. A text-book of botany for secondary schools. Botany. ALG^ 105 65. Ulothrix.—These are bright green, thread-like plants found in the shallow, moving water of streams or lake margins, where they are anchored to sticks or stones. Each plant is a simple (unbranched) filament, composed of a single row of cells; and the cells are all alike excepting that the lowest one is usually colorless, and is elongated and more or less modified to act as a holdfast, anchoring the filament to its support (Fig. 97, A). With the possi-. FiG. 97.—Ulothrix: A, base of filament, showing holdfast cell and five veget
. A text-book of botany for secondary schools. Botany. ALG^ 105 65. Ulothrix.—These are bright green, thread-like plants found in the shallow, moving water of streams or lake margins, where they are anchored to sticks or stones. Each plant is a simple (unbranched) filament, composed of a single row of cells; and the cells are all alike excepting that the lowest one is usually colorless, and is elongated and more or less modified to act as a holdfast, anchoring the filament to its support (Fig. 97, A). With the possi-. FiG. 97.—Ulothrix: A, base of filament, showing holdfast cell and five vegetative cells, each with a single conspicuous cylindrical chloroplast (seen in section) surrounding a nucleus; B, four cells containing swimming spores; C, one cell containing four swimming spores (a), a free swimming spore (6), a cell (c) from which most of the gametes have escaped, pairing gametes (rf), and the resulting oospores (e); D, young filament from a swimming spore; E, oospore growing after rest; F, oospore producing swimming spores.—E and F, after Dodel-Port. ble exception of the holdfast cell, in each cell there may be seen a nucleus and a single chloroplast of peculiar form, being a thick cylinder investing the rest of the cell-contents. As seen under the microscope in optical section, the cylin-. 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 Coulter, John Merle, 1851-1928. New York, D. Appleton
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1906
