584 



PHAGOCYTOSIS OF SOLID PARTICLES. Ill 



assurance than with the suspension method. From Figs. 10 and 11 

 the number of particles ingested during each hour of the experi- 

 ment has been determined graphically. This value divided by the 

 average number of particles present outside the cells during that hour 

 gives the percentage of particles taken up during the hour. These 

 figures are recorded in Table III. 



TABLE III. 



Comparison of Rates of Ingestion of Quartz and Carbon Particles by 

 "Film'' Method. 



* The experimental ratios are the ratios of the numbers of particles of carbon 

 and quartz ingested per hour expressed in per cent of the average number pres- 



per cent Carbon 



ent during that hour and = 



Data were obtained graphically 



per cent Quartz 

 from Figs. 10 and 11 for Experiments 8 and 9 and from similar unpublished 



figures for Experiments 10 and 11. The theoretical ratios are ^; 



R quartz 



R = C + P or the chance of collision, where C = 9^, the diameter of the leuco- 

 cytes, and P = the diameter of the particle. 



