IV] 



THE ORIGIN OF THE LIBYAN HOUSE 



461 



sterile (like Ewart's zebra hybrids), is a reversion to a remote 

 common ancestor of both Muscovy and Mallard, and not rather 

 to the Mallard, the immediate ancestor of the white Aylesbury 

 duck. 



But as the markings on the zebra hybrids resemble in 

 character the narrow markings of the Somali zebra, we are 

 led to conclude that this peculiar characteristic of the North 

 African horse is not due to a comparatively recent differentia- 

 tion under domestication of the domestic Asiatic horse in 



FIG. 134. The Muscovy drake 'Hans' and his hybrids by a white 

 Aylesbury duck. 



Libya, but rather that living for a vast period under conditions 

 similar to those which have produced the peculiar stripings 

 of the Somali zebra, it has been so highly specialised as to 

 constitute a separate species. 



The circumstance that large functional first pre-molars are 

 found in some of the horses of South-eastern Asia (as for 

 instance in Javanese and Sulu ponies), which I have shown to 

 be almost wholly of Libyan blood, and also in the Somali zebra 

 and some members of the Burchell group (p. 142), points to a 

 similar conclusion. 



