Adrenalectomized dogs may be maintained satisfactorily without adrenal cortical extract on a diet which has a low content of K and a high content of NaCl and Na citrate. Such dogs require a much greater, positive balance of Na and chloride than do intact animals, and they are less able to maintain a uniform daily balance. Symptoms of acute adrenal insufficiency caused by a high intake of K are associated with a high level of K in the cells. Recovery, produced either by the administration of Na salts or by inj. of adrenal cortical extract, or both, is accompanied by a return to the normal levels of K in the blood. The symptoms of adrenal insufficiency may or may not be accompanied by a high level of blood urea. There are changes in the concn. of blood sugar, Na, chloride, and hematocrit value, but only the increase in K was found to be characteristic. Symptoms of adrenal insufficiency due to a low intake of Na and chloride simulate those produced by a high intake of K. The adrenal cortical hormone probably is concerned with the permeability of cell membranes.