MULBIiRRV-DWARF TROUHLES IN JAPAN. 



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Takasuke Diseased leaves contained 2 times as much or more peroxidase. 



Akagi „ „ 



Roso ,, „ 4-5 times more, healthy leaves contained only traces. 



Jumonji „ „ 2 „ „ 



Nezumigayeshi „ „ 2 „ „ 



Tsuruta „ „ 2 „ „ 



Shimanouchi „ „ much, while the healthy contained only traces. 



Yanagita „ „ more 



Yeijiwase „ „ very much 



Ichihei „ „ „ „ 



Oct. 29. Roso. At Komaba. Diseased leaves contained 

 very much. 



We see from the above results that the diseased leaves 

 contain always much more peroxidase than the healthy ones ; 

 but here I must mention that all the above samples were taken 

 in October and never earlier in the year. It will be necessary 

 to repeat these experiments once more with the leaves of early 

 summer, though I have no doubt that essentially the same 

 results will be obtained. The root bark of the diseased plants 

 also contains sometimes much more oxidase than that of the 

 healthy ones. 



Some experiments were also made to see whether zymogens 

 of the oxidizing enzymes exist in the plant cells, but no 

 decisive result has thus far been obtained. 



As we have already stated, the transportation of starch in 

 the diseased leaves is very slow and sometimes becomes almost 

 insignificant and much of it is therefore retained in the leaves. 

 This is one of the most characteristic phenomena of the mulberry 

 dwarf disease. This fact was repeatedly observed by Prof. 

 Miyoshi by means of the jodine test. I have also stated in my 

 former report that much of the assimilation products in t lie 

 diseased leaves remains unchanged there. Miyoshi gathered the 

 leaves in the early morning and at 3 o'clock in the afternoon, and 

 compared the amount of starch. He found in the healthy leaves 

 almost always no starch in the morning but very much in the 

 afternoon ; in the diseased leaves, however, he found no essential 

 difference in the starch content at different hours of the day. 

 This shows that the starch formed in the healthy leaves during 

 the day time is completely dissolved during the night and fur 

 the most part transported to other organs, while one portion is 

 consumed by the respiration process. The migration of starch 



