. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. so MOSSES AND FERMS CHAt. cell are somewhat irregular, but more numerous than in Riccia, so that the stalk of the ripe antheridium is more massive (Fig. i6). In the upper cell a series of transverse walls is formed, varying in different species in number, but more than in Riccia, and apparently always perfectly horizontal. In Marchantia polymorpha Strasburger (2) found as a rule but three cells, before the first vertical walls were formed. In an undetermined species of Fiinbriaria (Fig. 15) pr
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. so MOSSES AND FERMS CHAt. cell are somewhat irregular, but more numerous than in Riccia, so that the stalk of the ripe antheridium is more massive (Fig. i6). In the upper cell a series of transverse walls is formed, varying in different species in number, but more than in Riccia, and apparently always perfectly horizontal. In Marchantia polymorpha Strasburger (2) found as a rule but three cells, before the first vertical walls were formed. In an undetermined species of Fiinbriaria (Fig. 15) probably F. Bolanderi, the antheridia were unusually slender, and fre- quently four, and sometimes five transverse divisions are formed before the first vertical walls appear. Sometimes all the cells divide into equal quadrants by intersecting vertical walls, but quite as often this division does not take place in the uppermost. Fig. 15.—Fimbriaria sp. (?). A, Part of a vertical section of a young antheiidial receptacle, showing two very young antheridia ((^), X420; B-E, older stages. and lowest cell of the body of the antheridium, or the divisions in these parts are rnore irregular. The separation of the cen- tral cells from the wall is exactly as in Riccia, and the lower segments do not take any part in the formation of the sperm cells, but remain as the basal part of the wall. In Fimbriaria the top of the antheridium is prolonged as in Riccia, but in Marchantia this is not the case. The wall cells, as the anther- idium approaches maturity, are often much compressed, but in Targionia hypophylla, where Leitgeb states that this com- pression is so great that the cells appear like a simple membrane, I found that, so far from this being the case, the cells were extraordinarily large and distinct, and filled the whole space between the body of the antheridium and the wall of the cavity, which in Leitgeb's figures ((7), vi., PL Fig. 12) is repre-. Please note that these images
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