PREFACE 



i. THIS booklet is to be regarded as in no sense a com- 

 ^ plete history of the science of plant pathology. The 

 author has endeavored only to set forth in outline what 

 appear to be the most outstanding features in the evo- 

 lution of the science, an^_lo_indicate the proper rela- 

 tion thereto of the men jvho have chiefly shaped its 

 progress. 



Tile 1 literature upon which a complete history of plant 

 \ pathology must be based is here largely brought to- 

 gether for the first time. It is hoped that this sketch 

 may be elaborated later into a more complete and critical 

 presentation of the subject. 



^ The author desires to express his appreciation of the 



N assistance of numerous friends and colleagues in the 



preparation of this book; to a number of them, and 



especially to Dr. Erwin F. Smith, for photographs, im- 



i portant historic data, and a final criticism of the com- 



3 pleted text; to Dr. L. R. Hesler and Dr. C. H. Kauff- 



t mann for critical reading of the manuscript. 



H. H. WHETZEL. 



CORNELL UNIVERSITY, ITHACA, N. Y. 

 May, iQi8. 



