. Fresh-water biology. Freshwater biology. ISO FRESH-WATER BIOLOGY 113 (114) Cells spherical Gloeocystis Nageli. The enveloping gelatinous substance showing a concentric lamellate structure. Reproduction by repeated cell division, several generations of cells often re- maining enclosed in the original mother-membrane. According to some authors reproduction also occurs by bicilliate zoospores. The authenticity of this genus is doubtful as the non-motile stage of certain species of Chlamydomonas answers this description. Fig. 163. Gloeocystis vesiculosus Nageli. X 150. (After Nageli.) 114(113) C
. Fresh-water biology. Freshwater biology. ISO FRESH-WATER BIOLOGY 113 (114) Cells spherical Gloeocystis Nageli. The enveloping gelatinous substance showing a concentric lamellate structure. Reproduction by repeated cell division, several generations of cells often re- maining enclosed in the original mother-membrane. According to some authors reproduction also occurs by bicilliate zoospores. The authenticity of this genus is doubtful as the non-motile stage of certain species of Chlamydomonas answers this description. Fig. 163. Gloeocystis vesiculosus Nageli. X 150. (After Nageli.) 114(113) Cells elongated Dactylothece Lagerheim. C:^-\ Chromatophore a parietal plate lying only on one side of the cell; no pyrenoids. As ii'^'i Gelatinous substance often lamellate. Fig. 164. Daclylothece braunii Lagerheim, X about 370. (After Lagerheim.) IIS (112) Gelatinous envelop not containing concentric lamellae about the cells. . ... 116 116 (117) Gelatinous mass containing segments of the antecedent mother cell Schizochlamys A. Braun. Cells spherical, scattered in a gelatinous mass together with the visible remnants of the old membranes which are split into distinct segments. West believes that it is the formation of the large amount of gelatinous material that causes the firmer portion of the membrane to become ruptured, and that this takes place previous to the formation of the two or four daughter cells. 5. gelatinosa is the only species reported in America, and this occurs as a pale green irregular mass either free or adhering to water Fig. i6s. Schizochlamys gelatinosa A. Braun. (Original.) X 600. 117 (116) Gelatinous mass not containing segments of the antecedent mother- membrane 118 118 (119) Cells throughout the gelatinous mass formed by the outer layers of the cell walls Palmella Lyngbye. Chromatophore parietal, with a pyrenoid. Reproduction by division in three directions, and according to Wille, by macrozoospores, microzoospores, and isogametes. 119 (118) Ce
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