132 BACTERIOLOGY. 



into rods. These observations point to the exis- 

 tence of a pleomorphic species, Bacterium urece, 

 and the former nomenclature micrococcus urece must 

 be regarded as untenable. They are aerobic ; 

 occurring 1 in urine they set up ammoniacal fer- 

 mentation, converting urea into carbonate of 

 ammonia.* 



Bacterium aceti. Cocci, short rods, long rods, 

 leptothrix-forms, and zooglcea. Cocci and short rods 

 may occur in the same thread. The long rods and 

 threads may develop irregular swellings, so-called 

 in volution -forms, which have a thickened membrane 

 and a grey colour. The effect of the action of this 

 microbe is to oxidise alcohol in wine and other 

 fruit juices into vinegar. The masses of zooglcea 

 united together form a membranous layer which 

 must not be mistaken for the pellicle formed by 

 Saccharomyces mycoderma. The latter prepares the 

 medium for the action of the bacterium aceti. 



Bacterium Pasteurianum, Hansen. Morpho- 

 logically similar to Bacterium aceti, but the cells 

 contain a starch-like substance, which is turned blue 

 by iodine. They occur in beer-wort. 



Bacterium Zopfii, Kurth. Cocci i 1-25 //, in 

 diameter, rods and threads. Cultivated in a streak 

 on nutrient gelatine spread out on a glass slide, a 

 peculiar development takes place. In twenty -four 

 hours after inoculation threads have developed, 

 in forty-eight hours, windings of the threads are 



* Zopf, Die Sfialtpilze, p. 62, 1885. 



