The Encyclopaedia Britannica; .. A dictionary of arts, sciences and general literature . Fig. 243. PISTIL.] B 0 T A 2^ Y 141 plant, in which small cells, microspores (fig. 2-19;, arefuund, each consisting of an outer covering or exospore,and an inner or cnJosporc. Within microsporeb (thpmanner vaV)ing iu diflcrcnt genera) smaller celk arc formed,.which are the mother-cells of the antherozoids. lu this. Fig. 244. Verltcal Bection of the disk-like receptacle of Livenvort {Marchantia), showinganthcrldia a, a In Ita eubstunce. These antheridia are flask-shaped sacs con-TftlmnR phytozoary ce
The Encyclopaedia Britannica; .. A dictionary of arts, sciences and general literature . Fig. 243. PISTIL.] B 0 T A 2^ Y 141 plant, in which small cells, microspores (fig. 2-19;, arefuund, each consisting of an outer covering or exospore,and an inner or cnJosporc. Within microsporeb (thpmanner vaV)ing iu diflcrcnt genera) smaller celk arc formed,.which are the mother-cells of the antherozoids. lu this. Fig. 244. Verltcal Bection of the disk-like receptacle of Livenvort {Marchantia), showinganthcrldia a, a In Ita eubstunce. These antheridia are flask-shaped sacs con-TftlmnR phytozoary cells. They communicate with the upper surface, andtheir coitents are discharged tlirauph It. Between the antheridia there areair cavities c, c, connected with stomata i, s. development of Lycopodiacese we have parts which areanalogous to those of the stamens in Phanerogams. Themicrosporangium evidently corresponds to the pollen-sac,and the microspores are the equivalents of the pollen-grains,—the forms seen in such Gymnosperms as Cycad-acese being the link connecting them with the highest forms.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectencyclo, bookyear1902
