PREFACE Vli 



ically, is simple and therefore useful. The authors have 

 attempted to discuss the diseases of each fruit somewhat in 

 the order of their general importance and occurrence in the 

 United States. Obviously, however, this arrangement is diffi- 

 cult to follow. 



Some difficulty has been encountered in compiling certain 

 parts of this book. The authors have had no opportunity to 

 become acquainted with several of the diseases under field 

 conditions. But in some instances inaccuracies have been 

 eliminated by a careful criticism of the manuscript by com- 

 petent men from other sections of the country. Many other 

 parts of the manuscript have been read by colleagues in the 

 Department of Plant Pathology at Cornell University. To 

 the following contemporaries the authors would express their 

 appreciation for valuable assistance along this line : Dr. H. 

 M. Fitzpatrick, Mr. E. F. Hopkins, Professor H. S. Jack- 

 son, Dr. W. H. Rankin, Dr. Donald Reddick, Dr. J. R. 

 Schramm, Dr. V. B. Stewart and Dr. J. L. Weimer. For 

 specimens from which some of the photographs were made, 

 and for other accommodations, the authors would make 

 acknowledgment to the following : Dr. J. T. Barrett, Pro- 

 fessor H. P. Barss, Dr. Charles Brooks, Mr. H. F. Dietz, 

 Mrs. L. R. Hesler, Dr. F. D. Kern, Professor W. H. Law- 

 rence, Dr. T. F. Manns, Mr. G. W. Martin, Mr. J. W. Roberts, 

 Professor W. H. Sackett, Mr. F. N. Wallace, Dr. F.. A. Wolf 

 and Mr. L. A. Zimm. For photographs loaned to the writers 

 due credit is given in each case. 



LEX R. HESLER. 

 H. H. WHETZEL. 



CORNELL UNIVERSITY, 



ITHACA, NEW YORK, 



October 1, 1916. 



