[Proliferative activity of bone marrow and blood cells in rats with phenylhydrazine anemia]

Anemia was induced in rats by phenylhydrazine. There were found in the blood basophil erythroblasts, macrocytes, both ortochromatic and polychromatophil and basophil reticulocytes (the number of which could attain 60%). The role of macrocytosis in the reaction of the organism is discussed. The mitotic activity of erythroid cells increased in the bone marrow. On the basis of comparison of hemopoiesis in mammals (rats) and birds, by the previous authors' publication, a suggestion is put forward to the effect that during evolution "reserve" erythropoiesis is preserved only in the forms with nucleate erythrocytes (birds) or in the cells which have not lost the nucleus (in the bone marrow of rats).