Can Old Leaves of Plants Produce Asparagine 

 by Starvation? 



BY 



T. Miyaehi, Nogakushi. 



It lias been asserted that only young plants or growing parts 

 of plants, as germinating seeds or buds, can produce asparagine 

 by decomposition of proteids. 



As it seemed to me of some interest to test the validity of 

 this assertion, I selected, on the 1st October, some old leaves of 

 Pceonia albiflora, which by some brown spots clearly showed 

 incipient decay. 



A portion was directly dried at IOO" C, and served for the 

 determination of total nitrogen, protein nitrogen, and asparagine 

 nitrogen. On the same day, another portion was very loosely 

 placed in a glass vessel, containing a little water, and covered 

 by a glass plate. From time to time fresh air was introduced. (1) 



The microscopical examination, repeatedly carried on, re- 

 vealed a gradual disappearance of the starch granules from the 

 mesophyll (the epidermis cells were free from it at the beginning), 

 and also a gradual decrease of the active albumin, stored up in 

 the vacuoles, as the test, made with caffeine, indicated/ 2 ' 



On the 15th October, the leaves were dried, all brown 

 dead portions being first removed. Active albumin was still pre- 

 sent in the healthy parts, although in much smaller quantity than 

 at the beginning ; but soluble passive albumen could not be 

 found/ 3 ' 



The results were as follows : — 



Fresh leaves. Starved leaves. 



Total nitrogen. 1.364% \.dfi2% w 



Protein nitrogen. 1 .312 0.801 



(1) The mean temperature was 17.68' C; the maximum 25.4'', and the minimum 

 n° C. 



(2) Cf. this Bulletin vol. II. No. 2 and 4. 



(3) I crushed some of the leaves with some water, filtered and heated the filtrate 

 with a little nitric acid, but no precipitate was obtained. 



(4) From this relative increase of nitrogen, it follows that 6.70 per cent of the origin- 

 al dry matter were consumed in the respiration process. 



