. Practical text-book of plant physiology. Plant physiology. 284 GROWTH <%i 19 IS U IS 16 17 18 19 50 si .» A \ periods of rest. Additions to the volume of a plant, like addi- tions to the volume of a cell, are also accompanied by permanent alterations in the form of the body. Unequal accretions along the various axes, and development of new members are the prin- cipal causes to which change of form may be directly ascribed. This unequal growth is due to the localization of the generative tissues, or growing points. Ad- ditions to the body may only oc- cur in the vicinity of growing regions
. Practical text-book of plant physiology. Plant physiology. 284 GROWTH <%i 19 IS U IS 16 17 18 19 50 si .» A \ periods of rest. Additions to the volume of a plant, like addi- tions to the volume of a cell, are also accompanied by permanent alterations in the form of the body. Unequal accretions along the various axes, and development of new members are the prin- cipal causes to which change of form may be directly ascribed. This unequal growth is due to the localization of the generative tissues, or growing points. Ad- ditions to the body may only oc- cur in the vicinity of growing regions, or cambium layers. Growth of the body is not al- ways attended by an increase in the gross weight. Thus during the earlier stages of development of a seedling, the combustion of material stored in the endosperm may be so great that the gross and dry weight decrease during the process, and the same is true of the germination of such for- mations as the tuber of the po- tato. Again, in the later stages of the life of the larger plants, the accretions from the formation of new material may not counter- balance that used in the liberation of energy, with no consideration Fig. 135. Measurement of growth of the apical portion of a stem of bindweed. A, showing terminal portion of stem with marks of India ink I cm. apart. B, same 24 hours later in which the elongation of the various sections may be seen. The maxi- mum rate of growth has been shown by the 5th interval from the apex (SeeFig. 136). After Bonnier and Leclerc du 15. 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 MacDougal, Daniel Trembly, 1865-1958. New York [etc. ] Longmans, Green, and Co.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplantph, bookyear1901
