DIFFERENCES BETWEEN ASSES AND HORSES. 415 



but have not observed it in the ass. This conservatism in 

 colour and freedom from irregular markings, shown by the 

 ass, is very remarkable ; considering how greatly the coat 

 of the horse varies in this respect, and that the ass has, in 

 all probability, been longer under the influence of domes- 

 tication than the horse. 



II. The ass is higher over the croup, than at the withers, 

 which is a peculiarity that tends to make his withers 

 appear unduly low (p. 241). The spines of the vertebras 



Fig. 444. — Side view of incisors of a 4 year-old horse (nat. size). 



at the withers are only a little shorter in the ass than 

 they are in the horse. As a rule, horses are higher at the 

 withers than they are at the croup. 



12. The horse's dock is thicker, stronger and shorter 

 than that of the ass. 



13. The horse, on each side of his croup and covering 

 his pelvis, ha.s, underneath and closely adhering to the skin 

 of the part, a thick and extremely dense layer of connec- 

 tive tissue, which is so close and hard, that it looks like 

 horn, when the skin has been tanned and dried. These 

 two patches of thickened skin are separated from each 



