. Fresh-water biology. Freshwater biology. THE FRESH-WATER ALGAE 153 13s (i33> 134) 136) Characteristics as in Pleurococcus, but sometimes forming short filaments Pseudo-pleurococcus Snow. This form may remain indefinitely in either a filamentous or unicellular state according to the conditions in the environment. In the filamentous state it resembles a small form of Stigeodonium, but is distinguished from it by the absence of zoospores. Chodat regards a form, similar to this as a true Pleurococcus and believes that short filaments are characteristic of that genus. Fig. 176. Pseudo-pleuroco
. Fresh-water biology. Freshwater biology. THE FRESH-WATER ALGAE 153 13s (i33> 134) 136) Characteristics as in Pleurococcus, but sometimes forming short filaments Pseudo-pleurococcus Snow. This form may remain indefinitely in either a filamentous or unicellular state according to the conditions in the environment. In the filamentous state it resembles a small form of Stigeodonium, but is distinguished from it by the absence of zoospores. Chodat regards a form, similar to this as a true Pleurococcus and believes that short filaments are characteristic of that genus. Fig. 176. Pseudo-pleurococcus vulgaris Snow. X 600. (Original.) 136 (133, 134, 13s) Reproduction by fission in three directions and by inter- nal division Palmellococcus Chodat. Chromatophore a parietal plate, without a pyrenoid. In addition to reproduction by fission and internal division, a rejuvenescence of the cell contents may occur, accompanied by a cast- ing off of the mother-membrane. An orange-red oil is sometimes present. 137 (132, i5Sj 174) Reproduction by internal division only. Family Chlorellaceae . 138 Cells spherical, ellipsoidal, or irregular. Membrane smooth. 139. 138 (142, 151) 139 (140, 141) 140 (139, 141) Cells spherical; chromatophore a single, hollow sphere with one pyrenoid. ... Chlorella Beyerinck. Cells spherical or somewhat elongated; chromatophore Ening the mem- brane, open on one side, with a single pyrenoid. The name Zoochlorella Brandt has been given to this same genus and ante- dates the name of Chlorella by some years, but the name Chlorella seems more appropriate. Fig. 177. Chlorella sp. X 600. (Original.) Cells spherical, chromatophore of many parietal discs, each with a p3rrenoid. Eremosphaera de Bary. Size relatively large; chromatophores many, parietal; nucleus prominent. Reproduction by internal division. The cells are large, spherical, and conspicuous. The nucleus is distinct, suspended in the middle of the cell by strands of proto- plasm. Two or four daughter in
Size: 2109px × 1185px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
