326 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1945 



Here we seem to have a linking up of different lines of research 

 in such a way that we may expect considerable progress. The recogni- 

 tion of the chemical constitution of a substance produced by a common 

 soil fungus which suppresses the growth of a plant pathogen suggests 

 that greater precision may soon be given to many of the older observa- 

 tions on fungal antagonism of various kinds. Incidentally, it may 

 also have some bearing on the question of natural compost versus 

 chemical fertilizers. There is a difficulty in establishing the growth 

 of antagonistic organisms in the soil ; this can be done only by modify- 

 ing the conditions, and an obvious way to do this is to add manure 

 or compost which favor fungal growth. That the matter is not quite 

 so simple as it appears at first sight, however, may be judged from 

 the fact that Barnum in 1924 showed that the filtrate of cultures of 

 Penicilliwm expansum caused wilting in certain herbaceous plants 

 placed in it. 



No more than mention can be made of the production by fungi of 

 fats, ethyl alcohol, lactic acid, vitamins, and enzymes, or of the im- 

 mense fermentation industries of the Orient. 



