THE EVOLUTION OF THE HORSE 



general pattern to the common mammalian foot, but the 

 stress for speed appears to have centered on the third toe, 

 leading to the elimination of four of the toes, resulting in a 

 one-toed, swift-running animal, as the geological record 

 shows. Relics of two of the last toes to disappear are seen 

 in the splint bones of the modern horse. 



The geological record reveals to us, of course, only the 

 bony parts of the numerous horses whose remains have been 

 preserved in the rocks and discovered. The differences in 

 these parts have enabled us to discriminate many species, but 

 if we knew the differences in mane and in tail and in colour 

 we might increase greatly the number of species. We do 

 know enough to assure us that a continuous series of horse- 

 like forms inhabited the earth for ages and that Western 

 North America was the principal scene of their remarkable 

 development. All the American horses, however, finally 

 became extinct from some cause or causes not yet discovered, 

 perhaps a parasitic or a contagious disease. Thus the horse, 

 which lived and developed for more than forty million years 

 in America, died out on its native soil; but it survived in the 

 Old World, though in smaller numbers and in forms less 

 varied than it had in America in the Ice Age. 



When America v^as discovered and explored by Europeans 

 there were no horses in the country. Although some horses 

 escaped from the Spanish. conquerors and became wild, both 

 in North America and South America, our domestic horse is 

 a descendant of European breeds, which are numerous and 

 extremely diverse in size as well ^s in other features. 



In early historical time tfie domesticated horse was used to 

 draw chariots and as a riding animal. From the earliest 

 stages of its domestication it was highly prized. The horses 

 of one country were traded for those of another, or were cap- 

 tured, and great care was taken in their breeding. Some of 



[231] 



