HIP PARI ON GR AGILE, 



291 



ancestors of the pig walked on these four toes, two of which, 

 apparently from disuse, have become reduced to their present 

 insignificant size. We may, with equal certainty, affirm that, 

 if the pig remains under its present conditions of life, which, 

 as we all know, do not demand work from its small side 

 toes, these digits will in process of time disappear, and their 



Fig. 379. — Left Fore 

 Foot of H. Gracile 

 (|th real height). 



Figs. 380 and 381. — Left Fore and Right Hind 

 Leg of same H. Gracile (|th real height). . 



metacarpal and metatarsal bones will become as rudimentary 

 as the splint-bones of the horse. Even if it were objected 

 that these facts do not warrant us in assuming that the 

 ancestors of the horse had, on each foot, three toes, two of 

 which were more or less rudimentary ; we have the still 

 stronger evidence afforded by fossils of horse-like animals 



u 2 



