278 



U. SUZUKI. 



Ti c-c experiments clearly; show that the migration of 

 nitrogen compounds in the diseased leaves is very much slower 

 than in the healthy ones. 1 These observations perfectly agree 

 with the fact that the stems, roots and dormant buds in the 

 diseased plants contain always very little reserve materials 

 during the winter. 



On the existence of diastase in mulberry leaves. 



On Oct. 5, leaves gathered at Komaba were dried at 

 30— 40 C C, pulverized and ground well in a mortar with some 

 water, and then, after addition of some more water, filtered 

 after 2 — 3 hours. The extract was devoid of reducing sub- 

 stances. A few c.c. of this extract was added to a highly 

 diluted .starch paste and kept at 50— 55 C C for half an hour. 



A small amount of reducing sugar was now clearly 

 recognized in the extract of the diseased leaves, but only a 

 trace in that of the healthy ones (The healthy leaves contained 

 no starch, while the diseassd contained much.) 



Oct. 6. Jumonji, at Nishigahara, dired at room temperature 

 and powdered. Here neither the healthy nor the diseased 

 leaves showed any diastatic power (Here the healthy leaves 

 contained no starch, while the diseased contained it moderately.) 



Oct. 6. Akagi at Nishigahara. 



Diastase. Starch content. 



Healthy. Diseased. Healthy. Diseased. 



Morning 6 o'clrek none much none much 



Noon 12 „ none much very much much 



Evening 6 „ somewhat s >me\vhat somewhat much 



As the boiled extract in both cases produced no sugar, 

 the presence of diastatic ferment in the diseased leaves is 

 most probable. 



Oct. 2. Roso at Komaba, 5 grams air dry sample were 

 finely pulverized, ground with addition of water, diluted to 

 100 c.c, let stand for 24 hours and filtered. 2 c.c. of the filtrate 

 was added to 10 c.c. of starch paste and kept for one and a 

 half hour at 50°C. The extract of the diseased leaves reduced 

 nearly 10 c.c. of Fehling's solution, while that of the healthy 

 leaves reduced only half as much. In the control test, where 



1 I have not yet proved the existence of a proteolytic enzyme in the mulberry leaves, 

 yet its presence is very probable and the oxidizing enzymes may probably inhibit also 

 the action of it, as it is the case with diastatic ferments. 



