The spore-cases remain after the plant is dried up and withered.
In the vascular cryptogams and phanerogams it takes place in the spore mother cells and the reduced number is found in all the cells of the gametophyte, the full number in those of the sporophyte.
The gametophyte, which bears the sexual organs, is either a free-living thallus corresponding in degree of differentiation with the lower liverworts, or it is a mass of cells which always remains enclosed in a spore and is parasitic upon the sporophyte.
The parasite effects a lodgment in the host either by invading it as a free-swimming planula, or, apparently, in other cases, as a spore-embryo which is captured and swallowed as food by the host.
The spore cell gives rise to a " sporelarva," which is set free in the coelenteron and grows into a medusa.