Nature and development of plants . antheridialbuds, the plants being monoecious or dioecious. The antheridiaand archegonia are essentially of the same structure as noted inprevious groups and they are usually associated with modifiedleaves known as paraphyses (Figs. 207, 6; 208). The germina-tion of the gametospore and the development of the sporophyte,while presenting many features in common with the hepaticsand Anthoceros in particular, shows a remarkable series of varia-tions that are of decided advantage to the plant. The gameto-spore in its early growth forms a spindle-shaped mass of cell
Nature and development of plants . antheridialbuds, the plants being monoecious or dioecious. The antheridiaand archegonia are essentially of the same structure as noted inprevious groups and they are usually associated with modifiedleaves known as paraphyses (Figs. 207, 6; 208). The germina-tion of the gametospore and the development of the sporophyte,while presenting many features in common with the hepaticsand Anthoceros in particular, shows a remarkable series of varia-tions that are of decided advantage to the plant. The gameto-spore in its early growth forms a spindle-shaped mass of cells,the basal portion of which reaches down into the stem of themoss plant and forms a well-developed absorbing organ or foot,while the upper portion elongates by means of an apical cell(Fig. 209, 10). Later, the growth becomes basal as in Antho-ceros. For a time, the archegonium keeps pace with the elonga-tion of the young sporophyte (Fig. 209, 11), but finally it isruptured and lifted up as a cap, called the calvptra, on the apex. 209. Germination of the gametospore: 10, base f the archegoniumin which the gametospore has germinated, forming a mass of cells witliapical growing cell, x. 11, later growth of the gametospore. The sporo-phyte, spy, still enveloped by the archegonium, or, appears as a cylindrical nia^s (if cells with font, />, penetrating the stem of the moss plant. Atright an unfertilized archegonium. See Fig. 205, B.—After Sachs. DEVELOPMENT OF PLANTS 277 of the young sporophyte. This is one of the most essentialdifferences between the mosses and hepatics. In the latter group,with the exception of the Anthocerotales, the spores were ma-tured in the archegonium. In the Bryales, the spores are usuallynot formed until the seta has elongated considerably. As thesporophyte elongates, the upper part enlarges and finally formsa complex capsule which remains covered for a varying lengthof time by the calyptra. The capsule and calyptra assume various forms and posi
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