192 BOTANICAL GAZETTE [march 



improbable when we reme 



compounds easily derived from alcohol, e. g., acetic acid, ethyl acetate, 



potassium acetate, fumi 



fimcnis 



It is also possible that the 



spores 



in the culture fluid, although it is difficult to see how a substance can 



same time 



poison. At first sight the cultures containing .both ethyl acetate and 



seem to bear 



formation 



fruit. In such cultures 



ever, it is probable that the more nutritious alcohol was absorbed 

 first, and largely to the exclusion of the acetate. Further work is 

 necessary to give a complete explanation of this unusual nhenomenon. 



be 



respect 



in the course of this investigation 



the great individual difference of resistance of spores to deleterious 



agents. 



substances 



growth, practically all spores germinated, forming a dense matlike 

 growth over the surface of the culture fluid. When, with increase of 

 concentration, the substance becomes deleterious, germination and 

 growth are not stopped abruptly, but the number of colonies becomes 

 fewer and fewer until the final concentration is reached, where germi- 

 nation of even the most resistant spores is inhibited. In most cases, 

 where only a few colonies were formed, these grew wath unusual vigor, 



o 



culture was often as great 



concentrations 



This was especiaUy weU shown in the series with potassium 



XV 



comparatively few spores germ 



hi^er concentrations, forming isolated floating colonies. Yet the 

 • " from these was equal to the vield from other flasks which were 



uniformly 



seems to indicate that the mycelium 



the more resistant spores continues itself to be more vigorous 



true 



although it is not impossible that the belief 



nere ; that is, while the concentration in aay given case may be 

 mjunous to germination, it does not interfere with later development. 



