SEX HORMONES AND SKIN 383 inflated, especially in the female, to reach their greatest natural develop- ment in the steatopygia of the African Bushwoman, and their ultimate cultural exaggeration in the bustle. Desmond Morris has made the further interesting suggestion that since all the remaining sexual signals are in front of the body, the breasts have developed as a buttock mimic, thus making the human female equally attractive from either aspect. I could discuss many more examples of structural releasers of sexual interest, such as lips, cheeks, eyes and hair, and it is hardly necessary for me to point out that all these are the targets of cosmetic chemistry in its efforts to improve on nature. I want, however, to confine myself to three features of the skin which are of sexual significance and which underlie the understanding of its hormonal connections, namely texture, smell and hair distribution. At the beginning of this century, a work on pathology described skin as 'a tissue which is silk to the touch, the most exquisitely beautiful surface in the universe to the eye... more beautiful than velvet, softer and more pliable than silk, more impervious than rubber... '. The sensation of touch is one of the earliest of all pleasurable experiences and it becomes a powerful sexual stimulus in the words of Havelock Ellis (1) 'Touch sensa- tions constitute a vast gamut for the expression of affection, with at one end the note of minimum personal affection in the brief and limited touch involved by the conventional hand-shake and the conventional kiss, and at the other end the final and intimate contact in which passion finds the supreme satisfaction of its most profound desire .... Even the hand-shake of a sympathetic man is enough in some chaste and sensitive women to produce sexual excitement or sometimes even the orgasm'. (He was, I think, writing of an age when women's sexual feelings were severely re- pressed.) The erotic appeal of skin is visual as well as tactile. It looks and feels best when it is unwrinkled, smooth or even wet--facts exploited by photographers as well as by cosmeticians--and for some persons it seems that leather or even rubber works even better than the real thing. Odour is a characteristic of the human body. In addition to the breath, Havelock Ellis (1) distinguished between the odours of the general skin, the hair and scalp, the armpit, the perineum, the mons veneris and the prepuce, and pointed out that the scents were detectable even in healthy and well- washed persons under normal conditions. Some of these regions of the body, for example the axilla and the genital areas, contain aggregations of tubular apocrine glands opening into the hair follicles and there is little doubt that these are responsible for the odorous secretion. But the general body skin

384 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS and the scalp have only holocrine sebaceous glands and the eccrine sweat glands one cannot dismiss the thought that the former, if not the latter also, may contribute to the smell as well as to the texture of the skin. Both the sebaceous and apocrine glands remain small during infancy and become active only after puberty. Body odours change at puberty, and characteristic odours are said to be emitted during sexual excitement by both men and women. Havelock Ellis (1) records the case of a woman who emitted a rose odour for 2 days after coitus, and mentions that in the seventeenth century there was a monk in Prague who was prepared to diagnose the chastity of women by their smell. Whatever is true of man, there is increasing recognition of the role of odours, or pheromones, as sexual or social signals in other mammals (2-4). They function not only as sex attractants, but also in the marking of territory and the establishment of social hierarchy, and they are produced by a wide variety of specialized skin glands, either apocrine, sebaceous, or mixed, which can occur in almost every region of the body. The rabbit, for example, has three pairs of apocrine glands (5), the chin and anal which are used for marking territory and appear to have similar secretions, and the inguinal which is concerned with sex attraction and produces a different chemical material (6). The chemical structure of a few animal scents is known and some, indeed, form the classic materials of human perfumery. Such are civetone, from the civet cat, and muscone, from the male musk deer, which are macro cyclic ketones (7). The musk rat produces dihydrocivetol, a saturated ring alcohol, and the black tailed deer a lactone (8). Facial and body hair are other features of the skin which develop at puberty, though follicles growing only a fine down have been present since birth. Whether male facial hair is sexually directed towards the female as well as serving for aggressive display to other males, I am unsure. Presum- ably it is commonly shaved off in many cultures, not to reduce sex appeal, but as a contribution to social harmony. And in spite of the exploitation of full frontal pubic hair to arouse sexual interest in the theatre, and a recent study in which 50•o of women admitted to being excited by male body hair, I suspect that the main evolutionary significance of the pubic and axillary hairs is to act as wicks for the dissemination of odour produced by the apocrine and, probably, the sebaceous glands. Whatever the function of facial, pubic, axillary and other body hair, it is clear that it is, whether in male or female, an adult character manifested only during the reign of male type sex hormones. It is reasonable to expect, therefore, that at least three features of the