52 BOTANICAL GAZETTE [january 



the herbaceous annual type (as pointed out by Sinnott 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 



J 



Rep. Mich. Forest. Comm. 1:25-29. 1888. 



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

 Mich. Acad. Sci. 209-217. 1917. 



3. Clements, F.E., Plant succession. Publ. 242, Carnegie Inst. Wash. 1916. 



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

 development. Bot. Gaz. 53:1-44, 115-140, 189-235. 1913. 



5. Cowles, Henry C, Ecological relations of the vegetation on the sand dunes 

 of Lake Michigan. Bot. Gaz. 27:95-117, 167-202, 281-308, 361-391. 

 1899. 



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



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



7. Gates, F. C, Vegetation of the region in the vicinity of Douglas Lake, 

 Cheboygan County, Michigan. 14th Rep. Mich. Acad. Sci. 46-106. 191 2. 



8, 



Bot. 4:161-178. 1917 



J 



9. Gleason, H. A., Vegetation of the inland sand deposits of Illinois. Bull- 

 Ill. State Lab. Nat. Hist. 9:23-174. 1910. 

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



>lant associations in northern Michigan. 



ii. 



Plant World 21:151-158. 1918. 

 Gleason, H. A., and McFarland 



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 

 of Michigan. 13th Rep. Mich. Acad. Sci. 193-198. 1913. 



14- , Superficial study of pine barren vegetation of Mississippi. Bull. 



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



