Text-book of botany, morphological and physiological . 5, B.) The globules of Chara fragilis are produced by metamorphosis of those leaflets whichform the innermost row on a leaf, and in fact, as is shown in Fig. 210, the develop-ment advances downwards to the primary leaf. The succession of cells and the modeof growth show no noteworthy difl^eren-ces from those of Nitella; the flask-shapedpedicel is here placed on a small cell wedded in between the cortical cells, the centralcell of the basal node of the leaflet, which Braun asserts to be present also in sterileleaves, where however I have no
Text-book of botany, morphological and physiological . 5, B.) The globules of Chara fragilis are produced by metamorphosis of those leaflets whichform the innermost row on a leaf, and in fact, as is shown in Fig. 210, the develop-ment advances downwards to the primary leaf. The succession of cells and the modeof growth show no noteworthy difl^eren-ces from those of Nitella; the flask-shapedpedicel is here placed on a small cell wedded in between the cortical cells, the centralcell of the basal node of the leaflet, which Braun asserts to be present also in sterileleaves, where however I have not succeeded in finding it. Antherozoids. The whip-shaped filaments in which the antherozoids arise, do notgrow merely at their apex, but have also an intercalary growth. This is shown by theelongated cells in the middle of young filaments, each with two nuclei, between which nodivision-wall has yet been formed (Fig. 205, C). The longer the filaments become, themore numerous are their divisions, until at length the individual cells have the appearance. Fig. 208. —Antheridium o{ Nitellaflexilis in a furtlierstage of development (X about 500). CHARACEM. 289 of rather narrow transverse discs. The further development of the contents of thesemother-cells of the antherozoids progresses backwards from the end of the filament •the antherozoids are formed in basipetal order in each filament. At first the nucleusof each mother-cell lies in its centre, later it places itself in contact with the septa; thenuclei then disappear, and their substance becomes mixed with that of the protoplasm,which now forms a central discoid mass in the mother-cell, surrounded by a hyalinefluid (Fig. 205, £?). From this is formed the antherozoid, in addition to which, whenit is mature, there is no granular protoplasm ^ The antherozoids begin to rotate evenwhile within their cell, and escape out of it after the rupture of the antheridium ;the filiform antherozoid has in Nitella 2 or 3, in Chara 3 or 4 coil
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
