[Sexual Selection] depends on the advantage which certain individuals have over others of the same sex and species solely in respect of reproduction.... [Where] the males have acquired their present structure, not from being better fitted to survive in the struggle of existence, but from having gained an advantage over other males, and from having transmitted this advantage to their male offspring alone, sexual selection must here have come into action.... A slight degree of variability leading to some advantage, however slight, in reiterated deadly contests would suffice for the work of sexual selection; and it is certain that secondary sexual characters are eminently variable. Just as man can give beauty, according to his standard of taste, to his male poultry, or more strictly can modify the beauty originally acquired by the parent species, can give to the Sebright bantam a new and elegant plumage, an erect and peculiar carriage—so it appears the female birds in a state of nature, have by a long selection of the more attractive males, added to their beauty or other attractive qualities.[6] [6] _The Descent of Man_, 1877, pp. 209-211. Thus, according to Mr. Darwin, it is through a long selection by females of the more attractive males that the present structure of the latter has been acquired. If, in a short time, a man can give elegant carriage and beauty to his bantams, according to his standard of beauty, he can see no reason to doubt that female birds, by selecting during thousands of generations the most melodious or beautiful males, according to their standard of beauty, might produce a marked effect. He says: To sum up on the means through which, as far as we can judge, sexual selection has led to the development of secondary sexual characters. It has been shown that the largest number of vigorous offspring will be reared from the pairing of the strongest and best armed males, victorious in contests over other males, with the most vigorous and best-nourished females, which are the first to breed in the spring. If such females select the more attractive, and at the same time vigorous males, they will rear a larger number of offspring than the retarded females, which must pair with the less vigorous and less attractive males.... The advantage thus gained by the more vigorous pairs in rearing a larger number of offspring has apparently sufficed to render sexual selection efficient.[7] [7] _The Descent of Man_, 1877, p. 220. Although the belief is common among naturalists that the appearance of secondary sexual characters belonging to males is greatly influenced by female choice, a majority of writers upon this subject are not in sympathy with Mr. Darwin’s theory concerning the origin of these variations. It is believed by them that Sexual Selection “may account for the perfecting, but not for the origin, of these characters.”