TAKEWO HEMMI 279 
of tannin are subject to disease is no argument against the preceding. The 
organism may live in tissues which bear little or no tannin, or which contain 
other substances that in a measure counteract the influence of the tannin. 
Furthermore, some species of fungi are much more resistant to tannin than 
others, and the species which attack these high tannin-bearing plants no doubt 
possess this quality." 
Clinton (191 3) 5) , who studied the effect of tannic acid on the chestnut 
blight fungus, Endotliia parasitica, and saprophytic Endothia gyrosa in arti- 
ficial cultures, asserts in his summary that both fungi can use tannic acid, at 
least in small amounts, as food. He also says : "To the writer it has occurred 
that possibly tannin may serve as an unusual source of food for certain trees 
rich in this product under unfavorable conditions for active formation of their 
normal food supply, such as drought years, and that such a use would lessen 
the supply of tannin laid down in the annual growth of wood formed in these 
years. Or possibly if not used for food, these unusual conditions do not 
favor its normal production. In any case, if tannin content bears a relation 
to the blight disease, it is not the tannin of the whole tree that counts so much 
as the tannin of the bark and wood of that year's growth. If it bears any 
relation to the chemical activity of the tree, we can readily see that it could 
easily vary from year to year according to external conditions more or less 
favorable for its production." 
b. Tannic Acid Cultures. 
To prove the above statements by Cook and Clinton, I made three series 
of cultures; one was prepared after Clinton's method which was used in 
his study of the chestnut blight fungus, and in the two others I used the 
corn-meal-agar after Cook's formula. I have always used for these cultural 
experiments the pycnospores produced on the fresh cultures of the causal 
fungus isolated from Prunns yedoensis. 
Experiment I. 
In this case, I used potato-juice-agar as the standard medium. At first 
