The Descent of Man

of N. America, Fringilla tristis, Linn., see Audubon,
'Ornithological Biography,' vol. i. p. 172.
For the Maluri, Gould's 'Handbook of the Birds
of Australia,' vol. i. p. 318.) With those species,
the sexes of which are alike during both the
summer and winter, the young may resemble
the adults, firstly, in their winter dress; secondly,
and this is of much rarer occurrence, in their
summer dress; thirdly, they may be intermediate
between these two states; and, fourthly, they
may differ greatly from the adults at all seasons.
We have an instance of the first of these
four cases in one of the egrets of India (Buphus
coromandus), in which the young and the
adults of both sexes are white during the winter,
the adults becoming golden-buff during the
summer.
With the gaper (Anastomus oscitans) of India
we have a similar case, but the colours are reversed:
for the young and the adults of both
sexes are grey and black during the winter, the