BNAKES. 
189 
and dive. The peculiar gliding motion of snakes is due to 
the movements of the large scales on the under side of the 
body. These are successively advanced, the hinder edges 
of the scales resting on the ground and acting as sup[)orts; 
resting on these the body is then drawn or pushed rapidly 
forwards. 
Snakes can swallow animals much thicker than their own 
bodies, because the bones of their skull and throat separate 
so that the mouth and throat can be greatly extended. 
Thus a boa can swallow a calf whole, or a common striped 
snake can swallow a toad or bullfrog. The bones of the 
mouth are also armed with teeth pointing backwards, to 
prevent the prey from slipping out of the mouth. Snakes 
occasionally are known to hiss, the noise being caused by 
the passage of the breath from the lungs through the wind- 
pipe. The fixed, stony gaze of snakes is due to the fact 
that the eye is covered by a thin stationaiy lid, the true 
lids not being present. 
Tiie proverb *'deaf as an adder" is not founded on fact, 
as snakes, like all reptiles, have internal ears. Their sense 
of hearing may be dull, but certain snakes, as the cobra 
de capcllo, are attracted by music* 
A few snakes are viviparous, as the vipers; others, as the 
common striped snake (Eiitmnia sirtalis), are ovovivipar- 
ous, the young developing in eggs, but hatching before the 
eggs are laid. This snake has been known to produce as 
many as 78 young ones.f When alarmed, a brood of young 
of this and other species have been known, since the days of 
Spenser, who refers to this habit in the Faerie Queen," 
* One remarkable characteristic of these dangerous serpents is their 
fondness for music. Even when newly caught they seem to listen 
■with pleasure to the notes, and even to writlie themselves into atti- 
tudes. The Indian jugglers improve greatly on this instinct, and, 
after taming them by degrees, instruct them to keep time to their 
flageolet. — Percival, Eng. Cyc. Nat. Hist. 
\ American Naturalist, p. 1009, Dec, 1882 
