542 The Descent of Man. Part II 



Equal iransmiisioH of ornamental characters to both sexes. — With 

 many birds, ornaments, which analogy leads us to believe were 

 primarily acquired oy the males, have been transmitted equally, 

 or almost equally, to both sexes ; and we may now euquire how 

 far this view applies to mammals. With a considerable number 

 of species, especially of the smaller kinds, both sexes have been 

 coloured, independently of sexual selection, for the sake of pro- 

 tection ; but not, as far as I can judge, in so many cases, nor in 

 so striking a manner, as in most of the lower classes. Audubon 

 remarks that he often mistook the musk-rat,^" whilst sitting on 

 the banks of a muddy stream, for a clod of earth, so complete 

 was the resemblance. The hare on her form is a familiar instance 

 of concealment through colour; yet this principle partly fails 

 in a closely-allied species, the rabbit, for when running to its 

 burrow, it is made conspicuous to the sportsman, and no doubt 

 to all beasts of prey, by its upturned white tail. No one doubts 

 that the quadrupeds inhabiting snow-clad regions have been 

 rendered white to protect them from their enemies, or to favour 

 their stealing on their prey. In regions where snow never 

 lies for long, a white coat would be injurious; consequently, 

 species of this colour are extremely rare in the hotter parts of 

 the world. It deserves notice that many quadi'upeds inhabiting 

 moderately cold regions, although they do not assume a white 

 winter dress, become paler during this season ; and this appa- 

 rently is the direct result of the conditions to which they have 

 long been exposed. Pallas^* states that in Siberia a change of 

 tliis nature occurs with the wolf, two species of Mustela, the 

 domestic hort-e, the Eqaus hcuionus, the domestic cow, two 

 species of antelopes, the musk-deer, the roe, elk, and rein- 

 deer. The roe, for instance, has a red summer and a greyish- 

 white winter coat; and the latter may perhaps serve as a 

 protection to the animal whilst wandeiing through the leafless 

 thickets, sprinkled with snow and hoar-frost. If the above- 

 named animals were gradually to extend their range into regions 

 perpetually covered with snow, their pale winter-coats would 

 probably be rendered through natural selection, whiter and 

 whiter, until they became as white as snow. 



Mr. Reeks has given me a curious instance of an animal profit- 

 ing by being peculiarly coloured. He raised from fifty to sixty 

 white and brown piebald rabbits in a large walled orchard; 

 and he had at the same time some similarly coloured cats in his 



'' Fiber zSiethicus, AiidHbon and Glirium ordine,' 1778, p. 7. What 



bachinaa, 'The Quadrupeds oi N. I have called the roe is the Capreo/ru 



KsiSTia,' 1846, p. 109. sibiricus suhecaudatus of Pallas. 



** * Novffi species Qi^adrupedum e 



