238 PLANT PHYSIOLCGY 



Miller, E. C. "Plant Physiology," Chap. IX. McGraw-Hill Book 



Company, Inc., New York. 1931. 

 MuRNEEK, A. E. Physiological role of asparagine and related substances 



in nitrogen metabolism of plants. Plant Physiol., 10: 447-464, 1935. 

 Nightingale, G. T. The nitrogen nutrition of green plants. Botan. Rev., 



3 : 85-174, 1937. 

 Osborne, T. B. "The Vegetable Proteins." Longmans, Green & Com- 

 pany, New York. 1924. 

 Rayner, M. C. Mycorrhiza. New Phytologist Reprint 15, 1927. 

 RoBBiNS, W. J. The assimilation by plants of various forms of nitrogen. 



Am. Jour. Botany, 24: 243-250, 1937. 

 Russell, E. J. "Soil Conditions and Plant Growth." Longmans, Green 



& Company, London. 1937. 

 Seifriz, W. "Protoplasm," Chap. XXV. McGraw-Hill Book Company, 



Inc., New York. 1936. 

 Teller, G. L. Changes in nitrogen compounds in the wheat grain at 



different stages of development. Plant Physiol., 10: 499-509, 1935. 

 Thomas, W. The nitrogenous metabolism of Pyrus malus L., III. Plant 



Physiol, 2: 109-137, 1927. 

 Tied JENS, V. A. Factors affecting assimilation of ammonium and nitrate 



nitrogen, particularly in tomato and apple. Plant Physiol., 9: 31-57, 



1934. 

 and W. R. Robbins. The use of ammonia and nitrate nitrogen by 



certain crop plants. N. J. Agr. Exp. Sta. Bull. 526, 1931. 

 Vickery, H. B. et. al. Chemical investigations of the tobacco plant, VI. 



Chemical changes that occur in leaves during culture in light and in 



darkness. Conn. Agr. Exp. Sta. Bull. 399, 1937. 

 ViRTANEN, A. I., S. Hausen, and T. Laine. Investigations on the root 



nodule bacteria of leguminous plants, XX. Excretion of nitrogen in 



associated cultures of legumes and nonlegumes. Jour. Agr. Sci., 27: 



584-610, 1937. 

 Waksman, S. a. "Principles of Soil Microbiology." WilUams & Wilkins 



Company, Baltimore. 1931. 

 Wilson, P. W. The carbohydrate-nitrogen relation in symbiotic nitrogen 



fixation. Wis. Agr. Exp. Sta. Res. Bull. 129, 1935. 

 . Symbiotic nitrogen fixation by the leguminosae. Botan. Rev., 3: 



365-399, 1937. 



