THE MALE SEX HORMONE SOME FACTORS CONTROLLING ITS PRODUCTION AND SOME OF ITS EFFECTS ON THE REPRODUCTIVE ORGANS

That the testis has a function other than the production of spermatozoa has been known for many years. Indeed, the first experimental demonstration of endocrine activity for any organ occurred in 1849 when Berthold transplanted testes in the male fowl and observed that the usual external effects of castration did not occur in the bird bearing a transplanted gonad. Ber-thold's work has been confirmed repeatedly and, indeed, the effect of testicular hormone on the comb is at this time the basis of the principle method employed in gauging the activity of male hormone preparations. Complete accounts of the effects of testicular hormone upon the plumage and head fur-nisriings of birds are given by Moore (1932) and Domm, Gus-tavson and Juhn (1932). Moore (1932) Witschi (1932) and Sil-lier (1932) have adequately considered the question for lower animal forms as well as the embryological relations