PREFACE 



This bulletin is designed to accompany the first bulletin of the 

 Chicago Geographic Society by Prof. Rollin D. Salisbury and Mr. 

 William C. Alden, and in many places it is assumed that the geographic 

 features of the Chicago area, as there outlined, are known to the 

 reader. The matter here presented has been gathered by the author 

 in the course of the past five years, and has recently been published in 

 the Botanical Gazette, essentially as presented here. 



The author desires to express his indebtedness to Mr. W. B. 

 McCallum, who has taken most of the photographs with which this 

 paper is illustrated. These illustrations, by common agreement, have 

 also appeared in the Botanical Gazette. Figs. 7 and 13 were con- 

 tributed by Prof. J. J. Allison of Joliet. Figs. 34, 35 and 36 have been 

 previously published by the author. The map shown in fig. jp appeared 

 in the first bulletin of the Chicago Geographic Society. 



