. Fresh-water biology. Freshwater biology. 268 FRESH-WATER BIOLOGY 193 (192) Colony flattened, horseshoe-shaped, with poles differentiated by arrangement of cells. Tails at posterior end. Platydorina Kofoid. Representative species. . Platydorina caudata Kofoid 1899. Colony slightly twisted in a left spiral. Cells sixteen or thirty-two imbedded in a transparent, gelatinous matrix and surrounded by a distinct sheath. Each cell has two flagella, an eye-spot, a nucleus, and a single chromatophore. Tails, in sixteen cell colonies, are three in number; in thirty-two cell colonies five tails are pres
. Fresh-water biology. Freshwater biology. 268 FRESH-WATER BIOLOGY 193 (192) Colony flattened, horseshoe-shaped, with poles differentiated by arrangement of cells. Tails at posterior end. Platydorina Kofoid. Representative species. . Platydorina caudata Kofoid 1899. Colony slightly twisted in a left spiral. Cells sixteen or thirty-two imbedded in a transparent, gelatinous matrix and surrounded by a distinct sheath. Each cell has two flagella, an eye-spot, a nucleus, and a single chromatophore. Tails, in sixteen cell colonies, are three in number; in thirty-two cell colonies five tails are present. Movement by rotation on the longitudinal axis. Length 150 ^u. Plankton of rivers and lakes. Fig. 449. Platydorina caudata. X 185. (After Kofoid.). 194 (191) Colonies spherical or ellipsoidal; cells differentiated as to size and function. ... ... 195 195 (198) No protoplasmic processes connecting the cells. Small vegetative cells at the anterior pole, large gonidial cells at the posterior pole. Pleodorina Shaw 196 196 (197) Cells sixty-four or one hundred and twenty-eight, about equally divided between large and small. Pleodorina californica Shaw 1893. Colony spherical, with gonidial cells two or three times the size of the vegetative cells. Cells biflagel- late, not in contact with each other. Reproduction asexual, by gonidial cells, in this and other species of the genus. Found in ponds, ditches, and streams. Fig. 450. Pleodorina calijornica. X 300. (After Shaw.). 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 Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
