LABORATORY MANUAL OF PHYSIOLOGY. 



V. CLASSIFICATION OF THE LEUCOCYTES. 



There is, at present, no perfectly satisfactory classification of 

 the white cells. One of the most logical is that of Kanthack and 

 Hardy (see Fig. 24). This is a classification according to reaction 

 to staining reagents and to presence or absence of granulation and 

 is as follows: 



A. Oxyphile (staining with acid dyes). 



1 . Finely granular. 



2. Coarsely granular. 



B. Basophile (staining with basic dyes). 



i. Finely granular. 



C. Hyaline. 



1. Small. 



2. Large. 



The more usual classification, however, is as follows: (a) poly- 

 morphonuclear neutrophiles, (b) eosinophiles, (c) mast cells, (d) 

 large mononuclear cells, (e) lymphocytes (large and small). 



Of these, (a) to (d} inclusive originate in the bone marrow. 

 Group (e) comes from adenoid tissue. 



1. Differential Count. Study one of the best stained speci- 

 mens of human blood until you are familiar with the different 

 forms of leucocytes enumerated above. Now go over the speci- 

 men carefully and systematically, using a mechanical stage so as 

 not to go over the same field twice, and keep count of the number 

 of individuals of the different varieties. Count five hundred cells 

 in all and estimate the percentage of each form. At the same 

 time keep careful watch for any abnormalities of the reds. 



Stain a specimen of frog's blood and compare the varieties of 

 white cells with those found in human blood. 



Stain smears of human blood with eosin and methylene blue, 

 after fixation for two hours in a mixture of alcohol and ether, equal 

 parts. 



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