SEX HORMONES AND SKIN 393 hair and the problem of hirsutism may be interrelated by common involve- ment in the transformation of steroids in the skin, which is possibly, at least in relation to the sebaceous glands, mediated by pituitary hormones. Perhaps the epidermis, also, may be affected by steroids, and the application of non-active precursors was not a foolish idea, even if pregnenolone did not produce a striking effect. To add one more facet to the problem, is it possible that one function, or perhaps by-product, of cutaneous androgen metabolism could be the manufacture of pheromones? When we injected testosterone-4-•4C into rabbits, we were able to recover the label from the odoriferous part of the inguinal gland secretion (6). We do not know the chemical nature of the rabbit scent. But not all musk-like scents are macro- cyclic ketones or lactones, some are 16-unsaturated steroids for example, the compound 5a-androst-16-en-3fl-ol has been identified in human urine as well as being responsible for the characteristic smell of the boar (37). Such a compound could, in theory, be formed from an endogenous andro- gen. My story has included a modicum of firm evidence, a deal of speculation, and even a whiff of pure innuendo, for which I should need to ask no forgiveness here. Perhaps it was just a convenient way of linking the dis- covery, over 25 years ago, that rat sebaceous glands were influenced by hormones with our current study of steroid transformations in the skin, taking in the work on anti-androgens and the pituitary on the way. Or perhaps, at least, in hindsight, and admitting the gaps in logic, there is a connecting thread. In either case, Mr Chairman, I present it to you as the 1974 Medal Lecture. And may I add that I have been not only honoured, but more than a little overcome by your invitation to me to give it. ! have been a member of the Society for 10 years, and although I cannot be des- cribed as a Cosmetic Chemist I have always felt, and feel now, that I am among friends. REFERENCES (1) Ellis, H. Studies in the Psychology of Sex. IV. Sexual selection in man (1905) (F. A. Davis, Philadelphia). (2) Dominic, C. J. Pheromonal mechanisms regulating mammalian reproduction. Gem Comp. Endocrinol., Suppl. 2 260 (1969). (3) Bruce, H. M. Pheromones. Brit. Med. Btdl. 26 10 (1970). (4) Ralls, K. Mammalian scent marking. Science, 171 443 (1971). (5) Mykytowycz, R. Territorial marking by rabbits. Sci. Amer. 218 116 (1968). (6) Strauss, J. S. and Ebling, F. J. Control and function of skin glands in mammals. Mere. Soc. Endocrinol. 18 341 (1970).

394 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (7) Kingston, B. H. The chemistry and olfactory properties of musk, civet and castoreum. Proc. Ilnd b•t. Congr. Endocrinol. 209-216 (1965) (Excerpta Medica, Amsterdam). (8) Brownlee, R. G., Silverstein, R. M., Muller-Schwarze, D. and Singer, A. G. Isolation, identification and function of the chief component of the male tarsal scent in black-tailed deer. Nature 221 284 (1969). (9) Eller, J. J. and Eller, W. D. Oestrogenic ointments. Cutaneous effects of topical applica- tions of natural oestrogens with report of three hundred and twenty-one biopsies. Arch. Dermatol. Syphilol. 59 449 (1949). (10) Montagna, W., Formisano, V. and Kligman, A.M. Hormonal factors in ageing. Abstracts of International Congress on Hormonal Steroids. Milan, 1962. Excerpta Medica Series 51 48 (1962). (11) Ebling, F. J. and Rook, A. Disorders of keratinization. In: Textbook of Dermatology. Eds A. Rook, D. S. Wilkinson and F. J. G. Ebling. 2nd edn, 1137-1191 (1972) (Blackwell Scientific Publications, Oxford). (12) Behrman, H. T. Hormone creams and the facial skin. J. Amer. Med. Ass. 155 119 (1954). (13) Hormone Creams. Which? February (1960) 24-27 (Consumers' Association, London). (14) Silson, J. E. Pregnenolone Acetate---A dermatologically active steroid. Soc. Cosmet. Chem. Symposium, 26th September 1961. (15) Sternberg, T. H., LeVan, P. and Wright, E. T. The hydrating effects of pregnenolone acetate on the human skin. Curt. Ther. Res. 3 No. 11 (1961). (16) Ebling, F. J. Steroid hormones and sebaceous secretion. Advances in Steroids, Vol. 2. Ed. M. H. Briggs (1970) (Adademic Press, London). (17) Ebling, F. J. The response of the cutaneous glands to steroids. Gert. Comp. Endocrinol. Suppl. 3 228 (1972). (18) Ebling, F. J. Sebaceous glands. I. The effect of sex hormones on the sebaceous glands of the female albino rat. J. Endocrinol. 5 297 (1948). (19) Wales, N. A.M. and Ebling, F. J. The control of apocrine glands of the rabbit by steroid hormones. J. Endocrinol. 51 763 (1971). (20) Strauss, J. S. and Pochi, P. E. The quantitative gravimetric determination of sebum pro- duction. J. Invest. Dermatol. 36 293 (1961). (21) Strauss, J. S. and Pochi, P. E. The human sebaceous gland: its regulation by steroidal hormones and its use as an end organ for assaying androgenicity in vivo. Recent Prog. Horm. Res. 19 385 (1963). (22) Ebling, F. J. and Skinner, J. The measurement of sebum production in rats treated with testosterone and oestradiol. Brit. J. Dermatol. 79 386 (1967). (23) Ebling, F. J. The action of testosterone and oestradiol on the sebaceous glands and epidermis of the rat. J. Embryol. Exp. Morphol. 5 74 (1957). (24) Ebling, F. J. The action of an antiandrogenic steroid, 17•-methyl-i3-nortestosterone, on sebum secretion in rats treated with testosterone. J. Endocrinol. 38 181 (1967). (25) Ebling, F. J. The effects of cyproterone acetate and oestradiol upon testosterone stimulated sebaceous activity in the rat. Acta Endocrinol. 72 361 (1973). (26) Ebling, F. J., Ebling, E. and Skinner, J. The influence of pituitary hormones on the response of the sebaceous glands of the rat to testosterone. J. Endocrinol. 45 245 (1969). (27) Ebling, F. J. Hormonal control and methods of measuring sebaceous gland activity. In: Advances in Biology of Skin Vol. XIV, Sebaceous glands and ache vulgaris. Eds W. Montagna, M. Bell and J. S. Strauss. J. Invest. Dermatol. 62 161 (1974). (28) Thody, A. J. and Shuster, S. The effect of hypophysectomy and testosterone on the activity of sebaceous glands of castrated rats. J. Endocrinol. 47 219 (1970). (29) Thody, A. J. and Shuster, S. Possible role of MSH in the mammal. Nature (London) 245 207 (1973).