All nuclei are stained with the hsematoxylin, the 

 protoplasm with the eosin. Eosinophile granules are also 

 stained red ; the other granules are not stained. 



On examining with high power the following varieties 

 of cells will be seen in the preparation : 



(1) Red blood cells stained in eosin. 



(2) Small lymphocytes, in size a little larger than the 

 red blood corpuscles, with a relatively large nucleus stained 

 quite deeply by the haematoxylin, and only a narrow 

 border of protoplasm. 



(3) Large mononuclear cells showing a much larger 

 border of protoplasm, and a nucleus which usually stains 

 quite faintly. 



(4) Transitional form with a horseshoe-shaped nu- 

 cleus. These develop from the large mononuclear. 



(5) Polynuclear cells, with a lobulated nucleus, which 

 usually stains quite deeply. They develop from the tran- 

 sitional forms, and form- about 70 to 75 % of the white 

 blood cells. 



(6) Eosinophile polynuclear cells, with lobulated nu- 

 cleus, and eosinophile granules in the protoplasm. 



Make a sketch of each of the above varieties. 



(d) Human Blood Stained in Ehrlich's Neutrophile 



Stain. 



Blood was spread and fixed as in (c) of this lesson, was then 

 stained in Ehrlieh's neutrophile stain for half an hour, washed in 

 flowing water, dried between filter paper, and ar.e to he mounted 

 on balsam. 



The red blood corpuscles are stained a reddish-brown, 

 all nuclei green, neutrophile granules in the protoplasm 

 of polynuclear cells a reddish-purple, and eosinophile 

 granules red. Study under high power, and the corpuscles 

 named in (c) will be seen. Look carefully for the neutro- 

 phile granules in polynuclear cells. They are not found in 

 lymphocytes nor in the mononuclear cells, and only in the 

 latter stages of the transitional forms. 



(e) Amphibian Blood Stained in Hsematoxylin 



and Eosin. 



The heart of a frog was opened, and a small drop of blood 

 placed on a cover glass, quickly covered with another cover a;lass, 



