Pollen grains i.e. microspores are liberated from the micro sporangia at the 3-celled stage. In Cycas the pollination is anemophilous.
Pollen grains are carried to the pollen chamber of the ovule by wind. At the time of pollination, a drop of mucilage called pollination drop oozes out of the micropylar end of the ovule.
The pollen grains are caught in this drop. As the drop dries up, the pollen grains are drawn into the pollen chamber.
Further drying up of the pollination drop the pollen chamber is closed. Thus the pollen grains are directly deposited on the nucleus of female gametophyte.