January] BOTANICAL GAZETTE 52 



the herbaceous annual type (as pointed out by SlNNOTT and 

 Bailey in past evolution also), as best suited to the mobile environ- 

 ment furnished. 



The author desires to extend his thanks to Professor Henry C. 

 Cowles, of the University of Chicago, whose help and encourage- 

 ment have made the completion of this work possible. He also 

 wishes to thank Mr. Charles W. Fallass, of Petoskey, and Pro- 

 fessor Charles H. Swift, of the University of Chicago, for their 

 cooperation during the progress of the work. 



Oak Park, III. 



LITERATURE CITED 



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2. Brown, F. B. H., Forest associations of Wayne County. 19th Rep. 

 Mich. Acad. Sci. 209-217. 191 7. 



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4. Cooper, W. S., Climax forest of Isle Royale, Lake Superior, and its 

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 1899. 



6. , Physiographic ecology of Chicago and vicinity. Bot. Gaz. 



31:73-108, 145-182. 1901. 



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8. ■, Relation between evaporation and plant succession. Amer. Jour. 



Bot. 4:161-178. 1917 



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10. — — — , The plant association. Bull. Torr. Bot. Club 44:463-481. 1917. 



11. — ■ — • — ■, Development of two plant associations in northern Michigan. 

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12. Gleason, H. A., and McFarland, F. T., Introduced vegetation in -the 

 vicinity of Douglas Lake, Michigan. Bull. Torr. Bot. Club 41:511-521. 

 1914. 



13. Harper, R. M., Car window notes on vegetation of the Upper Peninsula 

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Torr. Bot. Club 41:551-567. 1914. 



