Elementary botany . ccaceae. — The plantsmultiply only through cell division. Chroococ-cus, forms rounded, blue-green cells enclosedin a thick gelatinous coat, in fresh water andin damp places; certain species form lichen-gonidia in some genera of lichens. Gloeo-capsa is similar i;o Chroococcus, but the col-onies are surrounded by an additional commongelatinous envelope (fig. 168); on damp rocks,etc. 354. ORDER HORMOGONALES (HORMOGONEJE).—Plants filamentous, ^ simple celled or with false or true branching, usuallyseveral celled (Spirulina issingle celled). Multiplica-tion takes place throughho
Elementary botany . ccaceae. — The plantsmultiply only through cell division. Chroococ-cus, forms rounded, blue-green cells enclosedin a thick gelatinous coat, in fresh water andin damp places; certain species form lichen-gonidia in some genera of lichens. Gloeo-capsa is similar i;o Chroococcus, but the col-onies are surrounded by an additional commongelatinous envelope (fig. 168); on damp rocks,etc. 354. ORDER HORMOGONALES (HORMOGONEJE).—Plants filamentous, ^ simple celled or with false or true branching, usuallyseveral celled (Spirulina issingle celled). Multiplica-tion takes place throughhormogones, short sectionsof the threads becomingfree; also through restingcells. Two of the six fami-lies are mentioned. 355. Family Oscillatori-aceae.—This family is rep-resented by the genus Oscil-latoria, and by several othergenera common and widelydistributed. Oscillatoriacontains many are found on thedamp ground or wood, or floating in mats in the water. They often form on Fig. Fig. , Oscillatoria princeps, a. terminal cell; b, from the middle of a filament. In c, adead cell is shown between the living cells; B,Oscillatoria froelichii, b, with granules along thepartition walls. 164 MORPtiOLOG Y. the soil at the bottom of the pool, and as gas becomes entangled in the matof threads, it is lifted from the bottom and floated to the surface of the plant is thread-like, and divided up into many short cells. Thethreads often show an oscillating movement, whence the name Family Nostocaceae.—This family is represented by Nostoc, whichforms rounded, slimy, blue-green masses onwet rocks. The individual plants in theslimy ball resemble strings of beads, eachcell being rounded, and several of these ar-ranged in chains as shown in fig. 170. Hereand there are often found larger cells (hetero-cysts) in the chain. Nostoc punctiformelives in the intercellular spaces of the rootsof cycads (often found in greenho
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