THE DARWINIAN THEORY 33 



But though there can be no doubt that this is to be interpreted 

 as a reversion to a character of a remote ancestor, it by no means 

 follows that the direct ancestral form must have had this stripe. 

 I am more inclined to believe that the ancestor which bore this mark 

 was considerably more remote, and lived before the differentiation 

 of the horse from the ass. Darwin himself noted the remarkable fact 

 that in rare cases, especially in foals, not only may the stripe on the 

 back be present, but there may be more or less distinct zebra-striping 

 on the legs and withers,: this, however, must be interpreted as a 

 reversion to the character of a very much more remote ancestor, to 

 a common ancestor of all our present-day horses and asses, which 

 must have been striped over its whole body, like the zebra living in 

 Africa now. 



It cannot be proved of any of the wild horses of to-day that 

 they are not descended from domesticated ancestors ; indeed, we can 

 say with certainty that the thousands of wild horses which roam the 

 plains of North and South America are descended from domestic 

 horses, for there was no horse in America at the time it was dis- 

 covered by the Europeans. In all probability our horse originated in 

 Middle Asia, was there first domesticated, and has thence been 

 gradually introduced into other countries. In Egypt it appears 

 first on the monuments in the seventeenth century B.C., and it seems 

 to have been introduced by the conquering Hyksos. On the ancient 

 Assyrian monuments the chase after wild horses is depicted, and 

 they were not caught, but killed with arrow and lance, like the lion 

 and the gazelle. 



But even if two wild species of horse had been tamed in different 

 parts of the great continent of Asia, these two domesticated animals 

 would have varied much and in the most diverse manner, as we may 

 infer from our different breeds of horses at the present day. There 

 are a great many of these, and many of them differ very considerably 

 from each other. If we think of the lightly built Arab horse, and 

 place beside it the little pony, or the enormous Percheron, the 

 powerful cart-horse from the old French province of La Perehe, 

 which easily draws a load of fifty kilogr ams, we are face to face with ^ 

 differences as great as those between natural species. And we may 

 realize how many breeds of horses there are now upon the earth if we 

 remember that nearly every oceanic island has its special breed of 

 ponies. Not only in the cold Shetland Islands, England, Sardinia 

 and Corsica, but in almost every one of the larger islands of the 

 extensive Indian Archipelago there is one. and Borneo and Sumatra 

 have several. 



