. Botany for high schools and colleges. Botany. CHAPTER IV. THE FOEMATION OP NEW CELLS. 43.—There are two essent'ally different ways in which cells originate, viz., (1) by the division of a protoplasmic body into two or more bodies; (3) by the union of two or more protoplasmic bodies. 44.—Cell-Formation by Division. The simplest cases of the formation of cells by division occur in the Myxomy- cetes. The swarm-spores {a, Eig 25), which are naked masses of freely moving protoplasm, first lose their nuclei (as in b), and then become constricted (as at c); the constriction deepens, and finally div
. Botany for high schools and colleges. Botany. CHAPTER IV. THE FOEMATION OP NEW CELLS. 43.—There are two essent'ally different ways in which cells originate, viz., (1) by the division of a protoplasmic body into two or more bodies; (3) by the union of two or more protoplasmic bodies. 44.—Cell-Formation by Division. The simplest cases of the formation of cells by division occur in the Myxomy- cetes. The swarm-spores {a, Eig 25), which are naked masses of freely moving protoplasm, first lose their nuclei (as in b), and then become constricted (as at c); the constriction deepens, and finally divides each mass into two parts {d, e,f). 45.—This may be taken as the type of cell-formation by division, and in no case does it differ in any essential particular from this. Most plant-cells, however, are surrounded by a wall, whose deportment during division enables us to distinguish two more or less welt-marked modes of cell-formation by division. On the one hand the wall divides as well as the protoplasm [Fission), while on the other the wall takes no part in the division, and it is only the protoplasm which divides {Internal Cell-For- mation). 46.—The best examples of Fission are to be seen in those unicellular plants which have been frequently described under the name of Protococcus* "The cell elongates and the protoplasm divides into two across its longer axis, and. S Fig. 35. —Division of the swarm-spores of Cfiondnoder- madifforme: a, withnucleas; 6, nncleua diegolved ; c. two nuclei, divisioTi of protoplaam begun ; d, e,/, compli-tion of the process.—After DeBary. * See "Huxley and Martin's Biology," Chap. 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 Bessey, Charles E. (Charles Edwin), 1845-1915. New York : H. Holt
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