. The cell in development and inheritance. Cells. 4 INTR ODUC TION thetical character, but a generalized statement of observed fact which may be outlined as follows : — -^ In all the higher forms of life, whether plants or animals, the body may be resolved into a vast host of minute structural units known as cells, out of which, directly or indirectly, every part is built (Figs. I, 2). The substance of the skin, of the brain, of the blood, of the bones or muscles or any other tissue, is not homogeneous, as it appears to the unaided eye, but is shown by the microscope to be an aggregate compose
. The cell in development and inheritance. Cells. 4 INTR ODUC TION thetical character, but a generalized statement of observed fact which may be outlined as follows : — -^ In all the higher forms of life, whether plants or animals, the body may be resolved into a vast host of minute structural units known as cells, out of which, directly or indirectly, every part is built (Figs. I, 2). The substance of the skin, of the brain, of the blood, of the bones or muscles or any other tissue, is not homogeneous, as it appears to the unaided eye, but is shown by the microscope to be an aggregate composed of innumerable minute bodies, as if it were a. Fig. 2. — General view of cells in the growing root-tip of the onion, from a longitudinal section, enlarged 800 diameters. a. non-dividing cells, with chromatin-network and deeply stained nucleoli; b. nuclei preparing for division (spireme-stage); t. dividing cells showing mitotic figures; e. pair of daughter-cells shortly after division. colony or congeries of organisms more elementary than itself. The name cells given to these bodies by the early botanists, and ulti- mately adopted by nearly all students of microscopical anatomy, was not happily chosen ; for modern studies have shown that although the cell may assume the form of a hollow chamber, as the name indicates, this is not one of its characteristic or even usual features. Essentially the cell is a minute mass of protoplasm, a substance long since identified by Cohn, Leydig, Max Schultze, and De Bary as the essential active basis of the organism, afterward happily characterized. 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, Macmillan
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcells, bookyear1911
