154 Illinois State Laboratory of Natural History. 



quickly deepeniug, considerable cui-reut, a little vegeta- 

 tion, west bank of mud, low and wooded, steeply slop- 

 ing, water almost without vegetation, decided current. 

 I. Bed of the "Slough,'' with grass, rushes, and wil- 

 lows, and a very shallow stream of spring water when 

 river is low. 



F. Phelps Lake; verj' shallow, often entirely dry 

 mud, almost no vegetation, dead water, shores densely 

 wooded. 



G. Thompson's Lake; exposed sandy shore, moder- 

 ately sloping, grass and considerable aquatic vegeta- 

 tion, bottom of lake muddy, dead water. 



K. Flag Lake; shallow, muddy, bordered with rushes, 

 thick with floating vegetation. 



LIFE AT THE DIFFERENT STATIONS. 



It is not too sweeping a statement to say that the 

 full lists for each station of every species observed there 

 during the year do not conspicuously differ. On the 

 other hand, variations in relative abundance of the 

 forms at each station and of the total life at each, 

 with the presence or absence of some prominent species 

 or group of species, impart an individuality to each 

 station. These lists are unusually large, and I have at 

 hand a much greater variety and number of species than 

 a single locality will usually furnish. It will be best 

 therefore to point out merely the leading differences, with 

 special refei-ence to the forms herein reported upon, 

 leaving the full treatment of the subject until the 

 material collected has been more fully studied. 



Evidently the main requ'sites of insect life are food and 

 protection from enemies. An abundant growth of 

 aquatic vegetation, therefore, supports a large number 

 and variety of insects; those which find in it food and 

 shelter, as do many Diptera and the case-flies, and 

 those which prey upon the plant-feeding forms and upon 

 each other while sheltered from vertebrate enemies. The 



