. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 370 MOSSES AND FERNS CHAP. Osmunda, and the lamina of the leaf does not show any peculi- arities. In G. pectinata (Boodle (3) ), the stele is a hollow cyl- inder with both internal and external phloem and endodermis (Fig. 210, B). The Sporangium The development of the sporangium has been studied by Bower (19). The young receptacle begins to develop while the leaf is still tightly coiled. From the margin of the circular receptacle, and in some cases also from its upper surface, the r-. Fig, 212
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 370 MOSSES AND FERNS CHAP. Osmunda, and the lamina of the leaf does not show any peculi- arities. In G. pectinata (Boodle (3) ), the stele is a hollow cyl- inder with both internal and external phloem and endodermis (Fig. 210, B). The Sporangium The development of the sporangium has been studied by Bower (19). The young receptacle begins to develop while the leaf is still tightly coiled. From the margin of the circular receptacle, and in some cases also from its upper surface, the r-. Fig, 212.—a, Pinnule of Gleichenia dichotoma, showing the position of the sori (j), X4; B, ventral; C, dorsal view of the ripe sporangium, X8s. young sporangia arise as small conical outgrowths. Each spo- rangial outgrowth undergoes a series of regular segmentations resulting in a central, nearly tetrahedral, sporangial cell, from which successive segments are cut off which give rise to the short, massive stalk of the sporangium. Finally a periclinal wall is formed resulting in the archesporium. The further de- velopment is much like that of Osmunda, except that the inner of the two layers of tapetal cells become very large and their nuclei. 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
