. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. FILICINEM LEPTOSPORANGIAT^ 317 Mottier (3) has recently examined the structure of the sper- matozoid in Struthiopteris. He could detect no cytoplasmic envelope investing the posterior coils, which seemed to be of exclusively nuclear nature. The vesicle showed a fine cyto- plasmic reticulum in which the larger granules were imbedded. The separation of the sperm cells begins at about the time the development of the spermatozoids commences. The muci- laginous walls stain now very strongly, and in
. The structure and development of mosses and ferns (Archegoniatae). Plant morphology; Mosses; Ferns. FILICINEM LEPTOSPORANGIAT^ 317 Mottier (3) has recently examined the structure of the sper- matozoid in Struthiopteris. He could detect no cytoplasmic envelope investing the posterior coils, which seemed to be of exclusively nuclear nature. The vesicle showed a fine cyto- plasmic reticulum in which the larger granules were imbedded. The separation of the sperm cells begins at about the time the development of the spermatozoids commences. The muci- laginous walls stain now very strongly, and in a living state appear thick and silvery-looking. The inner layer of the cell wall, however, remains intact, so that when the sperma-. FlG. 175.—Onoclea struthiopteris. A, Longitudinal section of the apex of a female prothallium, showing the apical cell (x) and a nearly ripe archegonium, X215; B-D, development of the archegonium; longitudinal sections, X430; h, neck canal cell. tozoids are ejected, they are still enclosed in a delicate cell mem- brane, which swells up as the water is absorbed and finally dissolves completely. The vesicle derived from the remains of the cytoplasm is very conspicuous here, and the granular contents usually, but not always, show the starch reaction. The body of the free spermatozoid has the form of a fiattened band with thickened edges, which tapers to a fine point at the anterior end, but is broader and blunter behind. The peripheral cells of the antheridium become so much compressed by the crowding of the sperm cells that they are scarcely 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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