Acknowledgments 



We wish to express our appreciation for the assistance 

 rendered by many individuals who contributed references, provided 

 corrections of citations, loaned originals or reprints of articles 

 for examination, or otherwise assisted in the preparation of this 

 bibliography. We are particularly indebted to the following per- 

 sons: Miss Margaret I. Smith, Chief Reference Librarian, and Hiss 

 nary E. Rollman of the staff of the University of Michigan Libraries 

 for their assistance in securing the originals, or reproductions, 

 of articles which were not available in that university library; 

 Mr. Harlan B. Holmes for assistance in locating the originals of 

 articles cited in his report on electric fish screens; Mr. Ellwood 

 G. Johnson who assisted in the preparation of portions of the bibli- 

 ography; and, Dr. Ralph Hile whose editorial advice guided the pre- 

 paration of this report. 



INT.-DUP. SEC, WASH.. D.C. 611)S9 



