. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . h the sameposition as the PalmellaceaB among theTetrasporine Protococcales. The non-motilecondition is the dominant one, and inChlorosaccus and Racovitziella the cells areembedded in a copious mucus. Cell-divisiontakes place abundantly in this state. InStipitococcus (fig. 255) and Peroniella thecells are attached by delicate stalks to thefilaments of larger Algae, and in many casesthe length of the stalk is determined by thethickness of the m
. Algæ. Vol. I. Myxophyceæ, Peridinieæ, Bacillarieæ, Chlorophyceæ, together with a brief summary of the occurrence and distribution of freshwat4er Algæ . h the sameposition as the PalmellaceaB among theTetrasporine Protococcales. The non-motilecondition is the dominant one, and inChlorosaccus and Racovitziella the cells areembedded in a copious mucus. Cell-divisiontakes place abundantly in this state. InStipitococcus (fig. 255) and Peroniella thecells are attached by delicate stalks to thefilaments of larger Algae, and in many casesthe length of the stalk is determined by thethickness of the mucous investment of thehost. It seems probable that in both generathe stalk is the modified longer cilium. InMischococcus the cells are globular and are united to form small branched colonies by thick tubular stalks of mucilage inthe distal ends of which the cells are embedded (fig. 256). Each cellpossesses from one to four chromatophores. Reproduction is by zoogonidia,which in Chlorosaccus and Mischococcus have each a pair of unequal cilia are attached at the anterior extremity. Aplanospores areknown to be formed in Fig. 255. Stipitococcus urceolatus W. &G. S. West. A—C, epiphytic on afilament of Mougeotia • D, epiphyticon Sphserozosma excavatum. A andD, x500; B and C, x 780. BotryococcacesB 405 Isogametes occur in Mischococcus, in which genus the zygospore ongermination divides in two directions in one plane, forming an epiphyticcushion, all the cells of which are situated on short, broad, mucilaginousstalks. This condition might almost be regarded as a palmella-state. The genera are: Peroniella Gobi, 1887 ; Stipitococcus W. & G. S. West, 1898 ;Jfisikococcus Nageli, 1849 ; Chlorosaccus Luther, 1898 ; Racovitziella De Wildeman, 1900[ = Tetrasporopsis Lemmermann & Schinidle (according to Wille); DictyosphxropsisSchmidle, 1903]. Peroniella and Stipitococcus might be compared with Physocytium among the Palrnellacese,and similarly a compar
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