. Botany for high schools and colleges. Botany. Pig. 257<z.—Longitudinal section of the apex of the root of PteHs hastata. », apical cell; o, o, epidermis ; e, cortical tissue ; c-c, c-c, the primary fihro-vascular bundles ; n, m, I, A, the root-cap ; k, A, daughter-cells recently cut off from the apical cell.—After Nageli and Leitgeb. ' and composed at first of but a single row of cells, but later of extended layers of cells. Thuy are monoecious, and bear tlieir antheridia on the basal portion of thf- ander surface, wliile the archegonia are found near the apical margin of the same surface
. Botany for high schools and colleges. Botany. Pig. 257<z.—Longitudinal section of the apex of the root of PteHs hastata. », apical cell; o, o, epidermis ; e, cortical tissue ; c-c, c-c, the primary fihro-vascular bundles ; n, m, I, A, the root-cap ; k, A, daughter-cells recently cut off from the apical cell.—After Nageli and Leitgeb. ' and composed at first of but a single row of cells, but later of extended layers of cells. Thuy are monoecious, and bear tlieir antheridia on the basal portion of thf- ander surface, wliile the archegonia are found near the apical margin of the same surface. After fer- tilization the germ-cell divides into four parts, the uppermost one (or two) of which becomes the foot, or organ which remains in contact with the prothal- lium ; one of the other parts develops into the first root, and the other into the first leaf. The young plant is thus formed on the under side of the pro- thallium, from which it grows up as shown in Figs. 256 and 355. The stems of Ferns are mostly short, or slender and creeping in our species, but in the tropics they are often of considerable height and thickness, some tree-ferns attaining the height of 34 metres or more (80 feet or more). They increase in length only, and this takes place by the continued division of an apical cell) They contain flat fibro-vascular bundles (Fig. 357, A and B), wliich are' usually disposed in a single circle, as seen in a cross-section, but iu some cases there are bundles in the medullary portion also. On ac- count of the presence of thick masses of thick-walled cells, (scleren-. Fig. 257*.—Portion of under surface of a leaf of Polypodium. showing sori.—From Le Maout and I)e- 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
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1888
