Carrageenin pellets, implanted subcutaneously in adrenalectomized rats, produced in 5 days compact, easily dissected granulomata. Accepted anti-inflammatory steroids administered as single daily subcutaneous injections or in the diet, but not as single daily oral doses, reduced the granuloma wet weight. The relative anti-inflammatory activities of cortisol, prednisolone and betamethasone, administered subcutaneously or in the diet, duplicated their relative clinical values. The relative activity of dexamethasone to cortisol was three times that reported on patients. Corticosterone acetate was weakly active in this test, desoxycorticosterone acetate increased granuloma weight, and oestrone, mepyramine maleate, mersalyl, progesterone, norethandrolone, testosterone propionate and Pitressin were inactive.