. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . K ft-1 H I A — G,Carteri,t A and B, vegetative cells (= zoogonidia); C,four daughter-cells within old wall of mother-cell; D, gametes; E, conjugating gametes;F, zygote. H and /, Chlamydomonas Debary-ana Gorosch. J and K, Chi. grandis Stein(=Chl. Kleinii Schmidle). All x 475. cr, con-tractile vacuoles; n, nucleus; p, pyrenoid;zg, gamete; z, zygote. 1 In Aijloe there is an additional group of three contractile vacuoles at the posterior
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . K ft-1 H I A — G,Carteri,t A and B, vegetative cells (= zoogonidia); C,four daughter-cells within old wall of mother-cell; D, gametes; E, conjugating gametes;F, zygote. H and /, Chlamydomonas Debary-ana Gorosch. J and K, Chi. grandis Stein(=Chl. Kleinii Schmidle). All x 475. cr, con-tractile vacuoles; n, nucleus; p, pyrenoid;zg, gamete; z, zygote. 1 In Aijloe there is an additional group of three contractile vacuoles at the posterior end ofthe cell (vide Pascher, 12). 170 Volvocineae. Fig. 99. Spondylomorum qun-ternarium Ebrenb., a colonyof 16 cells, n, nucleus ; s,stigma; v, contractile vacu-ole. (After Stein, fromWille.) x 650. fuse in pairs to form zygotes (fig. 98 D—F). One species of Carteria occurssymbiotically in the marine Planarian worm Convoluta roscoffensis (Keeble & Gamble, 07); this species is also of interest onaccount of the very few marine species of the Volvo-cacea> which are known to exist. An interestinggenus is Scherffelia Pascher (12), in which the cellis compressed, so that in cross-section it has some-what the appearance of a thin biconvex lens. Thereare two plate-like chloroplasts, sometimes unitedposteriorly in Scherffelia Phacus, and no pyrenoid ispresent. In Sch. Phacus the cell-wall is laterallyexpanded into the rudiments of wings such as aremore prominently developed in Pteromonas. Tetrablepharis (fig. 102 G) is a colourless genuswhich is probably a degenerate derivative of Carteria,having assumed a saprophytic mode of existenc
Size: 1422px × 1757px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublishercambridgeengtheuni
