Hall, Inc., was very cooperative in having two or 

 three and occasionally four people read various 

 chapters, and two persons read the entire manu- 

 script. The final manuscript was expertly edited 

 by Oren Hunt, whose help was invaluable. 



Illustrations come from several sources. I am 

 most grateful to Dr. Victor E. Shelford for sup- 

 plying many drawings originally published in his 

 Animal Communities of Temperate America 

 (1913); to the Illinois Natural History Survey 

 for original illustrations from several of their 

 publications; to the U.S. Forest Service who al- 

 lowed me to select what I wanted from their ex- 



tensive file of photographs; to the Friez Instru- 

 ment Division ; to the University of Wisconsin 

 News Service, to a number of individuals for sup- 

 plying photographs or other illustrative material 

 for which acknowledgement is made in the legends 

 of the figures, and to Colleen Nelson, Katherine 

 Little, and Nan Brown for preparing special 

 drawings. 



University of Illinois 

 Champaign, Illinois 



Preface 



