Methyl testosterone, like testosterone propionate, does not exert its specific effect on the genital organs of castrate male rats when implanted in pellet form in the spleen. When the pellet is placed in the transplanted spleen, with the splenic vessels ligated, the specific effect returns. As both androgens appear to be destroyed in the liver, it is suggested that the differences in the specific effects of these two substances when administered orally may be due to different routes of absorption from the intestinal tract (e. g., via the lymphatics), rather than different sites of inactivation.