386 



INFLUENCE OF THE DILUTION OF SERUM, 



Oil the other hand, pliagocytosis should proceed more slowly as- 

 the leucocytes become filled with bacteria; and, whiie this will 

 cause tlie curve to have a convex shape, it does not explain why 

 the curve should rise above unity as the serum becomes dilute. 



Tlie injliience of thin sufipensions of bacte7'ia. — In accordance 

 with these views, an experiment was made in which the suspen- 

 sion of staph3dococci was of such an opacity that from 5 to 6 

 cells were ingested in 5 and 10 minutes by the leucocytes of the 

 undiluted serum-test. The ratio of serum to corpuscles and 

 bacteria in all the following experiments was the usual 1:1:1. 



Fig.l. — Thin suspensions of bacteria. 

 These curves are interesting, inasmuch as they do not rise 

 above unity from normal serum to tlie half dilution, and are 



