EVIDENCES OF EVOLUTION 23 



a thrill of admiration at the wonderful recon- 

 struction of the ancient history of the noblest 

 race of animals, and that most widely identi- 

 fied with man. Since Huxley's day the 

 fossil horse has been "the cheval de bataille of 

 the evolutionist." 



In spite of many puzzles, the pedigree Js 

 one of the completest and most striking in- 

 stances pf a L ._ wel1-pre r served genealogical , 

 series. It illustrates evolution,, as it were, in 

 process, for the gradations are very gradual; 

 and natural selection .also, for the advances 

 in the adaptation of the limbs to swifter lo- 

 comotion, of the neck to reach the low grass, 

 of the teeth for more effective chewing, and 

 so on, are all such as may be reasonably in- 

 terpreted in terms of the selection of rela- 

 tively better-fit fogd variations. Let us, since 

 the case is a classic one, attempt an outline 

 of the geological history of the horse family, 

 following the careful work of the successors 

 of Marsh and Cope, notably of Lull and 

 Matthew. 



.The horse-like animals probably sprang 

 om_an extinct stock known as the Qondyl- 

 ^arthra, which was first represented in Europe 

 and Asia, and afterwards in North America. 

 The Condylarthra had five toes on each foot 

 and a large part of the sole was on the groundT 

 One of them, Phenacodus, was called by its 



