EXTRANEOUS OBJECTS IN STAINED FILMS 105 



Normally 60-70% of leucocytes . When rounded as is usually 

 seen in a stained blood film, the cell is about 10^ in di- 

 ameter. The nucleus is of irregular shape and often tri- 

 lobed. The cytoplasm is stippled with fine neutrophilic 

 granules. 



Eosinophile leucocytes (Fig. 27, i"*). Normally 2-4'/ of 

 leucocytes. These cells are about 12-14|j in diameter. The 

 nucleus is l:)i- or tri-lobed. The c\toplasm is filled with 

 coarse red-stained granules. These cells increase in num- 

 ber in cases of helminth infection. 



Basophile leucocytes (Fig. 27, 15). Normally about 0.5%. 

 These cells are about 10m in diameter and similar to neu- 

 trophile, but the granules are stained purplish or blue. 



Lymphocijtes. NormalK^ 20-30% of leucoc\'tes. The nu- 

 cleus is large and compact, and stains deep dark red. The 

 c\ toplasm is comparatively scanty and stains blue. Small 

 lymphocytes (Fig. 27, 16) are about 5-8^ in diameter, while 

 larger ones (Fig. 27, 1'^) measure 8-10m in diameter. 



Large mononuclear leucocytes (Fig. 27, ^^). Normally 

 3-6%. They are the largest blood cells and measure 12-20m 

 in diameter. The nucleus is rounded, elongate, or reniform, 

 and chromatin material is loosely packed so that the stained 

 nucleus is much lighter than that of the lymphocytes. The 

 cytoplasm is yoluminous and stains a clear pale-blue. In 

 malaria and trypanosomiasis these leucocytes increase in 

 number and in the former they may show ingested haemo- 

 zoin granules. 



