[Electron microscopic study of the olfactory organ of the sterlet (Acipenser ruthenus)]

Three variations of olfactory cells were found in the olfactory organ of the sterlet Acipenser ruthenus. They were different in the shape of their peripheral processes: rod-shaped ones supplied with flagella and solitary microvilla; cone-shaped ones with solitary flagella and a great number of microvilla; filiform ones without flagella but with numerous microvilla and groups of centrioles in the cytoplasm of the peripheral process. The character of the structural and functional organization of these cells is discussed.