The Descent of Man

In most of the species of the splendid family of
the Pheasants, the males differ conspicuously
from the females, and they acquire their ornaments
at a rather late period of life. The eared
pheasant (Crossoptilon auritum), however,
offers a remarkable exception, for both sexes
possess the fine caudal plumes, the large eartufts
and the crimson velvet about the head; I
find that all these characters appear very early
in life in accordance with rule. The adult male
can, however, be distinguished from the adult
female by the presence of spurs; and conformably
with our rule, these do not begin to be developed
before the age of six months, as I am
assured by Mr. Bartlett, and even at this age,
the two sexes can hardly be distinguished. (44.
In the common peacock (Pavo cristatus) the
male alone possesses spurs, whilst both sexes of
the Java Peacock (P. muticus) offer the unusual
case of being furnished with spurs. Hence I
fully expected that in the latter species they
would have been developed earlier in life than