To cultivate a _mujerado_, a very powerful man is chosen, and he is induced to masturbate excessively and ride horseback constantly. This combination of activities gradually produces an irritable weakness of the genital organs, resulting in great loss of semen. Paralytic impotence follows this condition of chronic irritability, and finally atrophy of the testicles and penis sets in. This condition is accompanied by characteristic physical changes; the beard falls out, the voice loses its depth and volume and physical strength and energy decrease. The disposition and inclinations become feminine. Thenceforth, the _mujerado_ loses his position in society as a man. He adopts feminine customs and manners, and associates quite exclusively with women. Notwithstanding his effeminization, he is for religious reasons, held in honor. It is probable that at other times of the year than during the festival occasions, he is used by the chiefs for pederasty. Hammond was privileged to examine two _mujerados_. One, then thirty-five years of age, had undergone his metamorphosis seven years previously, when he was fully masculine and potent. Gradually atrophy of the testicles and penis came about, and concurrently he lost his potency and the power of erection. At the time of examination he differed in no way in dress or manner from the women with whom he associated. In contrast to the degeneration of his genital organs, he had developed large breasts like a pregnant women, and claimed that he had nursed several children whose mothers had died. The other _mujerado_, who was then thirty-six years of age, had been effeminate for ten years. He presented the same general peculiarities as the one already referred to, but with less development of the mammary glands. Like the first, his voice was high-pitched and thin, and the body plump. The relation of excessive horse-back riding to underdevelopment of the male genitals has been noted by many authorities. The Apaches and Navajos, who spend practically all their waking hours on horse-back are remarkable for small genitals and mild libido and vitality. Kraproth and Chotomski record that even at the present time impotence is very prevalent among the Tartars, which was attributed to riding on unsaddled horses. Westermarck, in his monumental work, _The Origin and Development of the Moral Ideas_, remarks, in describing the Koriaks: “Krasheninnikoff makes mention of the _Ke’yev_, that is men occupying the position of concubines, and he compared them with the Kamchadale (a Behring’s Strait Tribe) _Koe’kcuc_, as he calls them, that is men transformed into women. Every _Koe’kcuc_ is regarded as a magician and interpreter of dreams.... The _Koe’kcuc_ wore women’s clothes, did women’s work, and were in the position of wives or concubines.”