686 



THE EYE IN EVOLUTION 



Figs. 830 to 834. — Panoramic Vision in Placentals. 



Fig. 830. — Prejvalski's horse, 

 Equus przeualskii. 



Fig. 831. — Somali wild 

 ass, Equus soma- 

 liensis. 



Fig. 832. — Cotton's giraffe, 

 Girajfa camelopardalis. 



To show the configuration of the eyes for panoramic vision in Ungulates. 

 The laterally directed eyes of the horse have a considerable binocvilar field 

 particularly in the horizontal direction (see Fig. 838). In the giraffe, because 

 of its long neck, the eyes are directed downwards to obtain the greatest field 

 on the ground (Zool. Soc, London). 



Fig. 834. 



Figs. 833 and 834. — The positioning of the eyes in the rabbit to 

 allow for the wide panoramic field (see Fig. 805). 



