. Practical botany. Botany. 200 PRACTICAL BOTANY. 185. Vaucheria: reproduction. As suggested in Sect. 183, it sometimes occurs tliat brandies are left as separated in- dividuals by the death of the older portions of the plant. This re- sults in vegetative re- production. Asexual reproduction may be started by having the end of a branch cut off by a cross wall. The part that is thus cut off proceeds to form an immense zoospore (Fig. 162, ^, 5). The wall which contains it breaks, and it slowly emerges, and, after a period of separate ex- istence in the water, it germinates and forms a new plant
. Practical botany. Botany. 200 PRACTICAL BOTANY. 185. Vaucheria: reproduction. As suggested in Sect. 183, it sometimes occurs tliat brandies are left as separated in- dividuals by the death of the older portions of the plant. This re- sults in vegetative re- production. Asexual reproduction may be started by having the end of a branch cut off by a cross wall. The part that is thus cut off proceeds to form an immense zoospore (Fig. 162, ^, 5). The wall which contains it breaks, and it slowly emerges, and, after a period of separate ex- istence in the water, it germinates and forms a new plant (Fig. 162, C). This zoospore is composed of many cells. It is therefore a com- pound zoospore, and iscoenocytic. But the compound zoospore produces only one new plant. Forma- tion of zoospores may be induced in the lab- oratory by keeping Vaucheria plants in a dish of shallow water. Another kind of re- production may occur at the same time that zoospores are being formed, though it usually occurs at other times. Upon the sides of the plant Fig. 162. The formation of zoospores by Vaucheria A, a piece of a plant at the tip of which a section has' been cut oft to prod iice the zoospore (2); B, a zoospore which has become free from the plant which formed it, and has assumed the rounded swimming form; C, a zoospore germinating to form a new plant. Considerably magnified. 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 Bergen, Joseph Y. (Joseph Young), 1851-1917; Caldwell, Otis William, 1869- joint author. Boston, New York [etc. ] Ginn and company
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