511 



things, if possible, determine former conditions and project those yet to be 

 introduced. 



The Leesburg swamp was selected. It is located in Kosciusljo County, 

 Indiana, one and one-fourth miles south of Leesburg on tlie east side of the 

 C, C, C. & St. L. R. R. It has an area of 02 acres. 



Tlie worlv was carried on under tlie general direction of Dr. C. H. 

 Eigenmann, director of the Indiana University Biological Station, and 

 under the immediate direction of Dr. O. W. Caldwell. I wish also to ac- 

 knowledge the assistance rendered by Mr. W. D. Curtis in collecting, and 

 Mr. A. M. Mahaffey for most of the accompanying photographs. 



Fig. 2. Sphagrniim. 



In this investigation Schimper's' division of ecological into climatic 

 factors and edaphic factors Avas assumed and the edaphic factors only 

 considered. 



One of the main purposes has been to test the theories and factors 

 proposed by Warming- and Cowles.^ 



1898. 



'Schimper, A. F. W.: Pflanzengeographie auf physiologisclier. Grundlage, Jena 



^Warming, E.: Plantsamfund. Copenhagen, 1895. 



'Cowles, H. C: The Physiographic Ecology of Chicago and Vicinity. Bot. Gaz., 1901. 



