NATURAL BACTERIAL SYSTEM 273 



Just as the behavior towards the different sugars is one of 

 the most valuable characteristics of the acid-forming bacteria, 

 so the relation to the different amino-acids can be used to divide 

 the ammonia-forming bacteria, and this probably is the way to 

 arrive at a closer division of the genus Bacillus. 



The use of the term Clostridiuin as a generic name presents the 

 inconvenience that under the same we must group together not 

 only the Clostridia but also the plectridia. The division into 

 true butyric acid bacteria {Butyriclostridium) , the requirements 

 of which in regard to nitrogenous nutriment are very moderate 

 (they are able to assimilate even the nitrogen of the air) and 

 anaerobic, putrefying bacteria {Putriclostridium) seems natural 

 to me. 



As all Pseudomonades — so far as I know — are completely or 

 partially decolorized by Gram, it is reasonable to seek a connec- 

 tion with the peritrichic bacteria among the Gram-negative 

 representatives of the latter group, and it ranges naturally from 

 the denitrificating species of the genus Fluormonas to the denitri- 

 ficating species of the genus Bacterium. The development then 

 from here has gone farther in one direction to the putrefying 

 bacteria, characterized by breaking down amino-acids, and in 

 the other direction to the lactic acid bacteria, which are not able 

 to attack amino-acids, but demand the most complex nitrog- 

 enous nutriment. 



REFERENCES 



Barthel, C. 1917 Zeitschrift fiir Garungsphysiologie, 6, 13-17. 



Breed, R. S., Conn, H. J., and Baker, J. C. 1918 Jour. Bact., 3, 445-459. 



Buchanan, R. E. 1917 Jour. Bact., 2, 155-164, 347-350. 



BuRRiLL, T. J. AND Hansen, R. 1917 111. Agr. Exp. Stat. Bull. 202. 



Orla-Jensen, S. 1907 Det kgl. danske Videnskabernes Selskabs Oversigter, 



No. 5. 

 Orla-Jensen, S. 1909 Centralblatt f. Bacteriologie, 2 Abt., 22, 305-346. 

 Orla-Jensen, S. 1914 International Dairy Congress at Bern. 

 Rogers, L. A., Clark,W. M., and Davis, B. J. 1914 Jour. Infect. Dis., 14,411-475. 

 WiNSLow, C.-E. A., AND OTHERS 1917 Jour. Bact., 2, 505-566. 



