Organography of plants, especially of the archegoniatae and spermaphyta . e most highly magnified. a periclinal wall (Fig. 122, i), and thus we have four inner cells which may be calledthe endothecium, and a number of outer ones which may be called the amphithecium(Fig. 120, //, ///). A primitive sporogonium would be one in which the amphithe-cium formed the wall of the sporogonium, whilst the endothecium gave rise to thespores. As a fact there are differences in the cell-contents between these layers inNanomitrium, and the endothecium is much more rich in protoplasm. In Archidiumthe whole end
Organography of plants, especially of the archegoniatae and spermaphyta . e most highly magnified. a periclinal wall (Fig. 122, i), and thus we have four inner cells which may be calledthe endothecium, and a number of outer ones which may be called the amphithecium(Fig. 120, //, ///). A primitive sporogonium would be one in which the amphithe-cium formed the wall of the sporogonium, whilst the endothecium gave rise to thespores. As a fact there are differences in the cell-contents between these layers inNanomitrium, and the endothecium is much more rich in protoplasm. In Archidiumthe whole endothecium is an archesporiuni, l)ut all its cells are not fertile ; only a few,one to seven, become sporocytes ; the others are nutritive cells ^ as in Riella. In theother Musci we always have an archesporiuni in the form o{ 0fie cell-layer (Fig. 122, 2). ^ Nothing is known regarding the nature of their eonlents. Leitgeb speaks of them as clear aswater, so that possibly there is water-storage. 156 SPOROGONIUM OF MUSCI In Andreaea and Sphagnum this is dome-shaped (Fig. x. em 2 1, C s/)o); in the others itis pierced both above andbelow by sterile tissue, andthus has the form of abarrel open at both sterile tissue is veryearly laid down, and it isthe coluinella. In Sphag-num the archesporiumarises out of the amphi-thecium, the endotheciumforms the columella all other Musci the en-dothecium divides by peri-clinal walls into an outercell-layer, the archespor-ium, and a central sterilepart, the columella. Bothundergo further divisions;in the archesporium spo-rocytes are produced (Fig. Fig. 121. B, C E, F, Sphagnum acutifolium. B^ archegonium withembryo, eni^ in longitudinal section ; the representation of the arrangementof cells in the embrj-o is incorrect. C, young sporogonium in longitudinalsection ; ah, neck of archegonium ; ca, calyptra; i, capsule; s/>o, spore-sac with spores ; co, columella ; sfif, foot of the sporogonium; ps, pseudo-podium. E, opened anther
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