The size and development of the sebaceous glands lining the inner and outer surfaces of the ear were compared in intact rabbits, castrated juvenile rabbits, and castrates subsequently treated with relatively high doses of a depot androgen preparation (Triolandren®). It was found that the glands in the inner surface skin reacted much more strongly than those in the outer surface, especially in the androgen-treated castrates. Only slight differences in reactivity were found in the untreated castrates, and the controls showed no clear-cut differences at all