310 MINNESOTA BOTANICAL STUDIES 



vicinity, a study of the origin, development and classification 

 of plant societies. Bot. Gaz. 31 : 73-108, 145-182. 1901. 



32. . The causes of vegetative cycles. Bot. Gaz. 51 : 



161-183. 1911. 



33. Darton, N. H. Preliminary report on the geology and water 

 resources of Nebraska west of the one hundred and third 

 meridian. U. S. Dept. Interior, Geol. Surv., Prof. Paper 17. 

 1903. 



34. Drabble, E., and Lake, Hilda. The osmotic strength of 

 cellsap in plants growing under different conditions. New 

 Phytologist 4:189-191. 1905. 



35. Free, E. E., and Westgate, J. M. The control of blowing 

 soils, U. S. Dept. A^gri., Farmer's Bui. 421. 1910. 



36. Gerhardt, P. Handbuch des deutschen Diinenbaues. 1900. 



37. Gleason, H. A. The vegetation of the inland sand deposits 

 of Illinois. 111. State Lab. Nat. Hist. Surv. Bui. 9:23-174. 

 1910. 



38. Harshberger, J. W. An hydrometric investigation of the in- 

 fluence of sea water on the distribution of salt marsh and estu- 

 arine plants. Proc. Am. Phil. Soc. 50: No. 201. 1911. 



39. Harvey, L. H. Floral succession in the prairie-grass forma- 

 tion of southeastern South Dakota. Bot. Gaz. 46 :81-108, 

 277-298. 1908. 



40. Hedgcock, G. G. The relation of the water content of the 

 soil to certain plants, principally mesophytes. Bot. Surv. 

 Neb. VI. 1901. 



41. Hitchcock, A. S. Methods used for controlling and reclaiming 

 sand dunes. U. S. Dept. Agri., Bur. Plant Ind., Bui. 57. 1904. 



42. Jentzsch, A. P. 54 in "Handbuch des deutschen Diinenbaues" 

 by P. Gerhardt. 1900. 



43. Jennings, O. E. An ecological classification of the vegetation 

 of Cedar Point. Ohio Nat. VIII., No. 6. 1908. 



44. Kellogg, R. S. Forest belts of western Kansas and Nebraska. 

 U. S. Dept. Agri., Forest Service, Bui. 66. 1905. 



45. Livingston, B. E. The relation of desert plants to soil mois- 

 ture and evaporation. Carneg. Inst. Washington, Publication 

 No. 50. 1906. 



46. Massart, J. Esquisse de la Geographic Botanique de la 

 Belgique. 1910. 



47. Merriam, C. Hart. Life zones and crop zones of North 



