108 SEXUAL SELECTION. [Chap. IY. 



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 occurs. 

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

 Sexual Selection. This form of selection depends, not 

 on a struggle for existence in relation to other organic 

 being's or to external conditions, but on a struggle 



~ ' CO 



between the individuals of one sex, generally the males, 

 for the possession of the other sex. The result is not 

 death to the unsuccessful competitor, but few or no off- 

 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 vigour, 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 allow- 

 ing the victor to breed, might surely give indomitable 

 courage, length to the spur, and tgth to the wing to 



strike in the spun . in nearly the same manner as 



does the brutal cockfighter by the careful selection of 

 his bet -. How low in the s le of nature the law of 



battle descends, I know not ; male alligators have been 

 describe 1 as fighting, bellowing, and whirling round, like 

 Indians in a war-dance, for the pos» d of the females; 

 male salmons have been observed fighting all day lon^r ; 

 male - .-beetles sometimes bear wounds from the huge 

 mandibles of other males ; the males of certain hymen ap- 

 terous insects have been frequently seen by that inimit- 

 able er M. Fabre, fighting for a particular female 

 who sits by, an apparently unconcerned beholder of the 

 struggle, and then retires with the conqueror. The war 



