Ultrastructural study of the follicle cells in the freshwater gastropod Viviparus viviparus L.

The morphology and the role of the follicle cells of Viviparus viviparus were examined by means of light and electron microscopy. The follicle cells appear to contain glycogen and fat, and often lysosomes or heterogeneous inclusions. Therefore, they seem to be active in phagocytosis and storage. They are probably involved in the nutrition of the oocyte. Their role in the formation of a selectively permeable barrier is discussed.