PREFACE 



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, and to indicate the proper rela- 

 tion thereto of the men who have chiefly shaped its 

 progress. 



The 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 

 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- 

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

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

 mann for critical reading of the manuscript. 



H. H. Whetzel. 



Cornell XjNrvERSiTY, Ithaca, N. Y. 

 May, igi8. 



