Remarks on the so-called woody and vascular tissues of ferns / by George Ogilvie.

  • Ogilvie, George.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: Remarks on the so-called woody and vascular tissues of ferns / by George Ogilvie. Source: Wellcome Collection.

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    how unsatisfactory all the systems of classification are which have been proposed in this order^ these particulars may possi-. bly have a certain value, as increasing the store of facts bear¬ ing on the general organography of the group, from which it is to be hoped that some botanist may yet draw materials for a more natural method of arrangement than any which has yet been brought forward. The peculiarities, too, in these points, are in some cases so striking that they appear worth recording as specific characters * *. A brown-coloured principle is very extensively distributed in the organization of Ferns. It is particularly conspicuous in the sporangia and other parts of fructification, and in the epidermis of the stem, and the ramenta or scales with which it is clothed; and it is so characteristic of the group, that it communicates a peculiar rusty tint to the vegetation of districts in which (as in some parts of New Zealand) Ferns form a prevailing feature. It is probably identical with the brown principle which occurs in other foliaceous Cryptogamia, particularly in the stems and capsules of Mosses; and, whatever may be its chemical relations —a point on which I can say nothing,—it at least resembles the woody matter of phanerogamic plants in being deposited in the interior of cells, in concentric pitted layers, on the inner aspect of the first-formed wall of cellulose. The tissues in which it is deposited often acquire great hardness, but are deficient in the toughness of true wood; on drying, especially, they become very brittle. This brown matter is very constantly met with in the epider¬ mic cells of the Fern-stem. The hardening of the cortical layer in these plants, as in arborescent endogens, is even more neces¬ sary for the support and defence of the stem than the accumu¬ lation of the layers of bark in exogenous trees, on account of the occasional deficiency of hard tissues in the interior of the rhi¬ zome. Generally, however, there is a certain limited amount of internal induration also; for we find that particular tracts of the (see a criticism by Mr. Moore, Pliytoh, n. s., i. p. 378). There is a still greater indefiniteness about the sectional views in Mr. Francis’s ‘ Analysis of the British Ferns.’ Another reference given me by the same gentleman (Duval Joiive, Etudes sur le Petiole des Fougeres,’ in Billot’s ‘ Archives de la Flore de France,’ pp. 50-149) I have been unable to verify, though I have made inquiry for the work in the principal libraries in London. I have not had access to the works either of Mohl or others of the German botanists who have discussed the structure of Fern-stems, so that I cannot say how far they may have gone over the same ground. * In this connexion I may refer to the great similarity in the disposition of the dark tissue in the petioles of Scolopendrium vulgare and of Ceterach officinarum {Gramm,itis Ceterach), once referred to the first-mentioned genus.