The previously observed extra-adrenal preputial gland stimulating action of commercial ACTH prepns. have been reproduced by a purified ACTH extract in female, adrenalectomized and ovariectomized rats. At the dose level used this ACTH prepn. failed to cause thymolysis in adrenalectomized rats maintained on small doses of cortisone. The preputial gland stimulating effect exhibited by ACTH prepns. after adrenalectomy and gonadectomy could not be ascribed to gonadotropins.