On the forms and structure of fern-stems / by George Ogilvie.

  • Ogilvie, George
Date:
1859
Catalogue details

Licence: Public Domain Mark

Credit: On the forms and structure of fern-stems / by George Ogilvie. Source: Wellcome Collection.

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    EXPLANATION OF PLATES. Plate VIII. Fig. 1. A portion of the branched and creeping rhizome of Polypodium Phegopteris, showing the fringe of wiry rootlets and the persistent bases of old leaf-stalks. Fig. 2. The branched and creeping rhizome of Polypodium vulgare. It is more thickly set with rootlets than the last, and marked with the scars of fallen petioles. Fig. 3. The dichotomous caudex of Blechnum boreale, with the axis exposed by cutting off, close to their origin, all the foot-stalks of former years' fronds. Plate IX. Fig. 4. The dichotomous caudex of a large bushy specimen of Allosurus crispus, stripped of the rootlets, the petioles of former years, and of most of the fronds. Fig. 5. The dichotomous caudex of Asplenium Filix fcemina, exposed by a section along the axis of its several branches, to show the con¬ nexion of the bases of the leaf-stalks of successive years with the core of the stem. Fig. (). Another specimen of the same species, with the caudex stripped of its rootlets and petioles, the scars with which it is marked indi¬ cating their points of attachment. Of these there must be con¬ siderably more than a thousand : the plant had certainly upwards of a hundred fresh fronds when dug up. Plate X. [Illustrations of the rhizome of Lastrea Filix mas.'\ Fig. 7. A caudex which has been forced into an upright line of growth. Fig. 8. Another specimen, showing the usual horizontal direction of growth, the terminal bud forming an angle with the rhizome. Both these specimens are in their natural state. Fig. 9. Tessellated appearance of the surface of the caudex when the pe¬ tioles are cut off close to their origin. The dots indicate the cut ends of the vascular bundles going to the fronds. Fig. 10. Perpendicular section of an upright caudex, showing the inter¬ rupted line on each side of the axis, where the reticulated fibro- vascular cylinder has been divided by the section. The figure shows also the connexion of the bases of the petioles, and a lateral bud arising from one of them. Fig. 11. A portion of a preparation showing the netted fibro-vascular cy¬ linder of the caudex, removed entire by careful dissection from the cellular matrix. The further side of the cylinder is imper¬ fectly shown, from having been out of focus in the photograph. The secondary fasciculi, proceeding to the leaf-stalks and root¬ lets, give the exterior a bristly appearance. Fig. 12. A diagrammatic transverse section of the caudex. The interrupted circle represents the cut extremities of the fasciculi of the netted cylinder, and the scattered dots on its exterior those of the secondary fibro-vascular bundles of the petioles and rootlets. [The above figures are mostly from photographs of the original specimens (now in the Museum of the Royal Botanic Garden, Edinburgh) by Mr„ Andrew Adams of Aberdeen.]
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