Completely adrenalectomized cats, some surviving 35 days, showed increased blood solids, blood urea, and acid-soluble phosphates of the blood. The Ca, creatinin and uric acid of the blood were slightly above normal. Blood sugar fell in the later stages to as low as 50% of normal in some instances. Increase in blood urea ran parallel in part with loss of appetite and other symptoms. Anatomical changes most constantly found were: purplish discoloration of the gums, hemorrhages in the thymus, general hyperemia of the internal organs, and accumulation of large quantities of lipoid substances in the tubuli contorti.