DIFFERENTIATION OF SERTOLI CELLS AND POST--REPRODUCTIVE EPITHELIAL CELLS IN THE HERMAPHRODITE GLAND OF ARION ATER(L.) (MOLLUSCA, PULMONATA)

Differentiation of Sertoli cells and post-reproductive epithelialcells during development of the hermaphrodite gland has beendescribed in Arion ater (L.) at the fine structure level. Twodifferent stages of Sertoli cells, active and atrophic, arerecognized. The cytoplasm during the active stage shows highmetabolic activity by many lysosome-like inclusions and otherorganelles. The possible role of steroidogenesis of these cellsis discussed in relation to their fine structure. The post-reproductive epithelial cells appear in the gland approximatelyafter the sheddingof both spermatozoa and oocytes. These cellsmay fill the lumen of the gland and appear syncytial. ^*Present address: Department of Biology, School of Sciences,Mashad University, Mashad, Iran (Received 12 January 1979;     

ORGAN CULTURE STUDIES ON CELL DIFFERENTIATION IN THE HERMAPHRODITE GLAND OF ARION ATER L. (MOLLUSCA, PULMONATA)

Organ culture experiments were set up to investigate cell differentiationin the hermaphrodite gland of Arion ater L. They were carriedout in the absence and presence of oestradiol, oestriol, testosteroneand follicle stimulating hormones. In the absence of hormonesexplants of young animals showed mitotic divisions in spermatogonia;newly-differentiated spermatogonia were also observed in explantsof the hermaphrodite gland of young and old animals. In thepresence of oestriol hormone new germinal cells differentiatedfrom the neck region of the hermaphrodite glands of mature animals.Other hormones did not affect the explants. (Received 31 August 1981;     

A HISTOLOGICAL SURVEY OF GONADAL DEVELOPMENT IN ARION ATER L. (MOLLUSCA, PULMONATA)

A method of breeding the slug Arion ater L. in the laboratorywas established. Measurements were made at monthly intervalsof body weight, weight and volume of the hermaphrodite gland,diameter and number of acini, oocytes and other cell types insidethe acini in field and laboratory-reared animals. Male and femalegametes grow simultaneously in the hermaphrodite gland of fieldanimals during the year. High humidity and low temperature causedinhibition of spermatogenesis and increase in the number offemale gametes in laboratory-reared animals. The average rateof increase in diameter of the oocytes of field samples was10 µm per month and in laboratory samples 9 µm permonth. ^*Present address: Department of Biology, School of Sciences,Ferdowsi University, Mashhad, Iran. (Received 30 September 1977;