56 Synopsis of the Bacteria and Yeast Fungi. 



A Fungus which is often very troublesome, because it defiles the 

 water and stops up the narrower pipes. The cylindrical threads, some- 

 what clavate above, are visibly articulated ; the joints afterwards 

 separate from one another, but are then surrounded by a sheath, which, 

 originally colourless, becomes of a yellow or yellowish-brown colour by 

 impregnation with iron. The sheath, at first closed, is burst at last 

 by the continually dividing joints, which then escape. Each joint can 

 develop a new thread. In other cases, however, the thread remains 

 enclosed in the sheath ; its joints are divided by closely contiguous 

 transverse partitions into flat discs, which then break up by vertical 

 partitions into smaller roundish cells : the latter may be designated the 

 spores of the Fungus. They often develop, even while still within the 

 sheath, into new threads, which grow through the gelatinous swollen 

 sheath ; or else they leave the sheath, and undergo further develop- 

 ment outside it. They either grow into threads, or form by repeated 

 bipartition larger or smaller colonies of roundish cells, held together 

 by their membranes, which assume a gelatinous consistence. These 

 colonies are designated the Palmella form (probably the Palmellina 

 fiocculosa of Radlkofer) ; each of their cells can again form a thread. 



[According to Eyferth, Bot. Zeitung, xxxviii. 673, C. Kiihniana 

 is identical with Sphcerotilus natans. A. Giard, Revue Internat. des 

 Sciences, x. igo, in describing the infection of the drinking water of 

 Lille, in 1882, by this Fungus, says that the " microgonidia, " which 

 are formed by transverse division of the clavate ends of the tubes, 

 exhibit for some time an active movement, and with a high power 

 (Hartnack, No. 12, immersion) he saw the flagellum. A full account 

 of this Fungus will be found in Quart. Jour. Micr. Sci., 1873, p. 163. — 

 Tr.] 



