THE STORY OF THE HORSE 22$ 



the soft and tender herbage of his woodland home, 

 his teeth had as yet no tendency to become special- 

 ized. The molars had mounds upon them, develop- 

 ing, perhaps, more into the shape of the points of the 

 hog's, but even still quite generalized teeth. His main 

 enemies, from whom, perhaps, he could with little dif- 

 ficulty escape, were creatures related to the hyenas 

 of to-day. Perhaps, like their modern representa- 

 tives, they preferred eating their flesh tainted to ex- 

 erting themselves enough to capture and kill their 

 prey. By the time we advance a little further into 

 the Tertiary, though still in its early portion, a re- 

 markable change has already come about. The fifth 

 toe, which in the earliest horse hung upon the side of 

 the front foot, has completely disappeared. The 

 change in the hind foot has gone still further. The 

 hind leg in many animals evolves more rapidly than 

 the front. The heavy work of running is always 

 done by the hind feet, while the front feet serve 

 rather as a prop to keep the animal from falling than 

 as the actual means of locomotion. Hence the hind 

 feet and the muscles of the hind quarters are almost 

 always heavier than the front. Possibly on the front 

 foot the little fifth toe was less of an obstruction, and 

 persisted after the early horse had lost the corre- 

 sponding toe on his hind foot. This process has gone 

 on still further in this second stage, and the hind foot 



