of estrogenic substance recovered or the severity of the symptoms.Positive spreads occurred with as little as 15 M.U.L., negative with as much as 200 M.U.L.Of the 5 physiological menopause patients (ages between 44 and 59 years, duratim 1 to 9 years) 2 showed a positive estrogenic blood reaction with 40 cc. of blood; 3 excreted from 60 to 400 M.U. per month. In only 2 (1 of which gave a positive blood reaction) was the excretion nil. The subjective symptoms of all 5 patients were severe,The 3 X-ray castrates corresponded to the surgical castrates in their hormone titres .Sumwry. The estrogenic factor continues to be excreted after surgical removal of the ovaries, as well as after the physiologZical menopause and X-ray castration. In spite of the presence of the estrogenic factor, excessive production of the gonadotropic factor ( luteinizing and follicle stimulating) takes place.No explanation of the source of the estrogenic factor, after the removal of the ovaries, can as yet be offered. Experiments to solve this problem are under way. c