EVIDENCES(?) OF WATER-DEPOSITION OF LOESS. 37 1 



have known that the importance of plants on soil- and sand- 

 accum illation is recognized by plant ecologists.* 



This most important phase of the subject has already been 

 briefly discussed by the writerf in its relation to loess-forma- 

 tion, but a much more detailed presentation of the subject is 

 now in preparation. 



In his paper Professor Wright presents what he considers 

 certain objections to the aeolian theory. 



1. He says that "at Omaha the bluffs of loess on the west 

 side of the river are scarcely, if any, less in dimensions than 

 those of Council Bluffs on the east side .... As the prevail- 

 ing wind in this region is from the southwest, it would be 

 hardly possible for it to pile up such deposits of loess upon the 

 west side of the river, and especially upon the southwest side, 

 as at Kansas City." As a matter of fact if Professor Wright 

 will examine the bluffs of the Missouri from Sioux City to 

 Kansas City, he will find that they are, as a rule, higher, more 

 abrupt, and with thicker loess deposits on the east side, and 

 the same is true of the Mississippi.^ Where deviations from 

 this rule occur they may usually be readily explained by local 

 topographic features, and by meanderings in the river-valley, 



* Those who are interested in the plant ecology of wind- deposits will 

 find the following incomplete list of references of use: 



Cowles, H. C. , "The Ecological Relations of the Vegetation of the 

 Sand Dunes of Lake Michigan," Bot. Gazette, vol. xxvii, pp. 95, etseq.y 

 1899. "The Physiographic Ecology of Chicago and Vicinity, " 1. c. , 

 vol, xxxi, pp. 73, et seq. 



Rydberg, P. A., Cont. U. S, Nat. Herbarium, vol. iii, p. 135, 1895. 



Gifford, John, "The Control and Fixation of Shifting Sands," The 

 Engineering Magazine, Jan. , 1898. 



Schimper, Dr. A. F. W. , Plant Geographv, trans, by Wm. R. Fisher, 

 revised ed. , pp. 654—5, 1903. 



King, F. H. , "Destructive Effect of Winds on Sandy S°ils and Light 

 Sandy Loams," 11th An. Rep. Ag. Ex. Sta. , Univ. of Wisconsin, 1895. 



Udell, Geo. , The Strand Magazine for March, 1904, p. 176. 



tSee especially "Living Plants as Geological Factors," Proc. la. 

 Acad. Sci., vol. x, pp. 44-48, 1903. 



+ This fact is also reported by Leverett, Monograph U. S. Geol. Sur. , 

 vol. xxxviii, p. 156. 



