12 HISTORY OF PHYTOPATHOLOGY 



servations and interpretations of phytopathologic phe- 

 nomena as found in the preserved writings of the race. 

 There are, to be sure, a number of short papers or 

 chapters in books deahng with the subject, but they are 

 not at all comprehensive. One of the best is to be found 

 in the first volume of Sorauer's Handbuch der Pflanzen- 

 krankheiten (1909), a recent translation of which by 

 Miss Dorrance (1914) makes it available to the English 

 reader. Another interesting paper is that by Arthur 

 (1906), which gives one a very good notion of the ideas 

 of some of the earlier writers who undertook the organiza- 

 tion of our science. Count FiUppo Re, in the introduc- 

 tion to his essay on diseases of plants (1807), gives an 

 interesting list of phytopathologic writings prior to his 

 day. A preliminary survey of the field has been made 

 by Jensen (1909) in a thesis presented at Cornell Uni- 

 versity. 



We can best approach the subject through a chrono- 

 logic survey of the available data. This will insure a 

 logical consideration of the landmarks in the evolution 

 of the science and a sequential introduction of the men 

 who have shaped its progress. 



The history of phytopathology divides itself into eras, 

 and these again into periods. Each era is characterized 

 by a general and dominating point of view regarding the 

 nature, cause, and control of diseases in plants; the begin- 

 ning of each is marked by an epochal change in this point 

 of view. These changes from one era to the next come 

 as the result not only of accumulation and organization 

 of phytopathologic facts and theories, but are profoundly 

 affected, in fact often largely determined, by revolution- 

 ary discoveries in the fundamental sciences on which 



