Based on the histology of the female accessory sex glands (cement glands) and the sequential appearance of their secretory products, four stages have been distinguished in the development of the cement glands inS. Holoschista. This paper describes the various stages in ovarian development and correlates them to the cement glands activity. A further correlation between the ovarian and cement glands activity has been shown by statistical analyses. A possible endocrine mechanism regulating the synchronous activity of the ovary and cement glands is proposed.