The progestational activity of desoxycorticosterone acetate in the spayed immature rabbit was confirmed. A progestational type of endometrium was produced in spayed-adrenalectomized cats by the adm. of desoxycorticosterone acetate. The cats were pretreated with estradiol benzoate. The progestational action of desoxycorticosterone acetate in cats is evidently not dependent upon the presence of the animal''s own adrenal glands. The uterine response elicited is comparable to that obtained with progesterone.