338 
ORDERS OF REPTILES— SERPENTS 
mouth, well forward, and while not in use they 
lie up against the roof of the mouth. The tongue 
of a serpent is very extensible, and capable of 
being thrust out fully half the length of the head. 
Its greatest use is in examining food, or possible 
food. From the fact that when travelling the 
tongue is so frequently thrust out, even when 
there is no excitement, it seems highly probable 
that it is used to detect vibrations in the air. 
(R. L. Ditmars.) The tongue is forked, and 
being entirely harmless, its sole use in defence is 
to threaten and intimidate its enemies. 
The lower jaws are loosely attached to the 
skull, and to each other at their front end, by 
ligaments so elastic that when prey is being 
swallowed, the gape expands to enormous pro- 
portions. Mammals, birds and fishes to be 
swallowed are always seized head first, in order 
that the limbs, and also the feathers or scales, if 
there be any, will lie snugly against the body. 
Frogs and toads are usually taken hind feet 
first. The lower jaw is forced forward and over 
the animal, always one side at a time, as far as 
it will go; and when the teeth are inserted, that 
side is drawn back. The upper part of the head 
slides forward as far as possible, one side at a 
time, to match the lower jaw. Sometimes it 
seems as if the lower jaw will be torn loose from 
the head. Often after an animal has vanished, 
the jaws are a bad misfit, and do not come back 
into shape for half an hour. 
The skin stretches like India-rubber, and 
over a heavy meal the scales are widely separated. 
The manner in which serpents feed in a wild state 
is certainly one of the most cruel processes of 
Nature. 
The eyes of a serpent have no lids, and the 
eyes never close; but they are protected by a 
thin and perfectly transparent section of the 
outer skin, or epidermis, which is shed and re- 
newed periodically. 
The epidermis, or outer skin, is completely 
renewed about three times per year. To free 
itself from the old skin, the serpent usually 
crawls through a small aperture, the edges of 
which catch the old skin at the head and hold 
it fast while the owner crawls out of' it. The 
first intimation of an impending change of 
epidermis is found in the dull appearance of the 
eye, over which a glassy film seems to be form- 
ing. Strange to say, even the eye sheds its outer 
surface, and emerges clear and brilliant. Most 
snakes shed their skins about three times a year. 
A serpent is always most beautiful immedi- 
ately after it has shed its epidermis, for then its 
colors are brightest and most iridescent. In 
captivity it often happens that the atmosphere 
in which a snake lives is not sufficiently moist 
to enable the old skin to loosen and be cast off. 
In such cases, if the serpents are non-venomous 
species, the owner must moisten the old skin, 
and peel it off by hand, or with forceps. 
Reproduction. — Some snakes lay eggs, with 
soft, tough shells, that are hatched by the sun. 
A serpent which develops in an egg of this sort 
is provided with a special, temporary tooth, set 
on the tip end of its jaw, with which it easily 
punctures the shell sufficiently to escape. Oth- 
ers do not develop eggs with shells, but instead 
retain their eggs in their own bodies until the 
young are fully developed. Finally they are 
brought forth, each fully enclosed in a thin, 
membranous sac, which the little serpent quick- 
ly bursts. Snakes that lay eggs are called o-vip'- 
a-rous, and those that bring forth their young 
alive are called vi-vip'-a-rous. 
Although serpents are cold-blooded animals, 
they reach their highest development in warm 
latitudes, and in regions of arctic cold they do 
not survive. In the temperate zone and the 
tropics, Nature has fitted them for life upon 
the ground, in the water, and in the tree-tops; 
and they inhabit swamps, uplands and deserts. 
They live under stones and logs, in hollow trees 
and stumps, and in holes in the earth; and they 
seldom attack man wilfully, and without provo- 
cation. 
Food of Serpents. — In a wild state, snakes 
feed chiefly upon frogs and toads, fish, other 
snakes, small birds and mammals. Large ser- 
pents feed upon mammals of all sizes, up to small 
deer and goats. Water-snakes feed chiefly upon 
fish and frogs. Land species find frogs, toads 
and small lizards their cheapest prey, but the 
extent to which snakes feed upon each other is 
quite surprising. For example, the king cobra , 1 
a large, athletic, and very deadly land-serpent 
of the Malay Peninsula, feeds exclusively upon 
other snakes and lizards, and while a greedy 
feeder upon what it prefers, it persistently re- 
fuses all other food. During the three years that 
1 Na'ja bun-gar'us. 
