The Pi - Iagocytosis of Solid Particles

In the preceding paper of this series (1) it was shown that carbon particles are ingested by rat leucocytes three or four times as readily as quartz particles of approximately the same size. Variations were found, however, in this ratio between the rates of ingestion of carbon and quartz during the course of a single experiment which suggested that significant variations might be produced by varying the fluid environment of the cells. The present paper includes experiments which indicate a reversal of this ratio with acidification of the solution, quartz becoming more readily ingested than carbon. I t was hoped that a further study of this comparatively simple phagocytic system of leucocytes with quartz and carbon particles might yield results which could be interpreted in terms of physical chemistry and hence give some quantitative experimental clue as to the fundamental nature of phagocytosis.