154 
SEXUAL SELECTION : BIRDS. 
Part II. 
CHAPTER XV. 
Birds — continued. 
Discussion why the males alone of some species, and both sexes of 
other species, are brightly coloured — On sexually-limited in- 
heritance, as applied to various structures and to brightly- 
coloured plumage — Nidification in relation to colour — Loss of 
nuptial plumage during the winter. 
We haye in this chapter to consider, why with many 
kinds of birds the female has not received the same 
ornaments as the male ; and why with many others, 
both sexes are equally, or almost equally, ornamented ? 
In the following chapter we shall consider why in some 
few rare cases the female is more conspicuously coloured 
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 colour of the male capercailzie 
dangerous, to the female during the period of incubation ; 
and consequently that the transmission of these charac- 
ters 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 differ, the successive variations have 
generally been from the first limited in their transmis- 
sion to the same sex in which they first appeared. Since 
my remarks appeared, the subject of sexual coloration 
^ Fourth edition, 1866, p. 241. 
