BY R. GREIG-SMITH. 693 



serum in the tubes measured 10 centimeters in the narrow and 

 1 *7 centimeters in the wide tube. 



Cocci per leucocyte. 



Narrow capillary 32 



Wide capillary 28 



The effect of agitation during phagocytosis. — That the corpuscles 

 settle so quickly as compared with the bacteria is doubtless 

 responsible for the comparatively long time that is required for 

 complete phagocytosis. We know that by placing the capillary 

 pipettes in an incubator /or 15 minutes only a partial phagocy- 

 tosis is obtained, but when all the tests are made in the same 

 manner this is of no consequence, and it is certainly the easier 

 process to employ. One can obtain a greater phagocytosis by 

 agitating the capillary pipette during incubation. This has been 

 done by Millar,* who attached the pipette to a rotating wheel. 



Before seeing this method, I had noted the effect of agitation 

 as obtained by blowing the mixed suspensions in and out of a 

 pointed tube for three minutes at 37°. The count showed that 

 the process undoubtedly increased the phagocytosis, but the 

 experience showed that the method would introduce many sources 

 of irregularity, and it could not be recommended for consistent 

 work. 





Cocci 



per 



leucocyte. 





a 



b 



Ordinary method, 15 min. at 37° 



Agitated, 3 min. at 37° 



3-5 



55 



4 4 



8-2 







The fact that agitation as produced by blowing the suspensions 

 in and out of the capillary pipette increased the phagocytosis so 

 much, suggested the possibility that ingestion might occur while 

 the suspensions and serum were being mixed previous and sub- 

 sequent to incubation. 



* Centrlb, fur Bakt. Orig. 41 (1908), 728. 



