. A compendium of general botany. Plants. Fig. 75.—Surface-view of an open {a) breathing-pore (stoma) and of one closed (ft). (Diagramatic.) Illustrating types I and II. wall of the guard-cell wliich are nearest each other cause a curva- ture of the guard-cells when the hydrostatic pressure of the interior is increased. (By the presence of two such thickenings this cur- vature is much more marked than it would be if only one such ridge were present.) The thin areas of each guard-cell nearest the cen-. FiG. IQ.—Uelleborus. Type II. (After Schwendener.) tral passage may permit a hinge-joint move
. A compendium of general botany. Plants. Fig. 75.—Surface-view of an open {a) breathing-pore (stoma) and of one closed (ft). (Diagramatic.) Illustrating types I and II. wall of the guard-cell wliich are nearest each other cause a curva- ture of the guard-cells when the hydrostatic pressure of the interior is increased. (By the presence of two such thickenings this cur- vature is much more marked than it would be if only one such ridge were present.) The thin areas of each guard-cell nearest the cen-. FiG. IQ.—Uelleborus. Type II. (After Schwendener.) tral passage may permit a hinge-joint movement of the thickened ridges, or by mutual contact they may form a better means of clos- ing the pore than do the thickened ridges. The chief mechanical change involved is the greater expansibility of the thin distal walls as compared with the thick proximal 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 Westermaier, Max; Schneider, Albert, 1863-1928. New York : Wiley
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896