IMPLICATIONS 421 



compulsory as a consequence of competition and the desire to gain 

 recognition in a chosen field. 



The control of plant diseases is based mainly upon ( 1 ) preven- 

 tion and (2) natural resistance. Prevention may be accomplished 

 by attention to sanitary measures, rotation of crops, seed treat- 

 ment, establishment of quarantines, application of fungicidal 

 sprays and dusts, and other means. Natural resistance is sought 

 and isolated by selection and hybridization. Little has been done 

 in the field of chemotherapy, or the cure of plant diseases bv 

 chemical agencies, especially by the use of vaporous substances, 

 although this field of inquiry seems to offer inviting possibilities 

 for development. The principle involved in the use of chemicals 

 as therapeutic agents is the existence of a differential between 

 pathogen and suscept in tolerance for the chemical or drug. That 

 such studies have merit is indicated by results from the use of 

 benzol and related compounds in the cure of tobacco downy mil- 

 dew. Similarly the vapors of ethyl mercury chloride and ethyl 

 mercury phosphate have been found effective against Glomerella 

 gossypii in cotton-seed treatment [Lehman ( 1943) ]. It is of more 

 than passing interest to note that studies of chemotherapy in hu- 

 man diseases, beginning with the work of Ehrlich, resulted in the 

 discovery of only a few specifics until the recent introduction of 

 the use of sulphonamides and antibiotics oroduced by certain 

 fungi and bacteria. 



IMPLICATIONS 



Mycology and phytopathology, parent and offspring, respec- 

 tively, have not always worked together harmoniously. ' Seem- 

 ingly, parents have not learned to accept gracefully the counsel 

 and dictation of their children! The offspring have become 

 numerically larger than the parent, and as an outcome the irritat- 

 ing question of their relative importance has been raised. If their 

 relation were to become synergetic rather than antagonistic, both 

 mycology and phytopathology would profit. It is indicated that 

 such a development is in process of accomplishment. This end 

 could be attained most effectively and most rapidly if teachers 

 earnestly strove to impart instruction that not only embodied all 

 tradition, theories, and useful truth about fungi but also indicated 

 the relation of such knowledge to a balanced, well-rounded edu- 

 cation. Moreover, teachers with this viewpoint are true scientists 

 and cannot be nationalistic, for science, like literature, music, and 



