The seed is enclosed when ripe in the fruit, a development of the ovary as a result of fertilization of the egg-cell.
The Bryophyta and Pteridophyta have sprung from the higher Thallophyta, and together form the larger group Archegoniatae, so-called from the form of the organ (archegonium) in which the egg-cell is developed.
The female gametophyte is extremely reduced; there is a sexual apparatus of naked cells, one of which is the egg-cell which, after fusion with a male cell, divides to form a large siispensorial cell and a terminal embryo.
Fertilization.The formation of the zygote or egg-cell takes place usually by the fusion of the contents of two cells, and always includes, as -
In many of the Fungi the non-motile male cell or nucleus is carried by means of a fertilizing tube actually into the interior of the egg-cell, and is extruded through the apex in close proximity to the egg nucleus.