1：Appearance of mature ovules at fertilization is similar to that of seeds.
2：Two egg cells are seen in a female gametophyte.
3：Pollen tubes are pendulous in an archegonial chamber；hemispherical strucure at pollen tube tip is part of pollen exine.
4：Depressed area at the tip of female gametophyte is an archegonial chamber；female gametopytes at stage just before sperm discharge secrete liquid.
5：Archegonial chamber at center.
6：Sperm enters open space surrounded by neck cells towards the egg cell；SEM photograph.
7：SEM photograph.