Bone marrow of normal guinea pigs.

1053 B,y ARTHUR SAWITSKY, M.D.,* AND LEO M. MEYER, M.D. M ARROW aspiration is a well standardized technic for the study of hematopojetic function in the human. The method has been applied to dogs’ and cats’ with success. In these animals bone marrow is obtained by aspiration of the iliac crest. The disadvantages of the aspiration method are loss of architecture and mixture of marrow and blood in varying unknown proportions. A great advantage is that frequent, serial examinations showing distinct qualitative differentiation of marrow cells may be obtained.3 No anesthesia is required, nor is any special aseptic surgical approach necessary. Epstein and Tompkins’ reported values obtained both by microscopic section and supravital stain technic. \Ve are presenting data on normal bone marrow as obtained by iliac aspiration, and comparing our values for bone marrow and peripheral blood with those of other investigators.