PREFACE V 



E. W. Kemmerer of Princeton University, both of whom 

 read the manuscript and were during its preparation con- 

 stant sources of advice; and to the following gentlemen 

 engaged in the citrus industry : Mr. F. O. Wallschlaeger, 

 Secretary of the Citrus Protective League, who answered 

 queries innumerable and placed the library of the League 

 at the writer's disposal; Mr. P. J. Dreher, Manager of the 

 San Antonio Fruit Exchange, and Mr. D. G. Arbuthnot, 

 Manager of the La Verne Orange Growers Association, 

 for constant courtesy and much necessary information, and 

 particularly to Mr. G. Harold Powell, General Manager of 

 the California Fruit Growers Exchange, whose criticism 

 of the manuscript was invaluable. Finally, to my father, 

 Mr. J. F. Cumberland, whose profound knowledge of the 

 citrus industry has been freely drawn upon, my thanks are 

 rendered. . For efficient aid in reading the proof, and pre- 

 paring the index thankful acknowledgments are made to 

 my wife. W. W. C. 



January 2, 191 7. 



