210 THE DESCENT OP MAN. 



larger number of offspring than the retarded females, which 

 would be compelled to unite with the conquered and less power- 

 ful males, supposing the sexes to be numerically equal; and this 

 is all that is wanted to add, in the course of successive genera- 

 tions, to the size, strength and courage of the males, or to im- 

 prove their weapons. 



But in very many cases the males which conquer their rivals, 

 do not obtain possession of the females, independently of the 

 choice 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 that they would at the same 

 time prefer the more vigorous and lively males, and this has in 

 some cases been confirmed by actual observation." 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 at- 

 tractive. Both sexes, therefore, of such early pairs would, as 

 above explained, have an advantage over others in rearing off- 

 spring; and this apparently has suflSced during a long course of 

 generations to add not only to the strength and fighting powers 

 of the males, but likewise to their various ornaments or other at- 

 tractions. 



In the converse and much rarer case of the males selecting par- 

 ticular females, it is plain that those which were the most vigor- 

 ous and had conquered others, would have the freest choice; and 

 it is almost certain that they would select vigorous as well as at- 

 tractive females. Such pairs would have an advantage in rear- 

 ing offspring, more especially if the male had the power to de- 

 fend the female during the pairing-season as occurs with some 

 of the higher animals, or aided her in providing for the young. 

 The same principles would apply if each sex preferred and se- 

 lected certain individuals of the opposite sex; supposing that 

 they selected not only the more attractive, but likewise the more 

 vigorous individuals. 



Numerical Proportion of the Two Sexes. — I have remarked 

 that sexual selection would be a simple affair if the males were 

 considerably more numerous than the females. Hence I was led 



each year. See his remarkable essay, 'Anwendung der Darwin'schen 

 Lehre auf Bienen,' 'Verb. d. V. Jahrg.' xxix. p. 45. 



° With respect to poultry, I have received Information, hereafter to 

 be given, to this effect. Even with birds, such as pigeons, which 

 pair for life, the female, as I hear from Mr. Jenner Weir, will desert 

 Uer mate if he is injured or grows weak. 



