Chap. V. LAWS OF VARIATION. 165 



crosses with the dun stock. But I am not at all satisfied 

 with this theory, and should be loth to apply it to breeds 

 so distinct as the heavy Belgian cart-horse, Welch ponies, 

 cobs, the lanky Kattywar race, &c, inhabiting the most 

 distant parts of the world. 



Now let us turn to the effects of crossing the several 

 species of the horse-genus. Kollin asserts, that the 

 common mule from the ass and horse is particularly apt 

 to have bars on its legs. I once saw a mule with 

 its legs so much striped that any one at first would 

 have thought that it must have been the product of a 

 zebra ; and Mr. W. C. Martin, in his excellent treatise 

 on the horse, has given a figure of a similar mule. In 

 four coloured drawings, which I have seen, of hybrids 

 between the ass and zebra, the legs were much more 

 plainly barred than the rest of the body; and in one 

 of them there was a double shoulder-stripe. In Lord 

 Moreton's famous hybrid from a chestnut mare and male 

 quagga, the hybrid, and even the pure offspring sub- 

 sequently produced from the mare by a black Arabian 

 sire, were much more plainly barred across the legs than 

 is even the pure quagga. Lastly, and this is another 

 most remarkable case, a hybrid has been figured by 

 Dr. Gray (and he informs me that he knows of a second 

 case) from the ass and the hemionus ; and this hybrid, 

 though the ass seldom has stripes on its legs and the 

 hemionus has none and has not even a shoulder-stripe, 

 nevertheless had all four legs barred, and had three 

 short shoulder-stripes, like those on the dun Welch 

 pony, and even had some zebra-like stripes on the 

 sides of its face. With respect to this last fact, I 

 was so convinced that not even a stripe of colour 

 appears from what would commonly be called an acci- 

 dent, that I was led solely from the occurrence of the 

 face-stripes on this hybrid from the ass and hemionus, 



