Volume 4

The natural history of plants : their forms, growth, reproduction, and distribution / from the German of Anton Kerner von Marilaun ; translated and edited by F.W. Oliver, with the assistance of Marian Busk and Mary F. Ewart ; with about 2000 original woodcut illustrations and sixteen plates in colours.

  • Kerner von Marilaun, Anton, 1831-1898.
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: The natural history of plants : their forms, growth, reproduction, and distribution / from the German of Anton Kerner von Marilaun ; translated and edited by F.W. Oliver, with the assistance of Marian Busk and Mary F. Ewart ; with about 2000 original woodcut illustrations and sixteen plates in colours. Source: Wellcome Collection.

    22/365 (page 14)
    Horse-tails exhibit a process of spore-formation quite peculiar to themselves. Two species of this group—namely, Equisetum arvense and E. sylvaticum are shown in figs. 1902 and 1907. At the top of the hollow stem thei-e is a spike of peltate scales borne on short stalks and arranged in whorls, each of which must, in consideration of its origin, he looked upon as a metamorphosed leaf (cf. fig. 1903). Fig. 190.—Horse-tails. 1 Summer Shoot of Equisetum arvense. 2 Vernal fertile Shoot of Equisetum arvense. > Spike of whorled sporangiophores from the same Equisetum. 4 A single sporangiophore. 8, 6 Spores. 1 Equisetum sylvaticum. 8 Prothallium of a Horse- tail. >, 2, : natural size; 8 x 3; 4 X 6; 5, 6 x 25; 8 x 30. On the inner surfaces of the scales—i.e. those turned towards the axis of the spike— little warts arise, which develop into sporangia (cf. fig. 1904). The outer cell-layers of these multicellular warts become the walls of the sporangia, whilst the inner tissue breaks up into cells. These cells then divide into four cells, each of which becomes a spore.