Chorionic gonadotrophin is produced primarily by some part of the fertilized ovum, after it becomes embedded in the uterine wall, subsequently from the corresponding part of the placenta. The hormone production continues until detachment of the placenta. The hormone is excreted in the urine. In animal experiments it has the same effect as the pituitary gonadotrophin ICSH (interstitial cell stimulating hormone): in the ovary maturation of follicles and luteinization, in the testis stimulation of the interstitial cells but also – probably indirectly through stimulation of the hormone secretion of the interstitial cells – of the tubuli seminiferae (literature: see FEVOLD 1939, ENGLE and LEVIN 1941). Chorionic gonadotrophin has got some use in the therapy of metrorrhagia (Eeiprich 1934, Novak 1938, Jacoby and Der Briicke 1940). It is, however, emphasized in «The Report of the Council on Pharmacy and Chemistry» 1940, that the hormone itself is of little therapeutical value in gynecology (see also Davis and Hellbaum