. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. THE HOMOSPOROUS LEPTOSPORANGIATM 36; hedral, and contain no chlorophyll. When the ripe spores are sown, after a few days the oil-drops become much smaller but more numerous, and the first chloroplasts become evident. The latter increase in number and size, and small starch grains are developed. The exospore is ruptured in from two to three weeks from the time the spore is sown, and the spore contents surrounded by the intine project through the opening. The first wall usually separates the fir
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. THE HOMOSPOROUS LEPTOSPORANGIATM 36; hedral, and contain no chlorophyll. When the ripe spores are sown, after a few days the oil-drops become much smaller but more numerous, and the first chloroplasts become evident. The latter increase in number and size, and small starch grains are developed. The exospore is ruptured in from two to three weeks from the time the spore is sown, and the spore contents surrounded by the intine project through the opening. The first wall usually separates the first rhizoid, which, like that of Osmunda, often contains a good deal of chlorophyll, from the larger prothallial cell. As a rule the development of the pro- thallium corresponds closely to that of the Polypodiacese, but. Fig. 209.—Gleichenia pectinata. A, Ripe archegonium; B, nearly ripe antheridium; 1, surface view; 2, optical section; C, apex of open antheridium, showing the method of dehiscence; D, section of very young antheridium. All figures X about 250. it may have a midrib like that of Osmunda. The growth is normally from a two-sided apical cell, which is replaced later by marginal initials. A point of resemblance to Osmunda is the abundant production of adventitious shoots, which are formed in numbers upon the margin or from the ventral sur- face, and may develop into perfectly normal prothallia. RauwenhofFs account of the sexual organs is not as com- plete as might be wished, but is sufficient to show some inter- esting points of resemblance to the Osmundacese. The first wall in the antheridium cuts off a basal cell, and the next wall is somewhat like the funnel-shaped wall in the 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 M
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