PREFACE vii 



Industry, for figures 18 a and 18 b ; to Passenger 

 Dept. S. P. Lines in Oregon for figure 173 a; to Mr. 

 Paul Shoup for figures 7, 15, 25, 158, 159, 163, 165, 

 166, 168-172, 174, 177, 179; to the Phoenix Board of 

 Trade for figure 16; to the U. S. Forestry Bureau 

 for figures 18, 175, 176, and 178; to Prof. A. G. McAdie 

 for figures 77 (photograph by Prof. J. E. Church), 78, 

 80 (photographs by Professor Ellerman), and 81; to 

 Dr. B. T. Galloway for figures 19, 31, and 160; to the 

 Walla Walla Commercial Club for figure 24; to the 

 German Kali Works, New York, for figure 76 (from Wag- 

 ner's Dungetafeln) ; to Mr. J. W. Sievers for figure 161 ; 

 to the Utah Experiment Station for figures 162 and 

 164; to Mr. Colvig for figure 167; to the Sunset Magazine 

 Home Seekers' Bureau, Portland, for figure 173; to 

 the Yakima Commercial Club, Washington, for figure 

 15 a; to Mr. J. E. Peabody for figures 184-186; to 

 C. P. Bailey & Sons for figure 199; to the De Laval 

 Separator Co. for figure 198; to Prof. L. H. Bailey 

 for permission to take from the Cyclopedias of Agri- 

 culture and of Horticulture, as well as from the 

 Rural Science Series, figures 10, 30, 32, 33, 36, 37, 38, 

 40, 43, 46, 47, 49, 52-57, 182, 183, 187-197, and 

 200-209. 



The portions of this book dealing with the physical 

 and chemical aspects and the practice of Agriculture 

 have been written by E. W. Hilgard; the biological 

 and physiological portions, by W. J. V. Osterhout. 



