C* 
; AP. XVI. 
the young like the adult fe mal es. 191 
ctl>Q 
tli e il - ™* a t possessed, by the three first species during 
lu * er an d in their immature state ; and this plum- 
dfif 18 common to several distinct species at 
ages and seasons, probably shews us liow the 
^ gonit or of the genus was coloured. In all these 
°rir/ S ’ nil ptial plumage which we may assume was 
jj 1( ; lUl % acquired by the adult males during the breed- 
^ t f easoa > auc l transmitted to the adults of both sexes 
tli Q ® oorresponding season, has been modified, whilst 
, "later and immature plumages have been left un- 
ified. F ° 
question naturally arises, how is it that in these 
t] le Ca ses the winter plumage of both sexes, aud in 
,r 6 ]j 0lI aer cases the plumage of the adult females, as 
as the immature plumage of the young, have not 
°v at all affected ? The species which represent each 
1 fori 
iu distinct countries will almost alwa 
U(i^ " ^xoi/ALi^u WUUtUCO YI'J.J.J, tt-JLILlVOli CUvVciyS llciVe 
ex posed to somewhat different conditions, but we 
in ' ar dly attribute the modification of the plumage 
f( ;i]|r males alone to this action, seeing that the 
li 0 j , 68 and the young, though similarly exposed, have 
U s eea affected. Hardly any fact in nature shews 
(l; rc ° re clearly how subordinate in importance is the 
Wj tli Ct action of the conditions of life, in comparison 
the accumulation through selection of indefinite 
l0ns > than the surprising difference between the 
^ °i many birds; for both sexes must have con- 
the same food and have been exposed to the 
ligjj ^imate. Nevertheless we are not precluded from 
that in the course of time now conditions 
induce some direct effect; w r e see only that this 
of 0r dinate in importance to the accumulated results 
Hew ec ti°m When, however, a species migrates into 
te Iu r C0Untr J r > an( l this must precede the formation of 
Putative species, the changed conditions to which 
