400 DIVERSIONS OF A NATURALIST 



the pure-bred foals so produced have never in a single 

 case resembled either an ass or a mule. 



A celebrated case to which Darwin attached im- 

 portance was that of Lord Morton's mare, reported to 

 the Royal Society in 1820. This mare, after bearing a 

 hybrid by a quagga (a striped equine related to the 

 zebra) produced, to a black Arabian horse, three foals 

 showing a number of stripes, and in one of them more 

 stripes were present than in the quagga hybrid. This 

 seems at first sight strong evidence in favour of " infec- 

 tion " of the mare by the early quagga mate. But it 

 appears that stripes are frequently seen in high-caste 

 Arab horses, and colts cross-bred from such and other 

 breeds of horse sometimes present far more distinct bars 

 across the legs and other zebra-like markings than were 

 seen in the late offspring of Lord Morton's Arabian mare. 

 The fact appears to be that all the living species of the 

 horse family (horses, asses, quaggas, and zebras) are 

 descended from an ancestry of " striped " equines, and 

 are liable occasionally to " throw back " to their striped 

 ancestry, more or less. 



Professor Cossar Ewart determined some years ago 

 to submit the matter to direct experiment, and has 

 related his results in a book (" The Penicuik Experiments," 

 1899). The South African equine called the quagga, 

 which was that used by Lord Morton, having become 

 extinct, Professor Ewart made use of a richly striped 

 Burchell's zebra. Thirty mares put to this animal pro- 

 duced seventeen hybrids, and subsequently these mares, 

 put to horse-stallions, produced twenty pure-bred foals. 

 All the zebra hybrids were richly and very distinctly 

 striped. Of the twenty later pure-bred horse-foals from 

 the same mares three only presented stripe-like markings 



