THE ANCESTRY OF THE HORSE 161 



his descendants have survived, while most of 

 theirs have dropped by the wayside ; and 

 finally, by the aid of man, the horse has be- 



Fig. 33. Skeleton of the Modern Horse and of His 

 Eocene Ancestor. 



come spread over the length and breadth of 

 the habitable globe. 



Now right here it may be asked, How do 

 we know that the little Hyracothere was the 



