. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. x: LEPTOSPORANGIATM HETEROSPOREM 427 usually continue long, and the subsequent growth is purely basal. The cotyledon is alike in both genera, and is a slender cylindrical leaf tapering to a fine point, where the cells are much elongated and almost colourless. Its growth is at first slow, but at a later period (in Pilularia glohulifera about the eighth day) it begins to grow with great rapidity and soon reaches its full size. This is largely due to a simple elongation and ex- pansion of the cel
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. x: LEPTOSPORANGIATM HETEROSPOREM 427 usually continue long, and the subsequent growth is purely basal. The cotyledon is alike in both genera, and is a slender cylindrical leaf tapering to a fine point, where the cells are much elongated and almost colourless. Its growth is at first slow, but at a later period (in Pilularia glohulifera about the eighth day) it begins to grow with great rapidity and soon reaches its full size. This is largely due to a simple elongation and ex- pansion of the cells, which are separated in places, and form a series of longitudinal air-channels separated by radiating plates of tissue (Fig. 251, i). The simple vascular bundle traversing. Fig. 251.—Longitudinal section of the young sporophyte of Pilularia glohulifera, still enclosed in the calyptra (co/), and attached to the macrospore Up), X75; B, the lower part of the same embryo, X215; r, apical cell of the root; st, apical cell of the stem; i, lacunx. the axis is concentric, with a definite endodermis, but the tracheary tissue is very slightly developed. This becomes first visible about the time the leaf breaks through the calyptra. The Stem Of the two octants in the stem quadrant one becomes at once the apical cell of the stem, the other the second leaf, as in other Leptosporangiatse. The first wall in each octant meets octant and quadrant walls, and cuts off a large cell from each. 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
