OENBRAL INTRODUCTION. V 



eral and economic appendix, it will be so constructed as to 

 make it a practically independent manual of our economic or- 

 nithology, — using this tei'm in its broadest sense. 



The long delay in the publication of Volume I. has been due 

 partly to the pressure of other duties and to lack of ofBce 

 assistance, but chiefly to the destruction by fire in the printing 

 office, in February, 1887, of an entire edition of the volume 

 and of the plates and cuts from which it was printed. 



To the characteristic generosity of the honored and lamented 

 Dr. Spencer F. Baird, we owe the illustrations of this volume, 

 with the exception of the fi'ontispiece, — all being printed from 

 copies of cuts loaned to the Laboratory by the Smithsonian 

 Institution. 



S. A.*FORBES, 



Director of Laboratory. 

 Champaign, June 30, 1889. 



