SNAKES. 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 sepai-ate 

 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 tlie breath from the lungs tlirough the wind- 

 pipe. The fixed, stony gaze of snakes is due to the fact 

 that the eye is covered by a thin stationary lid, the true 

 lids not being present. 



Tlie proverb "deaf as an adder" is not founded on fact, 

 as snakes, like all I'cptiles, have internal ears. Their sense 

 of hearing may be dull, but certain snakes, as the cobra 

 de capello, are attracted by music* 



A few snakes are viviparous, as the vipers; others, as the 

 common striped snake {Eittcenia sirfalis), are ovovivipar- 

 ous, the young developing ii- 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 cliaracteristic of tlicse dangerous serpents is their 

 foudoess for music. Even wlien newly cauglit they seem to Hsten 

 with pleasure to tlie notes, and even to ■vvritlie 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. 



j American Naturalist, p. 1009, Dec, 1883 



