( -±07 ) 



steeping of the ilax in water, tliat is in the white- and the blue- 

 I'Ottin^. 



Tn the dew-rotting a most unequal product is obtained ; this 

 process shall not further be discussed here. 



In the blue-rotting in ditches and ponds, as also in the white-rotting, a 

 so-called anaerobic bacterium is the active agöiit. This highly interesting 

 organism belongs to the genus Granulobacter and shall be called G. pec- 

 tinovorum ^) {(Jj) fig. 2). At the present moment the whole rotting indus- 

 try is nothing else but a more or less rational culture-method of 

 this bacterium. 



From a theoretical point of view it is interesting that there are 

 also some aerobic bacteria w^itJi which rotting is possible with free 

 access of air. These are the various kinds of the so-called hay- 

 bacteria group, also known by the name of potato-bacteria, the chief 

 species of which are Bacillus mesentericus vulgatus, B. subtllis, and 

 Granulobacter (Bacillus) poly my xa (= B. solaniperda Kramer). 



4. Arramjement of the rotting experiments in the laboratory for the 

 examination of microbes in pure culture on their power of rotting. 



In order to ascertain if any microbe can be used for rotting it is 

 necessary to dispose of perfectly sterile flax. This is obtained b}' 

 heating the flax for some time at 125 — 130° C. in the steam sterilis- 

 ator, whereby it is seen that it is not rotted at all by this overheating. 



For the laboratory experiments with the "anaerobes", thick walled 

 test-tubes were so closely filled with flax, washed out or not, that 

 the pressure against the glass-wall prevents it from mounting up 

 whon the tube is further filled with w^ater. After cotton-plugging 

 tlio tilled tubes are sterilised in the sterilisator. 



It is true that in these tubes air can penetrate from above, but 

 if the [»ieces of the flax-stalks are not too short, say 20 cm., the entrance 

 of air is not noxious to the anaerobes, provided some ordinary aerobic 

 microbe be added, which lives at the surface and there absorbs the 

 oxygen. We always used to this end a Torula yeast. 



For testing the aerobic microbes the flax is spread in a thin layer 

 at the bottom of a wide ERLENMEUER-flask, and after immersing in 

 a little water the whole is sterilised, after cooling infected with the 

 species concerned and cultivated at 35"*, or lower, in accordance with 

 the microbes to be examined. After 2 or 3 dajs the rotting is finished. 



2) First discovered by Winogradsky (Comples rondus T. 121, pag. 742, 1895). 

 Störmer (Miltlieil. der deulschen Landwirlhschafts Gesellschaft Bd. 32, pag. 193 

 1008) used for it the name of Pleclridium pedinovorum. 



31 

 Proceedings Royal Acad. Amsterdam. Vol. VI. 



