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; M^l. 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; 

 C;has. 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. Manus ; H. 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 



