100 



MONOCYTES 



cell an'Li 



AREA m p'^ 



Figure 15.3. — Frequency dislriliiition curves of cell area and nuclear area foi' .300 nionocyles cliosen 



at random. 



same usefulness for the agranulocytes that the 

 Arneth counts do for the granulocytes. 



Mainland et al. (1935) studied statistically 

 the significance of lymphocyte size in the human 

 species and concluded that cell size was a uni- 

 modal curve, but with skewness in most cases, 

 and tliat a small and a large lymphocyte did not 

 exist as classes. From their data, there was no 

 indication that age, sex, or state of health were 

 factors influencing the size of lymphocytes in 

 man. 



These opinions on size are in agreement with 

 those of Magath and Higgins (1934), who 

 measured the diameters of lymphocytes from 

 each of eight ducks and concluded that they all 

 I (('long to one series with a size range from 4.0 

 to 8.1 M and that all attempts to classify them 

 into small, medium, and large were futile. Cul- 



len (1903) finds that monocyte diameters range 

 from 6.7 to 9.3^; l)olIi of these values are below 

 the average given in table 4. Magath and Hig- 

 gins found the average to be Jietween 11 and 

 13.5. 



Cell shape. — The variety of shapes exhil)ited 

 by the monocyte can be appreciated best by glanc- 

 ing over figures 125-138 and the cells outlined 

 in figure 151. In general, the monocyte has a 

 round shape. Occasionally there may be small 

 bleb projections such as seen in figures 126, 127, 

 and 138. Whether they serve the same function 

 in monocytes that they are said to sei-ve in lym- 

 piiocytes, namely, contributing globulins to the 

 plasma, is not known. 



There is another type of cytosomal protrusion 

 that occurs rather frequently. It is a hyaline 



67 



