35 



much greater caution would have been necessary In discussing many 

 phases of the problem. 



ACKNOWLEDGMENTS 



The study of the Charleston area was carried out with the coop- 

 eration of the Illinois State Laboratory of Natural History, through 

 its director, Prof. Stephen A. Forbes, and with the further coopera- 

 tion of Professors E. N. Transeau and T. L. Hankinson, of the East- 

 ern Illinois State Normal School, located at Charleston. Personally I 

 am indebted to Professor Forbes for the opportunity of taking part in 

 this study as the State Laboratory representative, and for the aid he 

 has given in the illustration of the report. To Professor Transeau I 

 am particularly indebted for the plant determinations, for lists of the 

 plants, and for evaporation data. To Professor Hankinson I am 

 under especial obligation for many specimens, which materially added 

 to my lists, and for a large number of photographs. I am indebted 

 likewise to my associates in this study for their hearty cooperation 

 throughout the progress of the work. 



For the determination of entomological specimens I am indebted 

 primarily to Mr. C. A. Hart, Systematic Entomologist of the State 

 Laboratory of Natural History, who named most of the insects col- 

 lected. For the names of certain flies I am indebted to Mr. J. R. Mal- 

 loch, of this Laboratory. Others who have determined specimens are 

 as follows: N. Banks (Phalaugiida), J. H. Emerton (spiders), R. V. 

 Chamberlain (myriapods), F. C. Baker (Molkisca), Dr. W. T. M. 

 Forbes (lepidopterous larvae), Dr. M. C. Tanquary (ants). Dr. M. T. 

 Cook (plant galls), J. J. Davis {Aphididcc) , and Dr. A. E. Ortmann 

 (crawfishes collected by T. L. Hankinson). I am indebted to the U. 

 S. Geological Survey for photographs. Acknowledgments for illus- 

 trations are made under text figures and in explanations of plates. 



GENERAL DESCRIPTION OF THE REGION AND LOCATION 

 OF THE ECOLOGICAL STATIONS 



I. General Description of the Region 



The town of Charleston, Coles county, Illinois, in the vicinity of 

 which these ecologic studies were made, is situated on the Shelbyville 

 moraine which bounds the southern extension of the older Wisconsin 

 ice-sheet. To the south of this moraine lie the poorer soils which char- 

 acterize so much of southern Illinois ; to the north, upon the older Wis- 

 consin drift, are some of the most productive soils found in the upper 



