In the intact rat, D.C.A. (desoxycorticosterone acetate) decreased the whole blood chlorides, while in adrenalectomized animals whose blood chlorides were subnormal the same dose of D.C.A. temporarily raised them to or towards normal. Prolonged D.C.A. adm. decreased the blood chlorides even after adrenalectomy. The plasma chlorides ran roughly parallel with the whole blood chlorides in most cases but their variations were less pronounced than those of the latter. The hypochloremia caused by adrenalectomy or by adm. of D.C.A. in normal rats was evidently due mainly to a decrease in red cell chlorides. As a rule the muscle chlorides were only insignificantly increased by D.C.A. or adrenalectomy but always showed a pronounced increase in D.C.A.-treated adrenalectomized animals. The brain and liver chlorides revealed no consistent change after adrenalectomy or after the adm. of D.C.A. to intact or adrenalectomized animals. The blood vol. which was decreased by adrenalectomy was restored by D.C.A. adm. and in the intact rat, D.C.A. caused a slight rise in blood vol. Progesterone given in doses as high as 10 mg. per day had no effect on the low blood vol., blood sugar and blood chlorides of adrenalectomized rats in acute expts. This is of interest because in the case of chronic treatment with this compound other investigators reported progesterone to have essentially the same life-maintaining effect in adrenalectomized rats as D.C.A.