24 HARPER: PLANT POPULATION OF MICHIGAN 
C. Kedzie. The jack pine plains. Mich. Exp. Sta. Bull.37. 8 pp. 188 
. M. Coulter. in Ge. al comparison of some typical swamp areas. Rep. Mo. 
Bot. Gard. 15: 38-71. pl. 1-24. 1904. (See pp. 41-49 for Michigan 
B. E. Livingston. gle: relation of soils to natural vegetation in EEA and 
Crawford Counties, Michigan. Bot. Gaz. a 22-41, with map. Jan. 1905. 
Also in Rep. Mich. Geol. Surv. 1903: 9-30. pl. 
H.H. Rusby. Observations in economic seiciins at Oscoda, Michigan. Jour. N. Y. 
ot sees Sept. 1906. 
W. J. Geib. Soil survey of Wexford County, Michigan. Field Operations U. S. 
Bur. Soils 1908: 10 51-10 066. 1911. (Advance copies, separately paged, dis- 
tributed in October, 1909.) 
S. Whitaker. A vacation in northern Michigan. Forest & Stream 77: 806-807. 
Dec: 2, 
Hu Max a ad. -using industries of Michigan. (State publication, no series or 
number.) 101 pp.,2folded tables. Lansing, 1912. (The notes on this region are 
mostly on pp. 7-10. See criticism in Proc. Soc. Am. Foresters 11: 350. 1916. 
Frank Leverett. Surface geology and agricultural conditions of 8 southern penin- 
sula of Michigan. (With a chapter on climate by C. F. Schneider.) Mich. Geol. 
& Biol. Surv. Publ. 9 (Geol. Series 7). 144 pp., 15 plates saad 3 folded maps), 
16 figs. 1912 
F.C. Gates. The vegetation of the region in the ig tate of Douglas Lake, Cheboy- 
gan County, Michigan, 1911. Rep. Mich. Acad. Sci. 14: 46-106, with 24 half- 
tones on 17 plates. 1913. 
H. A. Gleason & F. T. McFarland. The introduced vegetation in the vicinity of 
Douglas Lake, Michigan. Bull. Torrey Club 41: 511-521. Oct. 1914. 
az. Se Gates. The relation between evaporation and plant succession ina given area. 
Am. Jour. Bot. 4: 161-178. f. 1-9 (including 5 half-tones). March, 1917. (Area 
igan.) 
H. A. Gleason. Some effects of excessive heat in northern Michigan. Torreya 17; 
176-178. Oct. 1977. 
The plant population statistics given below are based on notes 
taken by the writer while occupying the post of research assistant 
in botany at the Biological Station of the University of Michigan 
in the summer of 1912. Most of the observations were made while 
walking out in all directions from the station (which is on Douglas 
Lake), as far as Cheboygan and Topinabee on the east and Pellston 
on the west. Copious notes were also taken from trains on the 
Michigan Central R. R. from Cheboygan to Mackinaw City, on 
the Grand Rapids & Indiana Ry. from Cadillac and Mackinaw 
City to Pellston, and on the Pere Marquette R. R. from Petoskey 
southward to the limits of the region and beyond. 
Geology and soils.—The whole of lower Michigan is underlaid 
by nearly horizontal Paleozoic strata, largely limestones and 
shales of Devonian and Carboniferous age, but in the region under 
