WHITE CATTLE : AN INQUIRY INTO THEIR ORIGIN, ETC. 229 



of Choiseul Sound (which almost divides the island into two 

 parts) white beasts with black heads and feet are the most 

 common. In all parts, black and some spotted animals may be 

 observed . . . It is thus," he adds, " interesting to find the 

 once-domesticated cattle breaking into three colours." This, of 

 course, indicates the prepotency of three separate ancestral types. ^ 



^ As regards the question of colour, a writer in the Quarterly Review for 

 1869, saj^s — "But we know that colour is the most variable of all an animal's 

 characters, and yet in a state of nature colour as a rule is very constant in 

 each species. Mr. Darwin has shown, however, that colour is often 

 intimately associated with other constitutional peculiarities. In Virginia 

 the paint root {Lachnanthes tincioria) is eaten by pigs, and makes their 

 hoofs drop off. But black pigs are uninjured by it. Consequently, in 

 places where this plant is abundant the farmers never keep any but black 

 pigs, as no others can be raised except in confinement. Here we have a 

 beautiful illustration of the mode of action of ' natural selection.' The pigs 

 of Virginia are not all born black any more than in other countries, but 

 those of all other colours soon die, and therefore in a state of nature a 

 black race would be produced ; and from the powerful action of the law of 

 hereditary descent there can be little doubt that in time the litters would 

 consist almost entirely of black pigs. If after this had happened it were 

 first discovered that white or brown pigs could not live in the district, we 

 should have a striking example of adaptation ; but the adaptation would 

 evidently be an adjustment brought about by the simple law of 'natural 

 selection ' or ' survival of the fittest,' and the rigid extermination of all 

 individuals not adapted to the surrounding conditions. It can be easily 

 seen that in this case ' natural selection ' does not imply a personal selector, 

 since exactly the same result must happen whether the farmer kills off the 

 white pigs himself and turns the black ones loose, or turns out all together. 

 This case, although curious, is by no means isolated. White terriers suffer 

 most from distemper, and white chickens from the gapes. In Sicily the 

 Hypericum crispum is poisonous to white sheep alone. White horses suffer 

 severely from eating honey-dewed vetches, while chestnuts and bays are 

 uninjured. Purple plums in North America are subject to a disease from 

 which green and yellow plums are free. Again, the white pigeons of a 

 flock are the first to fall victims to the kite. White rabbits of a very 

 hardy kind have been turned loose but fail to maintain themselves, and 

 black fowls on the West coast of Ireland are picked off by sea-eagles. Here 

 we have the explanation of the otherwise puzzling fact, that white 

 quadrupeds and birds are so rare in nature, although abundant among all 

 domesticated animals ; and the explanation is all the more satisfactory 

 because it accounts for the exception to the rule in the case of many arctic 

 birds and quadrupeds as well as of sea birds, for to these the white colour 

 is a protection instead of a danger." 



