THE EQUID^E, OH HORSES. 201 



perhaps kindred genus, the Chalicotherium which 

 is discovered also in Western America, in China, 

 India, Greece, Germany, and France Marsh con- 

 cludes that the places where these remains were 

 found were the stages by which, in this and other 

 cases, the so-called * Old World ' received its animal 

 forms. 



2. THE EQUIDJE, OR HORSES. 



On Fig. 35 we have a drawing, made by Owen in 

 1857, to explain to his audience the derivation of the 

 one-hoofed animal from its three-hoofed ancestor, a 

 drawing which has been made use of countless times 

 since then by recent writers. The three-hoofed 

 animal is the Palceotherium medius discovered by 

 Cuvier ; in outward appearance the foot is precisely 

 like that of the tapir, but possesses four toes on 

 its fore-foot, and thus represents an earlier form. 

 The Palaeotheridae are essentially Eocene ; to judge 

 from their teeth, they obtained their food like the 

 tapirs, and (with a numerous kindred) inhabited 

 the marshy forests which had originated with the 

 upheaval of the weird depths of the Jura and Chalk 

 oceans. They, too, had found their way to 

 Southern America. It is, we know, perfectly use- 

 less, at the present state of our geological know- 

 ledge, to endeavour to determine by means of 

 19 



