The Descent of Man

uniform. (31. 'Mammals and Birds of E. Florida,'
pp. 234, 280, 295.)
A few exceptional cases occur in various classes
of animals, in which the females instead of the
males have acquired well pronounced secondary
sexual characters, such as brighter colours,
greater size, strength, or pugnacity. With birds
there has sometimes been a complete transposition
of the ordinary characters proper to each
sex; the females having become the more eager
in courtship, the males remaining comparatively
passive, but apparently selecting the more
attractive females, as we may infer from the
results. Certain hen birds have thus been rendered
more highly coloured or otherwise ornamented,
as well as more powerful and pugnacious
than the cocks; these characters being
transmitted to the female offspring alone.
It may be suggested that in some cases a double
process of selection has been carried on; that
the males have selected the more attractive fe-