IV PREFACE 



in writing the book, yet an effort has been made to use our 

 own woods for illustrations and to adapt the subject-matter to 

 American conditions. 



The collecting of the illustrations has been greatly facilitated 

 by the kindness of Dr. L. N. Britton, Col. Wm. F. Fox, Prof. 

 J. A. Holmes, Messrs. Newell and Gannett of the United States 

 Geological Survey, Dr. J. T. Rothrock, Prof. N. Gifford, and 

 Mr. Gifford Pinchot, Chief of the Bureau of Forestry of the 

 United States Department of Agriculture. To these gentlemen 

 I extend my sincere thanks. 



Especial thanks are due to Mrs. Anna B. Comstock of the 

 Bureau of Nature Study of Cornell University, whose kind 

 interest and request called this book into existence. Her good 

 judgment has proved of great value in the arrangement of the 

 subject-matter, and her assistance in seeing the book through 

 the press has made its early publication possible. 



FILIBERT ROTH. 



