SECRETIONS AND GYMNOSPERMS POLLINATION

This paper presents an historical review of the mechanisms of pollen collecting by the Gymnosperm ovules. Nucellar and/or epidermal secretions are involved in these mechanisms. Recently, the morphology, histology and cytology of the secreting tissues in ovules and nucelli have been explicited for some species using electron microscopy (transmission and scanning E.M.). The pollination drops were analysed for many species. However, the pollen-ovule relations remain much less known than the pistil-pollen relations in Angiosperms.