Intracisternal polycylinders: a cytoplasmic structure in cells of the terrestrial slug Arion empiricorum Férussac (Pulmonata, Stylommatophora).

Study of the digestive organs of the slug Arion empiricorum with the electron microscopy has revealed cytoplasmic structures that we call intracisternal polycylinders (ICPC). They consist of cylinders of cytoplasm (about 550 A in diameter) arranged in sheafs within cisterns of the endoplasmic reticulum. They appear in different cell types, being most common in the digestive epithelium of the midgut. Their morphology and apparent association with other cytoplasmic organelles such as mitochondria, peroxisomes, multivesicular and residual bodies suggests that the ICPC might be involved in exchange, transport and oxidation processes, contributing to the excretory function at a subcellular level.