26 ■ ^ ^— :iü JUS ir. Vi ifi tu « *. i'f. 6'] m ^ 



III nld cultures, tlic fungus j)roduccs brown coloured chlamydospores. 

 Sometimes in some mycelial cells the wall thickens and turns brown by 

 the deposition of a hniwn jiigment. 'I'hej- are known as " Dauelmycel." 



I have never found higher fruiting bodies of this fungus on my cultural 

 media, but the results of the further experiments tell us that the fungus has 

 very strong resistance to the unfavorable outer conditions, especially the 

 chlamydospores may be said to be almost absolutely insensitive to any 

 imaginable natural liad conditions In an unfavourable condition, the mj'cc- 

 lium forms chlam}'dospores or " Dauelm}cel," the cell of the conidium itself 

 changes to a chlamydospore, or the conidia by germination immediately 

 produce chlann'dospores or " Dauelmjxel." 



For such strong adaptabilitj' and resistance to several food conditions 

 and unfavorable influences, the lack of higher fruiting bodies is no disad- 

 vantage to the life of the fungus in nature, and it causes an obstinate soil 

 disease. 



n. Tannin Culture 



The effects of tannic acid on fnngi have attracted the attention of many 

 authors and considerable work on this problem has been done. Tannin has 

 been supposed to be a byproduct of the metabolism of plants, and it ser\'es 

 more or less as a j:)rotective agent against the attacks of organisms. 



Pfeffer (1897) sav's that tannins are undoubtedly produced for definite 

 purjioses, ai-^d are not a mere byproduct produced under all circumstances. 

 Cook (1911) also says that tannin serves no doubt as a protective agent. 

 Clinton (191 3), who studied Endothia parasitica and Endothia gyrosa, 

 noticed that these two fungi can use tannic acid, at least in dilute solutions, 

 as food. T. Hemmi (19 15), who made studies on Valsa japo)iica, says in 

 his summary that the fungus grows more luxuriantly on cultures containing 

 a low percentages of tannic acid than without it, but high percentages of 

 tannic acid inhibit its growth entirely. 



It seems to me somewhat unlikely that the tannin production of plants 

 has any ecological meaning. It would seem much more natural and rational 

 to think that tannin is produced in the bodies of plants merely as a b)-pro- 



