The structure & development of the mosses and ferns (Archegoniatae) . a rule but three cells, before the first vertical wallswere formed. In an undetermined species of Fimbriaria(Fig. 14), much like F. Californica, the antheridia were un-usually slender, and here frequently four, and sometimes fivetransverse divisions are formed before the first vertical wallsappear. Sometimes all the cells divide into equal quadrants byintersecting vertical walls, but quite as often this division doesnot take place in the uppermost and lowest cell of the bodyof the antheridium, or the divisions in these parts
The structure & development of the mosses and ferns (Archegoniatae) . a rule but three cells, before the first vertical wallswere formed. In an undetermined species of Fimbriaria(Fig. 14), much like F. Californica, the antheridia were un-usually slender, and here frequently four, and sometimes fivetransverse divisions are formed before the first vertical wallsappear. Sometimes all the cells divide into equal quadrants byintersecting vertical walls, but quite as often this division doesnot take place in the uppermost and lowest cell of the bodyof the antheridium, or the divisions in these parts are more ^ Strasburger (2). in MARCHANTIE^ 51 irregular. The separation of the central cells from the wallis exactly as in Ricda, and the lower segments do not takeany part in the formation of the sperm cells, but remain asthe basal part of the wall. In Fimbriaria the top of theantheridium is prolonged as in Ricda, but in Marduintia thisis not the case. The wall cells, as the antheridium approachesmaturity, are often much compressed, but in Targionia hypopJiylla,. Fig. 15.—Fimbriaria Calijornica (Hampe). A, Longitudinal section of a fully-developed male re-ceptacle, x8 ; B, longitudinal section of a nearly ripe antheridium, Xioo ; C, young sperm cells,x6oo; D, spermatozoids, X 1200. where Leitgeb ^ states that this compression is so great thatthe cells appear like a simple membrane, 1 found that, sofar from this being the case, the cells were extraordinarilylarge and distinct, and filled the whole space between the bodyof the antheridium and the wall of the cavity, which inLeitgebs figures ^ is represented as empty. The antheridiumbecomes sunk in the thallus precisely as in Ricda. The spermcells are nearly cubical and the spermatozoid is formed in the ^ Leitgeb (7), vol. vi. PI. X. Fig. 12. Leitgeb, 52 MOSSES AND FERNS chap. usual way. The free spermatozoid (Fig. 15, D) shows aboutone and a half complete turns of a spiral. The cilia are verylong, and the vesicle usually
Size: 1556px × 1606px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookidstructuredev, bookyear1895
