The Descent of Man

iii. p. 598.)—then it is not improbable that the
females would have been led to court the males,
instead of being courted by them. This indeed
is the case to a certain extent with some
birds, as we have seen with the peahen, wild
turkey, and certain kinds of grouse. Taking as
our guide the habits of most male birds, the
greater size and strength as well as the extraordinary
pugnacity of the females of the Turnix
and emu, must mean that they endeavour to
drive away rival females, in order to gain possession
of the male; and on this view all the
facts become clear; for the males would probably
be most charmed or excited by the females
which were the most attractive to them by their
bright colours, other ornaments, or vocal powers.
Sexual selection would then do its work,
steadily adding to the attractions of the females;
the males and the young being left not at
all, or but little modified.
CLASS III.