SUMMARY The rabbit has specialized apocrine glands in the submandibular (chin), inguinal and anal regions. The glands enlarge at puberty and are heavier and more active in mature males than females. Prepubertal castration causes the adult male to have lighter and less active glands than intact mature animals; this effect can be reversed by administration of testosterone (0·6 mg/24 h). Severe reduction in gland weight and activity below the level of the castrated animals was produced by administration of oestradiol (10–20 μg/24 h) either when given alone to intact males or together with testosterone to castrated males. The degree of depression by oestradiol varied between the three glandular regions. Progesterone (0·6 mg/24 h) was unable to stimulate the glands of castrated male rabbits but did modify the suppressive action of exogenous oestradiol. The sebaceous glands of the inguinal complex showed the same fluctuations in weight with hormone treatment as did the inguinal apocrine glands.