MAMMALS. 



625 



whose origin was probably in Asia, though in our western fossil beds 

 bones are found which can scarcely be distinguished from those of man's 

 faithful servant. The American stock, however, died out long before the 

 discovery of this continent, and when the Spaniards first conquered the 

 New World, no horses were known here. To go into the history of the 

 horse and its various breeds would require a volume of no mean dimen- 



Fig. 496. — Quagga (Equus qiiagga). 



sions, while many pages could be profitably devoted to the mental aspects 

 of the animal. We must, however, say a few words about the origin of 

 the domestic horse from some wild breed — a point on which there is great 

 uncertainty. 



In the steppes of central Asia four varieties, or species, of wild horse 

 are known, and one of these — a small dun-colored species with short, 

 stiff, dark-colored mane — is regarded by some as the ancestral form — a 

 view which receives considerable probability from the structural correspond- 



