25 



So much for the red corpuscles. What of the white ? 



They are of even more interest than the red. Of the 

 leucocytes there are six varieties to he briefly described, it 

 is most essential to have these clearly in our minds before we 

 proceed to discuss the variations in their number and relative 

 proportions. 



1. Lymphocyte, small or large, usually small and of 

 the size of a red corpuscle. Rounded nucleus; no 

 granules. 22-25 %. 



2. Large mononuclear leucocyte with no granules, 

 also called a hyaline cell. Twice or thrice the size of 

 a red corpuscle. These have nothing to do with lympho- 

 cytes. 1 %. 



3. Transitional cell. A cell intermediate between 

 the hyaline cell and the " polymorphonuclear cells." 

 The nucleus tends to become somewhat irregular and 

 there are fine granules (oxyphile) in the protoplasm. 

 2-3 %. 



4. " Polymorphonuclear cells." The " neutrophile " 

 cells of Ehrlich. Finely granular eosinophil leucocytes 

 with a divided or multiform nucleus, consisting of several 

 oval or round nuclei connected by thin threads of 

 chromatin. The fine granules stain with acid dyes ; these 

 cells are actively amoeboid and have the power of 

 phagocytosis. 70-72 %. 



5. Eosinophil cells characterised by the presence of 

 coarse granules staining with acid dyes. Nucleus 

 usually irregular, may appear double. They are amoeboid 

 but not phagocytic ; they are a little larger than red 

 corpuscles. 2-4 %. 



6. Basophil cells. Leucocytes containing granules 

 of an unequal size and irregular distribution, staining 

 with basic dyes. '5 %. 



Sometimes the granules are very large. The " mast cells " 

 of Ehrlich, 



