498 



U. SUZUKI. 



In this case also, a little decrease of nitrates nitrogen in the 

 plants kept in the dark, was observed. 



SUMMARY AND CONCLUSIONS. 



1) Nitrates can be assimilated by Phaenogams in perfect 

 darkness. 



2) Sugar has great influence upon the reduction of nitrates. 

 When the available amount of sugar is insufficient, the nitrates are 

 not assimilated. This is one of the reasons why contradictory 

 results have been obtained by various authors. 



3) Proteids can be formed from nitrates in perfect darkiiess 

 when the conditions are favorable, that is, when much sugar is 

 present in the plant cells. 



4) The intermediate product between nitrates and proteids 

 is most probably, asparagine, which accumulates when the condi- 

 tions for protein formation are imperfect. 



5) The reason, why my results differ from those of Godlewski, 

 is, that lie did not cjdtivate his plants in sugar solution. He found 

 that the nitrates can be converted into non-albuminous nitrogen 

 compound, but he did not ascertain what compound it was. 



6) Laurent's results have been subjected to some critical re- 

 marks by Godlezvski with whom I agree, 



7) After this investigation was finished Zaleski published 

 some preliminary results, showing also the possibility of protein 

 formation in darkness. (Ber. Botan. Ge^ellschaft. (1897) 75 536). 



ANALYTICAL DATA. 



Total nitrogen was determined according to Kjeldalils 

 method. 



Albuminoid nitrogen, according to Stut.'^ers method. 

 Asparagine nitrogen by that of Sacchsse. 

 Nitrates nitrogen by that of Tiemann and Schidz. 



