206 



The Plant World. 



problems connected with plant pathology at the present time, 

 a circular letter was sent to the pathologist or botanist of each 

 Station. A few university men who were more or less interested 

 in the subject were also included. I here wish to express mv 

 t hanks to the following men whose interesting, thoughtful 

 letters furnished so much material for this paper: SchafTner, 

 Ohio; Buckhout, Pennsylvania; Edgerton, Louisiana; Brookes, 

 New Hampshire; Heald, Texas (University) ; Swingle, Mon- 

 tana; Barre, South Carolina; Bolley, \orth Dakota; Norton, 

 Maryland; Freeman, Minnesota; Reed, Virginia; Jones, Vermont; 

 Ball, Texas; Rolfs, Florida; Beattie, Washington; Selbv, Ohio; 

 Ganong, Massachusetts; Garman, Kentucky; Barnes, Chicago 

 (University); Beal, Michigan. 



In the discussion of the various problems of plant pathology 

 I have endeavored to present the general concensus of opinion 

 as given in these different letters. The phases of the subject 

 which will be taken up are the recognized breadth of plant path- 

 ology, the permanency of the results of present investigations, 

 the effect of general cooperation, the real motives back of in- 

 vestigation work, repetition and superficial nature of many pub- 

 lications, non-development of pathology in our universities and 

 the probable future centers of activity. 



In the broadest sense plant pathology is one of the most far 

 reaching of botanical subjects. Although it has been one of 

 the last evolutionary processes, it has opened up new fields or 

 rather brought into greater prominence the weak points in 

 Physiology, Plant Chemistry and Physics, and consequently 

 there must now develop a revolutionary process. It is necessary, 

 for example, in the study of many so-called physiological dis- 

 eases that our knowledge of plant nutrition be worked out much 

 more completely. The normal functions must be exactly under- 

 stood before variations in conditions become evident. Con- 

 sequently in the development of plant pathology there is great 

 need for a closer application of chemistry and physics. "Plant 

 pathology combines pure botanical science with the practical 

 application of scientific principles. The standing of plant path- 

 ology as compared with other phases of botany has perhaps been 

 lowered on account of the tendency to over-emphasize the 

 practical side of the work." "Pathological investigations as 



