X.—Mitosis and Cell Differentiation in the Blood

Abstract

It was in 1878 that Ehrlich, with the aid of his triacid stain, described in terms of granulation of the cytoplasm six types of leucocytes. This marked the first real advance in our knowledge of the blood corpuscles. Present-day classification of cells in the blood-forming tissues gives six main groups with about thirty named types of cells. These fine subdivisions appear to represent different stages in different lines of development from one original type, chiefly by change in the shape of the resting nucleus. Divergence in opinion arises as to whether all these types of cell develop in the red bone marrow, or whether some arise elsewhere in the body.