[Cytological study of the post-embryonic development of the digestive gland of Sepia officinalis L. Mollusca : Cephalopoda (author's transl)].

A histological and ultrastructural study of the development of the digestive gland of Sepia officinalis L. was carried out on young Sepia reared in the laboratory, during the first month of post-embryonic life. The increasing complexity of the histological structure of the gland is related to the successive appearance of several cell types : immature cell, synthetizing cell, mature digestive cell ("cellule à boules"), and resting cell. These types are, in fact, just the evolutive stages of the same cell, the digestive cell. The sequence of appearance of the different cell types and the changes occurring in feeding can be used to define three stages in the post-embryonic development of the Sepia officinalis L. digestive gland : a multiplication stage (from hatching to the 5th day), a maturation stage (5th to 30th day), and adult stage (after the first month of post-embryonic life). These stages are identical to the three periods previously described by Richard and Decleir (1969) in the life of Sepia.