Kidney.—Very mild swelling of tubular epithelium but no exudative processes. Glomeruli show a few vacuoles but capsular space is negative to pigment. Bone marrow (Femur) fairly cellular in construction, but fat well mixed. Cellular areas well arranged, active, most of cells are small members of the larger mononuclear variety. Small lymphocytes abundantly represented. Most of the larger cells are non-granular, with centrally placed nucleus. Megakaryocytes fairly numerous, nuclei seem closely jammed into centre. No recognizable certain nucleated red blood cells, moderately number stippled cells, few adult red cells. Eosinophiles and basophiles quite few. Pigment small quantity. This is a case of primary anemia of moderate severity and short duration, and probably of hemolytic character if one may judge by the bone marrow, although excessive pigmentation of the liver and kidneys was not found. Unfortunately the spleen was not minutely studied, nor was the central nervous system investigated. Atrophy of the intestinal tract did not exist. Two cases occurred among the monkeys, but one example will answer, since the two were essentially the same. The case to be cited was that of a Japanese Macaque (Macacus fuscatus). ♀ Young, weight three pounds two ounces, exhibited in the Garden about four months, and apparently in good shape until two weeks before death when it rapidly became emaciated. DIAGNOSIS.—Aplastic anemia, chronic atrophic gastritis. Atrophy of heart muscle, fibrosis of liver, slight local cloudy swelling of liver. Perilobular diffuse nephritis (subcapsular type). Congestion of spleen. Fibrillar fibrosis of spleen. Hemosiderin pigmentation of spleen. Local amyloid infiltration of spleen. Calcareous infiltration in medulla of adrenal.