CH. XXIX.] 



THE COLOUELESS CORPUSCLES 



457 



chromatin. The protoplasm is finely granular, and stains with 

 neutral, and faintly with acid aniline dyes (such as eosin). In 

 certain pathological conditions for instance, in diabetes the cell- 

 protoplasm contains excess of glycogen. 



(e) Eosinopliile leucocytes. These are usually larger than the 

 preceding (12-15 JUL in diameter). They contain either a single 

 irregular-shaped nucleus, or more often two or three nuclei of 

 unequal size. Their protoplasm contains large distinct granules 

 which have an intense affinity for acid dyes such as eosin, and are 

 therefore termed oxyphile, acidophile, or eosinophile. They are 

 stated to be less actively amoeboid than the polynuclear leucocytes. 



Healthy bacillus 



Healthy bacillus k 



Healthy bacillus. 



Partially digested bacillus. 



Partially digested leucocyte 



Nuclei vacuolated 



Nucleus. 



-Bacillus in leucocyte. 

 A. .Partially digested leucocyte. 



--_--,:__. Foreign matter. 



Foreign matter _ fc; 



Particles of foreign matter. 



Particles of foreign matter. 

 Leucocytes ' ' i^ifl**- Particles of foreign matter. 



FIG. 322. Macrophages containing bacilli and other structures undergoing digestion. (Ruffer.) 



They comprise from 2 to 4 per cent, of the total colourless 

 corpuscles. 



(/) Mast-cells. These cells we have already seen in the connective 

 tissues (pp. 30-31) and they are very rare in normal blood. Less than 

 0-5 per cent, is usually present. They measure about 10 /x across ; 

 their nucleus is single and irregular in shape. The granules in the 

 protoplasm are much more basophile than the nucleus. (See coloured 

 plate.) 



Phagocytosis. The most important outcome of the amoeboid 

 movement of the colourless corpuscles is their power of ingesting 

 foreign particles, such as bacteria, which they engulf and digest. 



