108 THE VIVARIUM. 
It is well called the Glass Snake, for when it is quite still its 
smooth shiny appearance makes it look as if it had been moulded 
out of coloured glass, and its brittleness also entitles it to the 
same epithet; while its snake-like form often causes it to be 
mistaken by the unknowing in ophidian matters for a snake. 
However, anyone who at all understood these things, though 
quite unfamiliar with this particular Lizard, could tell almost at 
a glance that it was not a snake. He would see that the animal 
possessed eyelids which do not belong to any of the Serpent order. 
He would also notice that when the Scheltopusik (Russian), as it 
is called sometimes, put out its tongue, it had to open its mouth 
in order to do so; while asnake, because of a nick provided for 
the purpose, can extend that member without separating the jaws. 
Then again, the Glass Snake has decidedly a Lizard-like head ; 
besides this, if the observer watched the creature’s manner of 
locomotion, he would immediately see that it did not move with 
the grace and pliancy of a snake, and that it could not shape its 
body into so many curves. 
If a Glass Snake and a true Snake were dissected, further 
differences would be manifest between them. For example, the 
former would be found to have fixed jaws, certain ribs fastened to 
to a sternum or breast-bone, and what may be called hips and 
shoulder-bones ; whereas, the latter would be proved to possess 
loose jaws, 7.e., jaws capable of separation or dislocation at will, 
so to speak, and no sternum, or hips, or shoulder-bones. For this 
and other reasons the serpent can swallow, without danger to itself, 
prey of a diameter considerably greater than that of its body, which 
the Lizard cannot do. Finally, the Glass Snake has the rudiments 
of hind-legs, one of which may be seen situated in and near the 
extremity of each lateral fold or deep furrow which runs along 
the side. 
The Glass Snake, with gentle treatment soon becomes tame, 
and quickly learns. to distinguish its fosterer from all other 
people. It can easily be bought, as a rule, in this country, at 
sums ranging from 4s. to 7s. 6d. I have purchased very fine 
specimens at both the prices mentioned. 
It may be kept in the same Vivarium with snakes, but bigger 
than itself; for it might mistake a small snake for a large worm, 
