236 NATURAL HISTORY BULLETIN 



per (1903), p. 593). Prairies at first forested, but forests de- 

 stroyed by Indians for buffalo pastures. 



— Tarr, Ralph S. and McMurry, Frank M. — Geographies, Second 

 Book. Probably once wooded, but forest destroyed by fires 

 set to frighten bison, etc. 



— Winchell, Alexander— Walks and Talks in the Geological Field, — 

 2nd ed. Same as first (1886). 

 1891 — Call. R. E. — Annual Reports of the Geological Survey of Arkan- 

 sas, vol. II. Not difference in drainage, pp. 72, 73. Forest en- 

 croaching on prairie, p. 149. 



— McGee, W. J. — Pleistocene History of Northeastern Iowa. — United 

 States Geological Survey, vol. XL Fires pp. 208, 297. Geological 

 (prairie on drift). Inequality in rainfall, p. 297. 

 1892— Shaler, N. S.— The Origin and Nature of Soils. Report U. S. 

 Geological Survey for 1891. Neither fineness of soil nor great 

 lakes (p. 323), but dry seasons, and then fires. 



— Fernow, B. E. — Report of the Chief of the Division of Forestry 

 for 1891. Dry hot and cold winds are bane of trees, p. 207. 



— MacMillan, Conway — The Metaspermae of the Minnesota Valley. — 

 Geological and Natural History Survey of Minnesota, Botanical 

 Series, vol. I. Along Minnesota valley trees are scant or ab- 

 sent on north bluffs. 

 1894 — Macbride, Thomas H. — Trees of Allamakee County (Iowa) — Iowa 

 Geological Survey, vol. IV, pp. 115-116. Fires only one of the 

 factors, conditioned on moisture. 



— Redway, J. W.— The Treeless Plains of the United States.— 

 Geographical Journal, vol. III. Quoted by Warming (1909), p. 

 353. Fires. 



— Winchell, Alexander — Walks and Talks in the Geological Field. 

 3rd edition, revised by Frederick Starr. — Same as second edition 

 (1890). 

 1895 — Pammel, L. H. — Trees of Boone County (Iowa). — Iowa Geological 

 Survey, vol. V. Soil and geological formations, p. 233. 



— Upham, Warren — The Glacial Lake Agassiz. Monographs of the 

 U. S. Geological Survey, vol. XXV. Fires, pp. 46, 604. Rainfall, 

 p. 605. Prairie plants, pp. 606-610. * 



— Bush, B. F. — Notes on the Mound Flora of Atchison County, 

 Missouri. Sixth Annual Report of the Missouri Botanical Gar- 

 den, pp. 121-134. Prairie flora of the loess hills. 

 1896 — Moore, Willis L. — Some Climatic Features of the Arid Regions. 

 U. S. Department of Agriculture, Weather Bureau. Relative 

 humidity for U. S. Maximum winds for plains region. 



— Shaler, N. S. — Aspects of the Earth. Not fineness of soil, p. 286. 

 Partly drouth and partly fire, p. 288. 



— Macbride, Thomas H. — Notes on Forest Distribution in Iowa. — 

 Proceedings of the Iowa Academy of Sciences, vol. Ill, pp. 96-101. 

 Fires and nature of soil. 



