VISION OF RUMINATING ANIMALS. 



351 



To balance these advantages of attack, the stags, the antelopes, 

 the bisons, and other ruminants are equally well equipped for 

 defensive warfare. Their eyes are placed at the side of the 

 head, so that their range of vision is greatly extended. The 

 ears also are placed far back, and are very moveable, so that 

 they can be turned to catch sounds in any direction, and their 

 sense of smell enables them to detect the lurking enemy from a 

 considerable distance. 



Compared with these sharp and farsighted denizens of the 

 forest and the mead, the mole, whose eyes are so very minute 

 and well concealed by its fur that popular opinion supposes it 

 to be entirely deficient in these important organs, seems to be 

 but ill provided for ; but its limited powers of vision perfectly 

 agree with its subterranean life ; and when during the summer 

 months it sallies forth in quest of nocturnal prey (such as birds, 

 mice, frogs, and snails), its eyes, which are furnished with a 

 muscle that enables the animal to withdraw or to employ them 

 as circumstances may prompt, render it all the services it requires. 

 Though it has no external ears, as these would very soon be 

 choked up with earth, yet it is amply provided with the means 

 both of hearing and smelling senses which, in its peculiar situa- 

 tion, are of far more importance than sight. 



The Slepetz (Spalax typhlus), a small subterranean rodent 



Spalax typhlus. 



of Eastern Europe, is even totally deprived of vision, as its rudi- 

 mentary eyes, scarcely larger than a pin's head, are completely 

 covered with the skin, and hence we may infer that this deter- 

 mined burro wer hardly ever leaves his underground domains. 

 The most acute sense of the chamois is, beyond all doubt, 



