FORMATION OF ASPAR AGINE IN PLANTS. 



427 



In this table we see that the ratio of albuminoid nitrogen, etc. 

 is very low, but this does not indicate the decrease of these nitro- 

 gen compounds. The albuminoid nitrogen is only relatively 

 lowered, the total nitrogen being considerably increased. 



I sought to prove further that asparagine accumulates, even 

 in presence of much sugar, when some of the other necessary 

 agents for protein formation are wanting. For this purpose, the 

 young barley plants of about 32 CU1 - high, were first cultured in the 

 2 % sugar solution. After 7 days, a portion was directly dried 

 and analyzed, while another portion, was divided into three 

 equal parts, and cultured in the following solutions : — 



a. 0.2 % solution of urea. 



b. ,, ,, ,, sodium nitrate and 2 % sugar. 



c. ,, ,, ,, urea and 2 % sugar. 



The plants exposed to ordinary daylight, were after 7 

 days (March 26th, April 2nd) washed, dried, and analyzed : — 



Table XXVI. In 100 parts of dry matter : — 



Original* 1 ) , . Sodium nitrate Urea and 



plants. and sugar. sugar. 



Total nitrogen 4.60 6.09 5 64 5.98 



Albuminoid nitrogen 1.47 1.52 1.52 1.58 



Asparagine nitrogen 1.94 2.97 2.44 3.15 



Nitrate nitrogen 0.35 0.24 0.53 0.25 



In this case, it is seen that by offering sugar together with 

 urea, the asparagine nitrogen was increased considerably. By 

 the preliminary culture for a week in the sugar solution, some of the 

 conditions for protein formation had been removed, and, I suppose, 

 it was the sulphates, that were used up. Thus, all the am- 

 monium compounds had to be stored up as asparagine and could 

 not be transformed any farther. 



SUMMARY AND CONCLUSION. 



(1). Asparagine in plants has two sources :— • 



(a) . It is derived from the decomposition of proteids. 



(b) . It is a synthetical product of other nitrogenous 

 compounds : — 



(1) The quantitative determination of asparagine by the crystallization method was not 

 very satisfactory, as some slimy substance prevented a considerable portion from crystal- 

 lizing. 



