A handbook of systematic botany / by E. Warming ; with a revision of the fungi by E. Knoblauch ; translated and edited by M.C. Potter.

  • Eugenius Warming
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: A handbook of systematic botany / by E. Warming ; with a revision of the fungi by E. Knoblauch ; translated and edited by M.C. Potter. Source: Wellcome Collection.

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    with female organs of reproduction, is developed before fer- 'ITLISATION. The pollen-grains are carried by means of the wind to the ovules; these enclose the embryo-sac, and are situated on the open fruit-leaf (carpel), which has no stigma. Alternation of generations : I. Prothallium = Endosperm in ovule. II. Leaf-bearing plant, with flowers which produce the pollen- sac and ovule. 3 Classes: I. Cycadeoe. 2. Coniferas. 3. Gnetaceae. Division V’.—Angiospermae. The members of this group are very similar to those of Division IV. The ovules are, however, encased in closed fruit-leaves (ovary), which have a special portion (stigma) adapted for the reception and germination of the pollen- grains. The pollen-grains are bicellular, but with only a mem- brane separating the two nuclei; they are carried to the stigma by animals (chiefly insects), by the wind, or by some other means. Endosperm is not formed till after fertilisation. Alternation of generations in the main as in the Gymnosperms, but less distinct; while the sexual generation, the prothallium, with the organs of fertilisation, is also strongly reduced. 2 Classes:^ I. Monocotyledones. Embryo with one seed-leaf. 2. Dicotyledones. Embryo with two seed-leaves. For a long time the vegetable kingdom has been divided into Cryptogams (so called because their organs of reproduction remained for some time undis- covered), and Phanerogams or Flowering-plants which have evident sexual organs. The first three divisions belong to the Cryptogams, and the third and fourth divisions to the Phanerogams. This arrangement has no systematic value, but is very convenient in many ways. The Cryptogams are also known as Spore-plants, since they multiply by unicellular organs (spores), and the Phanerogams in contradistinction a’^e culled Seed-plants (Spermaphyta), since they multiply by seeds, multicellular bodies, the most important part of which is the embryo (a plant in its infancy). Mosses, Ferns, and Gymnosperms are together known as Arche- goniatfe, hince they possess in common a female organ of distinct structure, the Archegonium. ^ See Augiospermte.
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