Darwin's Theory of Sexual Selection 215 
since they will transmit the characters of all the males, it is 
evident that the secondary sexual characters could not be 
formed in the way imagined. 
3._If the female fails to select only t the more ornamental 
males, no no result will follow. It has not been shown that she 
“WS capable ot of making ng such a choice, and in the lower forms 
particularly, it does not seem probable that this is done. 
The argument that Darwin often employs, namely, that 
unless she does select, the display of the males before her is 
sn eanIe eee) is not to the point. So far as we can detect 
the “cause” of the display of the male, i it appears ‘to be due 
“to-his own excitement j and even i if we go so far as to admit 
that the “ purpose’ "is to attract the other sex, it still does 
not in the least follow that the most or namental male is se- 
Tected, and unless this occurs the display has no ) bearing on 
the hypothesis of sexual selection. oe sae 
eae The two forms of sexual-selection, namely, competition 
of the males with one another (really one form of natural 
selection), and the selection of the most ornamental or gifted 
individuals, are both used by Darwin to explain secondary 
sexual. characters, the one for organs of offence and defence, 
and the other for ornamental characters. If we fully appre- 
ciate the difficulties that any theory of selection meets with, 
we shall realize how extraordinarily complex the action must 
be, when two such processes are carried out at the same 
time, or even during alternating periods. 
* 5: It has been objected to Darwin’s theory of sexual selec- 
tion, that he suddenly reverses its mode of action to explain 
those cases in which the female is the stronger and more 
ornamented sex; but if, as Darwin shows, the instincts of 
the male have also changed, and have become more like those 
of the female, I can see no inherent difficulty in this way of 
applying the theory. A much more serious objection, it 
seems to me, is that the male is supposed to select the female 
for one set of characteristics, and the female to select the 
