. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 324 MOSSES AND FERNS CHAP. the growing point and the production of two apical cells like the original one (Fig. 179, C). The division is first brought about by. a nearly central longitudinal division of the apical cell, and on either side of this, by a curved wall running to the outer wall of each cell, two new apical cells, separated by two elongated central cells, result. Each of these new growing points develops one of the lobes of the cotyledon, which undergo one or more bipartitions befor
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 324 MOSSES AND FERNS CHAP. the growing point and the production of two apical cells like the original one (Fig. 179, C). The division is first brought about by. a nearly central longitudinal division of the apical cell, and on either side of this, by a curved wall running to the outer wall of each cell, two new apical cells, separated by two elongated central cells, result. Each of these new growing points develops one of the lobes of the cotyledon, which undergo one or more bipartitions before the cotyledon breaks through. Fig. 179.âOnoclea struthiopteris. A, Longitudinal section of young sporophyte still connected with tlie prothallium (Pr), x6o; B, the apex of same, Xi8o; C, surface view of the young cotyledon showing the first dichotomy; D, central region of A, -showing the primary tracheary tissue, Xi8o; E, young sporophyte with nearly â full-grown cotyledon and primary root, X3; st^ stem; L^, cotyledon; L*» second leaf; F, foot; Pr, prothallium. the prothallium. As in Marattia the growth is much stronger upon the outer side and the leaf is strongly curved over. It very early grows beyond the stem apex, and the embryo loses its oval form much earlier than is the case with any of the Eusporangiatse. The Stem The early segmentation of the stem apex is much the same as in the cotyledon; but later the divisions in the segments are somewhat dififerent, and the first wall is a radial one, instead of. 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 Campbell, Douglas Houghton, 1859-1953. New York, The Macmillan Company;
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Keywords: ., bookauthorcampbelldouglashought, bookcentury1900, bookdecade1910
