The Archegoniatae are characterized by a well-marked alternation of gametophyte and sporophyte generations; the former bears the sexual organs which are of characteristic structure and known as antheridia (male) and archegonia (female) respectively; the fertilized egg-cell on germination gives rise to the spore-bearing generation, and the spores on germination give rise directly or indirectly to a second gametophyte.
He was one of the first to point out the existence of certain cellular bodies in these plants which appeared to perform the functions of reproductive organs, and to them the names of antheridia and pistillidia were given.
In these cases we should expect to find some reduced process of fertilization similar to that of Humaria granulata among the ordinary Ascomycetes, where in the absence of the antheridia the female nuclei fuse in pairs.
In Peronospora, Saprolegnia, &c., the ends of the branches swell up into sporangia, which develop zoospores in their interior (zoosporangia), or their contents become oospheres, which may be fertilized by the contents of other branches (antheridia) and so form egg-cases (oogonia).
Sexual reproduction by oogonia and antheridia; asexual reproduction by zoospores or conidia.
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