. Botany for high schools and colleges. Botany. CHAPTER IV. THE FOEMATION OF NEW CELLS. 43.—There are two essentially different ways in which cells originate, viz., (1) by the division of a protoplasmic body into two or more bodies; (2) 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, Fig 25), which are naked masses of freely moving protoplasm, first lose their nuclei (as in l), and then become constricted (as at c); the constriction deepens, and finally div
. Botany for high schools and colleges. Botany. CHAPTER IV. THE FOEMATION OF NEW CELLS. 43.—There are two essentially different ways in which cells originate, viz., (1) by the division of a protoplasmic body into two or more bodies; (2) 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, Fig 25), which are naked masses of freely moving protoplasm, first lose their nuclei (as in l), 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 begun ;rf,.,/, completion of "^^^^ ^r Icss Well-marked modes of ccll-formation by divisiou. On the one hand the wall divides as well as the protoplasm (Fissioji), while on the other the wall takes no part in the division, and it is only the protoplasm which divides (Liternal Cell-For- mation). 46.—The best examples of Fission are to be seen in those unicellular plants which have been frequently described iinder the name of Protococcus.'^ ^^The cell elongates and the protoplasm divides into two across its longer axis, and. •Division of the swarm-spores of Chondrioder- ma difforme; a, with nucleus ; &, nucleus dissolved ; c. two nuclei, division of protoplasm ^See "Huxley and Martin's Biology," Chap. II,. 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 Edwin, 1845- [from old catalog]. New York, H. Holt and company
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