X THE PREFACE 



of the National Academy of Science. The account 

 set down here has been checked and often supple- 

 mented from the observations of more specialized 

 writers, to all of whom we are most grateful. 



We are indebted to Mr. Kenji Toda for making the 

 drawings; to Mr. James Zetek, United States ento- 

 mologist in the Canal Zone, Dr. F. E. Lutz of the 

 American Museum of Natural History, Dr. Curt P. 

 Richter of Johns Hopkins University, the United States 

 Army Air Service, and the Field Museum for permis- 

 sion to use photographs taken by them. The manu- 

 script was read and helpfully criticized by Miss Bertha 

 Morris Parker, of the University of Chicago Elemen- 

 tary School. 



Several authors and publishers have kindly allowed 

 us to copy drawings from their books. We are indebted 

 to the following: Cambridge Natural History, Organic 

 Evolution by R. vS. Lull, Vertebrate Zoology by H. H. 

 Newman, Medical Zoology by W. B. Herms, all pub- 

 lished by the Macmillan Company; Ants by William 

 M. Wheeler, published by the Columbia University 

 Press, and Social Life among the Insects, also by 

 Dr. Wheeler, and published by Harcourt, Brace & 

 Company. 



