The Endocrine Function of the Human Testis, Volume II, contains the papers that were given in the third and final part of the course of lectures on "The Endocrine Function of the Human Testis," held in Florence, 17-19 April 1973. The first two parts of the course, dealing with assay and metabolism of androgens, and with the regulation of testicular function, were published in Volume I. The present volume contains 16 contributions and begins with an analysis of steroid secretion by the testis in man. This is followed by studies on the temporal variation of testosterone and plasma gonadotrophins in man; interactions between steroids and gonadotropins; gonadotrophins and plasma testosterone in senescence; androgen secretion in male hypogonadism; and testosterone metabolism and action in testicular feminization syndrome. Subsequent chapters deal with male sexual precocity; "fertile eunuchism" (Leydig cells reduced in number and size with preserved spermatogenesis); male idiopathic hypogonadism associated with idiopathic hypothyroidism, and with idiopathic renal tubular acidosis; and the medical management and treatment of male hermaphrodites.