262 
THE PRINCIPLES OF 
Part IL 
strongest, and with some species the best armed, drive 
away the weaker males ; and the former would then 
unite with the more vigorous and best-nourished fe- 
males, as these are the first to breed. Such vigorous 
pairs would surely rear a larger number of offspring 
than the retarded females, which would be compelled, 
supposing the sexes to be numerically equal, to unite 
with the conquered and less powerful males ; and this 
is all that is wanted to add, in the course of successive 
generations, to the size, strength and courage of the 
males, or to improve their weapons. 
But in a multitude of cases the males which conquer 
other males, do not obtain possession of the females, 
independently of choice on the part of the latter. The 
courtship of animals is by no means so simple and short 
an affair as might be thought. The females are most 
excited by, or prefer pairing with, the more ornamented 
males, or those which are the best songsters, or play the 
best antics; but it is obviously probable, as has been 
actually observed in some cases, that they would at the 
same time prefer the more vigorous and lively males. 4 
Thus the more vigorous females, which are the first to 
breed, will have the choice of many males ; and though 
they may not always select the strongest or best armed, 
they will select those which are vigorous and well armed,, 
and in other respects the most attractive. Such early 
pairs would have the same advantage in rearing off- 
spring on the female side as above explained, and nearly 
the same advantage on the male side. And this ap- 
parently has sufficed during a long course of generations 
to add not only to the strength and fighting-powers of 
4 I have received information, hereafter to be given, to this effect 
with respect to poultry. Even with birds, such as pigeons, which 
pair for life, the female, as I hear from Mr. Jenner Weir, will desert 
her mate if he is injured or grows weak. 
