ARRANGEMENT AND STRUCTURE OF PLATES IN THE CORTICAL ALVEOLI OF THE HYPOTRICH CILIATE, EUPLOTES-VANNUS

Each alveolus of the pellicle of Euplotes vannus contains a plate about 40 nm thick. Each plate consists of three layers of electron-dense material interconnected by ill-defined, irregular bridges. The margins of each plate appear strengthened. The entire cell is covered by a layer of these plates, interrupted only at the site of emergence of the dorsal bristles, cirri, and membranelles. At these sites specific modifications of the plates are apparent. These plates appear to give the cell rigidity, but otherwise their function is obscure. © 1979 Academic Press, Inc.