembrance. As soon, however, as
the device of unpalatable animals was adopted,
immunity from experiment resulted, and with
it, the consequent gain to the species. This
being so, the warning-colours of reptiles, them-
selves now mimicked, originated in mimicry,
they being palatable, by their colours are mis-
taken for unpalatable.

Although the coloration of reptiles can, for
the most part be accounted for, with more or
less probability, there are some instances which
are not so easily to be explained. Thus, it is
a fact that the young of many reptiles are often
much more brilliantly coloured than their parents.
Why this should be is not clear, unless this more
brilliant livery was too conspicuous, and so was
exchanged for one of a more sombre type, and
now only reappears in the course of development
like other rejected characters.

Again, some snakes, though practically blind,
are most beautifully coloured, as in some of the
burrowing-snakes belonging to the family Uro-
peltidae. What is the use of colour here ?

Plow the coloration of reptiles has been
affected by courtship, we shall discuss in another
chapter.

CHAPTER VIII.

FLYING-DRAGONS.

SURELY no phase in the story of Reptile-life is
more pregnant with interest than that which
concerns the creatures which form the subject of
the present chapter.

Relics of an ancient past, appearing and dis-
appearing with a mysterious suddenness, much
of their history is hid in mist that can never be
penetrated. They are a contradiction in them-
selves, for a flying reptile is an anomaly. The
raison d'etre of their existence seems to have been
to point a moral and adorn a tale, the moral
being the unwisdom of dogmatising as to what
Nature can or cannot do. Inasmuch as, but for
the fortunate accident of the preservation of
their remains, the existence of creatures so
strangely made, and from a stock so proverbially
earth-bound, would have been deemed, by those
who affect the gift of prophesy, an impossibility.

If, familiarly, we may speak of them as
"flying-dragons," thereby in vesting ' them with
a species of eerieness to which they may well be
entitled, we must, when recalling their peculiar
features, do so in more severe language, using
the Christian and surname, so to speak, whereby
they have been made members of the kingdom
of animals.

The Pterodactyles, then, are so called on
account of the structure of the fore-limb, which
had become modified, by the extraordinary elon-

165

166 THE STORY OF REPTILE LIFE.

gation of one of the fingers, into a support for a
membrane or thin fold of skin, thereby converting
this limb into a wing, hence the name Ptero-
•dactyle, or wing-fingered.

In accordance with its powers of flight, we
iind the bones of the shoulder-girdle very strongly
•developed, whilst the bones of the hip-girdle and
the hind-limbs were weak. The sternum, or
breast-bone, forming the base of attachment for
the shoulder-girdle, was well developed, and
furthermore bore a large keel projecting from
its anterior border, for the attachment of the
powerful muscles needed to move the wings.
The position of this keel, it may be noted, agrees
closely with that of the G-annet among birds, it
being placed at the extreme anterior end of the
.sternal plate. This resemblance is extremely
interesting, as it suggests that the method of
flight was gannet-like. And this in turn lends
colour to the view that these strange creatures
fed upon fish which they picked up from
amongst the shoals swimming at the surface of
the sea. The method of capture pursued by
these old Reptiles, however, probably resembled
that of the Terns rather than that of the Gannet,
which seizes its victim by plunging, like a bolt
from the blue, beneath the surface of the water.

The bones of the skeleton generally, and of
the wings in particular, were hollow, and during
the life of the creature contained air, as in birds.
They are furthermore remarkable for their thin-
ness, a point of considerable importance in the
larger flying forms.

The head, which was very bird-like in many

FLYING-DRAGONS. 167

respects, varied greatly in size and shape among
the different groups. The jaws were either
armed with teeth lodged in sockets, and appar-
ently adapted for holding slippery prey, such as
fish ; or were toothless and ensheathed in horn,
or in thin leathery skin, as in birds.

The tail was in some species exceedingly short,
in others of great length.

In size these creatures varied greatly, the
smallest species not exceeding that of a sparrow,
the largest having an expanse of wing of over
twenty feet, these reaching the highest maximum
ever attained by any flying animal.

During life the body was probably invested
in a covering of scales, and it is quite probable,
especially having regard to the extreme activity
of these creatures, that these scales were bril-
liantly coloured, as in many Eeptiles of to-day.
When at rest, it is supposed that they passed
the time clinging to the surfaces of rock-cliffs by
the large claws on the short digits immediately
in front of the wing-finger.

Concerning the origin of this group of extra-
ordinary creatures we know nothing. They
appear suddenly, fully developed, in the Lower
Lias, e.g. Dimorphodon, and vanished from the
face of the earth quite as suddenly in the Cre-
taceous period. It is instructive to notice that
the earliest forms to appear were small, the
huge bulk ultimately attained by certain species
in the Cretaceous epoch being reached by slow
stages.

Since the wing is the most important feature
in these creatures we may profitably revert to

168 THE STORY OF REPTILE LIFE.

this organ, in order that we may study it a little
more closely.

As in the rest of the skeleton, this organ shows
signs of increasing complexity when traced from
the earliest known specimens onwards to the
time when they finally disappeared; though
these changes are not of a very marked character.
Of its origin we know nothing ; but of the five
digits which we may justly assume this limb
originally possessed, only four remain. The
missing digit is that answering to our little
finger. The first, second, and third fingers were
short, and armed with claws, which served pro-
bably to suspend the animal when at rest, whilst
the fourth was enormously elongated. This
served, during life, for the attachment of a large
fold of skin extending outwards from the body,
and backwards, to include the hind-limbs and tail.
It differs fundamentally from the wings of the bat
and bird. In the former, all the fingers are pre-
served, the thumb is free, and the remaining four
are enormously elongated and extremely slender,
serving to support a thin skin-fold much as the
ribs of an umbrella support its covering. In the
bird, three fingers remain, the thumb, which is
short, is free, whilst the second and third digits
are closely bound together, forming a rod for
the support of ribbon-shaped organs known as
the quill-feathers. Further details of this wing,
compared with that of the bat and pterodactyle,
by the way, will be found in the " Story of Bird
Life."

As in the bird and bat, there extended along
the front of the wing, from the shoulder to the

FLYING-DRAGONS. 169

wrist, a fold of membrane, like the large fold
which served the purposes of flight. This mem-
brane was probably bounded in front by a strong
tendon which, before it reached the wrist, passed
into, or was attached to, a long, slender bone
known as the "pteroid." This bone has been
the cause of much speculation, and by some
authorities is regarded as answering to the
thumb. Probably, however, it corresponds to a
similar but smaller bone found in a precisely
similar position in the bird, and known as the
os prominens. The development of bones in
tendons subjected to considerable strain is a
common feature. When nodular in form they
are known as sesamoids.

The wrist bones, as in the bird, were consider-
ably reduced in number. In the earlier ptero-
dactyles there were two distinct rows, made
up of several distinct bones ; but in the later
Cretaceous types, these became merged one into
another, so that those of each of the two origin-
ally distinct rows became fused, each row into a
single bone.

The bones of the middle-hand, or metacarpus,
are seen also to undergo modifications. In some
species they were very short, whilst in others, as
in the species of the genera Cynorhamphus and
Ptenodmcon, they were extremely long, thus
giving an extra joint to the wing, comparable to
that formed by the elongation of certain ankle-
bones in the Frog, for example. What purpose
this elongation may have served is unknown ;
but it is interesting to note that those species in
which those middle-hand bones were elongated

170 THE STORY OF REPTILE LIFE.

the fore-arm was relatively shorter than in those
with shorter hands.

Here this examination of the wing must stop,
lest we become wearisome.

The method of locomotion when on the ground
has given rise to much speculation. According
to Professor Seeley, these creatures walked on all
fours on upright legs, the wing-finger and its
membrane being folded and turned upwards
like a pair of umbrellas, to allow the palm of the
hand to reach the ground. Though it savours of
presumption to question the verdict of one so
versed in all that concerns these creatures, we
venture to doubt whether this was possible.
Rather, we believe, they scrambled along the
ground after the fashion of a bat.

Whilst the majority of these creatures hunted
their prey by daylight, others would appear to
have been crepuscular in habit, inasmuch as the
eyes in these forms are of great size. Whether
these nocturnal species were also fish-eaters we
'do not know.

In general appearance, as we have already
remarked, the Pterodadyles varied considerably,
.at least when extreme types are compared. The
earliest known species, Dimorphodon macronyx,
from the Lower Lias of Dorsetshire, had a
relatively enormous head and a relatively small
brain. Its jaws were armed with large teeth,
and the tail was extremely long. This species
was, by the way, by no means a pigmy in point
of size, having a skull of some eight inches in
length and an expanse of wing of four feet. The
Pterodactyles of the genus Rhamphorhynchus, of

FLYING-DRAGONS. 171

the Lithographic Stone of Bavaria, differed from
Dimorphodon chiefly in that the head was long
and pointed, and that the tail, which was of great
length, terminated in a leaf -like expansion.

Side by side with these long-tailed, tooth-
bearing forms there lived numerous short-tailed
types, which exhibit evidences of increasing
specialisation in the gradual decline of the teeth
and the evolution of toothless types, whose jaws
were either encased in horn or a thin leathery
skin as in birds. These new types are repre-
sented by the species of the genus Ptertdadylus.
In Pterodadylus antiquus, for example, we find
only a few small teeth confined to the anterior
end of the jaws, whilst in P. spectabilis they have
completely disappeared. Curiosity is naturally
stimulated to account for this loss of the teeth,
but so far, no explanation appears to be forth-
coming. Assuming them to have preyed upon
fish, as is generally believed, the advantage of
such weapons seems obvious, for fish are pro-
verbially slippery creatures. Nevertheless, we
find indubitable evidence, if we turn to the birds,
that toothless jaws are by no means incompatible
with a fish diet, as witness the Corrnorants and
Kingfishers, Herons, Divers and Grebes, and
Penguins, for example. Among the fish-eating
birds, however, we must not forget that some
seem to have had to make shift to replace the
lost teeth of their ancestors by developing tooth-
like processes on the edges of the horny jaws, as
in the case of the Mergansers among the Drakes,
and in the Darters, allies of the Cormorants.

Further evidence of specialisation in the form

172 THE STORY OF REPTILE LIFE.

of increased size, and in the development of
ornament, appear in the Pterodactyles of the
Cretaceous or Chalk age, some of the largest
of which attained a gigantic size, having an
expanse of wing of twenty feet, and a skull
a yard in length. Whilst some species were
tooth-bearing, others were entirely toothless.
But with or without teeth they must have been
formidable creatures — flying-dragons, indeed !
Animals of such enormous size, would, one
would have imagined, have become incapable
of flight, as in the case of the Ostrich-tribe
among birds. As a matter of fact, however,
the bodies of these flying monsters were remark-
able for their lightness, partly owing to the
extreme thinness of the bones, which were
almost paper-like in thickness. Furthermore,
the trunk, in proportion to the size of the head
and wings, was really extremely small. In one
genus at least, the bones of the shoulder-girdle
underwent a peculiar modification on account
of the great size of these wings ; inasmuch as
the shoulder-blade, instead of running backwards
parallel with the spine, and over the ribs, turned
directly inwards so as to lie parallel with the
ribs and at right angles to the spine with one
of the neural-arches of which it is articulated by
a special joint. This gave rigidity to the girdle.
Among the birds this very necessary stay is
provided by the merrythought, a bone con-
spicuous by its absence in the pterodactyle.

The question of ornament is a delicate one,
inasmuch as this is for the most part an entirely
superficial character, and therefore leaves no

FLYING-DRAGONS. 173

record after death. As we have already re-
marked, the general coloration of the body
may have been extremely brilliant. The play
of colour over the wing-like expansions of the
Flying-Lizard of to-day (Draco wlans), is at times
wondrously vivid, and there is certainly no
reason why the wings of these old-world creatures
should not have been equally beautiful. The
only evidence, however, that we can produce

FIG. 12.— Outline restoration of an extinct Flying-dragon (Pteranodori).
By the author.

in support of this hypothesis, is of an indirect
character. This is afforded by the giant Pter-
anodon longiceps, of the Cretaceous of North
America, wherein the hinder regions of the
skull was produced backwards and upwards
into an enormous bony crest, comparable to
that of the Cassowaries among living birds,
which is certainly an ornamental feature. We
may conceive that this ancient flying-dragon,
then, was one of the beaus of his kind. His great
toothless stork-like beak — a yard long — and
cranial crest ensheathed in a gaily-coloured case,
and his body made resplendent with all the

174 THE STORY OF REPTILE LIFE.

colours of the rainbow, glistening with iri-
descence, as only the scales of a reptile can, he
used these charms, perchance, to overcome the
indifference of a much-exacting mate ; wheeling
and turning in the sunlight, in amorous flights,
till finally he conquered.

During the time that these creatures lived
they appear to have spread themselves almost
over the whole world. Their remains occur in
abundance in the British Islands, in the Lias,
the Great Oolite, the Cambridge Greensand, and
the chalk of Kent, some of them measuring as
much as twenty feet across the expanded wings.
In Europe, beautifully preserved examples occur
in the Lithographic Stone of Bavaria, others in
the earlier Oolitic and Lias formation. They
do not appear to have reached America until the
Cretaceous period, where remains of some of the
very largest examples have been obtained from
the chalk of Kansas. That they occurred else-
where on the earth's surface, and both earlier
and later in time than present records show,
is highly probable, and proof of this may at
any time be produced. The preservation, as
well as the discovery, of the remains hitherto
unearthed is the result of a series of those
accidents by which the world has benefited;
although the list appears now to be practically
exhausted, we may live in hope that this will
not prove to be so. In any case, enough remains
to form one of the most striking and impressive
chapters in the history of the animal life of this
wonderful world of ours yet pieced together.
To the Story of Reptile Life, these creatures

EARTH DRAGONS. 175

have contributed much, for their mysterious
origin, sudden extinction, and wonderful organisa-
tion, has caused their much-despised cousins of
to-day to shine with a kind of reflected glory !

CHAPTER IX.

EARTH DRAGONS.

WHILST the creatures described in the last
chapter mark but an episode in the story we
are endeavouring to tell, the history of those
which we are immediately to consider, marks
an epoch of the greatest magnitude in the
development of animal life upon the earth. In
this same chapter we shall also deal with creatures
of brobdignagian proportions, and the question
of their ancestry. Our survey, however, must
necessarily be brief, for these themes bristle
with difficulties, and can only be rightly under-
stood by those qualified by a life study of such
questions, to discern the value and true per-
spective of the evidence so far collected.

It will be remembered that at the very com-
mencement of our story we showed that the
origin of the Reptile people is to be traced from
the lowly stock to which the Frogs, Toads and
Newts belong. But we then made no mention
of the fact that simultaneously there arose from
this same stock a second group, which, develop-
ing along different lines to those followed by the
main branch, terminated in a coterie of forms

176 THE STORY OF REPTILE LIFE.

known collectively as the Anomodontia, or,
according to some, as the Theriodontia, in refer-
ence to the form of the teeth. These creatures
have excited the most profound interest, not
only because they present so many important
differences from the members of the other
branch, but also, and chiefly, because it is from
their ranks that we are enabled to trace, with
no small degree of certainty, the origin of the
mammalia, the highest of all the Vertibrates;
though we can, at present, point to no known
form as the actual ancestor thereof. The close
resemblance, sometimes most striking, between
certain species of these ancestral reptiles and the
Carnivora among the mammalia, is to be put
down to the fact that both trace their descent
from the same source, and leading similar lives
have developed similar organs.

As a sample of the rarity of this likeness let
us take a single instance, that furnished by the
species known as Cynognathus crateronotus of the
Karoo formation (Permian or Triassic) of South
Africa — the source from which most of these
remarkable forms have been obtained. The
skull of this beast presents a quite astonishing
similarity, especially in regard to the teeth, to
that of a dog or wolf. The component elements
of the skull, however, and the character of the
vertebrae, reveal the reptilian nature of these
remains. The teeth of another species (Trity-
lodon) were of the type adapted for grinding
purposes, and for a long time were actually
believed to be those of a mammal. Further
pursuit of this subject would be a departure

EARTH DRAGONS.

177

from the legitimate object of this book, and
must accordingly be left for another volume
which we propose to devote to Mammal Life.

But, as we have already hinted, besides these
singularly mammalian types yet other types
existed which, somewhat differently constituted
to the forms which gave birth to such dis-
tinguished progeny, developed and intensified

FIG. 13.— Outline restoration of the skull of an Extinct Mammal-like
Reptile Cynognathus. Note the general dog-like shape of the
skull.— After Smith Woodward.

their several peculiarities, so that they eventu-
ally died out unmistakable reptiles. Since they
too present traces of distinct mammalian lean-
ings, we may regard them as creatures striving
after an unattainable ideal, achieved, however,
by people of their own blood.

The forms in question constitute three distinct
groups. The most primitive of these, that is to
say, the nearest to the ancient giant Salamanders
or Labyrinthodonts, the ancestral stock just re-
ferred to, is that represented by an anomalous
M

178 THE STORY OF REPTILE LIFE.

looking beast known as Pariesaurus. This was
a heavy, clumsily built animal, with a short,
massive head, and short tail and legs. The
limbs, however, were sufficiently long to carry
the body well above the ground. The jaws
were armed with teeth having serrated edges.
But in addition to these, small teeth occurred
also on the palate. From the heavy build of
this beast, we may infer that it was of a sluggish
disposition, but others, notably the Carnivorous
types, doubtless displayed extreme agility. The
carriage of the body is an extremely interesting
feature of these animals, for among the reptiles,
with the exception of the Chameleons and the
Pterodactyles, and the forms to be described
presently, the body must be said to be dragged
rather than carried over the ground.

The last group to be considered is remarkable
for the extreme specialisation which it displays
in the matter of the teeth. In the forms known
as the Dicynodontia, or double dog-toothed, the
jaws were either toothless or encased in horn, as
in the Tortoises, or were armed with a single
pair of tusk-like teeth which projected down-
wards from the upper jaw. It is from the
presence of these teeth that the group takes its
name.

Whether the remains of certain large Eeptiles
which have been found in Texas really belong to
this group or not is uncertain. But the genera
known as Dimetrodon and Naosaurus are remark-
able, indeed unique, on account of the enormous
development of the spines of the anterior trunk
vertebrae, which projected above their case of

EARTH DRAGONS. 179

attachment, some two feet, and probably formed an
immovable but fin-like crest along the back. In
Naosaurus these spines acquire a still more
eccentric character developing some half dozen
cross-pieces, like the yards of a ship's mast.
What part these could have played is a mystery !

We must turn now to a very different group
of Reptiles, long celebrated both on account of
their bizarre shape, as well as for the colossal
size which many of them attained. It has been
suggested indeed that the numerous legends of
dragons handed down to us from remote times
are founded upon remains of these creatures,
which may have been unearthed by unsophis-
ticated people with a love for the marvellous.
Mythical these stories undoubtedly are, in so far
as they affect to record the conflicts which have
taken place between men and beasts of this kind,
inasmuch as the advent of man took place some
millions of years after the last of these monsters
had ceased to exist, nevertheless the author of
the first fable may have been inspired by the
discovery of the remains of some unusually well-
preserved fossil. But whether or no, they are
the dragons indicated in the title chosen for this
chapter. To the serious student they are known
as Dinosaurs — terrible Eeptiles — an appropriate
name enough !

As touching their origin, we may remark that
they arose during the Triassic period, as Dr
Smith Woodward reminds us, as a race of land
reptiles, " at first so generalised that it is dinicult-
to separate them from the Hhyncocephalia (p.
11) and Crocodilia, but afterwards constituting

180 THE STORY OF REPTILE LIFE.

at least one distinct order." An alliance with
the Anomodonts has recently been suggested,
but this is not likely to receive much favour.
They reached the dignity of a dominant race
during the Jurassic and Cretaceous periods,
succeeding the Anomodontia, and disappearing as
the Mammalia commenced their era of ascendancy.
These singular creatures, like other notorious
groups which preceded and followed them, make
their first appearance on the stage in a compara-
tively humble guise, the earliest known forms
being small carnivorous types, having the jaws
well armed with cutting teeth lodged in sockets,
and hollow bones, like those of birds. In the
course of the evolution of the group we find
specialisation taking place in many directions.
Originally quadrupedal, some became bipedal,
developing enormous hind-limbs, and reducing
the size of the fore-limbs, a method of pro-
gression which, at different times and in various
places, during the history of this group, deve-
loped into leaping, as in the Kangaroo and
Jerboa of to-day. Witnesses to this we have
in the remains of ffallopus, from the Jurassic of
Colorado, and Compsognathus, a beast about the
size of a fowl, from the Lithographic Stone of
Solenhofen in Bavaria. As the body increased
in size, attaining that enormous bulk which has
made these creatures famous, such agility became
impossible. Indeed, it is now generally believed
that the huge size of the very largest species
made life on land almost impossible. But to
this we shall return. There is good evidence to
show that the larger species at least of these

EARTH DRAGONS. 181

bipedal types when at rest supported the body
on the downwardly directed branches of the
hip-girdle, known as the pules, and it is probable
that the skin immediately covering these deve-
loped a thick callous pad like that on the breast
of the Ostrich, which serves a similar purpose.

One of the earliest known of these carnivorous
forms was a beast named Anchisaurus colurus.
Measured by the standards of to-day, he would
have been called large, standing about four feet
high. But he was a veritable pygmy compared
with some of the forms which arose during the
later Jurassic era. By way of illustration, we
will select the species known as Ceratosaurus
nasicornis, since this lived in what is now North
America, its remains having been found in the
Upper Jurassic of Colorado. Standing, when
erect, some twelve feet high, this monster was pro-
bably capable of considerable activity, since its
bones were hollow. With an enormous head,
armed with powerful and pointed teeth, and a
formidable horn on its snout resembling that of
a Rhinoceros, it preyed, in all probability, upon
equally huge herbivorous species of its own kind.
But earlier than this, there lived 'in our own
islands similar bipedal carnivorous types, quite
as huge as the Ceratosaurus. The remains of one
such, known as Megalosaurus bucklandi, having
been found in the Great Oolite of Stonesfield,
near Oxford. The teeth of this animal were more
than three inches long, and had finely serrated
edges, therein differing in this respect from the
teeth of Ceratosaurus.

The development of the herbivorous types, to

182 THE STORY OF REPTILE LIFE.

which reference has been made, proceeded simul-
taneously with that of the carnivorous, and it
would appear attained even more striking results
in the matter of bulk, some species having reached
a quite colossal size.

In the course of their evolution many changes,
other than mere increase in size, are to be
remarked. Thus in some we find more or fewer
of the teeth suppressed, and their place taken
by horny plates ; in others, we meet with the
development of heavy armour, intended to serve
the purposes either of offence or defence. Again,
it is to be noted that bipedal and quadrupedal
forms alike competed in the race for size, and
though in the end victory rested with the
quadruped types the race was keen and close.

The huge beast known as Brontosaurus excelcus
from the Jurassic of Colorado may be taken as
a type of the quadrupedal group. Attaining a
length of between 50 and 60 feet, this creature
was remarkable for the small size of its skull,
which was smaller in proportion to the size of
its body than in any other known Reptile. The
jaws were armed with blunt-pointed teeth. The
neck and tail were of great length, whilst the
trunk was comparatively short. The weight of
such an enormous body was greatly reduced by
the hollo wn ess of the bones, which were, through-
out the skeleton, permeated by large air cavities.
In another closely allied contemporary, Diplodocus
longus, we see the effect of specialisation in regard
to feeding habits reflected in the dentition, which
was of a very curious type. Only the front of
the jaws bore teeth, and these were extremely

EARTH DRAGONS. 183

feeble, long and slender in character : longest in
the middle of the jaws and decreasing and finally
disappearing on each side, so that by far the
greater part of the jaws were quite toothless.
The suggestion that this peculiar dentition is due
to adaptation to feeding on succulent aquatic vege-
tation is borne out by several features in the skele-
ton. Chiefest of these is the fact that there was
but a single external bony nostril, and this opened
on the middle of the top of the skull, as in whales
and porpoises. From this we may gather that
the creature led a more or less completely aquatic
life, the position of the nostril allowing it to come
to the surface to breathe without exposing the
rest of the body. But hugest of all these giants
was the great Atlantosaurus, with a length of 80
feet, and a height of thirty feet ! Mere figures will
not convey any idea of the real proportions of
this living mountain of flesh. This can only be
done by comparing it with some of the giants of
to-day. An elephant beside this monster becomes
a pygmy : only some of the largest whales equal
it in length, but they do not approach it in
height, being to all intents and purposes legless.
As we have before remarked, somfe are inclined
to believe that the great size of these monsters
was incompatible with a life on land, and that
accordingly they must have lived in the water.
Bodies of such huge size, it is argued, could
scarcely be moved on land, but, buoyed up by
water locomotion would be easy. That many
species were indeed aquatic, obtaining their sus-
tenance by browsing on aquatic vegetation, there
is good reason to believe ; indeed, in the remains

184 THE STORY OF REPTILE LIFE.

of the Diplodocus just described we have almost
convincing proof of this. The limbs of this
species, it is interesting to note, were of the same
type as those of the Atlantosaurus and Bronto-
sauruSj pillar-shaped and short-toed, that is to
say, they resembled the limbs of the Elephant,
Hippopotamus and Rhinoceros in the main feat-
ures, and these, it is to be noticed, all have ex-
tremely heavy bodies. Accordingly this type of
limb has been adopted as most suited to bear the
strains imposed thereon.

The existence of limbs of this type in an ex-
clusively aquatic animal is an extremely inter-
esting feature, and shows that this mode of life was
adopted long after the limbs had become adapted
to the requirements of a terrestrial life, as in the
case of the Hippopotamus among the Mammalia.
The latter, it is to be remarked, is an expert
swimmer, though we would not gather as much
from the shape of the legs ! Possibly, like the
Hippopotamus, these ancient reptiles passed a
certain amount of time on shore, and hence the
need of preserving the terrestrial form of the
limbs.

Among the bipedal types we have equally
gigantic species. As an example we may select
the celebrated Iguanodon bernissartensis, repre-
sented as in life opposite. Like the four-footed
types, some of these huge bipeds are believed
to have been aquatic, on account of their
great size. Although there is much to be
said in support of this view, there yet seems
room for doubt as to whether this aquatic
habit was as universal as the hypothesis de-

FIG. 14.— Restoration of land-dragon — Iguanodon bemissartensis.
The thumb of this hupe monster was armed with a powerful
spur, which was probably used as a weapon of defence.— By the
Author.

186 THE STORY OF REPTILE LIFE.

mands. The Iguanodons seem to show that
at least all but the very largest may have lived
on land.- Of the reptiles now in question, four
or five species are known, remains of which
have been found in this country, though not in
such completeness as in Belgium. Of these two
species, the smaller Iguanodon mantelli was about
equal in size to the extinct Giant Sloth, Mega-
therium. Now the latter, one of the Mam-
malia, was most emphatically a forest-haunting
species, and we may well imagine that Man-
tell's Iguanodon, which is known to have been
herbivorous, lived in a similar habitat. This
being so, it seems more reasonable to suppose
that the still larger species, Iguanodon bernissar-
tensis, which was some thirty feet long from the tip
of the snout to the tip of the tail, was, in spite
of its great size, also a dweller on land. Other-
wise, we must suppose either that the aquatic
life was adopted after the size of the smaller
species had been surpassed, or that, though
living in environments totally different, they
acquired a form practically indistinguishable
save in point of size. Between Iguanodon and
Diplodocus there is an interesting point of
difference in the matter of the dentition, for
whereas in the latter only the front of the jaws
bear teeth, and these of a peculiarly slender
character, in the former the front of the jaws
were toothless and ensheathed in horn, whilst
the sides of the jaws bore teeth in closely serried
ranks. From their close resemblance to the teeth
of the living Iguanas this giant derives its name,
which being translated means Iguana toothed.

EARTH DRAGONS. 187

The general appearance of this monster can be
seen from the accompanying illustration. As we
have already remarked, remains of these huge
reptiles occur in the British Islands, but com-
plete skeletons have been found in Belgium.
Indeed, the manner of their discovery surpasses
all similar records, inasmuch as no less than
twenty-nine were found in one spot during
mining operations for coal at Bernissart, in
Belgium. Probably they were overwhelmed by
some great flood, swept into the river, and their
bodies borne down by the stream and deposited
at the estuary, where they were slowly covered
up in the mud which always collects at this
point.

Among the armoured types were some very
formidable creatures, in every way worthy of
the name of Dragons. One of the most striking
forms is that known as Triceratops, he of the
three horns. The head of this beast was five
feet long, being longer than in any other known
land animal. From the roof of the skull there
arose three formidable horns, one above each
eye and one on the snout, whilst the bones of the
back of the skull were expanded to form an
enormous frill overlapping the neck. Like the
Iguana, the front of the jaws were toothless and
ensheathed in horn, so as to form a sharp cutting
beak. That the trunk was heavily armoured
with bony plates is probable, though we have no
positive evidence on this point as yet. The total
length of this brute exceeded twenty-five feet.
Whether these weapons were worn by the males
only, and whether they were used offensively by

188

THE STORY OF REPTILE LIFE.

rival males when fighting for the females of their
choice, as is the case among the horned ruminants
of the present day, or whether they were used
defensively against their giant carnivorous
relatives, we, of course, shall never know. Be
this as it may, their presence seems to argue
considerable activity on the part of the wearers
thereof. A fight between a couple of infuriated

FIG. 15. — Outline restoration of an extinct gigantic Land-dragon
(Stegosaurus). Note the remarkable double row of plates running
down the back, and the huge spines on the tail. — After a drawing
by C. E. Knight.

beasts of this description would have been an
exciting scene to witness !

Still more remarkable animals in many respects
were the Stegosaurs, from the Upper Jurassic
of Colorado. The largest of these was about
twenty feet long. The head, unlike that of
Triceratops, was remarkably small, whilst the
brain seems to have been smaller, in proportion
to the size of the animal, than in any other land
animal. The armature consisted of a double row
of enormous bony plates running along the back,
from the neck to the base of the tail, in the form

EARTH DRAGONS. 189

of a double crest. The largest of these plates is
two feet high, and this probably does not repre-
sent their full size since they were almost
certainly invested in a horny sheath. The tail,
some ten feet long, was armed with a formidable
array of spines, forked at the top, and some of
them as much as three feet in length, with a
diameter of six inches at the base ! Whether
the sides of the body were also protected by
bony plates we do not know; neither can any
hazard a guess as to the use or probable need
of such an extraordinary armour as that which
surmounted the back.

In not a few instances these wonderful reptiles
have left their mark upon the world in the shape
of footprints. ^4ncJiisaurus colurus, the carnivor-
ous beast mentioned earlier in this chapter, is
one of the species which has impressed the world
in this fashion ! For a long while these foot-
prints were believed to be those of birds, inas-
much as the marks of two feet only were dis-
cernible, and they had apparently but three toes
apiece. Undoubtedly these impressions bear an
unmistakable resemblance to those made by birds,
and as the Dinosaurs were then unknown, the
obvious inference was that birds had made
them.

We now know their true origin, and there is
the less room for doubt since, at that period of
the world's history, birds had not appeared.
These " footprints on the sands of time" were
apparently made in soft, clayey soil, probably
near the margin of some pool or shelving river
bank, and then covered at high tide with turbid

190 THE STORY OF REPTILE LIFE.

water, which filled up the impress with fine mud.
In some other cases where these footprints of
bipedal dinosaurs are preserved, the smaller
prints of the fore-limbs are also visible, showing
where the creature had progressed on all fours, just
as kangaroos do when feeding. The feet of the
gigantic Brontosaurus made an imprint covering
an area of a square yard ! In England, foot-
prints ascribed to Dinosaurs have also been
found. As Mr Lucas remarks, " oddly enough,
these numerous tracks all run one way, from
west to east, as if the animals were migrating, or
were pursuing well-known and customary routes
to their feeding-grounds."

Whether these huge creatures laid eggs or
produced their young alive is a legitimate subject
for speculation. The probability is that they
were viviparous. In one species, indeed (Compso-
gnathus longipes), what appears to be the remains
of an embryo have been traced.

In the matter of brains they seem to have
been singularly deficient, those of the very hugest
species not exceeding a weight of two pounds.
Much the same holds good with the giants among
the Mammalia, Really, however, there is no
need that the size of the brain should increase in
the same ratio as the size of the body. The
amount of intelligence required of these giants is
no greater than that demanded of their relatively
pygmy relations, and of co-ordination of move-
ment much the same may be said. It is only
when creatures of low intelligence come into
contact with more highly gifted competitors
that brain power tells, as witness the results

EARTH DRAGONS. 191

which have followed the advent of man in com-
petition with the lower animals.

These huge reptiles lived in an age of reptiles,,
when the Mammalia were at most only just emerg-
ing. They were the dominant type, and there-
fore had just as much intelligence as the times
required and no more. They do not owe their
structure to lack of reasoning powers, but to
other causes which we shall discuss later.

As touching the relationship which has long
been held to exist between the dinosaurs and
the birds, those who have read the "Story
of Bird Life," may remember that certain strik-
ing points of resemblance were pointed out
between the hip-girdle and hind-limbs, in the
bipedal dinosaurs and birds. These resemblances,
it was suggested, were to be attributed rather
to a derivation from a common stock, than to
parallel development due to a similar mode of
locomotion. This view, first promulgated by
Huxley, has been widely accepted. Neverthe-
less, it is now being as widely discarded, and
we think rightly so. This is not the place
wherein to discuss the question of the bird's
ancestry, but we may perhaps be fairly expected
to offer some justification for the rejection of
an association apparently so well-founded and
commonly believed in. The view advanced by
Dr Gradow, that those dinosaurs which most
resemble Archseopteryx, the oldest known bird,
were its contemporaries, and therefore cannot
be regarded as ancestral forms, has this ob-
jection, that it does not take into considera-
tion the fact that though Archaeopteryx is the-

192 THE STORY OF REPTILE LIFE.

oldest known bird, it is certainly not the first
bird. Whether their remains are ever found or
not, there can be no doubt but that yet more
primitive types than Archaeopteryx must have
existed, and similarly there must have lived
more primitive types than the most primitive
known dinosaurs — Anchisaurus and Zandodon, cf
the Upper Trias. Consequently there is no
reason why the bird and the dinosaur should
not, after all, have been derived from the same
incipient stock. That is to say, the mere fact
that the oldest-known bird and the most bird-
like dinosaurs were contemporaries, or that the
wing of the bird is totally different from the
fore-limb of these contemporaries, is no proof
that the two forms must be of totally distinct
origin. The real objection to such an alliance
seems to lie in the structural plan of the skull.
The dinosaurs exhibit the same wing-like ex-
pansions of the hinder-end of the parietal, and
splint-like squamosal that is found to obtain in
all the members of that great branch of the
reptilia, which apparently derive their origin
from the Rhyncocephalian stock. Whilst this
region of the skull in the birds rather resembles
that of the Anomodonts and Chelonia, whether
the latter really derive their origin from this
stock or not, is a moot point. But there is
good reason to believe that the Anomodonts,
as we have already pointed out, are direct
descendants from the ancient Amphibia. The
birds then, perchance, may have arisen from
a stem quite distinct from the dinosaurs, though
we are as yet in ignorance of the precise nature

DRAGONS OF THE DEEP. 193

of the creatures which may have given them
birth. The geological record is notoriously
incomplete, but nevertheless there is no reason
why many types totally undreamed of to-day
should not in the near future come to light,
and among these we may find the links we
require.

CHAPTEE X.

DRAGONS OF THE DEEP.

NOWHERE perhaps are

' ' The steps of Time — the shocks of Chance —
The blows of Death ..."

more luridly manifested than in the history of
the rocks, and the creatures entombed therein.
They show, furthermore, that history repeats
itself, and that the world we live in, though
strangely changing in the nature of its in-
habitants, is in respect of its physical laws, a
world of monotonous uniformity.

. We have seen in earlier chapters of this little
book, how creatures originally fashioned to live
on land, have, by slow degrees, become shaped
anew to enable them to dwell in the great deep.
This transformation, effected by imperceptible
degrees, on creatures strangely unlike, results
in a singular uniformity of type. But having
regard to the uniformity of their environment,
this is only what one should expect. The
N

194 THE STORY OF REPTILE LIFE.

subjects of these transformations, probably in
all cases, began by haunting streams, then be
came amphibious, and finally drifted out to sea,
where the final stages of their evolution were
worked out. Thus has the sluggish tortoise
passed into the ocean-dwelling turtle; and
similarly, the scaly crocodiles and the ponderous
dinosaurs have furnished colonists to Neptune's
domain.

The creatures we are now to discuss bear
further witness of this strange migration.

Known as the Sauropterygia, the earliest
members of this group are represented by
certain primitive types, which dwelt probably
in the streams and estuaries of the old Triassic
rivers. Their descendants, strangely modified,
lived on until the Cretaceous. One of the best-
known of the ancestral forms, was a beast known
as Lariosaurus, a lizard-like animal some four
feet long. This represents the amphibious phase
of development, as is shown by the peculiar
form of the limbs, which are obviously more
adapted for swimming than walking. Indeed,
it is doubtful whether anything more dignified
than a shuffle was ever possible on land. We
have, indeed, in these legs, an intermediate
stage between the walking limbs of an earlier
period, and the swimming paddles which ulti-
mately succeeded them. Without describing
them in detail we may say that the hinder
pair were the longer, that the bones of tho
fore-arm and shank were moderately long, though
shorter than the arm and thigh, that the wrist
bones were small, and the hands and feet were

DRAGONS OF THE DEEP. 195

of moderate size. The fingers, indeed, might be
described as short. The head was small, and
the neck and tail only moderately long, the
length of each being, roughly, about the same
as that of the trunk. Judging by what are
known as the transverse processes of the base
of the tail, this organ was much used in swim-
ming. The typical species (Lariosaurus lalsami\
is known by nearly complete skeletons from the
Triassic shales of Pelerdo, on the shores of Lake
Como.

From this we must pass, with a jump, to the

FIG. 16. — Outline restoration of an extinct long-necked Sea-dragon
(Plesiosaurus).

well-known Plesiosaurus, whose remains have
been found in comparative abundance in the
Lias limestone of England. If size alone can
qualify for the distinction of dragonhood, then
the Plesiosaurus number, in their ranks, some
undoubted dragons, the largest species being
nearly forty feet long. Monsters of this size, how-
ever, do not appear till late in the history of this
group, the culmination being reached in the
chalk period, as is shown by remains found both
in Europe and North America.

Compared with the Lariosaurus the Plesio
saurs and their allies will be found to have

196 THE STORY OF REPTILE LIFE.

undergone very profound changes, indicating an
exclusively aquatic, probably marine, life. The
neck and tail have increased enormously, the
former containing between thirty and forty verte-
brae, that is to say, more than double the number
of the more primitive type. The tail contained
about the same number of vertebrae as the neck.
But it is in the limbs that we note the greatest
transformation. These have assumed the peculiar
paddle-shape so characteristic of the extremely
specialised aquatic types. The bones of the fore-
arm have become extremely shortened, whilst
the wrist and ankle bones have lost the intimate
relation one with another which they present in so
many of the terrestrial types, and have become
reduced to nodules imbedded in cartilage. Simi-
larly, the bones of the middle hand and foot
have become much reduced, whilst the bones of
the fingers have increased enormously in number,
to form long tapering fingers, of which the third
and fourth were the longest. One can picture
this animal, when alive, as a huge beast having
a swan-like neck in point of length, surmounted
by a relatively small head and jaws armed with
formidable teeth, a body like an attenuated
barrel, and a tail in many species rivalling the
neck in length, and provided with a broad fin at
the end. Locomotion was apparently effected
by the tail, whilst the paddles served as balancers.
Carnivorous in habit, this beast probably chased
and captured the curious armour-clad fishes which
abounded in the seas of that date, as well as the
smaller members of its own species. Concerning
the covering of the body we know nothing.

DRAGONS OF THE DEEP. 197

As touching the scientific name of these crea-
tures, we may remark that it is derived from two
Greek words, plesios, nearer, sauros, a lizard,
apparently on account of the structure of the
paddles, for these, though strangely different
from the feet of the lizard, are still structurally
nearer this type than are the paddles of the
"Fish-lizards," to which we now pass.

Returning for a moment to the Lariosaurus,
we may remark that these creatures are regarded
as the connecting links between the "Sea-
dragons" just described and certain equally
remarkable fresh-water and terrestrial animals
forming a group known as the Nothosauria,
among the most remarkable of which were the
" Placodonts," or Plate-toothed Eeptiles. These
were singularly flat-headed creatures, and have
become notorious on account of their teeth,
which were unique among reptiles, though
closely resembling those of many fishes.

One of the best known of the Placodonts is
Cyamodus laticeps. Herein the teeth have the
form of large flattened knobs, and are borne not
only by the edges of the jaws, but on the palate
as well, the largest of all being a pair on the
back of the roof of the mouth. From their shape
it is supposed that these teeth were used for
crushing the shells of molluscs, and hence it is
assumed that the beast frequented the sea-shore.
Only recently parts of the skeleton of the trunk
have come to light, and these show that the
body was armour-clad.

The exact opposite of the Plesiosaurs, inas-
much as the head passed imperceptibly into the

198 THE STORY OF REPTILE LIFE.

trunk, as in the whales and porpoises of to-day,
these "Fish-lizards" nevertheless bear a sufficiently
close structural resemblance to the long-necked
" Sea-lizards " or Plesiosaurs to justify the older
naturalists in regarding them as closely allied
forms. A more complete knowledge of their
anatomy, however, has since shown that in reality
they are probably not in any way related. What
their origin may have been, however, we do not
know. That they were derived from terrestrial
creatures there can be no doubt, though no such
terrestrial types such as lead up to the Plesio-
saurs are known. Instead, these strange crea-
tures appear suddenly in time with all their
specialised features in full development. In
shape, we may repeat they were strangely whale-
like, at least these are the forms which they are
considered to-day to most nearly resemble. The
older naturalists, however, seem to have con-
sidered them more fish-like, hence the name by
which they are scientifically known — Ichthyosaurs,
" Fish-lizards." The earliest known species occur
at the very base of the secondary system of
zoological deposits, occurring in what is known
as the New Eed Sandstone of the Triassic era.
But it is in the Lias that their remains are best
preserved, though they lived on till the end of
the Cretaceous system. . It is a point of extreme
interest to note that, as with many other types
described in earlier chapters of this book, we
have evidence of specialisation having taken
place among these singular creatures in response
to a change in the character of the food. For
whilst the earlier species invariably have the

DRAGONS OF THE DEEP. 199

jaws well armed with teeth, and fed, as we
know from the remains of prey found in the
bodies of the fossils, on the mail-clad fishes which
abounded in the seas of that time, and on the
young of their own kind, many of the later
members of this tribe were entirely toothless.
These toothless forms occur in the Upper Jurassic
rocks. They probably lived on cuttle-fish and
similar boneless creatures. Furthermore, we
may trace other phases in the evolution and

FIG. 17. — Outline restoration of an extinct Fish-lizard (Ichthyosaurus).
Note the downwardly directed tail seen through the lower lobe of
the tail fin.— After Fraas.

decline of the teeth. In the members of the
Triassic age the teeth were irregular in size ;
during the Liassic times they became uniform in
size ; and finally in the Jurassic and Cretaceous
we find almost a quite toothless species. But
to this question of the teeth we must return
later.

The general form of the body of these crea-
tures, as will be seen in Fig. 16, was remarkably
whale-like, but a little scrutiny will quickly
reveal many points wherein they are peculiar.
In the first place, the back was provided with
several fin-like structures, which served as

200 THE STORY OF REPTILE LIFE.

balancers. These resemble the single back fin
of certain whales, in that they were unsupported
by a bony skeleton as in fishes. Then the tail
differed in a very important particular, in a way,
indeed, which makes it unique among animals,
inasmuch as it turned sharply downwards. In
the whales and other allies this organ is
perfectly straight, just as in the primitive fishes.
In the "Story of Fish-life," it may be remem-
bered, it was pointed out that these primitive
types were succeeded by others in which the
tail was bent directly upwards, and that finally
this upturned portion was gradually suppressed.
It is with those fishes in which the upturned
portion of the tail is still retained that we must
compare the tail of the Ichthyosaurus. This
portion of the tail then supported a tail Jin which
was made up of a number of rods supporting a
membrane. In the Ichthyosaurus the correspond-
ingly downwardly directed tail also supported a
fin, but this again resembles the back fin in that
it was entirely fleshy and had no supports. Inas-
much as this fin was vertical in position, it resem-
bled the fin of fishes, and differed conspicuously
from the huge tail fin of the whales and their
allies, which is horizontal in position. This is a
point of some importance. The horizontal posi-
tion of the tail fin is peculiar to the aquatic
mammalia, such as the whales and their imme-
diate allies, and the manatees and dugongs, and
has apparently been evolved to suit the need of
these creatures for a constant and frequent
supply of fresh air ; the up and down motion of
the tail driving the animal either up to the

DRAGONS OF THE DEEP. 201

surface for air or down into the deep for food.
The vertical tail of the Eep tiles now in question
shows that the need for fresh supplies of air was
not of such importance ; they could exist for a
much longer time without inconvenience. Con-
sequently a vertical tail would be advantageous,
since its undulations would serve to drive the
body forward through the water, as in the fish,
and thus facilitate the capture of prey.

Turning to the limbs, we note again a differ-
ence from the whale, inasmuch as all four were
present instead of the fore-limbs only, though
the hind-limbs were in many cases extremely
reduced. From the walking limbs from which
they were evolved, they differ profoundly, being
now reduced to the condition of paddles, effective
as swimming organs, but of little use on land.
The skeleton of these paddles will well repay
brief study, for whilst they resemble the similar
organs of the whale tribe, and that ancient croco-
dile the Geosaurus, they still more closely approach
those of the Plesiosaurs. The paddles of these
old Fish-lizards, however, differ from all others,
in the greater specialisation which they dis-
play: they appear indeed to have reached the
maximum development ever attained by a
paddle. In the earliest known members of the
tribe — the species of the genus Mixosaurus from
the Triassic formations, we find the simplest
form of the Ichthyosaurian paddle. Herein
the humerus or arm bone and the bones of the
forearm were relatively long, the latter being
readily distinguished from the first row of wrist-
bones. But in the later forms, as will be seen in

'202 THE STORY OF REPTILE LIFE.

the figure, these became much shortened, so that
the forearm bones differ but little in size from
the wrist-bones in question. Still more note-
worthy is the relation of the digits one to
another, for they no longer remain separate
fingers and toes, but are so closely pressed
together that the separate joints have become
squeezed into a series of more or less hexagonal
plates interlocked to form a perfect mosaic — an
arrangement unknown elsewhere among animals.
By a considerable addition to the number of the
finger bones or phalanges the length of the hand
has been greatly increased, whilst additional
width has been gained partly by adding a row
of bony nodules down the free border of the
innermost digits, and partly by a fold of skin,
which formed a kind of fringe around the paddle.
The fold along the hinder margin of the front
paddles at least was especially wide, and impres-
sions in the rocks of some of the best preserved
species show that in many cases it was stiffened
by a series of little rods resembling the fin spines
of fishes, like those supporting the fin running
round the plaice or sole, for example. In yet
other cases, additional width was gained by in-
creasing the number of the digits from five to
six. This was accomplished by splitting the
third digit. In some of the species which
appeared later in time, as in Ophthalmosaurus,
we find a considerable modification in the form
of these paddles. In the first place, the number
of the digits was reduced to four, whilst the
finger bones or phalanges exchanged their hexa-
gonal for an oval shape, and thus, becoming

FIG. 18. — A. Left- arm of Crocodile, showing the normal form of the
walking limb in Reptiles. B. The arm of an extinct ally of the
long-necked Lizards (Plesiosaurs), showing the conversion of the
limb into a paddle. C. The arm of the Plesiosaur, showing
further evolution of the paddle. D. The arm of the extinct
Crocodile Geosaurus, showing its transformation into a paddle.
E. The arm of the Hawksbill Turtle, showing the same modifica-
tion. F. The paddle of the old Fish-lizard Ichthyosaurus, showing
the most extreme point reached in the evolution of the paddle.

A=Humerus or arm bone. F= Fore-arm. w= Wrist-bones.
D= Digits.

204 THE STORY OF REPTILE LIFE.

isolated, were embedded in cartilage. Further-
more, the fingers appear to have been reduced
in length, and the nodules of bone along the
hinder border of the paddle, designed to increase
its width, were almost completely suppressed.

The skin of these strange creatures appears to
have been quite smooth, like that of the modern
whale.

The eyes of the Ichthyosaurs were, like those
of birds, of enormous size, and further resembled
birds' eyes in that they were surrounded by a
ring of overlapping bony plates.

But besides these normal, lateral eyes, the
Ichthyosaurs, like most of the ancient reptiles,
were provided with a third placed in the middle
of the roof of the skull. Traces of this, it will
be remembered, are still preserved in many
living reptiles; especially is this true of the
Hatteria (Sphenodon). What necessitated the
development of this third eye we do not
know.

Like the Plesiosaurs, these old Fish-lizards
were viviparous, skeletons having been found
with remains of the young preserved within the
body cavity. Attaining a length of between 30
and 40 feet, the largest of these marine monsters
may well be entitled to rank among the dragons
of the deep. That they lived in the sea is shown
by the fact that their remains occur only in
marine deposits ; but there is nothing improbable
in the supposition that they occasionally ventured
ashore, perchance to bask on the beach. Walk-
ing would of course have been impossible; at
most they could but shuffle. What their origin

DRAGONS OF THE DE$P. 205

may have been we do not know, but the struc-
ture of the teeth seems to point to a descent
from the giant Salamanders or Labyrinthodonts,
and for the reason that these teeth present the
remarkably complicated infoldings of enamel so
wonderfully developed, and so characteristic of
the ancient amphibians.

Remembering that both Ichthyosaurs and
Plesiosaurs were not only contemporaries but pro-
bably lived side by side, one cannot help suspecting
that conflicts between members of the two rival
houses were not unusual. They were indeed the

" Dragons of the prime,
That tare each other in the slime."

perchance rending the air the while with hoarse
bellowings, like the crocodiles of to-day. With but
a slight effort of the imagination, one can picture
some such contest, can see the water lashed into
foam as the combatants writhe and twist about,
whilst overhead those dragons of the air, the
Pterodactyles, flutter in the hope of picking up
some newly-swallowed fish disgorged by the
excited and infuriated monsters. Suddenly the
fray is over. The bull-necked Ichthyosaur has
seized his neighbour by that long neck of his
and dragged him down to die !

Whether studied individually as separate
groups, or collectively, the creatures described
in this chapter present us with a series of
peculiarly instructive object lessons in evolution
and adaptation to environment. The simul-
taneous development of monsters like the
Plesiosaurs and Ichthyosaurs, from totally distinct

206 THE STORY OF REPTILE LIFE.

stocks with walking limbs, and the transforma-
tion of these limbs into paddles, so similar, yet
so different, is in itself a revelation. But the
marvel and the interest of this convergent
evolution, as it is called, becomes intensified
when we remember that it has been repeated
with variations several times in the history of
animals. The last to undergo these structural
alterations were members of the warm-blooded
mammals — the whales and their allies, and the
manatees, whilst a close approximation thereto
is going on among the seal-tribe. The uniform
environment has produced a marvellously uni-
form result, moulding reptile, bird and mammal
into creatures strangely alike ; and just as they
have come more and more to resemble one
another, so they have come to differ more and
more from the stock which gave them birth.
Surveyed as separate groups, we remark that the
earliest known examples of each tribe are the
smallest, and least perfectly adapted to their
environment. As we follow their development,
we find not only an increase of specialisation,
which means perfection of function, taking place,
but also an increase in bulk. Finally, just before
extinction takes place, we find the most highly
specialised of all. Toothlessness is one of the
commonest of these last phases of development,
and bespeaks adaptation to a very special kind
of food. Any disturbance in the balance of
nature, whereby this food supply became seriously
lessened, would necessarily bring about extinction
of these highly specialised forms, for variation in
new directions would be impossible. The Ptero-

DKAGONS OF THE DEEP. 207

dactyles and the Dinosaurs, as well as the creatures;
described in the present chapter, are all originally
tooth-bearing forms, but each of these groups
presents at least a considerable number of tooth-
less types. At the same time, we would make
it perfectly clear that it is not to be supposed
that extinction was in any case actually due to
the loss of the teeth ; we only wish to indicate
how easily extinction may be brought about
among highly specialised types from their in-
ability to vary further to meet new demands.
The fact that the tooth-bearing forms suffered
extinction equally with the toothless types, shows,
the fallacy of such a supposition.

Some extremely valuable suggestions on the
causes of extinction, recently made by Mr C. B.
Crampton and Dr C. W. Andrews, may fittingly
be reviewed here. According to the first-
mentioned author, the possible variations of an
organism become less and less as specialisation
advances ; on this account any change in the
environment threatens the life of the species,,
since only a very few individuals will have
chanced to vary in a direction favourable to
the changed circumstances. As a consequence
of this process of weeding out, the stock becomes,
more and more highly specialised, and therefore
more and more physiologically similar, "until
at length the same results as arise from close
inter-breeding — weakening of the stock, and
finally extinction. Yet another possible factor
in the process of extermination is that suggested
by Dr Andrews. Discussing the evolution of the
elephants he pointed out, another possible cause

210

INDEX.

Dinosaurs, herbivorous, 181.
meaning of name,
179.

E.

Elaps, colour of, 161.
Extinction, causes of, 206.

F.

Fish-lizards, nature of, 198.

G.

Gadow, on origin of reptiles,

14.

Gecko, climbing of, 80.
,, colour of, 152.
,,' protective colours of,

152.

,, voice of, 81.
Geosaurus, paddle of, 203.

, , specialised char-

acter of, 51.
Gharial, snout of, 60.
Gila-monster, colours of, 160.
,, poison of, 160.

Grass-snake, colour of, 156.
Greek tortoise, 33

H.

Hallopus, bipedal locomotion

in, 180.

Hatteria, origin of, 14.
Horned-toad, armour of, 87.
Hydrophis, devoured by

eagles, 161.
,, poison of, 161.
, , warning colours of,
161.

Ichthyosaurus, eyes of, 204.
„ tail of, 200.

toothless, 206.
,, whale-like

shape of, 178,

Iguana, aquatic forms of, 97.
,, diving powers of, 99.
Iguanodon, 184.

,, size of, 78.
,, teeth of, 186.

Lizard, English, 84.

frilled, device of, 157.
great size of, 85.
numbers of, 84.
stump-tailed, armour

of, 91.

swimming of, 96.
tail-shedding of, 16.
Lizards, care of young in, 143.
climbing of, 100.
courtship of, 133.
pugnacity in, 133.
running of, 98.
scale-footed, 92.
snake-like, 93.
thorn-tailed, 89.
warning colours of,
156.

Lyriocephalus, adaptation in,
106.

M.

Moloch - lizard, armour of,

87.

Monitor-lizard, cruel treat-
ment of, 86.
,, gruesome habit

- of, 85,
„ nest of, 136.

INDEX.

211

N.
Naosaurus, spines of, 178.

P.

Palseohatteria, descendants

of, 12.

Placodonts, teeth of, 197.
Plesiosaurus, form of, 197.
Protective coloration, 149.
Pteranodon, flight of, 173.
Pterodactyles, first appear-
ance of, 167.
,, head of, 166.

ornament of,

172.

,, wing of, 166.

Python, colours of, 156.
,, legend of, 123.

R.

Rattle-snake, "homing" of,

145.

,, rattle of, 159.

Reptile, definition of, 10.

S.

Sauropterygia, primitive

types of, 194.
Snakes, blind, 114.

burrowing, 113.
care of young in,

142.

constricting, 122.
egg-eating, 128.
limbs of, 112, 114.
method of feeding,

120.
poison of, 134.

Snakes, ribs used for walking,
in, 112.

,, scales of, 113.

,, shield- tailed, 114.

,, swimming, 116, 118.

,, torpor of, 145.
Snapping- turtle, device of, 40.

T.

Terrapins, love-making of,

131.

Tortoise, armour of, 19.
beauty of, 34.
eggs of, 138.
feet of, 31.
gigantic, 35, 37.
home of, 33.
limb-girdles of, 23.
modifications of

shell of, 25.
pond, 38-42.
voice of, 131.
Tortoise-shell, how obtained

45.

Tuatera, burrows of, 17.
eggs of, 136.
extinction of, 17.
third eye of, 16.
Tur le, edible, 44.

Hawk's-bill, 45.
leathery, shell of, 26.
snapping, device of,
40.

Turtles, adaptation in, 43.
,, eggs of, 140.

U.

Uromastix, thorny tail of,

88.
Uroplates fimbriatus, strange

colours of, 82, 151,

212

V.

INDEX.

Viper, various forms of, 127.

Varanus salvator, length of,

97.

Viper, colours of, 150.
,, torpor of, 145.

Zanclodon, age of, 194.

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