-YU- 



(12) IlcCall, A.G. The physiological balance of nutrient 



solutions for plants in sand cultures. Soil 

 Sci. 2:207-253. 1916. 



Idem. The physiological requirements of wheat and soy 

 beans growing in sand media. Proc. Soc. Prom. 

 ..^ric. Sci. 1916:46-59. 1916. 



(13) McOall, A.G.,and Richard, P. 5. Mineral food requirements 



of ?/heat plant at 'different stages of its 

 development. Jour. Amer. Sod . Agron. 10:127-134. 



1918. 



(14) Hichards, P.E. See HcGall, A.G. , and Richards, P.E. 



(15) Schreiner, Q.^ana Skinner, J.J. Ratio of phosphate, 



nitrate, and potassium on absorption and grov/ th . 

 Bot. Gaz. 50:1-50. 1910. 



Idem. Some effects of harmful organic constitiients. 

 U.S. Jept. Agric. Bur. Soils Bui. 70. 1910. 



Idem. The triangle system for fertilizer experiments. 

 Jour. Amer. Soc. Agron. 10:225-246. 1918. 



(16) Skinner, J.J. See Schreiner, 0. and Skinner, j. J. 



(17) Shive, J. ',7. A study of the physiological balance in 



nutrient media. Physiol. Res. 1:327-397. 1915. 



Ideuu A study of physiological balance for bvxclmheat 

 gro'7n in three-salt solutions. I'. J. Agric. lap. 

 Sta. Bui. 319. 1917. 



(18) Shive, J.'..'.; and I.Iartin, V;.K. a comparison of salt 



requirements for young and mature buckv;heat plants 

 in v;ater cultures and. sand cultures. Amer. Jour. 

 Bot. 5:186-191. 1918. 



(19) Tottingham, "' .E. A quantitative chemical and physiological 



study of nutrient solutions for plant culture. 

 Physiol. Res. 1:133-245. 1914. 



Idem. See Livingston, B.E..and Tottingham, ''-.F.. 



(20) True, R.H. Ilari-iful action of distilled water, nnev. Jour. 



Bot. 1:255-273. 1914. 



(21) True, R.M. ,and Bartlett, H.H. Absorption ard excretion of 



salts by roots, as influenced by concentrations and 

 composition°fculture solutions. U.S. Dept. iigric. 

 Bur. Plant Ind. Bui. 231. 1912. 



