lO 



G. Oaikuhai'u an<1 T. Iinacekl. 



B. Sugar content in the leaves of paddy rice with different manures. 



Thus we see that the first assumption by Nagaoka was not justified. 



Some tests were made by Nagaoka with regard to the second cause^ 

 rendering however further observations desirable and we have therefore 

 further studied the behavior of swamp plants towards nitrate, being certainly 

 of considerable theoritical and practical importance. 



With the denitrifying organisms in a wide sense the following groups 

 may be distinguished after Jensen'^ : 



" I. Reduktion von Nitraten zu Nitriten und Ammoniak (Salpeter- 

 reduktion). 



2. Reduktion von Nitraten zu Nitriten und niederiegeren, gasformigen 

 StickstofT-Sauerstoffverbindungen (N^O und NO). 



3. Reduction von Nitraten und Nitriten unter Abspaltung elementaren 

 Stickstoffes (Denitrifikation im engeren und eigentlichen Sinne). 



4. Umb'ldung des SalpeterstickstofTes in organische Verbindungen 

 (Salpeterassimilation). 



5. Freiwerden von Stickstoff bei der Faeulnis organischer Stickstoff 

 verbindungen." 



Denitrification will proceed much more energetically in moist land 

 than in dry land and also nitrates will be reduced to nitrites more 



i). Lafer, Handb. d. Techn. mycologie Band III., S. 182. 



