( 479 ) 



remain much longer unchanged and continue distinctly to show the 

 shape of the bacteria. This phenomenon of bacteriolysis is perhaps 

 associated with the pectosinase secretion and is also observed in the 

 hay-bacteria. 



The essential difference between G. urocephaluni and G. pectino- 

 vorum is that the former with ammonium-salts as source of nitrogen, 

 can ferment all kinds of carbohydrates, such as glucose, milk-sugar, 

 cane-sugar and dextrine, for which G. pectinovorum requires peptone 

 or broth. On the other hand, pectose is so little attacked by G. uroce- 

 phahim that fermentation cannot be observed with this substance, 

 even not when broth is present as source of nitrogen. Trypsine- 

 formation is ^^'illl G. u. about as vigorous as with G. p. and much 

 more abundant than with G. sacchaivbutyricum. The secretion of 

 diastase, on the other hand, is extremely feeble in both species and 

 much less vigorous than in the butyric-acid ferment. 



12. Accumulation experiment for G. urocephalum. Why the butyric 

 cicid- und the lactic-acid ferment.-^ disappear from good flax-rottings. 



That G. pectinovorum so strongly accumulates in our "current-" 

 and "decanting experiments", reposes on the double ada})tation of 

 this ferment, on the one hand to the insoluble albuminoids of the 

 flax-stalk by a strongly peptonising enzyme, on the other hand to the 

 insoluble pectose by the secretion of pectosinase. 



Why G. urocephalum also accumulates in the flax, but much' less- 

 strongly, and why the common and vigorous butyric-acid ferment 

 disappears nearly completely, was made clear by the following accu- 

 nudation-experiment for (r. urocephalum, devised by Mr. G. van 

 Itkrson, at the occasion of a researeli on the butyric-acid fermentation. 



If to any carbohydrate, for exam})]c insoluble starch, glucose, 

 cane-sugar, or milk-sugar, a slight quantity of egg-albumine or peptone, 

 or very little broth, is added as nitrogen source, in the proportion: 



Ta|>water 100, Glucose 5, Albumiuo 0.1, K^HPO^005, (!halk 5, 



infected with garden-soil and cultivated in a sto|)i)ored bottle at 

 35" C, there will first, that is so long as soluble carbon compounds 

 are still present, originate a butyric fermentation, but this is soon 

 replaced by a Urocephahi m-fevmenisinou. 



If from the thus obtained first fermentation a small drop is 

 transported into the same mixture, the butyric-acid ferment, indeed, 

 does not completely disapj)ear, but the intensity of the Uroceplialum- 

 fermentation becomes therebv much enhanced. If at the end of the 



