. Elements of botany. Botany; Botany. KOOTS. 37 covers the inner surface of the cell-wall of the root-hair. When the student has learned how active a substance proto- plasm often shows itself to be, he will not be astonished to find it behaving almost as though it were possessed of intelligence I from cell to cell, a root-hairs is forced stem, just as the the tube shown in with which the up- may be estimated and will. Traveling by osmotic action current of water derived from the up through the roots and into the contents of the egg was forced up into Mg. 21. 56. Boot Pressure. — The force ward
. Elements of botany. Botany; Botany. KOOTS. 37 covers the inner surface of the cell-wall of the root-hair. When the student has learned how active a substance proto- plasm often shows itself to be, he will not be astonished to find it behaving almost as though it were possessed of intelligence I from cell to cell, a root-hairs is forced stem, just as the the tube shown in with which the up- may be estimated and will. Traveling by osmotic action current of water derived from the up through the roots and into the contents of the egg was forced up into Mg. 21. 56. Boot Pressure. — The force ward flowing current of water presses by attaching a mercury gauge to the root of a tree, or the stem of a small sapling. This is best done in early spring after the thawing of the ground, but before the leaves have appeared. In Fig. 22 the ap- paratus is shown attached to the stem of a dahlia. The large glass tube W, filled with mercury up to the level g and with water from g to near s, is fastened tightly to the cut stem at s. As water absorbed by the roots is forced over into W, the mercury level in Q will rise higher and the difference of level in the two mercury-columns will measure the root pressure. For every foot of difference in level there must be a pressure of nearly six pounds per square inch on the stump at the base of the tube g. A black-birch root tested in this way at the end of April has given a root pressure of 37 pounds to the square inch. This would sustain a column of water about 86 feet Fig. 22.—Apparatus for Measure- ment of Boot Pressure. s, cut-off stem of "dahlia; c, a piece of rabber tubing slipped over the stump s and the glass tube g and tied fast; g, bent glass tube; W, water (sap forced up by the roots); Q, mercury-column sus- tained by the root 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
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1896
