The Descent of Man

former period. But since this period the male
black-grouse has acquired his fine black plumage,
with his forked and outwardly-curled
tail-feathers; but of these characters there has
hardly been any transference to the female,
excepting that she shews in her tail a trace of
the curved fork.
We may therefore conclude that the females of
distinct though allied species have often had
their plumage rendered more or less different
by the transference in various degrees of characters
acquired by the males through sexual
selection, both during former and recent times.
But it deserves especial attention that brilliant
colours have been transferred much more rarely
than other tints. For instance, the male of the
red-throated blue- breast (Cyanecula suecica)
has a rich blue breast, including a sub- triangular
red mark; now marks of nearly the same
shape have been transferred to the female, but
the central space is fulvous instead of red, and