There has been some discussion as to why, and indeed how far, blushing is confined to the face. Henle (_Ueber das Erröthen_) thought that we blush in the face because all nervous phenomena produced by mental states appear first in the face, owing to the anatomical arrangement of the nerves of the body. Darwin (_Expression of the Emotions_) argued that attention to a part tends to produce capillary activity in the part, and that the face has been the chief object of attention. It has also been argued, on the other hand, that the blush is the vestigial remains of a general erethism of sex, in which shame originated; that the blush was thus once more widely diffused, and is so still among the women of some lower races, its limitation to the face being due to sexual selection and the enhanced beauty thus achieved. Féré once had occasion to examine, when completely nude, a boy of thirteen whose sexual organs were deformed; when accused of masturbation he became covered by a blush which spread uniformly over his face, neck, body and limbs, before and behind, except only the hands and feet. Féré asks whether such a universal blush is more common than we imagine, or whether the state of nudity favors its manifestation. (_Comptes Rendus, Société de Biologie_, April 1, 1905.) It may be added that Partridge mentions one case in which the hands blushed. The sexual relationships of blushing are unquestionable. It occurs chiefly in women; it attains its chief intensity at puberty and during adolescence; its most common occasion is some more or less sexual suggestion; among one hundred and sixty-two occasions of blushing enumerated by Partridge, by far the most frequent cause was teasing, usually about the other sex. "An erection," it has been said, "is a blushing of the penis." Stanley Hall seems to suggest that the sexual blush is a vicarious genital flushing of blood, diverted from the genital sphere by an inhibition of fear, just as, in girls, giggling is also very frequently a vicarious outlet of shame; the sexual blush would thus be the outcome of an ancestral sex-fear; it is as an irradiation of sexual erethism that the blush may contain an element of pleasure.[65]