. Nature and development of plants. Botany. NATURE OF PLANTS 6i number of cells in the root exerts a pressure that often amounts to considerably more than one atmosphere, i. e., 15 lbs. to the square inch. It is the steady expressing of fluids by these cells that causes the familiar phenomena of the "bleeding," or flow of water from stumps in the spring; likewise the "bleeding," of injured branches, or the flow of sap, for in the stem the living. Fig. 36. Cross-section of root taken above section shown in Fig. 33: ^ epidermis with root hairs; c, cortex bounded on inner side
. Nature and development of plants. Botany. NATURE OF PLANTS 6i number of cells in the root exerts a pressure that often amounts to considerably more than one atmosphere, i. e., 15 lbs. to the square inch. It is the steady expressing of fluids by these cells that causes the familiar phenomena of the "bleeding," or flow of water from stumps in the spring; likewise the "bleeding," of injured branches, or the flow of sap, for in the stem the living. Fig. 36. Cross-section of root taken above section shown in Fig. 33: ^ epidermis with root hairs; c, cortex bounded on inner side by endodermisr end. Within is the central region containing vascular bundles; x, xylem; p. phloem.â I. D. Cardiff. â cells are constantly absorbing and giving off water as in the root. In the summer, stumps and stems do not "bleed" as a rule be- cause the water lost by transpiration nearly empties the cells, whereas in the spring before the leaves appear they become filled with fluid. 26. The Sensitiveness of the Root.âWe may now ask how does this elaborate root mechanism become so perfectly adjusted to the soil. If the root of a pea or bean seedling is placed hori- zontally in sawdust, after one or two hours it will begin to curve down toward the earth center. No matter in what position it is placed the result is always the same. We are so familiar with the downward growth of roots into the soil that we never. 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 Curtis, Carlton Clarence, 1864-1945. New York, H. Holt
Size: 1671px × 1494px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisher, booksubjectbotany
