BIRDS. 505 



CHAPTER XV. 



BIRDS continued. 



Discussion as to why the males alone of some species, and both sexes 

 of others, are brightly colored On sexually limited inheritance, 

 as applied to various structures and to brightly colored plumage 

 Nidification in relation to color Loss of nuptial plumage dur- 

 ing the winter. 



WE have in this chapter to consider why the females of 

 many birds have not acquired the same ornaments as the 

 male; and why, on the other hand, both sexes of many 

 other birds are equally, or almost equally, ornamented? In 

 the following chapter we shall consider the few cases 

 in which the female is more conspicuously colored than the 

 male. 



In my "Origin of Species"* I briefly suggested that 

 the long tail of the peacock would be inconvenient and the 

 conspicuous black color of the male capercailzie dangerous 

 to the female during the period of incubation; and conse- 

 quently that the transmission of these characters from the 

 male to the female offspring had been checked through 

 natural selection. I still think that this may have occurred 

 in some few instances; but after mature reflection on all 

 the facts which I have been able to collect, I am now 

 inclined to believe that when the sexes diifer the successive 

 variations have generally been from the first limited in 

 their transmission to the same sex in which they first 

 arose. Since my remarks appeared the subject of sexual 

 coloration has been discussed in some very interesting 

 papers by Mr. Wallace,! who believes that in almost all 

 the successive variations tended at first to be trans- 

 mitted equally to both sexes; but that the female was saved, 



* Fourth edition, 1866, p. 241. 



f " Westminster Review," July, 1867. " Journal of Travel," vol. 

 i, 1868, p. 73, 



