AUTHOR'S PREFACE xv 



All the illustrations reproduced herewith are from 

 photographs taken by the author, excepting those 

 acknowledged below or credited in the text. To the 

 following the author desires to express his thanks : to 

 the Secretary of the California State Board of Horti- 

 culture, for photographs and drawings from which 

 Figs. 8 to ii inclusive, 13, 30 and 31 were reproduced; 

 to the Director of the California Experiment Station, 

 for permission to use electrotypes of Figs. 14 to 21 in- 

 clusive, 23, 45, and 46 ; to Mr. R. P. Cundiff, Horti- 

 cultural Commissioner Riverside District, California, 

 for photographs of Figs. 26, 27, 28, and 29 ; to the 

 Director of the New York Agricultural Experiment 

 Station, for permission to use photographs of Figs. 43, 

 79, and 80 ; to the Secretary of the Pennsylvania State 

 Board of Agriculture, for loan of electrotypes of 

 author's photographs; to Mr. D. M. Moore, of Utah, 

 for photograph from which Fig. 62 was made; to Prof. 

 William Lochhead, of the Ontario Agricultural Col- 

 lege, for photographs of Figs. 64 and 65 ; to Mr. W. 

 J. Allen, of New South Wales, for use of Figs. 75, 76, 

 77, and 78 ; to Dr. E. P. Felt, State Entomologist of 

 New York, for photograph of Fig. 81, and finally to 

 Mr. C. M. Heintz, editor of the Rural Calif ornian, 

 for photographs from which Figs. 82 and 83 were 

 reproduced. 



Although the author has taken unusual pains to 

 make this work technically correct yet popular in 

 style, there have, no doubt, crept in some mistakes. 

 When readers note any error, typographically or oth- 

 erwise, they will confer a great favor on the writer by 

 reporting same, so corrections can be made in future 



