BACTERIA. 35 



and after treatment witli picric acid, which causes the chain-like 

 structure to become apparent. G a portion of a plant with con- 

 spicuous sheath, two lateral branches are being- formed. JET part 

 of a plant, whose cells have divided and form Cocci. The original 

 form of the cells in which the Cocci are embedded may still be 

 recognised. I. Leptothrix-Gla,m.Qa.ta with conspicuous mucilaginous 

 sheath, from which a series of rods is about to emerge ; the rod 

 near the bottom is dead, and has remained lying in the sheath. 

 K part of a plant which is forming Cocci, those at the top are in 

 the zoogloea-stage, at the base they are elongating to form rods 

 and Leptothrix-fil&meui,B. L a portion of a branched Cladothrix, 

 which divides into motile Bacillus-forms ; the rays at the free 

 ends indicate the currents which the cilia produce in the water. 

 M a spirally-twisted, swarming filament, before and after division 

 into halves. N part of a tree-like zoogloea with Cocci and short 

 rods. All of these spirilla, zoogloea, etc., which Zopf has con- 

 nected with Clad, dichotoma, are according to Winogradsky, inde- 

 pendent organisms. 



Micrococcus urece produces urinal fermentation (transformation of 

 urinal matter into ammonium carbonate) ; aerobic ; round cells 

 generally united to form bent chains or a zoogloea. Several other 

 kinds of Bacteria have the same action as this one : in damp 

 soil containing ammonia-compounds, saltpetre-formations are pro- 

 duced by M. nitrificans and several different kinds of Bacteria. 



Micrococcus prodigiosus is found on articles of food containing 

 starch ; " bleeding bread " is caused by this Bacterium, which has 

 the power of forming a red pigment ; it also occurs in milk, and 

 produces lactic acid. 



Leuconostoc mesenterioides is the frog-spawn Bacterium (Fig. 27) 

 which is found in sugar manufactories, and has the power of 

 producing a viscous fermentation in saccharine solutions which 

 have been derived from plants, e.g. in beetroot-sugar manu- 

 factories, where large accumulations of mucilage are formed at 

 the expense of the sugar, with an evolution of carbonic acid. The 

 cell-rows, resembling somewhat a pearl necklace, have thick 

 mucilaginous cell-walls, and form white " Nostoc "-lumps. The 

 mucilage eventually deliquesces and the cells separate from each 

 other; arthrospores ? -Similar viscous deteriorations occur in 

 beer and wine, which may then be drawn out into long, string 

 like filaments " ropiness." 



Bacterium aceti, the Vinegar-bacterium, oxidizes alcohol into 



