vi PREFACE 
Waid of the Michigan Agricultural College, both of 
whom read the entire manuscript and made many valu- 
able suggestions and criticisms. Acknowledgment is 
also due Dr. William Frear of The Pennsylvania State 
College for assistance in connection with the chapter on 
Mushrooms, and to Mr. Harold Ware, a practical and 
scientific grower of mushrooms, who made many timely 
comments on this subject; to Dr. C. W. Stoddart of The 
Pennsylvania State College for reading the section on 
fumigation with hydrocyanic gas; to Prof. J. F. Adams 
of The Pennsylvania State College, who read the notes on 
diseases affecting lettuce, tomato and cucumber; to Prof. 
R. W. DeBaun of Rutgers College and B. C. Haines of 
Norfolk, Virginia, for data furnished relating to culture 
of frame crops; and to Miss Julia C. Gray for editorial 
services. 
Most of the illustrations were made by the author upon 
visits to commercial establishments, and we gratefully 
acknowledge the courtesies extended in this connection 
by a large number of growers, including M. L. Ruetenik, 
Cleveland, Ohio; Searles Brothers, Toledo, Ohio; 
Chauncey West, Irondequoit, N. Y.; Dunbar and Hop- 
kins, Ashtabula, Ohio; J. H. Rice, Ashtabula, Ohio; R. 
Hittinger, Belmont, Mass.; Wyman Brothers, Arlington, 
Mass.; F. J. Zuck, Frie, Pa.; W. H. Weinschenk, New 
Castle, Pa.; H. H. Mishler, Johnstown, Pa.; and others. 
We are indebted to Kroeschell Bros. Co., Chicago, II1., 
for illustrations Nos. 1, 148 and 149; to H. F. Tompson, 
Arlington, Mass., for illustration No. 2; to Lord and 
Burnham Company, New York City, for illustration 
No. 8; to Hitchings & Company, New York City, for 
illustration No. 10; to John A. Evans Company, Rich- 
mond, Ind., for illustration No. 19; to Skinner Irri- 
gation Co., Troy, Ohio, for illustrations No. 26 and 54; to 
R. W. De Baun of Rutgers College for illustrations Nos. 
27, 183, 185, 140, 141, 148, 144 and 145; to C. O. Jelliff 
