The fine structural organization of sensory nerve endings in the lip of Helix pomatia L.

The fine structural and cytochemical characteristics of sensory nerve cells have been studied in the lip of Helix pomatia. A ruthenium red positive cuticular layer was found on the surface of the sensory epithelium. Among the undifferentiated epithelial cells two types of sensory dendrites were observed, namely ciliated and non-ciliated ones. A large amount of smooth surfaced endoplasmic reticulum, microtubes and ribosomes were present in the neuroplasm of the sensory dendrites. However, rough surfaced endoplasmic reticulum, mitochondria, and electrodense bundles of long filaments were characteristic in the simple epithelial cells. The cell bodies of the sensory dendrites lie subepithelially among the muscle cells and they generally contain empty or dense core vesicles.