210 
SEXUAL SELECTION: BIRDS. 
PAR 
rll- 
Before proceeding, I may remark that under 
present and two next classes of cases the tacts are 
tl' e 
SO 
tr O 3 ® 
complex, and the conclusions so doubtful, that any - 
who feels no especial interest in the subject had b^ e! 
pass them over. 
The brilliant or conspicuous colours which char^j 
terise many birds in the present class, can rar^' 
or never be of service to them as a protect! 0 ® ’ 
so that thev have probably been gained bv the n 1 : 1 ' 
’ ’ ’ • - • ' tb e 
that 
fe- 
to 
vo° 1(1 
► ^ -r J 
through sexual selection, and then transferred to 
females and the young. It is, however, possible 
the males may have selected the more attractive 
males ; and if these transmitted their characters 
their offspring of both sexes, the same results wo^ 
follow as from the selection of the more attract 1 
males by the females. But there is some evidence 
this contingency has rarely, if ever, occurred in any ° r 
s 
■ — U | U<1 JMIVi"— - 
tailed to bo transmitted to both sexes, the fern 3 ^ 
would have exceeded to a slight degree the ® 3 ^! 
in beauty. Exactly the reverse occurs under nat®’ 6 ’ 
for in almost every large group, in which the se* e _ 
generally resemble eacli other, the males of some ^ 
species are in a slight degi'ee more brightly colo®' 1 c 
than the females, it is again possible that the fe® 3 ^ 
may have selected the more beautiful males, these m fl 1 , 
having reciprocally selected the more beautiful 
but it is doubtful whether this double process of 
those groups of birds, iu which the sexes are gen®' 3 
alike ; for if even a few of the successive variations ’’ 
tion would be likely to occur 
------ -*J t/LUU, OWlIlg LU IUD £>' 
eagerness of one sex than the other, and whether 
der 
to the gre flt . 
ri* 
»Jg 
would be more efficient than selection on one ■ * ^ . 
alone. It is, therefore, the most probable view ^ 
sexual selection has acted, in the present class, 3S ^ 
as ornamental characters are concerned, iu accords® 
