. Fossil plants : for students of botany and geology . Paleobotany. X] LEAVES OF CALAMITES. 381 epidermal layer with a limiting cuticle. Internal to this we have radially elongated parenchymatous cells forming a loose or spongy tissue, the cells being often separated by fairly large spaces. Pig. 86. A leaf of Calamites. 1. Transverse section; t, vascular bundle; a;, aheath of cells, x 35. 2. Vascular bundle consisting of a few small tracheids, t. 3. A tracheid and a few parenebymatous cells, the latter with nuclei. 4. A stoma; s, s, guard-cells. 5. PaUisade cells and intercellular spaces. From
. Fossil plants : for students of botany and geology . Paleobotany. X] LEAVES OF CALAMITES. 381 epidermal layer with a limiting cuticle. Internal to this we have radially elongated parenchymatous cells forming a loose or spongy tissue, the cells being often separated by fairly large spaces. Pig. 86. A leaf of Calamites. 1. Transverse section; t, vascular bundle; a;, aheath of cells, x 35. 2. Vascular bundle consisting of a few small tracheids, t. 3. A tracheid and a few parenebymatous cells, the latter with nuclei. 4. A stoma; s, s, guard-cells. 5. PaUisade cells and intercellular spaces. From a section in the Manchester Museum, Owens College. (fig. 86, 5), especially in the region of the blunt lateral wings of the leaf Some of these cells contain a single dark dot, which in all probability is the mineralised nucleus. These pallisade- like cells probably contained chlorophyll and constituted the assimilating tissue of the leaf In the centre there is a circular strand of cells limited by a layer of larger cells with black contents, enclosing an inner group of small-celled parenchyma and traversed by a few spiral or scalariform tracheids constituting the single median vein. It is hardly possible to recognise any phloem elements in the small vascular bundle; there appear to be a few narrow tracheids surrounded by larger parenchymatous. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Seward, A. C. (Albert Charles), 1863-1941. Cambridge : University Press
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
