THE EGG-EATING SNAKE 
attends the gliding of the snake. The former suggest 
forcibly that they want practice in the art of walking 
without limbs. When the snake feeds it engulphs its 
food in a way totally different to that of the lizard. The 
two halves of the lower jaw, instead of being bound to- 
gether by solid bony union, as in the lizards, for the most 
part, are only connected by softish ligament, and thus 
can be stretched and allow their possessor to manage a 
very big morsel. The lizards are compelled to exercise 
greater moderation in the size of their prey. Were a 
python a lizard, it would have to be content with rats 
instead of being able to get outside a goat. A flickering 
bifid tongue is a character of the snakes, and though it is 
found in lizards it is not by any means universal in that 
group. For the rest, snakes have, like lizards, the same 
alternation between extreme alertness and _ sluggish 
laziness. Snakes are entirely animal feeders and devour 
living prey, with the exception of two egg-eating snakes, 
of which one, the African Dasypeltis scabra, is often to 
be seen at the Zoo. Lizards vary their diet more, and 
they not only eat living prey and eggs, but also are in 
the case of some species, vegetarians. When we come 
to internal characters there are more means of distin- 
guishing between the two orders. The principal one, and 
it is one that is not usually so much dwelt upon in books 
contrasting the anatomy of the two groups, is seen in 
the way in which the internal organs are packed in the 
body. In all lizards the stomach, intestines, liver, and 
so forth, lie in a spacious cavity known to anatomists as 
the ccelom. In snakes the ccelom is still there; but, 
instead of forming one large cavity, with plenty of room 
for more organs than already lie in it, it is divided up 
into a series of more restricted cavities, in each of which 
lies some special organ. Thus, the long and narrow 
liver is enveloped in two sacs meeting in its middle line 
and showing incidentally that the apparently single- 
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