EDITOR'S NOTE 



MY father completed the writing of this last book of 

 his shortly before his death. It had become familiar to 

 me through copying his manuscript and in the trips we 

 took together to various nurseries and forest lands to test 

 the working power of his book. As a natural outcome of 

 this long and close association with him, the editing of it 

 has devolved upon me. He made the illustrations in 

 pencil, almost entirely from nature, and I have since 

 inked them in, at the request of the publishers. 



Grateful acknowledgments are due to a number of my 

 father's colleagues and friends for their assistance and 

 offers of help, and particularly to Professor John W. 

 llarshberger of the University of Pennsylvania, who has 

 given a last critical reading to the manuscript and the 

 proof sheets and has prepared the glossary and the index. 



ADA APGAR DRAYCOTT. 



