88 
SEXUAL SELECTION. 
Chap. 17. 
with insects. And this leads me to say a few words on 
what I call Sexual Selection. This depends, not on a 
struggle for existence, but on a struggle between the 
males for possession of the females; the result is not 
death to the unsuccessful competitor, but few or no 
offspring. 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 on general vigour, but on having 
special weapons, confined to the male sex. A hornless 
stag or spurless cock would have a poor chance of 
leaving offspring. Sexual selection by always allow¬ 
ing the victor to breed might surely give indomitable 
courage, length to the spur, and strength to the wing 
to strike in the spurred leg, as well as the brutal cock- 
fighter, who knows well that he can improve his breed 
by careful 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 whirling round, like Indians in a war- 
dance, for the possession of the females; male salmons 
have been seen fighting all day long; male stag-beetles 
often bear wounds from the huge mandibles of other 
males. The war is, perhaps, severest between the males 
of polygamous animals, and these seem oftenest pro¬ 
vided with special weapons. The males of carnivorous 
animals are already well armed; though to them and to 
others, special means of defence may be given through 
means of sexual selection, as the mane to the lion, the 
shoulder-pad to the boar, and the hooked jaw to the 
male salmon; for the shield may be as important for 
victory, as the sword or spear. 
Amongst birds, the contest is often of a more peaceful 
character. All those who have attended to the subject. 
