196 
SEXUAL SELECTION: BIliDS. 
Part 1 
IV 
auritum and Pliasianus Wallichii) the two sexes close*- 
resemble each other and their colours are dull- ^ 6 
may go so far as to believe that if any part of 
plumage in the males of these two pheasants had hc e |j 
brilliantly coloured, this would not have been transfer^ 
to the females. These facts strongly support 
Wallace’s view that with birds which are exposed ® 
much danger during nidification, the transference 0 
bright colours from the male to the female has b eCI ' 
checked through natural selection. We must IlD ’ 
however, forget that another explanation, before gi reI 'j 
is possible ; namely, that the males which varied 
became bright, whilst they were young and > ne * 
perienced, would have been exposed to much dang** 
and would generally have been destroyed; the d , 
and more cautious males, on the other hand, if * j 
varied in a like manner, would not only have been 
to survive, but would have been favoured in 
rivalry with other males. Now variations occur 11 *’® 
late in life tend to be transmitted exclusively to * 
same sex, so that in this case extremely bright 
would not have beeu transmitted to the females. ^ 
the other hand, ornaments of a less conspicuous 1 ;|U ’ 
such as those possessed by the Eared and Cheer 
sants, would not have been dangerous, and if they ^ 
peared during early youth, would generally have h® e 
transmitted to both sexes. 
In addition to the effects of the partial transfer 61 ' 
of characters from the males to the females, some of t .' , 
differences between the females of closely-allied sV eCi ^‘ 
may be attributed to the direct or definite actio 11 
the conditions of life. 11 With the males any 
o' 
sucl> 
11 See, on this subject, chap, xxiii. in the ‘Variation of Aninr 
Plants under Domestication.’ 
