U. SUZUKI. 



peated cuttings. This view has been tested by numerous ex- 

 periments, and no doubt remains in my mind of its correctness. 

 Moreover, experiments have shown that the same disease can 

 also be induced by excessive plucking of the leaves, 

 which would evidently have the same physiological effect as re- 

 peated cuttings of the stem. There is therefore no doubt that 

 the present disease is caused by nothing else but the deficiency 

 of reserve material. This, I believe, is proved by the analyses 

 and experiments detailed in the following pages. 



Chapter I. Chemical Composition of Healthy and 

 Diseased Plants. 



It is the object of this chapter to compare the chemical 

 composition of healthy and diseased plants and to find out 

 the characteristic differences between them. The samples used for 

 analysis were all taken from the mulberry farm of the Tokyo 

 Sericultural Experiment Station at Nishigahara. 



i. TSURUTA. MAY 6, 1S98. 



Healthy. Diseased. 



Number of stems 



1 1 



61 



Number of leaves 



627 



1880 



Average length of stem 



96.1 cm. 



45- 



Total fresh weight of stems 



656.6 g. 



919.0. 



Average fresh weight of 1 stem 



59-7 



15. 1. 



Total fresh weight of leaves 



143-25 



122.50. 



Average fresh weight of 1 leaf 



0.229 



0.065 



Total dry weight of leaves 



25.90 



25-83. 



Average dry weight of 1 leaf 



0.041 



0.04. 



Moisture in fresh leaves 



81.20 



78.14. 



Dry matter in fresh leaves 



18.S0 



21.86. 



Number of leaves on 1 stem 



57- 



3i- 



Dry matter in leaves of 1 stem 



2-355 



0.423 



In 100 parts of dry matter, 



Healthy leaves. Diseased leaves. 



Crude proteids 47.94 34-5 6 



Crude fats 1.92 3- IQ 



