542 Dr. R. D. Keith. Relationship between [Feb. 15, 



polymorphonuclear leucocytes containing red blood cells was taken as a 

 criterion of the phagocytic action, 100 leucocytes being counted in each case. 

 Some of the large mononuclear leucocytes contained occasionally one or two 

 red cells, but these were so few as to be insignificant. 



It was found that at corresponding dilutions the unheeded serum produced 

 a considerably greater amount of phagocytosis than did the heated and 

 further that it bore greater dilution before giving up this property. 



Using the above-mentioned method of enumeration the following results 

 were obtained in the experiment. 



Dilution. 



Unheated 

 serum. 



Heated at 

 55° C. 



Heated at 

 59° C. 





Per cent. 



Per cent. 



Per cent. 



1 in 3 





. 71 



91 



1 in 6 





61 



81 



1 in 12 





57 



72 



1 in 24 





27 



43 



1 in 45 



45 



18 



28 



lin60 



28 



8 



7 



1 in 90 



23 







Saline control = 7 per cent. (The percentages refer to the number of 

 polymorphonuclear leucocytes containing red blood cells.) 



Percentage of 

 Leucocytes 

 containing 



Erythrocytes 



Dilutions of Che serum in Che various mixtures. 

 1 in 3 iin6 I in 12 lin24 iin45 iin6o iin90 



90 

 80. 

 70 

 60 

 50 

 40 

 30 

 20 

 10 

 

















































V 



% 















Sg 













\ 

















V > 

 \* 





9 



V 















































