ACKNOWLEDGMENT 



While the authors drew their information to a large 

 extent from personal experience with the diseases dis- 

 cussed, the descriptions are necessarily largely compiled 

 and the authors wish to acknowledge their great indebted- 

 ness to the publications of the various State Agricultural 

 Experiment Stations and of the United States Department 

 of Agriculture. In many instances the words of the orig- 

 inal description are used, almost as quotations except for 

 slight modification for brevity or to secure a change of 

 sequence. In such cases the authors could not always 

 indicate the quoted words. They desire here to record 

 their special indebtedness to the writings of the following 

 investigators: Ralph E. Smith; G. P. Clinton; Mel. T 

 Cook; H. S. Fawcett; J. C." Arthur; F. D. Kern; C. W, 

 Edgerton; Ernst A. Bessey; J. B. S. Norton; E. M. Free 

 man; F. M. Rolfs; Chas. E. Bessey; E. Meade Wilcox 

 Chas. Brooks ; B. D. Halsted ; F. C. Stewart ; H. A. Har 

 ding ; J. G. Grossenbacher ; H. H. Whetzel ; B. M. Duggar 

 H. L. Bolley ; A. D. Selby ; Thomas F. Manns ; II. R. Ful- 

 ton ; E. W. Olive ; S. M. Bain ; L. R. Jones ; N. J. Giddings 

 H. S. Reed ; W. H. Lawrence ; J. L. Sheldon ; D. Reddick 

 Roland Thaxter; W. G. Farlow; M. A. Carlton; W. W 

 Gilbert; G. G. Hedgcock; Haven Metcalf; W. A. Orton 

 Mrs. Flora W. Patterson : W. M. Scott ; Erwin F. Smith 



