276 



U. SUZUKI. 



portion of the leaves was gathered from the same branches 

 10— 14 days later. Both samples were now carefully compared 

 in regard to their nitrogen contents. As in this period nitrogen 

 compounds migrate from the leaves into other organs in larger 

 quantities and more quickly than they are formed by synthesis, 

 the leaves must show a considerable decrease in the amount of 

 nitrogen, and this decrease must be greater if the migration is 

 quicker. This method would, of course not be applicable in the 

 growing season, when the synthesis of proteids in the leaves 

 surpasses the intensity of transportation. Another method of 

 comparison was as follows: In late autumn, portions of leaves 

 from a healthy and a diseased plant were taken and directly 

 dried at 5o c C, while the plants were covered with large black 

 paper cylinders and kept thus in the dark for 10—14 days. 

 Hereby the synthesis of proteid, was suppressed, since glucose, 

 the product of carbonic acid assimilation is hereby absolutely 

 required. The results were as follows : — 



Oct. 15—26. Takasuke. Kept normal, not in dark. 



Healthy. Diseased. 





Oct. 15 



Oct. 26 



Oct. 15 



Oct. 26 





26 



25 



25 



25 



Fresh weight 



48.8 



4i.3 



18.80 



20.6 



Dry weight 



19,711 



16.309 



6.948 



6.816 



Moisture 



59-6% 



60.5 



63.1 



66.9 



Dry matter 



4o. 4 % 



39-5 



36-9 



33-1 



Fresh weight of one laef. ... 



1.88 



1.65 



0-7S 



0.82 



Dry weight ,, „ ,, 



0.76 



0.65 



0.28 



0.27 



Ratio of dry matter ,, ,, ... 



100.0 



85.5 



100.0 



96.4 



Total nitrogen „ ,, ... 



0.0293 



0.0223 



0 00997 



0.0103 



This table clearly shows that the nitrogen compounds are 

 transported far more quickly from the healthy leaves than 

 from the diseased ones. In the former case nearly 14.5% of 

 the dry matter and 2$.g% of the nitrogen disappeared from the 

 leaves during 11 days, while in the latter case only a decrease 

 of 4% of dry matter and no decrease of nitrogen was observed. 



