76 CONTROLLED NATURAL SELECTION 
Another favouring fact is that animals, not 
liable to be attacked, either make no pre- 
copulatory displays or only poor ones. It is 
also noteworthy that the displays made by 
the parents for the protection of their young 
during the attack of an enemy, are very 
similar to and sometimes exactly like pre- 
copulatory displays. In one case an enemy 
as the stimulating agent ; may it not be so in 
both ? 
Just as there is no direct evidence in favour 
of this conception, so there is none against 
it. Other theories have been propounded to 
account for the facts; these will be discussed 
under Sexual Colour (Chapter VIII); and 
what contrary indirect evidence there is will 
be also then considered. | 
Some have likened these displays to car- 
esses, and have supposed that by them 
the male overcomes a coyness of the 
female. Females appear to be coy be- 
cause they take no notice of the male’s 
display ; for this reason, when the male’s 
display appears to be kindly in nature to- 
wards the female, it is called a caress; and 
no heed is taken of the many cases in 
which the male’s display appears quite brutal. 
Further, much coyness on the part of the 
