. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 468 MOSSES AND PERNS CHAP. Their researches, however, showed conclusively that this was not the case, but that the origin is exogenous. In most species they are produced abundantly, and a bud is formed in the axil of each leaf, although it frequently happens that some of them do not develop fully. In E. telmateia they do not occur at all, as a rule, upon the colourless sporiferous shoots, but are regu- larly formed from all but the lowest nodes of the sterile stems. L-. Fig. 372.—Longitudinal
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 468 MOSSES AND PERNS CHAP. Their researches, however, showed conclusively that this was not the case, but that the origin is exogenous. In most species they are produced abundantly, and a bud is formed in the axil of each leaf, although it frequently happens that some of them do not develop fully. In E. telmateia they do not occur at all, as a rule, upon the colourless sporiferous shoots, but are regu- larly formed from all but the lowest nodes of the sterile stems. L-. Fig. 372.—Longitudinal section of a young vegetative shoot sliowing two young leaves (L.), X200; B, section passing tlirough tlie base of a somewhat older leaf; fb, vascular bundle; C, section passing through a young bud (fe). In E. scirpoides they are absent from all the aerial stems, but whether rudiments of them are formed does not seem to have been investigated. Their development may be readily traced in a series of median longitudinal sections through a vigorous sterile stem of E. telmateia or E. arvense before it appears above ground. The young bud (Fig. 272, C) originates from a single epidermal cell just above the insertion of the leaf. This cell enlarges and is easily recognisable. In it are formed three intersecting walls cutting out the apical cell, which at first is somewhat irregular, but soon assumes its definite form, and the subsequent growth of the branch resembles in all essential points that of the main. 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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