DIFFERENTIAL LEUCOCYTE COUNT 2/1 



thus, with Jenner's stain it stains a variable mixture of pink 

 (from the eosin) and blue (from the methylene blue). It may 

 be lilac, purplish, or almost pure blue. The change is readily 

 recognizable in ordinary films stained by Jenner's method. 



The corpuscles are now thought to be new and imperfectly 

 matured forms : they were formerly regarded as degenera- 

 tions. 



They are especially common in pernicious anaemia and in 

 von Jaksch's anaemia of children, but may occur in almost any 

 form of anaemia, if very severe. They do not form a very im- 

 portant diagnostic feature. 



5. Granular degeneration or punctate basophilia (Plate 

 VIIL, Fig. 2) takes the form of numerous granules of varying 

 size, which occur in the red corpuscles, and which stain almost 

 black with the basic portion of the stain; the rest of the cor- 

 puscle often shows polychromatophil degeneration. 



It occurs also in any severe anaemia, especially in von 

 Jaksch's anaemia, where corpuscles in which it occurs may be 

 extremely plentiful. Except where this occurs it is not of 

 much diagnostic importance, unless it is true that it occurs as 

 a very early and constant sign in lead-poisoning. 



NUCLEATED FORMS (-BLASTS). 



i. Normo blasts (Plate VIII., Figs. 7, 8, 9). These are cor- 

 puscles which resemble the normal in shape and size, but 

 which have a nucleus. This is central, large in proportion to 

 the corpuscles, surrounded by a comparatively narrow band 

 of stroma, and circular; in some cases it is double or multiple. 

 Normoblasts can usually be recognized with ease from any 

 other cells which occur in the blood, from the fact that the 

 nucleus stains very deeply more deeply than any other found 

 in the blood. It frequently happens that the narrow ring of 

 stroma may. show polychromatophil degeneration and stain 

 blue; in this case it is difficult to distinguish the cell from a 

 lymphocyte, but the deeply stained, almost black, nucleus 

 should prevent mistakes. 



Normoblasts are the cells from which the normal blood- 

 corpuscles are formed, but in health they are confined to the 

 bone-marrow, except in very young infants, in whom a very 

 few may be found in the circulation. Their presence in the 

 blood of older persons indicates that there is an anaemia of 



