. Fresh-water biology. Freshwater biology. BLUE-GREEN ALGAE 107 24 (2) Cells epiphytic; with a distinct base and apex. Family Chamaesiphonaceae. Only one genus. . Chamaesiphon A. Braun and Cells small, ovoid, pyriform, or cylindrical; attached by their base and generally widening upwards to their free apex. Solitary or aggregated; sheaths present; cell walls very thin; cell contents homogeneous, blue- green, violet, or yellow; reproduction by one-celled, non-motile cells which are successively cut off from the upper portion of the plants, gradually escaping from the open apex. Common
. Fresh-water biology. Freshwater biology. BLUE-GREEN ALGAE 107 24 (2) Cells epiphytic; with a distinct base and apex. Family Chamaesiphonaceae. Only one genus. . Chamaesiphon A. Braun and Cells small, ovoid, pyriform, or cylindrical; attached by their base and generally widening upwards to their free apex. Solitary or aggregated; sheaths present; cell walls very thin; cell contents homogeneous, blue- green, violet, or yellow; reproduction by one-celled, non-motile cells which are successively cut off from the upper portion of the plants, gradually escaping from the open apex. Common on Oedogonium and other algae in ponds. Fig. Chamaesiphon incrustans Grunow. (After West.) X 8cxj. 25 (i) Plants filamentous; filaments simple or branched; consisting of one or more rows of cells generally enclosed within a more or less evident sheath. Asexual reproduction by means of hormogonia, and more rarely by spores. Order Hormogoneae Thuret. 26 26 (64) Filaments cylindrical, sometimes narrowed at the extremities. Suborder Psilonemateae . 27 27 (53) Filaments not branched 28 28 (43) 29 (39) Filaments consisting of a single row of cells, seldom {Spirulina] one-celled; not branched; heterocysts absent; sheaths vari- able, more or less gelatinous, and sometimes enclosing more than one . Family Oscillatoriaceae . 29 Never more than one filament within a sheath. Subfamily Lyngbyeae . 30 30 (31) Filaments apparently one-celled, coiled into a regular spiral, often showing rapid rotatory movements. . Spirulina Turpin. Filaments very narrow, consisting of a single elongated cell, sometimes of great length, regularly spirally coiled; sometimes showing rapid oscillat- ing and rotatory movements. Common in stag- nant water. Fig. 43. Spirulina major Kutzing. inal.) X 1000. (Orig- 31 (30) Filaments many-celled 3:1 32 (36) Filaments simple, generally showing oscillating and gliding move- ments; sheaths thin, hyahne, sometimes not evident. 33. Please note that these images are
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
