. Morphology of gymnosperms. Gymnosperms; Plant morphology. Figs. 401, 402.—Torreya taxifolia: fig. 401, four-nucleate stage of proembryo; August 12, 1904; X460; fig. 402, proembryo showing the three tiers of cells; the entire egg is segmented; the proembryo passes the winter in this stage; August 27, 1904; X460.—After Coulter and Land (ioi). Among the podocarps Podocarpus (69) and Phyllocladus (144) have been investigated. In the former genus the fusion nucleus assumes the basal position, and sixteen free nuclei appear before wall-formation. The three tiers of the completed proembryo are made
. Morphology of gymnosperms. Gymnosperms; Plant morphology. Figs. 401, 402.—Torreya taxifolia: fig. 401, four-nucleate stage of proembryo; August 12, 1904; X460; fig. 402, proembryo showing the three tiers of cells; the entire egg is segmented; the proembryo passes the winter in this stage; August 27, 1904; X460.—After Coulter and Land (ioi). Among the podocarps Podocarpus (69) and Phyllocladus (144) have been investigated. In the former genus the fusion nucleus assumes the basal position, and sixteen free nuclei appear before wall-formation. The three tiers of the completed proembryo are made up as follows: fourteen cells in the open tier, fourteen in the suspensor tier, and one binucleate cell in the embryo-forming tier. In Phyllocladus there are eight free nuclei before wall-formation. Among the Pinaceae, with the possible exception of the araucarians, wall-formation in connection with the mitosis which gives rise to the eight-nucleate stage of the proembryo is a remarkably uniform. 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 Coulter, John Merle, 1851-1928; Chamberlain, Charles Joseph, b. 1863; Coulter, John Merle, 1851-1928. Morphology of spermatophytes. Part I. Gymnosperms. Chicago, University of Chicago Press
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