. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . ty, and in it there is usually a centrallyplaced pyrenoid. Multiplication occurs by the formation of autocolonieswhich are miniatures of the adult form when set free, their liberation being 1 G. S. West, 04. The Ccelastraceffi of Wille (09) appears to he an unnatural group inwhich are included a number of genera having little close affinity with each other. Genera suchas Ankistrodesmus, Selenastrum, Acti>i<istrum, etc., are much less ad
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . ty, and in it there is usually a centrallyplaced pyrenoid. Multiplication occurs by the formation of autocolonieswhich are miniatures of the adult form when set free, their liberation being 1 G. S. West, 04. The Ccelastraceffi of Wille (09) appears to he an unnatural group inwhich are included a number of genera having little close affinity with each other. Genera suchas Ankistrodesmus, Selenastrum, Acti>i<istrum, etc., are much less advanced types than Cuelastrumor Sorastrum. 206 Tetrasporinese by a split in the wall of the mother-cell in Gaelastrum (fig. 133 D) and Soras-trum, but by the conversion of this wall into mucilage in Burkillia. The Ccelastrese mostly occur in bogs and at the margins of pools and lakes, althoughsome species of Ccelastrum are more particularly confined to the freshwater plankton. The genera are : Ccelastrum Nageli, 1849 [inclus. Hariotina Dangeard, 1889]; SorastrumKiitzing, 1845 [inclus. Sdenospheerium Cohn, 1879]; Burkillia W. & G. S. West, Fig. 134. A, Burkillia cornuta W. & G. S. West, x 455 ; a, young autocolonies. J3, largeccjenobium of Sorastrum spinulosum Nag. x 455. C, Sorastrum Hathoris (Cohn) Schmidle,x 530 (after Bohlin). Family Chsetopeltidacese. The Alga? included in this family are distinguished from all other membersof the Tetrasporinese by the setas or bristles which are attached to the plants are unicellular, or aggregates of cells, sometimes forming flatpseudo-parenchymatous expansions. For the most part they are attached,the cells showing a marked dorsiventrality. In Glifetopeltis (fig. 135), an Alga which lives attached to various aquaticmacrophytes, the thallus is flat and similar to that found in the Ulvacea?except for its small size, and the fact that it is attached by the whole of onesurface. A study of the development of this thallus
Size: 2725px × 917px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishercambridgeengtheuni
