. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 660 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. form a crown surmounting the oogonium (fig. 374«). At fertilization the spermato- zoids penetrate between the cells of the crown, so reaching the egg-cell. The whole oogonium is soon detached and remains dormant through the winter. In the sprmg it germinates, pushing out a tube which becomes transversely segmented. This is the pro-embryo. From it, as a lateral bud, the adult sexual plant arises. This process resembles that of the Mosses, in which the lea
. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 660 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. form a crown surmounting the oogonium (fig. 374«). At fertilization the spermato- zoids penetrate between the cells of the crown, so reaching the egg-cell. The whole oogonium is soon detached and remains dormant through the winter. In the sprmg it germinates, pushing out a tube which becomes transversely segmented. This is the pro-embryo. From it, as a lateral bud, the adult sexual plant arises. This process resembles that of the Mosses, in which the leafy Moss-plant arises from. 1 A portion of the plant. 2 a piece of the axis with appendages, upon which are inserted the sexual organs. 8 A single appendage, showing the flask-shaped archegonia and spherical antheridia, * A single antheridium. ^ A plate of an antheridium with manubrium and whip-like filaments of cells containing spermatozoids. ^ Several cells from one of the whip-like filaments: the cells in the middle contain each a spermatozoid; the spermatozoid is escaping from the upper- most cell; the lowest cell is already vacated. ' A single spermatozoid. 8 Archegonium inclosing the egg-cell. 1 nat. size; 2x10; 3x16; *x35; 6x100; 6x300; 'X600; 8x60. the protonema as a lateral bud. But the comparison with Mosses must not be pushed too far, as in Char a there is no sporogonium. There are some 67 species of Chara, of which G. foetida is also very common. Many of them are covered with stiff hairs, and they are for the most part brittle owing to the incrustation of carbonate of lime (c/. vol. i. p. 260). The phenomenon of parthenogenesis in Chara crinita has already been described in detail (pp. 463, 464). In Gha/ra stelUgera ( = Tolypellopsis ulvoides) the nodes of the stem become. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly rese
Size: 1713px × 1458px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1895
