4 FUNGOUS DISEASES OF PLANTS 



diseases of plants, — persons who should be, at the same time, 

 appreciative of the problems of disease control. Incidentally it may 

 be noted that plant diseases were, for the most part, understood 

 to be of fungous origin. In the United States this was more or less 

 coincident with the organization of a section of Plant Pathology in 

 what was then the Division of Botany at Washington, and with the 

 development of plant pathological work in many of the state ex- 

 periment stations. In a very short time there was unusual activity 

 in this study throughout the country. There was also much stimulus 

 to the further development of the work in Europe, and the outcome 

 was that the foundations were laid for a more careful study of the 

 fungi from a phytopathological point of view. In this country the 

 work was directed more especially toward immediately practical 

 ends, and that which was accomplished within a brief period of time 

 through the efforts initiated by Scribner and Galloway was remark- 

 able. In more recent times the work has also been put upon a 

 higher plane, and investigations along broader and more funda- 

 mental lines have gone forward rapidly at many points throughout 

 the country, so that to-day the extent of the organization and equip- 

 ment for research in this field is better than may be found anywhere 

 else in the world. It is perhaps fortunate that this work in the 

 United States has developed in conjunction with the agricultural 

 experiment stations, although, when the equipment in men, books, 

 and apparatus was new, many mistakes were made. This associa- 

 tion of the work insures that the direction of it will be at least 

 more practical than if confined more or less to investigations carried 

 on in botanical gardens or herbaria. It is perhaps to be regretted 

 that there cannot be more unity of action, or cooperation, in the 

 study and control of epidemic diseases. This, however, may be 

 brought about in the course of time. 



Some aspects of modern plant pathology. It is very evident from 

 the nature of the study, as well as from the historical notes which 

 have been presented, that an analysis of the modern work in plant 

 diseases indicates several important aspects, which may be grouped 

 in the following category : (i) mycological relations ; (2) anatomical 

 effects ; (3) physiological relations ; (4) control measures. 



Mycological relations. The mycological aspect will be concerned 

 more particularly with a minute investigation of the fungi from 



