580 WESTON 



in their practical applications, they have led to more effective measures of 

 prevention and control through the use of inert and immune materials where 

 possible, through the increasingly effective application of more efficient and 

 more persistent fungicides, and through alteration of the essential material 

 to render it less vulnerable, as in the case of the acetate and butyrate modifica- 

 tion of cellulose and the impregnation of vulnerable materials with invul- 

 nerable melamine and urea-formaldehyde resins. 



In the case of antibiotics, a field essentially mycological, stemming from 

 Fleming's perceptive recognition of this previously unappreciated aspect of 

 fungus activity, the development of higher-yielding strains of Penkillium, the 

 improvements in the production of penicillin and the extension of its applica- 

 tions, have marked notable advances. Also, although penicillin still retains its 

 paramount importance, there have been other valued additions to the thera- 

 peutic armament of the medical profession, derived not only from the more 

 typical and well-defined filamentous fungi, but also from the Actinomycetes 

 of less sure taxonomic position. There also has been an interesting and promis- 

 ing extension from the application of antibiotics in the control of the diseases 

 of human beings to their application in the control of diseases of crop plants. 

 An additional application, of interesting potentialities but only recently de- 

 veloped and still in its experimental stages, has been the use of antibiotics 

 in the feed of chickens, livestock, and other domestic animals. 



Even from the foregoing brief, condensed, and abridged review, it is clear 

 that this association of man and microbes, this exploitation by mycologists 

 of the powers and potentialities of the fungi, this combination of the imagina- 

 tion, resourcefulness, and ingenuity of man with the diversit}^ versatility, and 

 cooperation of the fungi has been a contributive and productive association 

 yielding results of value to Botany and to Biology in the last half century. 



The evidence extrapolates to the prospect and the probability that during 

 the next fifty years this will continue and will develop into ever-extending 

 areas in fruitful fields as yet unknown. 



Yet it should be remembered that if man does not control the chaos he has 

 contrived and fails to direct the course of his destiny; if man, through unheed- 

 ing employment to destructive ends of the tremendous, superhuman powers 

 he has discovered and developed, should finally destroy himself; then the 

 fungi unhindered and unheeding will continue their many activities undisturbed 

 and will remove the fragments of man's failure, the debris of his disaster and 

 destruction, the remains and the wreckage of his recklessness, until they 

 obliterate all traces of man himself. 



The responsibility rests with us, not with the fungi, and whether we con- 

 tinue in our successful utilization of their potentialities or whether we fail 

 and are ourselves removed by them depends on us. 



