Of 16 dogs in which double suprarenal-ectomy was performed in 1 stage all died in 8-58 hrs. except 1 which survived 388 hrs. Of 37 subjected to 2 stage operations with from 10-42 days interval, 12 survived less than 50 hrs.; 10, 50-100 hrs.; 10, 100-150 hrs.; 3, 150-200 hrs., and 2 from 200-238 hrs. Laboratory findings indicated that high urea and high non-protein N were to be expected in the terminal stages. Administration of saline followed by large quantities of urine resulted in a fall of the above constituents. However, death was not always averted by reduction of blood urea and non-protein N. Autopsy findings of long surviving dogs were characterized by enlarged lymph glands, spleen, and thymus, ulceration of stomach, and congestion of duodenum and rectum. Microscopically the principal changes were degeneration in liver cells, edema with proliferation of plasma cells and endothelial leucocytes, and enlarged macrocytes in lymph glands; hyperemia and small focal areas of hemorrhagin kidneys, edema, congestion with denudation of epithelium in gastric and intestinal mucosa. Dogs surviving the operation were 30 times more sensitive than normal to histamin and were also more sensitive to extract from enlarged lymph glands from desuprarenalized dogs. The final picture was precipitated earlier by giving a protein diet. The authors conclude that death following adrenal-ectomy is due to toxemia from a poison of protein-like nature.