STRUCTURE AND ULTRASTRUCTURE OF THE MOLLUSCAN PROSTATE

Abstract

SUMMARY In Aplysia depilans Gmelin an actual and well differentiated prostate does not exist. The functions of this organ are probably accomplished by a large number of secretory cells placed along folds in the wall of the oviducal groove of the large hermaphrodite duct. Cells of the same kind are also contained inside diverticula arising from the external wall of the groove itself. This should be a first indication almost of the formation of a prostate as an organ in itself, placed outside the male gonoduct and independent of them within certain limits. Structure and ultrastructure of the prostatic tissue of the species examined so far by the Author, and represented, besides Aplysia depilans Gmelin, by Milax gagates (Draparnaud), Vaginulus borellianus (Colosi), and Laevicaulis alte (Ferussac), apart from a few differences in details, are quite similar. This tissue appears to be formed everywhere by two different types of epithelial cells: one secretory the other with no secretory activity, usually evenly...