. Principles of the anatomy and physiology of the vegetable cell. Plant cells and tissues. THE VEGETABLE CELL. 5 (fig 8) are, as a rule, distinguished from the short parenchymatous ceils, not only by their elongated, often fibrous shape, but also by the two ends being attenuated to points. In this case they are not arranged end to end in lines, but their attenuated extremities are interposed between the lateral surfaces of the cells situated above and below them; while the parenchyma cells, if, as is usual, they are arranged in lines, stand one upon another with flattened ends, their cavities
. Principles of the anatomy and physiology of the vegetable cell. Plant cells and tissues. THE VEGETABLE CELL. 5 (fig 8) are, as a rule, distinguished from the short parenchymatous ceils, not only by their elongated, often fibrous shape, but also by the two ends being attenuated to points. In this case they are not arranged end to end in lines, but their attenuated extremities are interposed between the lateral surfaces of the cells situated above and below them; while the parenchyma cells, if, as is usual, they are arranged in lines, stand one upon another with flattened ends, their cavities being thus separated by partitions directed at right angles to their longitudinal axes. Link founded upon this differ- ence of the ends the distinction between parenchymatous and pro- senchymatous cells, a distinction which is indeed well grounded when we compare extreme forms, but which is by no means to be carried through, since the most manifold transitions occur from parenchymatous cells, with more or less oblique cross-walls, to perfect prosenchymatous cells. In many Thallophytes, especially in many^Fungi (e. g., Boletus iijniarms) and Lichens (e, g., in Evernia), isolated portions of the substance are found of fibre-shaped, frequently irregularly interwoven cells (IrregalaT cellular tissue of Kieser). Gradual transitions also occur from tliis form of cell to the form of the parenchymatous cell. The form of the parenchymatous cells is most intimately con- nected with theii' relative position. The simplest condition is afforded by such cells as lie one above another in a simple row, as the cells of the Oonfervce (pi. 1, fig. 1), articulated hairs, &;c. Here the cells become flattened on the sur- faces of contact, while the side-walls retain their natural curvature. Accordingly as these possess a cylindrical curvature, or one more approximating to a globe, does the entii^e cellular filament obtain a cylindrical or beaded shape. When parenchymatous cells lie side by side
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectplantcellsandtissues
