xii Preface 



stration Dairy Farm and Prof. Tom Carter, Bureau of 

 Soils, United States Depart of Agriculture. The chapter 

 on birds has been reviewed by Prof. Carl Hartman, 

 Superintendent of Public Instruction in Travis county, 

 Texas, and Mr. T. Gilbert Pearson, Greensboro, N. C., 

 Secretary of the National Association of Audubon Socie- 

 ties. Acknowledgements are also due to Dr. W. D. 

 Hunter, Bureau of Entomology, United States Depart- 

 ment of Agriculture, for assistance and suggestions in 

 the chapters dealing with the economic insects. We 

 are glad to acknowledge the valuable assistance and 

 criticisms that have been given by the persons named 

 above, and Bothers. 



The illustrations have been selected for their accuracy 

 and educational value. They have been drawn from 

 various sources, and to the gentlemen and firms who 

 have supplied or allowed the use of the illustrations we 

 wish to extend our thanks. Many of the illustrations 

 have been reproduced from publications of the United 

 States Department of Agriculture, and the several 

 state agricultural experiment stations. We are indebted 

 to Mr. Philip H. Hale, St. Louis, for figures 137, 138, 

 139, 146, 147, and 148, taken from his excellent book of 

 "Live Stock Champions," and to Suburban Life for fig- 

 ures 152 to 156 and 158. Other acknowledgements are 

 made in connection with particular illustrations. 



THE AUTHORS. 



