292 The Field Naturalist s Quarterly November 



The nostrils in their outline resemble those of the domestic 

 horse, while the long-pointed ears generally project obliquely 

 outwards, as in many heavy horses and in the Melbourne 

 strain of thoroughbreds. Further, in the wild horse the 

 forehead is convex from above downwards as well as from 

 side to side ; hence Prjevalsky's horse is sometimes said to 

 be ram-headed. In the hybrid the muzzle is fine as in 

 Arabs, the lower lip is decidedly shorter than the prominent 

 upper lip, the nostrils are narrow as in the Kiang ; and even 

 at birth the forehead was less rounded than is commonly 

 the case in ordinary foals. The ears of the hybrid, though 

 relatively shorter and narrower than in the Kiang, have, as 

 in the Kiang, incurved dark -tinted tips, and they are 

 usually carried erect or slightly inclined towards the middle 

 line. In the wild horse the croup is nearly straight, and 

 the tail is set on high up as in many desert Arabs. In the 

 hybrid the croup slopes as in the Kiang and in many 

 ponies, with the result that the root of the tail is on a 

 decidedly lower level than the highest part of the hind- 

 quarters. Further, in the young wild horses I have seen 

 the heels (points of the hocks) almost touch each other, as 

 in many Clydesdales, and the hocks are distinctly bent. 

 In the hybrid the hocks are as straight as in well-bred foals, 

 and the heels are kept well apart in walking. 



Another difference of considerable importance is, that 

 while the wild horse neighs, the hybrid makes a peculiar 

 barking sound remotely suggestive of the rasping call of 

 the Kiang. 



If Prjevalsky's horse is neither a Kiang-pony mule nor a 

 feral Mongolian pony, and if, moreover, it is fertile (and its 

 fertility can hardly be questioned), I fail to see how we can 

 escape from the conclusion that it is as deserving as, say, 

 the Kiang to be regarded as a distinct species. Granting 

 Prjevalsky's horse is a true wild horse, the question arises : 

 In what way, if any, is it related to our domestic horses? 

 It is still too soon to answer this question ; but I venture 

 to think that should we by and by arrive at the conclusion 

 that our domestic horses have had a multiple origin, — have 

 sprung from at least two perfectly distinct sources, — we 

 shall probably subsequently come to the further conclusion 



