Stages of oogenesis in the snail, Helix aspersa: Cytological, cytochemical and ultrastructural studies

Abstract

Oogenesis was studied in adult Helix aspersa using light and electron microscopy. The development of the female germ cells was divided into six stages based on morphological, cytochemical and ultrastructural criteria. The abundance and localization of cytoplasmic organelles, nuclear and nucleolar changes and the successive appearance of reserve substances during these stages have been described as well as the structural relations between oocytes and follicle cells.