. Carnegie Institution of Washington publication. iS8 ARCHEGONIATES. able, judging from the karyokinetic figures observed, that the nuclear division leading to the formation of the ventral canal-cell is of the heterotypic type, and takes place essentially as in the first division of the pollen mother-cells of the Liliacece. This is certainly an error, for in both Gymnosperms and Angiosperms the heterotypic nuclear division occurs in the micro- and macrospore mother-cells and nowhere else in ontogeny. Since the spore mother-cells of the Gymnosperms are homologous with those of the higher plants
. Carnegie Institution of Washington publication. iS8 ARCHEGONIATES. able, judging from the karyokinetic figures observed, that the nuclear division leading to the formation of the ventral canal-cell is of the heterotypic type, and takes place essentially as in the first division of the pollen mother-cells of the Liliacece. This is certainly an error, for in both Gymnosperms and Angiosperms the heterotypic nuclear division occurs in the micro- and macrospore mother-cells and nowhere else in ontogeny. Since the spore mother-cells of the Gymnosperms are homologous with those of the higher plants, we naturally expect to find the heterotypic division in Cycas in the first karyokinesis of the macrospore mother-cell. This is made all the more certain by the researches of Juel (1900), who finds in Larix that the first nuclear division in the macrospore mother-cell is heterotypic. In Larix and 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 Carnegie Institution of Washington. Washington, Carnegie Institution of Washington
Size: 1838px × 1359px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1900, bookyear1904
