. The cell in development and inheritance. Cells. PHYSIOLOGICAL RELATIONS OF NUCLEUS AND CYTOPLASM 253 point of growth. Thus, in the formation of epidermal cells the nucleus lies at first near the centre, but as the outer wall thickens, the nucleus moves towards it, and remains closely applied to it throughout its growth, after which the nucleus often moves into another part of the cell (Fig. 114, A, B). That this is not due simply to a movement of the nucleus towards the air and light is beautifully shown in the coats of certain seeds, where the nucleus. Fig. 114.— Position of the nuclei in g
. The cell in development and inheritance. Cells. PHYSIOLOGICAL RELATIONS OF NUCLEUS AND CYTOPLASM 253 point of growth. Thus, in the formation of epidermal cells the nucleus lies at first near the centre, but as the outer wall thickens, the nucleus moves towards it, and remains closely applied to it throughout its growth, after which the nucleus often moves into another part of the cell (Fig. 114, A, B). That this is not due simply to a movement of the nucleus towards the air and light is beautifully shown in the coats of certain seeds, where the nucleus. Fig. 114.— Position of the nuclei in growing plant-cells. [tiAKERLAXnT.] A. Young epidermal cell of Lmula with central nucleus, before thickening of the membrane. B. Three epidermal cells of Momtera, during the thickening of the outer wall. C. Cell from the seed-coat of Scopulina during the thickening of the inner wall. D. E. Position of the nuclei dur- ing the formation of branches in the root-hairs of the pea. moves not to the outer, but to the inner wall of the cell, and here the thickening takes place (Fig. 114, C). The same position of the nucleus is shown in the thickening of the walls of the guard-cells of stomata, in the formation of the peristome of mosses, and in many other cases. In the formation of root-hairs in the pea, the primary outgrowth alwavs takes place from the immediate neighbour- hood of the nucleus, which is carried outward and remains near the tip of the growing hair (Fig. 114, D, E). The same is true of the. 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 Wilson, Edmund B. (Edmund Beecher), 1856-1939. New York : The Macmillan company
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectcells, bookyear1896
