108 SEXUAL SELECTION. [Chap. IV. 



through natural selection in relation to different habits 

 of life, as is sometimes the case; or for one sex to be 

 modified in relation to the other sex, as commonly oc- 

 curs. This leads me to say a few words on what I have 

 called Sexual Selection. _This form of selection de- 

 pends, not on a struggle for existence in relation to 

 other organic beings or to external conditions, but on a 

 , struggle between the individuals of one sex, generally 

 the males, for the possession of the other sex. Theje- 

 sult is not death to the unsuccessful competitor, but Jew 

 or no ,Qff spring. Sexual selection is, therefore, less 

 rigorous, than natural selection. Generally, the most 

 vigorous males, those which are best fitted for their 

 places in nature, will leave most progeny. But in many 

 cases, victory depends not so much on general vigor, as 

 on having special weapons, confined to the male sex. 

 A. hornless stag or spurless cock would have a poor 

 chance of leaving numerous offspring. Sexual selection, 

 by always allowing the victor to breed, might surely give 

 indomitable courage, length to the spur, and strength to 

 the wing to strike in the spurred leg, in nearly the same 

 manner as does the brutal cockfighter by the careful se- 

 lection of his best cocks. How low in the scale of 

 nature the law of battle descends, I know not; male alli- 

 gators have been described as fighting, bellowing, and 

 whirling round, like Indians in a war-dance, for the pos- 

 session of the females; male salmons have been observed 

 fighting all day long; male stag-beetles sometimes bear 

 wounds from the huge mandibles of other males; the 

 males of certain hymenopterous insects have been fre- 

 quently seen by that inimitable observer M. Fabre, fight- 

 ing for a particular female who sits by, an apparently 

 unconcerned beholder of the struggle, and then retires 



