The surface morphology of the phagocytosis of micro-organisms by peritoneal macrophages

Scanning electron-microscopic studies of phagocytosis of various micro organisms by murine peritoneal macrophages has been made. Bacillus cereus, Staphylococcus aureus, and Brewer's yeast were easily ingested, whereas Cryptococcus neoformans was not. The development of intricate and tenuous filopodia preceded close-surface attachment, after which both thin and thicker lamellipodia invested the micro-organisms. Loss of the normal surface ridges characterised the replete cell. The technique of scanning electron microscopy is easily reproducible and adds a new parameter to the morphological appreciation of a fundamental biological phenomenon.