. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 242 MOSSES AND FERNS CHAP. endophytic fungus. The upper portion, hghter in colour, bears the reproductive organs. Some of the prothalHa bear only antheridia; the others have archegonia as well. As usual, the first antheridia appear before any archegonia are formed. Both archegonia and antheridia resemble those of Botrychium more than they do those of Ophioglossum. The Embryo The fertilised &gg, or oospore, becomes invested with a cell- membrane and enlarges to several times its original bu
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. 242 MOSSES AND FERNS CHAP. endophytic fungus. The upper portion, hghter in colour, bears the reproductive organs. Some of the prothalHa bear only antheridia; the others have archegonia as well. As usual, the first antheridia appear before any archegonia are formed. Both archegonia and antheridia resemble those of Botrychium more than they do those of Ophioglossum. The Embryo The fertilised &gg, or oospore, becomes invested with a cell- membrane and enlarges to several times its original bulk before. Fig. 130.—Botrychium Virginianum. A, two-celled embryo within the archegonium venter, X about 300; B, two sections of an 8-celled embryo; C, large embryo showing the primary organs, X about 25. the first division wall is formed. This primary (basal) wall is in most cases transverse, but may be somewhat oblique. The two cells are generally more or less unequal in size, the upper or epibasal cell being larger than the lower (hypobasal) one. Each primary cell is next divided by a median vertical wall, and the young embryo shows thus a regular quadrant formation. The next divisions occur in the epibasal quadrants and are also approximately transverse; at this stage, to judge from Jeffrey's figures 43, 44, the embryo presents a striking resemblance to a corresponding stage in 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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