NORMAL LEUCOCYTES 225 



phile granules have affinities in greater or less degree for basic stains (the blue and 

 the violet shading resulting from methylene blue as modified by polychroming). 

 With the granules in the cytoplasm of the polymorphonuclears and neutrophilic 

 myelocytes, and to a less extent in the transitional, we have a staining which merges 

 into a yellowish red on the one extreme and into a lilac on the other. As a standard, 

 neutrophilic granules should be a mean of these extremes. 



Not only by reason of the authority of Ehrlich, but because such a 

 division gives all variations, which can then be combined by one pre- 

 ferring a simpler classification, it would seem proper to divide the 

 normal leukocytes into hyaline and granular cells. Of the former we 

 have the lymphocytes, the large mononuclears and the transitionals. Of 

 the latter the polymorphonuclears, the eosinophiles and the mast cells. 



HYALINE LEUKOCYTES 



1. Lymphocytes. As a rule, the cells of this type are about the 

 diameter of a red cell. The nucleus is generally quite round but may 

 show one or more bulging processes. The large lymphocytes are rare 

 in the blood of adults but make up about 10% of the leukocytes of young 

 children. In making a count it is best to group large and small lympho- 

 cytes under one heading but for distinction we may divide them into: 



(a) Small Lymphocytes. These are small round cells about the size 

 of a red corpuscle with a large centrally placed, deeply violet staining 

 nucleus and a narrow zone of cytoplasm. This cytoplasm may not be 

 more than a mere crescentic fringe. This is the type of lymphocyte 

 which makes up the greater proportion of the leukocytes in chronic 

 lymphatic leukaemia. At times these cells seem to be composed of 

 nucleus alone. 



(b) Large Lymphocytes. These are of the same type as small lympho- 

 cytes, but possessing more cytoplasm. The nucleus, while round and 

 taking a fairly deep rich violet stain, does not stain so deeply as the 

 nucleus of the small lymphocytes. The cytoplasm is a clear, trans- 

 lucent, 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 i$n in diameter and are com- 

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

 predominate. 



2. Large Mononuclears. These are large round or oval cells with 

 a nucleus which has lost the richness of violet staining of the lymphocyte 

 nucleus. The nucleus is furthermore frequently irregular in outline 

 or may show the commencing indentation of the transitional nucleus. 



is 



