. Botany for high schools. Botany. FERNS 333 areas of stony tissue (sclerenchyma) which give the chief mechan- ical support (fig. 310). 503. Structure of the fern leaf.—In many respects the leaves of ferns are similar in structure to the leaves of the flower- ing plants (paragraphs 140-145). The blade of the leaves is thin and expanded, and shows the same light rela- tion as the leaves of the higher plants. There is a layer of epidermal cells on either side of the leaf, which are quite regular as seen in cross section of the leaf, but meet by very irregular edges in surface view. There are num
. Botany for high schools. Botany. FERNS 333 areas of stony tissue (sclerenchyma) which give the chief mechan- ical support (fig. 310). 503. Structure of the fern leaf.—In many respects the leaves of ferns are similar in structure to the leaves of the flower- ing plants (paragraphs 140-145). The blade of the leaves is thin and expanded, and shows the same light rela- tion as the leaves of the higher plants. There is a layer of epidermal cells on either side of the leaf, which are quite regular as seen in cross section of the leaf, but meet by very irregular edges in surface view. There are numerous stomates which are pro- tected by two crescent- shaped guard cells as in the higher plants. The mesophyll of the leaves consists usually of a pali- sade layer next the upper epidermis, while the rest is made up of the loose parenchyma or spongy tis- sue with large intercellular spaces which communicate with the stomates. The disk-shaped chlorophyll bodies lie in the cells of the loose parenchyma, the palisade and guard cells, and sometimes in cells of the epidermis. In the veins are the vascular bundles. In the arrangement of these veins is shown one of the differences in structure from that of the higher plants. The veins branch in a forked manner, which sometimes is very striking. The vascular system strengthens. Fig. 311. Rhizome with bases of leaves, and roots of the Christmas 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 Atkinson, George Francis, 1854-1918. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1910
