After ligating splenic and coronary veins of the stomach, the author studied and evaluated the blood and bone marrow pictures, and O(2)-consumption and glycolysis of femur bone marrow; and obtained the following results: 1. In the peripheral blood picture a transient decrease is brought about in the erythrocyte count and hemoglobin content, and it seems to present the so-called 'splenic anemia'. 2. An increase in the percentage of the erythroblast series can be observed in bone marrow. 3. The respiration of bone marrow is transiently accelerated, but changes in aerobic or anaerobic glycolysis show no fixed tendency. 4. By ligating splenic and coronary veins of the stomach it is possible to induce a transient congestion in the spleen, but the anemia observable 2-3 weeks after the operation seems to be caused by the blood cell arrest or the disturbance in the discharge of erythrocytes in bone marrow.