Phascum
Creators: name: Maier, Eva
name: Price, Michelle J.
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Bryophyta
Bryopsida
Pottiales
Pottiaceae
Phascum

description: <i>PHASCUM.</i> The lower and the central part of the capsule of <i>Phascum</i> show a construction that is found in all mosses, with exception of the previously described <i>Sphagnum.</i> During the growth the cell tissue of the capsule separates into two components, an outer and an inner one, in the way that the three or four inner cell layers are torn off from the other inner layers, but remain connected at the apex of the capsule and below at its base, and also partly by confervoid filaments, thus forming the structure of the so-called “outer capsule membrane” (Tab. LVI. Fig. 2. <i>me</i>). *) Even if I had the opportunity to convince myself of the formation of spores in a dense tissue of mother cells, and consequently to recognize the cited statement of Meyen as erroneous, I cannot avoid mentioning here a phenom- enon that is perhaps the reason for this error: in several capsules of such cited mosses which were enclosed in a specimen box [Botanisierbüchse] for some days during warm weather, and appeared to be in a normal state exter- nally, I found in their inner part, especially in the cavities with the mother cells, densely filled with a mold, com- posed of large, branched cells. This mold has not only displaced most of the mother cells, which already contained the young spores, but had partly grown on them, so that it seemed that the mother cells with the spores had grown on the mold. – Later on I found the same phenomenon in <i>Polytrichum commune.</i> <b>[original page 567]</b> In the column-shaped part, situated on the inside, again two different groups of cells are observable: the outer four cells, the mother cells followed by the spore surrounding layer – the spore sac (Fig. 2. <i>sc</i>)*) – and the inner, mostly composed of tissue of big cells – the columella (Fig. 2. <i>cc</i>). Between the latter named groups of cells appears here, as in most of the mosses, no special gap; as we will see later on, as this is the case in some species of <i>Polytrichum</i> only. In the upper and lower parts of the capsule where the columella passes through the capsule point and the seta, the tissue becomes denser and the cells smaller (Fig. 2. <i>csp</i> and <i>cin</i>), and in this region the membrane of the mature capsule is brown. The structure of the point itself shows nothing exceptional, no trace of the development of an annulus or a peristome. The capsule of <i>Phascum patens,</i> as well as that of <i>Phascum cuspidatum</i>, is of the same structure. *) In my above cited inaugural dissertation in 1844 I draw attention, for the first time, to the development of spores in mosses, the particularity of the cell layers surrounding the spore mother cells and their form and contents; in the Botanische Zeitung von Mohl und Schlechtendahl 1847. 2. I published a more detailed preliminary comment on some results of the current investigations. It seems to me that the anthers of phanerogam plants show a similar structure inasmuch as the mother cells that produce the spores are surrounded by a cell layer of which the construction and content of the cells is typical; see the figures of Nägeli in: Zur Entwickelungsgeschichte des Pollens u.s.w. 1842. Also: Meyen: Physiologie Vol. III, und Schleiden: Grundzüge, Vol. II, at the cited places. I consider that the rather important discovery of remarkable groups of cells that appear to fulfil particular functions is progress in the knowledge of the inner construction of a plant. <b>[original page 568]</b> Note. In <i>Phascum</i> also I could observe the development of the spores; it is the same process as in <i>Gymnostomum (pyriforme)</i> and <i>Funaria (hygrometrica):</i> from only one layer of mother cells develop two other mother cells from which the spores originate. There are few other mosses, their cell tissue being so clearly transparent as in <i>Phascum,</i> that make easier the observation of the cell development, and the cutting of the very small capsules into sufficiently thin sections. I saw most clearly in a mother cell with a completely preserved membrane, two younger cells, likewise with distinct membranes, enclosing each of the four separated small cells: the young spores.
description: Published as part of <i>Maier, Eva &amp; Price, Michelle J., 2014, Georg Bojung " Scato " Lantzius-Beninga and his contributions on the anatomy of moss capsules: a transliteration from the original German texts, pp. 1-79 in Boissiera 67</i> on pages 30-32, DOI: 10.5281/zenodo.10.5281/zenodo.5729519