284 U. SUZUKI. 



16. Jumonji, root bark, air dry 0.5 gram. 





Healthy. 



Diseased. 



After 2 hours. 



6.0 



4.0 



]/. Akagi, (cut in summer) root bark, air dry 0.5 gram. 





Healthy. 



Diseased. 



After 2 hours. 



1.0 



4.0 



We see from the above tables that the diseased leaves 

 contain generally much catalase, but there are still some 

 exceptions ; and further the air dried leaves develop oxygen 

 always less energetically than the fresh ones, hence I can not 

 draw any safe conclusion until further experiments can be 

 made next summer. 



According to Loew, there are two kinds of catalase, one 

 soluble, and the other insoluble in water, the latter being 

 perhaps a kind of nucleo-proteid. In the leaves of the mulberry 

 there exist also these two kinds. The soluble catalase develops 

 oxygen very quickly but stops very soon. On the contrary, 

 the insoluble catalase develops oxygen slowly but continues 

 longer. The action of soluble catalase is almost destroyed by 

 5 minutes heating to 70 C C, but after standing for 2-3 hours, the 

 activity somewhat returns and from 0.1 gram., 5 cc. of oxygen 

 were developed in two hours by frequent shaking. In another 

 experiment the pulverized leaves were heated to yo°C for five 

 minutes and filtered, the filtrate at that time had no activity, 

 which however after standing for 48 hours developed about 

 5 cc. oxygen in two hours. This was also the case when some 

 chloroform was added as an antiseptic. 



Influence of cutting upon the decay of roots. 



The decaying of small rootlets and finally of the entire root 

 system is one of the most remarkable phenomena of the mul- 

 berry dwarf disease, and many have believed it to be due to 

 parasites. But as I have already discussed in my former report, 



