298 SEXUAL selection: mammals. PartIL 



us to believe were primarily acquired by the males, have 

 been transmitted equally, or almost equally, to both 

 sexes ; and we may now enquire how far this view 

 may be extended to mammals. With a considerable 

 number of species, especially the smaller kinds, both 

 sexes have been coloured, independently of sexual selec- 

 tion, for the sake of protection ; but not, as far as I can 

 judge, in so many cases, nor in nearly so striking a 

 manner as in most of the lower classes. Audubon re- 

 marks 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, 

 namely the rabbit, for as this animal runs to its burrow, 

 it is made conspicuous to the sportsman and no doubt 

 to all beasts of prey, by its upturned pure- white tail. 

 No one has ever doubted that the quadrupeds whicli 

 inhabit snow-clad regions, have been rendered white to 

 protect them from their enemies, or to favour tlieir 

 stealing on their prey. In regions where snow never 

 lies long on the ground a white coat would be inju- 

 rious ; consequently species thus coloured are extremely 

 rare in the hotter parts of the world. It deserves notice 

 that many quadrupeds, inhabiting moderately cold re- 

 gions, although they do not assume a white winter dress, 

 become paler during this season ; and this apparently 

 is the direct result of the conditions to which they 

 have long been exposed. Pallas ^^ states that in Sibe- 

 ria a change of this nature occurs with the wolf, two 

 species of Mustela, the domestic horse, the Equus lie- 



^'^ Fiber ziheihieus, Audubon and BacliinaTi, ' The Quadruj)eds of 

 X. America.' 1846, p. 109. 



3« 'Novse species Quadrupedum e Glirium ordiue,' 1778, p. 7. Wliat 

 I have called the roe is the Capreolus Sihiricus suhecaudatus of Pallas. 



