Abstract Chick blastoderms were cultured in vitro by the New [5] technique and treated with either colloidal gold or carmine solution. Considerably larger amounts of foreign particles were phagocytosed by the edge cells than by other parts of the blastoderm. In an additional group of experiments it was shown that the edge cells phagocytosed particles only when they were actively migrating over the vitelline membrane. Electron micrographs showed that the particles were taken into membrane-bounded spaces.