[Control of secretory activity of multifid glands by castration and grafting in the snail Helix aspersa].

Castration of juvenile snails results in a cessation of multified gland cell differentiation. Many months later, the cells still resemble polarized epithelial cells and show no signs of secretory activity. Transplantation of nondifferentiated cells from multifid gland of castrated snails into normal adults initiated secretory activity. The experiments show that the presence of the gonad is essential for the multifid glands to develop secretory activity and that its influence is mediated by an endocrine factor which is transported in the hemolymph.