. Fecundation in plants. Plant embryology; Plants, Sex in; Karyokinesis. Fig. 40.—Development of ascogonium ai Spharotheca castagni.—(After Harper.) F, ascogonium with two cells; upper cell has two nuclei. G, mature ascogonium; the penultimate, or ascogenous cell, contains two nuclei. H, the two nuclei in the young ascus have fused, fiision nucleus containing two nucleoli. wall of the oogonium. In this respect the Ascomycetes differ from all other plants except the Rnodofhycece with which they form a striking parallel. A few steps further in the development of the fecundated egg will be traced
. Fecundation in plants. Plant embryology; Plants, Sex in; Karyokinesis. Fig. 40.—Development of ascogonium ai Spharotheca castagni.—(After Harper.) F, ascogonium with two cells; upper cell has two nuclei. G, mature ascogonium; the penultimate, or ascogenous cell, contains two nuclei. H, the two nuclei in the young ascus have fused, fiision nucleus containing two nucleoli. wall of the oogonium. In this respect the Ascomycetes differ from all other plants except the Rnodofhycece with which they form a striking parallel. A few steps further in the development of the fecundated egg will be traced to show the relation in the course of development of the fusion of the sexual nuclei to the vegetative nuclear fusion occurring in the young ascus. In speaking of this part of the development the term ascogonium will be used. A series of nuclear and cell-divisions now follow in the developing ascogonium, so that ultimately a row of five or six broad cells result (Fig. 39, D, E, and Fig. 40, F, G). Nuclear and cell-division are not dependent upon each other, and they do not seem to follow in the same order. In different stages of this growth, from one to three nuclei are to be seen in the distal cell of the ascogonium, but when the definite number of cells is formed two nuclei are always to be found. 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 Mottier, David Myers. [Washington] The Carnegie Institution of Washington
Size: 2142px × 1166px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherwashi, bookyear1904
