Microscopic Examination of Blood. 313 



Leucocytes. 

 Varielies. — In normal human blood, Ehrlich recognizes 

 five varieties of leucocytes. As quoted by Osier 1 they are as 

 follows: (Quotations from Osier slightly modified.) 



1. Lymphocytes. Small cells about the size of a red 

 blood-corpuscle, and probably derived from the lymphatic 

 glands, which leave a single large, round, deeply staining 

 nucleus, surrounded by a narrow rim of non-granular pro- 

 toplasm. 



2. Mononuclear. Cells several times as large as the red 

 blood-corpuscle, with an oval or elliptical nucleus and a rela- 

 tively larger amount of ungranulated protoplasm. 



3. Transitional. Cells which resemble the last variety, 

 but have indentations and irregularities in the nucleus. 



4. Polynuclear. These are about the same size or a little 

 smaller than the last variety. The nucleus is a long, deeply 

 staining body which is bent and twisted on itself into irregular 

 shapes. The protoplasm of these cells is filled with granules, 

 which are stained, not by acid or basic colouring matters 

 alone, but only by a combined fluid. The granules are there- 

 fore termed neutrophilic, and the name " neutrophils " is 

 given to these cells. 



5. Eosinophiles. Cells about the same size as the last, but 

 containing large, highly refractile, fat-like granules, which 

 have an affinity for acid colouring matters. On account of 

 their affinity for eosin, Ehrlich terms them eosinophiles. 



In normal blood these cells occur in definite proportion to 

 each other. 



Lymphocytes, . . . . 15 to 30 per cent. 



Mononuclear, . . 

 Transitional, 

 Polynuclear, . . 



Eosinophiles, 



Limbeck 1 gives but four varieties. 



6 per cent. 



6 per cent. 



65 to 80 per cent. 



2 to 4 per cent. 



1 Principles and Practice of Medicine, b_v William Osier. D. Appleton & 

 Co., New York. 1892. p. 699. 



