[Nitrogen excretion of Helix aspersa Müller (Mollusca Gastropoda Pulmonata)]

Helix aspersa, studied in Brittany, has not a complete uricolytic enzymatic chain. Allantoïnase and allantoïcase are absent, but, in vitro, uricase and urease are very active. A part from uric acid, Helix aspersa shows a high rate of urea and ammonia. The level of these substances is dependant on the age of the snail and on its physiological state.