Successful Demonstration of an Elusive Cell Coat in Amebae*

Cell coats were cytochemically demonstrated for the first time in myxamebae of Fulig- septica, Didymium iridis, Dictyostelium discoideum, Cavostelium apophysatum, and amebae of Naegleria grubei. The stain enhances the cell coats of Physarum polycephalum plasmodia, Ceratiomyxa fruticulosa myxamebae, and Acanthamoeba sp. Cell coats usually unstained by cationic dyes stain intensely with the aid of the new cytochemical protocol utilizing 0.5% Alcian blue in the primary fixative and 0.05% ruthenium red in the secondary fixative.