The occurrence of an oestrogenic substance in the sexual skin of monkeys.

OESTROGENIC substances can be recovered from the ovaries, placenta, urine, blood, faeces, bile, colostrum, testes, adrenals and pituitary [Doisy, 1932; Callow & Parkes, 1936]. Until recently there has been no evidence of their presence in tissues on which they specifically act. The present paper is an account of their occurrence in the sexual skin of monkeys, a tissue whose activity, it has been found, is controlled by oestrin. The sexual skin in the female is generally restricted to the circumanal and circumgenital zones. These regions become highly coloured, and in certain species considerably swollen, during the first or follicular phase of the menstrual cycle (for details as to species variation, see Zuckerman [1930]). Male monkeys do not normally exhibit a sexual skin, but it has been found recently that the injection of oestrone induces considerable swelling of the anus, scrotum, and surrounding regions [Dohrn et al., 1933; see Zuckerman & Parkes, 1936, for further references]. Both normal and experimental sexual skin and experimental scrotal swellings appear on section as a jelly-like avascular tissue. The tissue is either colourless or faintly blue; usually it is odourless, but occasionally it smells unpleasantly. The cut surfaces exude a pale straw-coloured grumous fluid, which in amount varies with the extent of surface and the degree of swelling. The effect which sexual skin swelling has on the water balance is discussed elsewhere [Krohn & Zuckerman, 1936].