. Essentials of botany. Botany; Botany. THE ALGiE 217 due to the pressure exerted upon each by its neighbors, since at the tips of the filaments and on each side of a dead cell the unopposed pressure of the protoplasm causes the cell-walls to become con- vex (see Sect. 280). Oscillatoria contains abundant coloring matter of a bright bluish green or steel blue. If a small quantity of dried Oscillatoria is pul- verized and then soaked in water, the water is colored blue by the pigment which it extracts from the cell- contents. The residue may then be treated with alcohol, which becomes green fro
. Essentials of botany. Botany; Botany. THE ALGiE 217 due to the pressure exerted upon each by its neighbors, since at the tips of the filaments and on each side of a dead cell the unopposed pressure of the protoplasm causes the cell-walls to become con- vex (see Sect. 280). Oscillatoria contains abundant coloring matter of a bright bluish green or steel blue. If a small quantity of dried Oscillatoria is pul- verized and then soaked in water, the water is colored blue by the pigment which it extracts from the cell- contents. The residue may then be treated with alcohol, which becomes green from the chlorophyll dissolved from the Oscillatoria. Photosynthesis is carried' on readily by this plant, as is evident from the oxygen bubbles which it gives off freely in sunlight. Reproduction in Oscilla- toria is usually performed by the breaking off of fila- ments at the places where dead cells occur. Each separ rated bit of filament continues to produce new cells by the formation of new partition walls (Fig. 152). The simple method of cell-division shown in the figure is not. Blue-Green A'l^., , a filament of Calothrix, reproducing by hormogonia, h, segmented portions which escape from the sheath of the filament; -B, Rivularia. (Both A and B greatly magnified.). 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 Bergen, Joseph Y. (Joseph Young), 1851-1917. Boston, Ginn
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1908
