86 THE HOKSE. 



general resemblance to each other — being all of a 

 uniform yellowish or isabelline color, lighter or white 

 below, and all having a dark brown stripe along the 

 middle of the back, and usually no cross-stripe on 

 the shoulders — that it is considered by many natu- 

 ralists that they should all be regarded as belonging 

 to one species — Equus hemionus of Pallas. There are, 

 however, such marked differences in size, form, and 

 shade of color, that they may be easily divided into 

 three local varieties, or races, which have been de- 

 scribed and named as distinct species. The true 

 Equus hemionus, the kiang or dzeggetai, is the largest 

 and the darkest in color, being of a rufous bay, and 

 more approaches the horse in general appearance. 

 It inhabits the high table-lands of Thibet, where it is 

 usually met with at an elevation of 15,000 feet and up- 

 wards. Smaller, and paler in color, being sometimes 

 almost silvery- white, is the onager (E. onager, Pall.), 

 from Persia, the Punjab, Scinde, and the Desert of 

 Cutch. Differing but slightly, if at all, from this, is 

 the Syrian wild ass, described by Geoffroy under the 

 name of Equus hemippus. These three all closely re- 

 semble each other in their habits, and are all remark- 

 ably swift of foot, having been known to outstrip 

 the fleetest horse in speed. None of them have ever 

 been domesticated. 



The origin of the domestic ass (Equus asinus, 



