CAN OLD LEAVES OF PLANTS PRODUCE ASPARAGINIC 459 



Fresh leaves. Starved leaves. 



Asparagine nitrogen. 0.037 0.206 



Amido-nitrogen except asp. nitrogen. 0.015 °-455 



In 100 parts of total nitrogen. 

 Fresh leaves. Starved leaves. 



Protein nitrogen. 96.19 54-79 



Asparagine nitrogen. 2.71 14.09 



Amido-nitrogen except asp. nitrogen. 1.10 31.12 



We observe, therefore, the proportion between asparagine 

 nitrogen in fresh leaves and that in starved leaves is I : 5.2. (1) 



The second experiment was made with tea leaves. 



On the 19th October I collected old leaves of The a chine/isis 

 for the determination of total nitrogen, protein nitrogen, and as- 

 paragine nitrogen. At the same time numerous small branches 

 (about 10 cm. long), taken from the same individual plant, were 

 placed in a large vessel containing some fresh water, which was 

 placed in the dark for 24 days' 2 ' (Oct. 19th to Nov. 12th). All 

 the young leaves had been first removed. While the branches 

 were kept in darkness, the water in the vessel was renewed 

 several times. 



Microscopical examination repeatedly made, revealed, as 

 usual, the gradual disappearance of the starch granules and the 

 decrease of active albumin, which was present in large quantity 

 at the beginning. Soluble passive albumin was not present at 

 all, as the test of the cold aqueous extract with nitric acid showed. 



Since some leaves commenced to show brown spots, on the 

 1 2th November and further exposure was likely to end soon in the 

 death of all the leaves, I dried the still healthy ones, and sub- 

 jected them to the same examination as the control leaves at the 

 beginning. 



(1) Young leaves of this plant, collected in May, contained according to Daikuhara 

 (Bull. Coll. of Agr. II. No. 2) 2.222% total nitrogen, and 2.648% after 25 days' starvation 

 by being kept at 25 0 — 30°C in darkness in a covered glass vessel containing some water, 

 hence the loss by respiration amounts to 16.09% in 25 days which when calculated to 15 

 days become 9.65%. The intensity of respiration in these young leaves was therefore 

 about one and half times as much as in the old leaves. The asparagine nitrogen was 

 there at the beginning 9.86% of the total nitrogen ; after 25 days, however, it became 

 45.73%. The proportion between asparagine nitrogen in fresh leaves and in starved 

 leaves was there 1:46. 



(2) 'I he mean temperature was I3.31°C, the maximum 23. 7.C. and the minimum 

 3-2°C. 



