476 THE ORIGIN OF THE LIBYAN HORSE [CH. 



to England from South Africa by Lord Kitchener as the re- 

 puted offspring of a horse and a zebra-horse hybrid, has been 

 proved to be only a zebra-horse hybrid (Fig. 136)\ this alterna- 

 tive must be summarily rejected. 



All zoologists are agreed in regarding the African wild ass 

 as a species distinct from the Asiatic group of asses on the 

 grounds that it is grey instead of being rufous-brown, that 

 it has a shoulder stripe, that its ears are a little longer, and 

 that it has more frequently dark bars on its lower limbs. 

 Mr Sclater holds that the Somali ass is a species separate from 

 the Nubian because it is more grey in colour, has no shoulder 

 stripe, has numerous black markings on the legs, smaller ears 

 and a longer mane, and some make the Asiatic ass into three 

 separate species, whilst those who do not, make them into three 

 or more sub-species or varieties; and some have even made four 

 valid species out of the Burchell group of zebras. Mr Lydekker 

 holds that the Burchell zebra and the Quagga are specifically 

 distinct on the grounds that (1) the pattern on the forehead of 

 the Quagga forms a shorter and more regular diamond than in 

 the Burchell zebra (Bonte quagga) and that in the former the 

 centre of the diamond is a pale stripe with four or five dark 

 stripes on either side of it, whereas in all Bonte quaggas or 

 Burchell zebras the diamond is made up of from five to nine 

 stripes, the middle line being black with from two to four 

 stripes on each side, and (2) on the ground that quaggas may 

 be distinguished from Burchell zebras by the presence on the 

 skull in front of the orbit of a depression (p. 76) ; and the same 

 authority regards as " subspecifically distinct from the kiang of 

 Tibet " a wild ass from Mongolia which differs simply in colour 

 from the kiang (pp. 44-5). Now as the Libyan horse differs 

 from the Asiatic by being bay instead of yellow-dun, by the 

 shape of its head, by a pre-orbital depression in the skull, by 

 the set of its ears, by frequent tendency to stripes on the back, 

 legs, shoulders and face, by having typically white ' bracelets,' 

 by having usually a white star or blaze on the forehead, by 

 its dark skin, by the absence of hock callosities, by the absence 



^ Proc. Zool. Soc, 1903, Vol. i. p. 2, fig. 1. The animal is the offspring of 

 a male zebra and a common pony. 



