Archegonia are flask shaped structure; each archegonium has a venter and a neck. The venter encloses the egg and venter canal cell. The neck encloses the neck canal; when the egg matures the disintegration of the neck canal cell and venter canal cell occurs. It creates an open passage for the entry of the sperm.
Whereas the antheridia are small globular structures which is enclosed in a jacket. It contains the sperm mother cell or the antherozoid mother cell. These mother cell gives rise to the multiflagellate, free swimming antherozoids or sperms.