BLOOD PICTURE 



73 



In making the classification of the cells the neutrophilic 

 myelocytes are included with the P.M.N. group. The transi- 

 tional cells are myeloid forms often grouped as large mono- 

 nuclears transitional group. 



The dividing line between the small and large lymphocytes is 

 fixed rather arbitrarily as the size of a P.M.N. The two forms 

 are often grouped as small mononuclears. The unclassified cells 

 are those of such morphology that it was impossible to place 

 them, or cells so badly broken as to be unrecognizable. 



In the spring of 1916 Margot, working at The Institute, ex- 

 amined the blood picture in 31 normal albino rats, arranged in 

 five age groups, sexes combined. Table 40. 



TABLE 40 

 Normal albino rat blood picture according to age (Margot MS. '16) 



The method used by Margot was as follows: For counting 

 both the erythrocytes and leucocytes, Thomas-Zeiss apparatus 

 was used. For dilution 0.9 per cent NaCl solution for eryth- 

 rocytes and 0.2 per cent acetic acid for leucocytes were employed. 

 For the erythrocytes 40 squares and for leucocytes the entire 

 field were counted. The haemoglobin determinations were made 

 with Oliver's haemoglobinometer. In some instances a modified 



