SHEDDING OF SKIN IN SNAKES 
The young when they leave the egg are not coloured like 
their parents, a common occurrence among animals ; 
they also illustrate another common feature in the col- 
oration of young creatures, which is that they are 
striped. The young pig and the young tapir are other 
examples of this same phenomenon. And it has been 
attempted to be proved by these and other causes, that 
animals in the course of their development go through a 
regular series of colour changes which are necessary 
accompaniments of that evolution. The tuatera can 
bite, and that effectively, since it possesses what few 
lizards do, an additional set of teeth upon the palatine 
bones which form part of the roof of the mouth, addi- 
tional, that is to say, to those upon the upper and lower 
jaws. Its native name of tuatera seems to mean “ pos- 
sessing spines,” and refers to its crest. 
SNAKES : THE ORDER OPHIDIA. 
Although the limbless lizards, such as the blind-worm 
and the European scheltopusik (Opiisaurus apus), dealt 
with on a previous page, run the snakes rather close in 
outward appearance, it is reallynot difficult to distinguish 
by external appearance and behaviour the Ophidia from 
the Lacertilia. The limbless, and so far, snake-like 
lizard has a milder look than the true snake, whose re- 
lentless and unwinking eyes produce even in the harm- 
less kinds that feeling of repulsion which is apt to be felt 
for the serpent. The mildness of the lizard is due to the 
fact that it has movable eyelids, while the eyes of the 
snake have no such eyelids, but are covered with a single 
and transparent scale ; this is removed when the snake 
sheds its skin and comes off with it in the form of a watch 
glass. That the geckos have not for the most part eye- 
lids does not lead to any confusion, for the blind-worms 
which offer the most difficulties have. The movements 
of the legless lizards have not that finished ease which 
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