ZEBEAS AND THEIR CHARACTERISTICS 155 



ished, and the foot-bones are exactly as they still 

 remain. 



It is a moot point where the ancestral home of 

 the present race of equidce (in which are included 

 the horse, zebra, and ass) is to be sought. More 

 recently a strong impression — created by the dis- 

 covery of immense deposits of fossil bones — seems 

 to have been gathered that America was the first 

 home of the family; and that by degrees they 

 moved westward into Asia, Africa, and Europe. 

 Despite the advances of palaeontology, however, 

 nothing certain upon this head can be absolutely 

 laid down. It is beyond question that the present 

 forms of cquidce became gradually specialized and 

 developed to suit a higher and drier habitat and a 

 firmer soil than their remoter ancestry — dwellers, 

 like the tapir, in damp, marshy forests — had used. 

 The gradual disappearance of the toes, and the 

 development of the ancient form of toed foot into a 

 single hoof, is strong evidence upon this point. Sir 

 W. H. Flower has well pointed out that " all existing 

 species of the family are dwellers in dry, open, and 

 generally elevated plains. None are inhabitants of 

 gloomy forests or reeking marshes. Fresh air, dry- 

 ness, and light, are essential to their well-being." 

 To no members of the equine family can these 

 remarks be said more truly to apply than to the 

 zebras, a group invariably revelling in high, dry 



