. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 105 While the formation of the pore is in progress the nuclei of the tricho- gyne degenerate, and, by the time that they are completely disorganized, a migration of the male nuclei through the pore begins. Ultimately the contents of the trichogyne degenerate still further, till the cytoplasm and nuclei together form a densely staining mass which may be recognized even in the mature fruit. The male nuclei continue to pass into the tube until it is densely filled, and sometimes a trifle swollen. According to most observers the
. Fungi, ascomycetes, ustilaginales, uredinales. Fungi. IV] PEZIZALES 105 While the formation of the pore is in progress the nuclei of the tricho- gyne degenerate, and, by the time that they are completely disorganized, a migration of the male nuclei through the pore begins. Ultimately the contents of the trichogyne degenerate still further, till the cytoplasm and nuclei together form a densely staining mass which may be recognized even in the mature fruit. The male nuclei continue to pass into the tube until it is densely filled, and sometimes a trifle swollen. According to most observers the wall at the base of the trichogyne now breaks down so that an open passage is formed and the male nuclei travel through (fig. 6313:), and mingle. Fig. 63. Pyronema confluens; u,. entrance of male nuclei into oogonium, x 1435; b. association of male and female nuclei, xii6o; t. ascogenous hyphae with nuclei in pairs, X820; after Claussen. with the female nuclei. After their migration is complete a fresh wall is laid down across the base of the trichogyne, cutting off the oogonium once more as a single spherical cell. The female nuclei meantime become aggregated together (fig. 62«) and form a hollow sphere or dome or a sickle-shaped group. This is no doubt a provision for insuring their association with the male nuclei with the greatest certainty and dispatch. According to both Harper and Claussen, the sexual nuclei now pair; Harper has recorded complete fusion at this stage (fig. 62U), while Claussen (fig. 63(5) regards the nuclei as merely associated in preparation for their ultimate union in the ascus. Dangeard, on the other hand, denies the dis- appearance of the wall between the oogonium and trichogyne or the passage of the male nuclei beyond the latter organ, and Brown has described a variety in which the trichogyne and antheridium fail to Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - c
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfungi, bookyear1922
