ANGIOLOGY 259 



more lobes. The nucleus stains a pale blue, and the chromatin is 

 diffused. The cytoplasm is colorless with bright red staining spindle- 

 shaped rods. There are 28 to 32 per cent, of this type of cell in 

 the blood of the hen. 



Polymorphonuclear leucocytes with eosinophilic granules (Fig. 

 74, No. 3 and 4) are of about the same shape and size as the preced- 

 ing. The nucleus is similar to the former except that it may 

 appear slightly picnotic. The cytoplasm stains not at all or faintly 

 blue; it contains round or spherical granules which stain a dull 

 red. There is from 4 to 6 per cent, of this tj^e of eosinophiles found 

 in the domestic fowl. 



Lymphocytes are round in shape and of about the diameter of the 

 width of a. thrombocyte (Fig.. 74, No. 11). The nucleus is round, 

 staining somewhat purple, and contains a diffused chromatin material. 

 The cytoplasm exists in only small amounts; it lies to the side of the 

 nucleus and stains a pale blue. This is the small lymphocyte. A 

 similar cell but much larger also exists. This is the large lymphocyte 

 (Fig. 74, No. 13). There is from 40 to 44 per cent, of the lym- 

 phocytes in the blood of the fowl. The small lymphocytes are most 

 abundant. 



Large monomidear cells (Fig. 74, No. 6) either round or oval, 

 in shape, whose diameter may be about that of an erythrocyte and 

 at times much larger. The nucleus may be round, ova,l, or irregu- 

 lar, and at times rather crescent or U-shaped (Fig. 74, No. 17). The 

 cytoplasm is abimdant and completely surrounds the nucleus. The 

 cytoplasm stains a paler blue than the nucleus. Both taking the 

 basic stain as do the lymphocytes. These constitute 18 to 20 per 

 cent, of the cells of the blood. 



Mast cells or basophiles (Fig. 74, No. i) are of about the same 

 size and shape as the eosinophiles. The nucleus is round or oval, 

 and stains a very pale blue. The cytoplasm is colorless, mostly to 

 one side of the nucleus, and contains round or spherical purple stain- 

 ing granules. This type of cell constitutes from 2 to 4 per cent, of 

 the white cells of the blood. 



Structure of the Red Blood Cell. — The red blood cell is composed 

 of a spongy stroma holding in its meshes the red coloring matter. 

 The stroma, or framework, of the erythrocyte consists principally 

 of nucleo-albmnin; it contains lecithin, cholesterin, and salts. The 

 red matter consists of an albuminous crystalUne substance called 

 hemoglobin, which forms about 90 per cent, of the total solid matter 



