. A manual of botany. Botany. Ficf. 664. Hellehorus ftelidux. A-fter Strasburger. ( X 540.) Quadripartition of mother-cell of pollen : in B the connecting threads and cell-plates are shown; in A the walls have been formed. Only three are visible, the fourth not 'being in focus ; the mode of development is tetrahedral. as buddinff, or (fiy. 662) among the lower Thallophytes. In a few cases in some of the lower plants the division of the cell is not preceded by division of the nucleus. In others, after the nucleus has divided, the new cell-wall is formed by an ingrowth from the walls
. A manual of botany. Botany. Ficf. 664. Hellehorus ftelidux. A-fter Strasburger. ( X 540.) Quadripartition of mother-cell of pollen : in B the connecting threads and cell-plates are shown; in A the walls have been formed. Only three are visible, the fourth not 'being in focus ; the mode of development is tetrahedral. as buddinff, or (fiy. 662) among the lower Thallophytes. In a few cases in some of the lower plants the division of the cell is not preceded by division of the nucleus. In others, after the nucleus has divided, the new cell-wall is formed by an ingrowth from the walls of the original cell. Free Cell-formation.—In this method of cell formation the nucleus divides repeatedly ti]l a number of nuclei are formed. The protoplasm aggregates round each nucleus, and a number of naked cells are so formed in the interior of the original cell. In some cases, as in the formation of the zoo- gonidia and gametes of many Algse and Fungi (fig. 665), they remain naked and are discharged in this condition from the cell in which they are formed. In other cases, each new cell secretes a cell-wall round itself. In its simplest form, this mode of cell-production results in the formation of a number of isolated cells (fig. 665). In certain cases, however, the cells are combined into a tissue, as in the. 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 Green, J. Reynolds (Joseph Reynolds), 1848-1914. London, J. & A. Churchill
Size: 1574px × 1588px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisher, booksubjectbotany
