Rare though the true hermaphrodite may be, the partial hermaphrodite is relatively frequent. The mixed ensemble of the directly contrasting type, such as the concomitance of testes with feminine secondary sex traits, or of ovaries with masculine sex traits, have been described from time immemorial as freaks. Occurring even more frequently is the mixed sex ensemble, in which the type of reproductive organs and of secondary sex traits run roughly parallel, emulsified with certain traits of the opposite sex. Physical features of one sex, instincts and mental attitudes of the other co-exist in the same individual by reason of an excess in one direction or a deficiency in another of the internal secretions. The degree of masculine trend in a woman is a crude measure of adrenal domination, the degree of feminine deviation in a man is roughly proportional to the amount of pituitary influences in his make-up. Whether one or the other sex tendency will dominate depends upon the quantity of sex hormone divergence from the ideal normal. But also determinant are the environment stimuli provoking excessive or deficient secretory reactions from the other endocrines involved, through the vegetative nervous system. Such especially are the associates of the mixed sex individual. Ordinarily the combative male and the submissive female are differentiated by contrasts of skin and hair, fat and bone structure. The combative male is built as a fighting machine, the submissive female as an organism of attractive grace and beauty for impregnation and parturition. When one sees the fragile woman aggressive, the masculinoid woman submissive, one may infer an education of experience that has brought the usually recessive glands into the foreground, and by their hyperactivity imposed a bisexuality of function upon a unisexual anatomic structure. A man apparently as formidable as a tyrannosaurus, may be ruled by his wife for the same reason. These combinations of a single organic sexuality with a functional bisexuality, based upon internal secretion disturbances, are frequent, and merit the name of functional hermaphrodites or mixed sex types. MIXED SEX AND THE FAMILY The psychology of the family in its relation to the endocrine traits of its members is something that still remains to be thoroughly worked out as a problem of tremendous importance. Particularly are the reactions of the mixed sex types to be carefully considered. For, since the family is fundamentally a sex institution, devised to satisfy the sex needs, all the way from companionship to parenthood, it is apparent that the mixed sex types will be tried the hardest by its inexorable conditions. It is in relation to the mother (or nurse) first, the father next, and other associates in proportion to their proximity, that the primary endocrine-vegetative mechanisms, the germs of the growing soul, become established. These are superimposed upon the hereditary instinct apparatus.