444 THE ORIGIN OF THE LIBYAN HORSE [CH. 



Nor must Darwin's second conclusion — that the ancestor of 

 all the Equidae was striped like a zebra — be accepted in its 

 entirety. We have already seen (p. 78) that the tendency to 

 stripes is least in the northern latitudes, where the genus first 

 made its appearance in Asia, that this tendency gradually in- 

 creases as we advance southwards, that it reaches its maximum 

 in the tropical and sub-tropical regions of Africa, and that the 

 stripes show a tendency to disappear in Burcheil's zebra of 

 the Transvaal and Orange River Colony, and to a still greater 

 degree in the quagga, whose range seems always to have been 

 south of the Vaal River. I showed that if the Equidae as 

 a whole or in part are gradually divesting themselves of stripes, 

 those of Africa have retained their stripes much more tenaciously 

 than those of Asia, or if as a whole, or only in the case of certain 

 species, they are gradually assuming stripes, those of Africa 

 have far outstripped their congeners of the northern latitudes, 

 and I argued that the presence of manifold stripes all over the 

 body in any member of the genus Equus is a strong indication 

 that it has been long domiciled in Africa, where its progenitors 

 for protection or recognition or for some other purpose, either 

 retained and modified the coat of a common ancestor of all the 

 Equidae, or else put on striping differing in different species 

 and varieties according to the nature of their environment 

 or for other reasons. These considerations suggest that the 

 tendency to zebra stripes in certain domestic horses may be 

 less due to reversion to the colour of a remote ancestor, than 

 to their being descended from the Libyan horse. 



It is therefore worth examining the evidence collected by 

 Col. Hamilton Smith, Darwin, Ewart and others for the exist- 

 ence of such markings in horses. If it should turn out that all 

 such animals are of undoubted North African origin, or at least 

 very probably have some of that strain in them, our contention 

 that the Libyan has been domiciled and highly specialised in 

 North Africa from a very remote period, and that he is distinct 

 from the Asiatic horses of recent epochs, will have received 

 very substantial corroboration. 



Let us now examine all the instances on which Darwin 

 based his conclusion, supplementing them as we proceed with 

 fresh examples: — 



