The microscope : and its application to vegetable anatomy and physiology / by Dr. Hermann Schacht ; edited by Frederick Currey, M. A.

  • Hermann Schacht
Date:
1855
Catalogue details

Licence: Public Domain Mark

Credit: The microscope : and its application to vegetable anatomy and physiology / by Dr. Hermann Schacht ; edited by Frederick Currey, M. A. Source: Wellcome Collection.

    155/230 (page 131)
    LSI Blasia the gemnue remain for some time united to the mother- plant by a many-jointed cellular stalk. In the liverworts the pistillidia always make their appearance before the })crigone or cup; the fonnation of the latter seems not to take place until the rudiments of the fruit have been formed in the interior of the pistillidium. The perigone is not foinied of leaves ginwu together; it originates in the form of an annular swelling around the pistillidium, as may be seen in Liochla3na lanceolata and Frullania dilatata. The developemcnt of the stems and leaves of cryptogams, as well as of their vascular bundles, must be investigated in the same manner as in the case of phanerogamous plants. On the inve^tig-atioii of the ileveloiieinent of tlie !^tein, the Hoot aiul tlie JLeaveM, and of tlie Vascular UundleM contained in tiieui.—In traciug the developement of the stem and leaves, two modes of proceeding may be adopted. The first is to ex- amine the ])lant at the time of, and subsequently to, germina- tion; the other is to follow out the developement of the bud, and of the young branch. In order to ariive at a satisfactoiy result, both methods should be pm’sued. In both it is neces- sary, in the first instance, to take very thin longitudinal sections directly through the middle of the apex of the stem. If a sec- tion is thus made, the apex, whether it originate from a germ or a bud, will be found to be a small closed protubemnce of a more or less conical shape, clothed with a delicate epidermis, and underneath this jjrotuberance will be found a tissue, con- sisting of small cells quite filled with a granular substance which is rich in nitrogenous matter. This tissue loses itself lower do^vn in the different tissues of the stem, and is therefore in dh-ect connexion with the cambium-ring. The vascvdar bundles originate in the cambium-ring, around which, and in which, and by means of which, these bundles become further developed; on this account the vascular bundles are always most fully de- veloped in the loxoer part of a branch, where the growth always takes place from below upwards; this is very remarkable aroimd the wood-ring at the time of the unfokUng of the buds of Dico- tyledons. If a very careful longitudinal section be made through the apex of a young branch, the age of the cells may be accu-