. Botany for high schools and colleges. Botany. 156 generally loosely arranged, with large intercellular spaces be- tween them (Figs. 131 and 133), and these are in free com- munication with the external air by means of the stomata. It most frequently happens that this loose tissue is in the under part of the leaf, while the upper portion is composed of one or more layers of closely placed cells ; and this agrees with the general distribution of the stomata, there being usually many more on the under than the upper surface. 203.—The upper denser tissue, termed palisade tissue, is comp
. Botany for high schools and colleges. Botany. 156 generally loosely arranged, with large intercellular spaces be- tween them (Figs. 131 and 133), and these are in free com- munication with the external air by means of the stomata. It most frequently happens that this loose tissue is in the under part of the leaf, while the upper portion is composed of one or more layers of closely placed cells ; and this agrees with the general distribution of the stomata, there being usually many more on the under than the upper surface. 203.—The upper denser tissue, termed palisade tissue, is composed of elongated cells, which stand at right angles to the surface of the Fig. tiie"pali- , » /tti- ioi\ t sade "tissue of the leaf of «i- leaf (ilg. 131). in CrOSS-SCCtlOn the thTiiVeS^faiJ^^rfe^w ofihe palisade-cclls are cylindrical, with rh"ororh™g4n*et Tmi Small intercellular spaces between them (Fig. 133), or in some cases they are more or less compressed and angular. In general, palisade tissue is confined to the upper surface of the leaf, the lower being occu- pied by the loose tissue previously mentioned ; but there are some cu- rious exceptions to this rule. The most notable of these is found in the leaf of Silpliium laciniatum— the so-called Compass Plant*—of the Mississippi Valley; its chloro- phyll-bearing parenchyma is almost entirely arranged as palisade tissue, so that the upper and lower por- tions are almost exactly identical in structure (Fig. 134). The ver- tical leaves of the Manzanita of the Pacific Coast {Arctostaphylos pungens, var. platypJiylla) have a similar 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 Bessey, Charles E. (Charles Edwin), 1845-1915. New York : H. Holt
Size: 1458px × 1714px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1885
