Prothallus of Ferns : (a) It is a heart shaped structure. The sex organs are present on the lower surface of the prothallus below the apical notch.
(b) Sex organs are antheridia and archegonia. Prothallus is produced from the meiospore as gametophyte of fern.
(c) Below the sex organs are rhizoids.
(d) Archegonia are flask shaped but antheridia are globose.
(e) Male and female gametes are produced in antheridia and archegonia.