A manual of botany : including the structure, classification, properties, uses, and functions of plants.

  • Robert Bentley
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: A manual of botany : including the structure, classification, properties, uses, and functions of plants. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    867/960 (page 831)
    UEPEODDCTION OF CHABACE.E. Fig. 1151. place before the spore has separated from its parent (see page 395, Jig. 804), and in others, after both the spore and ciliated antherozoids have been discharged, as in Fucus. (See page 397, Jigs. 866- . 868.) flWUfci (2) Reproduction of Characeae — In these plants we have two kinds of reproductive organs, called, respec- tively, the glob ule or antheridinm ( Jigs. 856, a, and 858 ), and the nucule or carpogouium (Jigs. 856, s, 859, and 860): the former is regarded as the male, and the latter as the female.. Fertilisation takes place by the pas- sage of the spiral antherozoids of the globule (Jig. 857) down the canal which extends from the apex of the nucule (Jigs. 859, a, and 860) to the central cell of the same structure, which then becomes fertilised. No free spore is, however, produced, but the nucule drops off, and after a certain period germinates, though the sexual leaf- forming plant is not directly deve- loped, but is preceded by a pro- embryo (Jig. 1151), which has, how- ever, only a limited growth, and from it are produced at one part the rhi- zoids w, and further on, as a sort of lateral branch, the CJiara or Nitella proper. B. Reproduction of Cormopliytes. Of the sexual nature of the plants in most orders of this sub-division of the Cryptogamia there can be no doubt. The sexual organs in all are also of an analogous character, and are of two kinds, one termed an antheriilin in, which contains spirally wound ciliated antherozoids, and is Fk regarded as the male organ ; and the cither, called an archegonium or pistil- lid ium, containing an embryonal cell or germ-cell, which is the female < trgan. Fertilisation is effected by the contact of an antherozoid with an embryonal cell or germ-eel]. We have already described the structure of the reproductive organs of Oorniophytes (pages 364-377), both before and after fertilisation ; it will be only necessary, therefore, in the present 1151. Pro-embryo of Chara fragilis. sp. Germinating spore. i, d, q, pi. The pro-embryo. At d are the rhizoids, w. «>'. Primary root. </. First leaves of the second generation, or Chara proper. (After Pringaheim.)