The auricle of the rabbit ear appears particularly well suited as a histometrically evaluable model for assessing the reactions of the sebaceous glands to topical and systemic influences. Treatment of juvenile castrate rabbits with eight doses of 100 mg of a depot androgen (Triolandren®) over a period of 4 weeks led to a pronounced hyperplasia of the auricular glands: their average sectional area increased by 127% in relation to the initial values, whereas untreated control animals showed an increase of only 39% within the same period