Ultrastructural localization of esterase and acid phosphatase in digestive gland cells of fed and starvedCepaea nemoralis (L.) (Mollusca: Helicidae)

Summary The ultrastructural localizations of thiolacetic acid esterase, indoxyl acetate esterase and acid -glycerophosphatase have been studied in the digestive gland cells of fed and starvedCepaea nemoralis. In fed snails the major localization of all three enzymes was in the green granule vacuoles of digestive cells. In addition, the cytoplasm of calcium cells and the Golgi apparatus and GERL (?) of all cell types were acid phosphatase positive. Many digestive cells of starved snails showed a similar enzyme distribution to that found in fed snails but other digestive cells showed a very high cytoplasmic activity of all three enzymes. It is suggested that these cells are in the process of autolysis. New light is also thrown on the process by which food is transported from the digestive gland lumen to the phagosomes of digestive cells.