592 PHAGOCYTOSIS OF SOLID PARTICLES. HI 



SUMMARY 



1. The rates of ingestion of quartz and carbon particles by leuco- 

 cytes, when both are in suspension in serum, was compared with the 

 availability of the two particles as predicted from the calculated 

 chances of collision with the leucocytes, and it was shown that carbon 

 is ingested about 4 times as readily as quartz. 



2. The greater ease of ingestion of carbon was verified by a new 

 method of measuring phagocytosis, described as the film method in 

 which the cells ingest particles as they creep about on a slide. 



3. The relative rates of ingestion of carbon and quartz depend 

 upon the condition of the cells, the difference increasing as the phago- 

 cytic activity of the cells decreases. 



4. Sponge cells also ingest carbon about 3 times as readily as 

 quartz. 



5. The hypothesis is suggested that the cause of the more rapid 

 ingestion of carbon may be identical with the cause of the greater 

 instability of the carbon suspensions. 



6. An inorganic analogy to this selective phagocytic action is 

 offered. 



7. The application to opsonins and agglutinins is discussed. 



BIBLIOGRAPHY. 



1. Haldane, J. S., Eng. and Min. J., 1918, cvi, 475. . 



2. Mavrogordato, A., /. Hyg., 1918, xvii, 439. 



3. Collis, E. L., Public Health, 1914-15, xxviii, 252. 



4. Fenn, W. 0., J. Gen. Physiol, 1920-21, iii, 439. 



5. Fenn, W. O., J. Gen. Physiol, 1920-21, iii, 465. 



6. Commandon, J., Compi. reitd. Soc. Biol, 1919, Ixxxii, 1171. 



7. Schaeffer, A. A., Biol Bull, 1916, xxxi, 303. 



8. Rickard, T. A., The flotation process, San Francisco, 1916. 



9. Rhumbler, L., Arch. Entwcklngsmechan., 1898, vii, 279. 



10. Reinders, W., Roll Z., 1913, xiii, 235. 



11. Hofmann, F. B., Z.f. physikal Chem., 1913, Ixxxiii, 385. 



12. Thompson, D'A. W., Growth and form, Cambridge, 1917, 461. 



13. Moore, W. C, /. Am. Chem. Soc, 1919, xli, 940. 



14. Bredig, G., Anorg. Fermente, Leipsic, 1901, 



15. Whitney, W. R., and Blake, J., /. Am. Chem. Soc, 1904, xxvi, 1339 



16. Rona, P., and Michaelis, L., Biochem. Zeit., 1919, xcvii, 85. 



