On the Assimilation of Nitrogen from Nitrates and 

 Ammonium Salts by Phaenogams. 



BY 



Y. Kinoshita, Nsgakushi. 



There exist many observations on the development of plants, 

 as to whether nitrogen is supplied in the form of nitrates or in 

 that of ammonium salts. One would naturally expect that 

 ammonium salts would be the better source of nitrogen, because 

 nitrates would have to undergo reduction to ammonia before 

 assimilation proper (formation of proteids) could take place, thus 

 causing not only loss of time, but also the waste of such organic 

 material (most probably glucose) as serves for this reduction. 

 But, contrary to expectation, nitrates have been found in many 

 cases to act more favourably than ammonium salts. This result 

 may be due to the noxious qualities which ammonium salts 

 have in a higher concentration than that immediately needed 

 in the cells. Nitrates can be stored up in roots and stems, 

 but ammonium salts cannot. The question, therefore, presents 

 itself, as to the form in which the nitrogen of ammonium salts is 

 stored up, when these salts are absorbed in greater measure than 

 that required for the immediate wants of the plant. 



Asparagine has been frequently found in the roots and bulbs 

 of many plants, but it has not been positively ascertained yet, 

 whether this compound is in these cases a decomposition 

 product of proteids, as it is in germination, and in the starva- 

 tion of plants kept in the dark. Some authors have assumed 

 that this asparagine is formed in the leaves by the action 

 of nitrates upon carbohydrates, and is then transported to 

 the roots, while others have supposed its synthetical formation 

 in the roots, leaving entirely unsettled whether nitrates, 

 or ammonium salts, or both, equally well contribute to its 

 formation. 



