158 NORMAL AND PATHOLOGICAL BLOOD. 



pure blue. It may contain pinkish granules known as azur granules, 

 but these are of rather large size and do not mar the glass-like 

 appearance. They are from 9 to 15/1 in diameter and are com- 

 mon in children. In the acute lymphatic leukaemias they at times 

 predominate. 



3 Large mononuclears. These are large round or oval cells with 

 a nucleus which has lost the richness of violet staining of the lympho- 

 cyte nucleus. The nucleus is furthermore frequently irregular in outline 

 or may show the commencing indentation of the transitional nucleus. 



There is not that sharp distinction between nucleus and cytoplasm 

 that exists in the lymphocytes. The cytoplasm of the large mononu- 

 clear gives the impression of opacity, as if it were frosted glass instead 

 of clear glass. The neutrophile mottling which begins to appear 

 causes a disappearance of the pure blue character of the cytoplasm 

 of the lymphocyte. It is principally by the washed-out staining 

 of the nucleus and the opaque lilac of the cytoplasm, that we 

 differentiate them from the lymphocytes. They greatly resemble 

 Turck's irritation forms or plasma cells and may be confused with 

 myelocytes. 



4. Transitionals. These appear as but a later stage in the 

 decay of the large mononuclears; the nucleus is more indented, 

 frequently horse-shoe shaped, and has a washed out violet shade of 

 less intensity than that of the large mononuclears. These are the 

 cells so often disrupted in smears. 



These four kinds of cells are frequently referred to as the lymphocyte 

 series, and although many authorities consider that the small lympho- 

 cyte represents a more mature cell than the others of this class, yet it 

 is thought by others that the age of the cell increases as we go from 

 small lymphocytes to large lymphocytes, thence to the large mononu- 

 clear; and then in the transitional we have the decrepit stage which 

 precedes dissolution. The old view that the transitional was the 

 precursor of the polymorphonuclear has few advocates at the present 

 time. 



While it is convenient to consider. these hyaline cells as representing 

 different stages in development, yet from a stand-point of immunity 

 this is untenable. The large mononuclears and transitionals are the 



