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 11 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. H. P. Felt, State Entomologist of 
New York, for photograph of Fig. 81, and finally to 
Mr. C. M. Heintz, editor of the Rural Californian, 
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 
