182 
SEXUAL selection: bieds. 
Part II. 
for some distinct purpose, perhaps for gaining a warmer 
winter covering; and that variations in the plumage 
occurring during the summer were accumulated through 
sexual selection, and transmitted to the offspring at the 
same season of the year. Such variations being inhe- 
rited either by both sexes or by the males alone, accord- 
ing to the form of inheritance which prevailed. This 
appears more probable than that these species in all 
cases originally tended to retain their ornamental 
plumage during the winter, but were saved from this 
through natural selection, owing to the inconvenience 
or danger thus caused. 
I have endeavoured in this chapter to shew that the 
arguments are not trustworthy in favour of the view 
that weapons, bright colours, and various ornaments, 
are now confined to the males owing to the conversion, 
by means of natural selection, of a tendency to the equal 
transmission of characters to both sexes into transmis- 
sion to the male sex alone. It is also doubtful whether 
the colours of many female birds are due to the preser- 
vation, for the sake of protection, of variations which 
were from the first limited in their transmission to the 
female sex. But it will be convenient to defer any 
further discussion on this subject until I treat, in the 
following chapter, on the differences in plumage between 
the young and old. 
