. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). ELEMENTS OF ORGANIC STKUCTUEE. 231 cases, however, the cells of plants are so small as to re- quire a i^owerfiil microscope to distinguish them,—arc, in fact, no more than l-1200th to l-200th of an inch in diam- eter ; many are vastly smaller. Growth.—The growth of a plant is nothing more than the aggregate result of the enlargement and multiplication of the cells which compose it. In most cases the cells at- tain their full si
. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). ELEMENTS OF ORGANIC STKUCTUEE. 231 cases, however, the cells of plants are so small as to re- quire a i^owerfiil microscope to distinguish them,—arc, in fact, no more than l-1200th to l-200th of an inch in diam- eter ; many are vastly smaller. Growth.—The growth of a plant is nothing more than the aggregate result of the enlargement and multiplication of the cells which compose it. In most cases the cells at- tain their full size in a short time. The continuous growth of plants depends, then, chiefly on the constant and rapid formation of new cells. Ccll-inultiplication.—The young and active cell always contains a nucleus, (fig. 34, h.) Such a cell may produce a new cell by division. In this process the nucleus, from which all cell-growth appears to originate, is observed to re- solve itself into two f)arts, then the protoplasm, «, begins to contract or in- fold across the cell in a line correspond- ing with the division of the nucleus, until the opposite infolded edges meet—like the skin of a sausago where a string is tightly tied around it,—thus separating the two nuclei and inclosing each within its new cell, which is comiDleted by a further external growth of cellulose. In one-celled plants, like yeast, (fig. 35,) the new cells thus formed, bud out from the side of the parent-cell, and before they obtain full size become entirely detached from it, or, as in higher plants, the new cells remain adher- ing to the old, forming a tissue. In free cell-formation nuclei are observed to develope in the protoplasm of a parent cell, which enlarge, surround themselves with their own protoplasm and cell-membrane, and by the resorption or death of the parent cell become independent of the Please note that these images are extracted from scanned page images that may have been digitally enhan
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectagricul, bookyear1868
