. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). THE VEGETATIVE ORGANS OP PLANTS. 279 as have been described. To answer the purpose of air and sap-channels, the wood-cells which constitute the con- centric rings of the old wood are constructed in a special manner, being provided laterally with visible pores, through which the contents of one cell may pass directly into those of its neighbors. Fis-, 53, -B, represents a por- tion of an isolated wood- cell of the Scotch Fir, {P
. How crops grow. A treatise on the chemical composition, structure, and life of the plant, for all students of agriculture ... Agricultural chemistry; Growth (Plants). THE VEGETATIVE ORGANS OP PLANTS. 279 as have been described. To answer the purpose of air and sap-channels, the wood-cells which constitute the con- centric rings of the old wood are constructed in a special manner, being provided laterally with visible pores, through which the contents of one cell may pass directly into those of its neighbors. Fis-, 53, -B, represents a por- tion of an isolated wood- cell of the Scotch Fir, {Pinus sylvestris,) mag- nified 200 diameters. Upon it are seen nearly circular disks, x, y, the structure of Avhich, while the cell is young, is shown by a section through them length- wise. ^ exhibits such a section through the thickened walls of two contiguous and adhering cells. X, in both A and Ji, shows a cavity be- tween the two primary cell-walls; y is the nar- row part of the chan- nel, that remains while the membrane thickens around it. This is seen in J?, y, as a pore or opening in the cell. In. Tig. 54. A it appears closed because the section passes a little to one side of the pore. In the next figure, (54,) representing a transverse sec- tion of the spring wood of the same tree magnified 300 diameters, the structure and the gradual formation of Digitized by Microsoft®. 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 Johnson, Samuel William, 1830-1909. New York, O. Judd & company
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectagricul, bookyear1868
