DISTRIBUTION AND HABITAT. 



11 



Analyses of soil samples taken from thi wild-rice beds near Bemidji, Minn. 



Analyses of soil samplesfrom mid-rice beds on Potomac flats. 



Analyse* of soil samplesfrom wild-rice beds at Chesapeake Beach, Md. 



oThis heading refers to the electrical resistance of the saturated soil. In a general war, the elec- 

 trical resistance of a saturated soil varies inversely with the content of soluble salts. Sec Bulletin 

 No. y . Division of Soils. I*. S. Department of Agriculture, "An Electric Method of Determining the 

 Soluble Salt Content of Soils," by Milton Whitney and Thomas H. Means; also see " Chemical Exam- 

 ination of Alkali Soils," by Atherton Seidell, page 65 et seq., in Bulletin No. 18, Division of Soils, 

 U. S. Department of Agriculture. "Solution Studies of Salts Occurring in Alkali Soils," by Frank K. 

 Cameron, Lyman J. Briggs, and Atherton Seidell. 



Water soluble constituents in soil samples from Chesapeake Beach, Md. 



Sample No. 1 was taken from near Bemidji. Minn. The lake bot- 

 tom at this point bore practically no vegetation except the wild rice 

 plants. The soil was hard and sandy and covered with a thin layer of 

 pine bark and debris. While the plants were not numerous, they were 

 vigorous and apparently doing very well. 



Sample No. 2 was also taken near Bemidji. Minn., from the midst 

 of a wild rice field where the water was 21 inches deep and the soil 

 was hard and sticky below a thin layer of soft mud. This layer of 

 soft mud, which the sample represents, was about 4 inches thick at 



