2 THE H0B8E. 



6r what naturalists term sub-species. TMs is possibly the 

 case with Prejevalsky's horse^ and may be so with the 

 Somali ass. The kiang and the hemippe are now regarded 

 by naturalists as local varieties of the onager j Chapman's 

 zebra appears to be but a variation of the older known 

 Burchell's zebra; and the quagga is now generally 

 believed to have been exterminated. 



The horse is distinguished from the other Equidae by 

 the tail being covered with long hair from its base to its 

 end ; it possesses also a small bare callus on the inner 

 side of the hind leg below the hock^ in addition to the 

 one on the inner side of the foreleg, which is present in all 

 the other species. Further distinctions are the longer mane 

 and forelock, and shorter ears, whilst, in proportion to its 

 size, its limbs are longer, its hoofs broader, and its head 

 smaller than in the species known as wild asses and zebras. 



An important distinction between the horse and the 

 other species of the genus, namely, the asses and. zebras, 

 appears to have been overlooked or mis-stated by preceding 

 writers — namely, the difference in the period of gestation ; 

 this in the horse is eleven months, whilst in the asses and 

 zebras it exceeds twelve months, as evidenced in the 

 succeeding chapters on those animals. 



It is remarkable that this difference should have been 

 so generally ignored. Thus, it is not mentioned by Capt. 

 Hayes in his " Points of the Horse," although he devotes no 

 less than five pages to the enumeration of the " Differences 

 between the Ass and Horse." Again, Mr. Blanford, 

 in his " Fauna of British India : Mammalia," writing of the 

 Asiatic wild ass, says : " The period of gestation is probably 

 the same as in the horse and ass, about eleven months " 

 and Sir William JPlower, in his "Mammals, Living and 

 Extinct," when describing the general characters of the 



