Abstract
The chromosomes were counted in cells of erythroid bone marrow and spleen of anemic mice, rats and rabbits. Diploid chromosome numbers were evident in most observed cells; however in a few cells, a hypo-ploid state was observed. The G-band karyotype did not revealed a regular absence of chromosomes. This suggests that the hypoploid number is an artifact resulting from inadequate chromosome preparation. The data indicate that in the mouse, rat and rabbit, the number of erythroblast chromosomes is main-tained at diploid level through the nucleated period and is not reduced in differentiation.
