6o 



THE GEOLOGICAL EVIDENCES 



illustrated in the chart before you, where the 

 supernumerary, and to an extent functionless, 

 toes of the Eocene Hyracotherium, which is fol- 

 lowed by the less and less distinctively polydactyl 



Hipparion gracile. Skeleton in the museum of Munich. 



forms of the Oligocene, Miocene, and early Plio- 

 cene periods, are seen to be represented in the 

 later Pliocene Pliohippus and the recent horse 

 (Equus) by a simple pair of " splints" attached 

 to the cannon-bone. Beyond the Hyracotherium 



