Claypole.] 1-*-^ [April 1, 



Every naturalist knows that among wild land animals, with some few 

 exceptions, this color is exceedingly rare. The cause of this rarity is obvi- 

 ous. In a green world a white individual is very conspicuous. Such an 

 animal has much less chance of escaping from its enemies if pursued, or 

 of capturing its prej' if a pursiier, than one whose color is more in har- 

 mony with its surroundings. Hence its prospects of living and of leaving 

 offspring are proportionally reduced. And in places where green is not 

 the prevailing color, we find the wild animals dressed in harmony with 

 their surroundings. In the Polar regions and in winter the fur-hearing 

 inhabitants are clad in white. No other livery would give them so good a 

 chance of life. In dry and sandy deserts the prevailing color of the fur 

 of the residents is nearly the same as that of the sand. Nevertheless in 

 the parts of the world that are clad in green, white individuals are 

 frequently produced. And we can hardly doubt that similar exceptions 

 to the prevalent color occur elsewhere. Thus we find white deer, white 

 mice, white blackbirds and white wild horses. But their extreme rarity 

 shows that there is some check to their multiplication. And in asserting 

 that this check is nothing more than early destruction in consequence of 

 their conspicuousness I am not going beyond what has often been ob- 

 served in cases falling within our notice. "On some parts of the conti- 

 nent," says Darwin, "persons are warned not to keep white pigeons" on 

 account of their liability to destruction by hawks. (Origin of Species, 

 1860, p. 84.) 



And when to these disadvantages we add those of deafness, of epilepsy 

 and of other diseases which often accompany the white color in animals, 

 cats for example, we find an accumulating variation which cannot fail of 

 being deeply prejudicial to the variant.* Darwin says, " Cats with blue 

 eyes are almost invariably deaf." He has collected a great number ot 

 cases showing the disadvantages to which animals are liable whose hair is 

 partially or altogether white, f 



Another instance is afforded by some pet rats kept by a relative of the 

 author's, which were with one exception wholly white. They all recently 

 became troubled with bronchitis or some similar complaint, and the sound 

 of their breathing was so unpleasant that they were destroyed except one. 

 The sole survivor was the rat that was not entirely white. This one, 

 though sharing in the disease, was much less severely affected. 



The case of albinoes may fairly be cited here. In this form of variates 

 not only is the increased color-risk a source of danger, but the imperfect 

 sight so frequently accompanying the whiteness is almost equally preju- 

 dicial . 



In regard to the vegetable kingdom similar facts may be given. Every 

 gardener is aware that the white seedlings that so frequently come up, in 

 a field of maize for instance, usually die down and yield no seed. Here, 

 as in the case of albinoes among animals, the radical cause of prejudicial 



• See examples of this published in various numbers of Nature, 1884. 

 tSee "Animals and Plants under Domestication," "Vol. i, p. 330. 



