VI PREFACE 



fornia ; Prof. G. Macloskie of Princeton University ; Prof. W. 

 A. Locy of Northwestern University; Prof. J. G. Needham 

 of Lake Forest University; Dr. S. H. Scudder of Cambridge, 

 Mass. ; Dr. George Dimmock of Springfield, Mass. ; Dr. 

 Howard Ayers of Cincinnati, Ohio ; Dr. W. M. Wheeler of 

 the American Museum of Natural History, New York City; 

 Dr. W. L. Tower of the University of Chicago ; Dr. A. G. 

 Mayer, Director of the Marine Biological Laboratory, Tortu- 

 gas, Fla. ; James H. Emerton of Boston, Mass. ; Dr. and Mrs. 

 G. W. Peckham of Milwaukee, Wis. ; Dr. Henry C. McCook 

 of Devon, Penn. ; Dr. William Trelease, Director of the Mis- 

 souri Botanical Garden ; Dr. Henry Skinner, as editor of " En- 

 tomological News " ; the editors of " The American Natural- 

 ist " ; and W. Saville-Kent, of Wallington, England. 



Acknowledgments are further clue to the Boston Society of 

 Natural History, the, American Philosophical Society and the 

 Academy of Science^of St. Louis. 



Courteous permission to use certain figures was given also 

 by The Macmillan Co. ; Henry Holt & Co. ; Ginn & Co. ; Prof. 

 Carl Chun of Leipzig; F. Diimmler of Berlin, publisher of 

 Kolbe's Einfuhrung; and Gustav Fischer of Jena, publisher of 

 Hertwig's Lehrbuch and Lang's Lehrbuch. 



