. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. THE HOMOSPOROUS LEPTOSPORANGIATJi The Embryo 369 To judge from the few rather vague statements made by Rauwenhoff in regard to the embryo, this more nearly re- sembles the typical leptosporangiate type than it does Osmunda. The primary root has a large and definite three-sided apical cell, and the divisions in the segments are very regular. The Adult Sporophyte Poirault (i) and Boodle (3) have made a study of the stem of various species of Gleichenia, which differs a good deal from 0. Fig. 311
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. THE HOMOSPOROUS LEPTOSPORANGIATJi The Embryo 369 To judge from the few rather vague statements made by Rauwenhoff in regard to the embryo, this more nearly re- sembles the typical leptosporangiate type than it does Osmunda. The primary root has a large and definite three-sided apical cell, and the divisions in the segments are very regular. The Adult Sporophyte Poirault (i) and Boodle (3) have made a study of the stem of various species of Gleichenia, which differs a good deal from 0. Fig. 311.—Gleichenia Habellata. Development of the sporangium; A, B, X300; C, X150. (After Bower.) that of Osmunda, and approaches that of the Hymenophyllaceae and Schizaeacese. A single axial bundle traverses the stem, and is separated from' the sclerenchymatous cortex by a distinct en- dodermis. Within the latter is a pericycle of several layers of cells, within which is a continuous zone of phloem containing large and small sieve-tubes, and phloem parenchyma. Within the phloem are also secreting cells. The whole central part of the stem, except in G. pectinata, is occupied by bundles of large scalariform tracheids separated by parenchyma (Fig. 210, C). The single bundle traversing the petiole is much like that 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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