THE PEAIEIES 239 



— Warming, Eugen. — Oeeology of Plants, English translation. Long 

 severe winters; hot and dry summers; low atmospheric humidity; 

 p. 2S5. 



1910 — Hopkins, Cyril I. — Soil Fertility and Permanent Agriculture. 

 Fires, p. 7S. 



1911 — Shimek, B. — Botanical Report (on Harrison and Monona counties, 

 Iowa). — Iowa Geological Survey, vol. XX, 1910 (issued February, 

 1911), pp. 426-174. The present paper is an elaboration of this. 



The following ecological papers are also of interest in this con- 

 nection : 



1898 — Pound, Roscoe and Clements, Frederic E. — The Vegetation Re- 

 gions of the Prairie Province. — Botanical Gazette, vol. XXA", 

 pp. 381-304. 



1899 — Cowles, Henry C. — The Ecological Relations of the Vegetation on 

 the Sand Dunes of Lake Michigan. — Botanical Gazette, vol. 

 XXVII, pp. 95-202 and 281-301. 



1900 — Pound, Roscoe and Clements, Frederic E. — The Phytogeography of 

 Xebraska. 



1901 — Thornber, John J. — The Prairie-Grass Formation in Region I. — 

 University of Xebraska Botanical Survey of Xebraska, pp. 

 29-143. 

 — Cowles, Henry C. — The Physiographic Ecology of Chicago and 

 Vicinity.— Botanical Gazette, vol. XXXI, pp. 73-108; 145-182. 



1903 — MacDougal, Daniel T. — Some Aspects of Desert Vegetation. — 

 Contributions from the Xew York Botanical Garden, no. 46. 

 — Transeau, Edgar N. — On the Geographic Distribution and Ecol- 

 ogical relations of the Bog Plant Societies of Xorthern America. 

 —Botanical Gazette, vol. XXXVL pp. 401-420. 

 — Schimper, S. W. — Plant Geography upon a Physiological Basis. — 

 pp. 593-598, etc. 



1904 — Clements, Frederic E. — The Development and Structure of Vegeta- 

 tion. — Vniversity of Xebraska. Botanical Survey of Xebraska, 

 VII. 



1905 — Transeau, E. N. — Forests of Eastern America. — Am. Xaturalist, 

 vol. 39, pp. 875-898. 



1906 — Bray, William L. — Distribution and Adaptation of the Vegetation 

 of Texas. — Bulletin of the L^niversity of Texas, no. 82. 

 — Livingston, B. E. — The Relation of Desert Plants to Soil Moisture 

 and to Evaporation. Xo. 50, Carnegie Institution. 



1907 — Daniels, Francis P. — The Flora of Columbia, Missouri, and Vi- 

 cinity.— The University of Missouri Studies, vol I. 

 — Hart, C. A. and Gleason, Henry A. — On the Biology of the Sand 

 Areas of Illinois. — Bulletin of the Illinois State Laboratory of 

 X'atural History, vol. VII. pp. 135-273. 



