222 



U. SUZUKI. 



The sap of Jumonji contained far less nitrogen than that of 

 Obata. The composition of the sap may therefore be very differ- 

 ent according to varieties, time of gathering and other conditions. 

 The nitrogen contained in the sap may come partly from the 

 reserve materials in the roots and partly from the freshly 

 absorbed nutriments. I have not determined the exact quantity 

 of the sap that flows out from one plant, as it is rather difficult. 

 But it is plain enough that Takasuke and Tsuruta furnish a far 

 greater quantity of it than Jumonji, which fact may have some 

 significance for the resisting capacity of these varieties towards 

 the disease, though I do not believe it has so much influence 

 upon the disease as many suppose. 



The numerous facts above mentioned are in full accord with 

 my view. 



I must here add a few words on a case that I have observed 

 very often, viz. that the cut ends of the stems decay and the 

 putrefaction preceeds between the wood and the bark towards the 

 inner part, and interrupts the connection between the vascular 

 bundles of the old stems and those of the new shoots, and thus 

 prevents a free circulation of the nutriments into the growing 

 shoots. For a time I thought that this putrefaction was the 



Sometimes the disease appears on plants which have never been cut, or on young 

 plants which has not yet attained the age of cutting ; but these cases are very rare and 

 may have some special cause, either attack of fungi or insects, etc , or some physiological 

 abnormality. I have analyzed a young plant which has never been cut, but some 

 ieaves of which showed signs of the disease, and obtained the following results :— 



Leaves. Stems. 





Healthy. 



Diseased. 



Healthy. 



Diseased. 





... 342 



3°4 



2 «5 



2 00 





... 2.94 



2-37 



1.50 



'•53 



Non-albuminoid nitrogen 



... 048 



0.67 



0.65 



0.47 



Ash 





8.6 



6.0 



6.1 





Leaves. 



Stems. 





Healthy. 



Diseased. 



Healthy. 



Disensed. 







88.8 



100.0 



93 2 







80.6 



»» 



102.2 



Non-albuminoid nitrogen 



... ti 



1404 





72-3 



Ash 





80.4 



11 



101.0 



Thus we see that the diseased leaves and stems are considerably poorer in nitrogen. 

 So we may conclude that the disease appears when the nitrogen supply is reduced beyond 

 a certain limit, whatever the efficient cause may be. 



