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glacial migration of both plants and animals ; the determination 

 of the methods of competition between biotic associations belong- 

 ing to four great centers of distribution ; the relation of great 

 tension lines to the origin of species. 



The fundamental plan of such a survey should be geographic 

 and involve the entire state. Its methods should be ecological 

 and involve the study of both plants and animals from the point 

 of view of the habitat. Taxonomic work should be subordinated 

 to the investigation of biological problems. The bearing of such 

 work upon agriculure, horticulture and forestry is well known. 

 It is the one method of working up the biological resources of a 

 state which will give results valuable alike to theoretical and 

 applied science. 



Such a survey carried out under competent direction will pro- 

 vide a fund of information for natural history students through- 

 out the state; will be of assistance to every teacher of botany, 

 zoology and geography ; will aid in the solution of many biological 

 problems ; will advance our knowledge of the natural resources 

 of Illinois; will aid in their conservation; and will suggest the 

 proper methods for their development. 



A VIRGIN PRAIRIE IN ILLINOIS. 



H. A. Gleason. 



Twenty miles northeast of Champaign is a five-acre strip of 

 untouched prairie lying along a small stream. It contains a 

 large number of the rare species of prairie plants, notably 

 Cypripedium candidum and Liliuiit nmbclhitnni. It is highly im- 

 portant that the strip should be preserved, and negotiations to 

 that effect are already under way. 



