THE PKJEVALSKY H0E8E. 11 



may be attained, thus approaching the maximum for the onager 

 000:172.5). In general terms it may be said that the hoof has 

 different average proportions in each of the three species of Equus ; 

 but different individuals reveal considerable variation. 



As Poliakof has already pointed out, the Prjevalsky horse has 

 callosities (" chestnuts ") on both the anterior and posterior limbs. 

 Their size is variable, but in general, as appears from the following 

 table, the anterior callosities are much better developed than those 

 of the posterior limbs, as is usually the case in the domestic horse. 

 As a rule, the callosities are oval, but not regularly so, and 

 gener.ally the posterior are relatively narrower than the anterior. 

 In position they agree with the callosities of the domestic horse. 



Dimensions of the Limb Callosities of Equus 

 Prjevalskii. 



THE COAT AND ITS COLOUR.— The hair of the Prjevalsky 

 horse is changed in winter and in summer. The tirst specimen 

 known to science, captured by Prjevalsky and described by Poliakof, 

 was in its winter coat, and, consequently, it was assumed by 

 Poliakof that the hair of E. prjevalskii is long and curly. The 

 winter and summer coats differ from each other, not only in 

 length and texture, but also in colour and markings. The colour 

 of the hair of the winter coat is lighter than that of the summer 

 one. Poliakof correctly described the former as yellowish on the 

 back, lighter over the sides and almost white on the under part 

 of the body. Among the skins at the present time in the Zoologi- 

 cal Museum both winter and summer coats are illustrated. Of 

 the two living horses brought to the Imperial stables, one (a mare 

 in her second year) had a winter coat, while the other (a stallion 

 in his third year) had already assumed the summer coat. The 

 difference between the two animals appeared to me to be very 



