INTRODUCTION. IX 



tional part of the work was practically all done by him, with what 

 assistance Doctor Bishop And the author could give him. No one 

 who has not done work of this kind can appreciate the mass of detail 

 to be handled and the expert knowledge necessary to handle it 

 properly. 



Finally, thanks are due to the author's devoted wife, Madeleine 

 V. Bent, for many weary hours of painstaking work in typewriting, 

 reading, and correcting manuscript and in proof reading. 



No one is so well aware of the many shortcomings and omissions 

 in this work as the author. Allowance must be made for the magni- 

 tude of the undertaking. If the reader fails to find mentioned in 

 these pages some things which he knows about the birds, he can blame 

 himself for not having sent them to 



The Author. 



