LIBRARY 



~~ ~ NEW YORK 



CONTENTS. 



BOTANICAL 



GARDEN. 



PAGE 



Introduction 137 



Part I. Glacial Geology and General Characters of the Illinois Sand Areas, 



especially those of Western Illinois. By Charles A. Hart 139-148 



Glacial Geology 139 



Topography: General 144 



The Surface Sands 145 



Other Sand Areas 146 



Part II. A Botanical Survey of the Illinois River Valley Sand Region. By 



Henry Allan Gleason 149-194 



Introductory 149 



Ecological Factors , 149 



The Plant Associations 157 



The Bunch-grass Association 158 



The Blow-sand Association 162 



The Blowout Association 167 



Reversion to Bunch-grass 169 



The Black-jack Association 171 



Some Adaptations of the Plants to the Environment 178 



List of the Plants Observed 181 



Phytogeographical Relationships of the Flora 189 



Part HI. Zoological Studies in the Sand Regions of the Illinois and Missis- 

 sippi River Valleys. By Charles A. Hart 195-267 



( ieneral Features 195 



The Localities Visited 197 



Geographical Distribution of the Species 199 



Sand as a Factor of Animal Environment 208 



The Relation of Sand and Climate to Insect Coloration 211 



Local Distribution of Species in the Sand Areas. The Insect Associa- 

 tions 220 



Annotated List of Species 227 



Systematic Notes 255) 



Bibliography 268 



05 



