AbstractA survey is given of experimental studies on the influence of treatment with androgenic hormonesin vivoon various intermediary reactions involved in ribonucleic acid (RNA) and protein synthesis in the prostate gland and seminal vesicle, with particular reference to the control of the growth and functional differentiation of these organs by testosterone and related steroids. Studies on the influence of androgens on RNA metabolism and protein biosynthesis in mouse kidney, certain muscles, and some other extragenital tissues are also considered.