Chap. IV. SEXUAL SELECTION. 91 



this leads ine to saj a few words on what I call Sexual Selec- 

 tion. This depends, not on a sti'ugf^le for existence, l)ut on a 

 struo^g'lc between the males for possession of tlie females; the 

 result is not death to the inisuccessful competitor, but few or 

 HO oifsprino-. Sexual selection is, therefore, less rit^orous than 

 natural selection. Generally, the most vigorous males, those 

 \vhich are best fitted for their places in Nature, will leave most 

 progeny. But, in many cases, victory depends not on general 

 vigor, but on having special weapons, confined to the male 

 sex. A hornless stag or spurless cock would have a poor 

 chance of leaving numerous ollspring. Sexual selection, by 

 always allowing the victor to breed, might surely give indom- 

 itable courage, length to the spur, and strength to the wing 

 to strike in the spurred leg, as in the case of the brutal cock- 

 fighter, who knows well how to improve his breed hy the care- 

 ful selection of the best cocks. How low in the scale of Nature 

 the law of battle descends, I know not ; male alligators have 

 been described as fighting, bellowing, and Avhirling round, like 

 Indians in a war-dance, for the possession of the females ; male 

 salmons have been seen fighting all day long ; male stag-])eetles 

 sometimes bear wounds from the huge mandibles of other 

 mules ; tlie males of certain hymcnopterous insects have been 

 fivcjuently seen by that inimitable observer M. Fabre, fighting 

 for a particular female, Avho sits by, an apparently imcon- 

 cerned beholder of the struggle, and then retires with the con- 

 queror. The war is, perhaps, severest between the males of 

 l)olygamous animals, and these seem oftenest provided with 

 special weapons. The males of carnivorous animals arc already 

 well armed ; though to them and to others, special means of de- 

 fence may be given through means of sexual selection, as the 

 mane to the lion, and the hooked jaw to the male salmon; for 

 the shield may be as important for victory as the sword or 

 spear. 



Among birds, the contest is often of a more peaceful char- 

 acter. All those who have attended to the subject, believe 

 that there is the severest rivalry between the males of many 

 species to attract l)y singing the females. The rock-thrush of 

 Guiana, birds of Paradise, and some others, congregate; and 

 successive males display tlieir gorgeous plumage and perform 

 strange antics l)efore the females, whieli, standing bv as spec- 

 tators, at last choose the most attractive partner. 1'hose who 

 have closely attended to birds in confinement well know that 

 they often take individual preferences and dislikes: thus Sir 



