262 THE PRINCIPLES OF Part II. 



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 tliis 

 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 acid 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. 



