on Plant Growth in Nutrient Solutions, &c. 
377 
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26. - (1908): Field Crop Experiments. Ibid., pp. 65 - 84 . 
27. Lehmann, J. (1875): Ueber die zur Ernahrung der Pflanzen geeignetste Form des Stick- 
stoffes. Biedermann’s Centralbl. Agr.-Chem., vol. vii, pp. 403 - 9 . 
28. Maz£, P. (1900): Recherches sur l’influence de l'azote nitrique et de l’azote ammoniacal sur le 
developpement du mais. Ann. de l’lnst. Pasteur, vol. xiv, pp. 26 - 45 . 
29. Nagaoka, M. (1904-5) : On the Behaviour of the Rice Plant to Nitrates and Ammonium 
Salts. Bull. Coll, of Agr., Tokyo Imp. Univ. (Japan), vol. vi, pp. 284 - 334 . 
30. Nathansohn, A. (1904) : Weitere Mitteilungen iiber die Regulation der Stoffaufnahme. 
Jahrb. f. wiss. Bot., vol. xl, pp. 403 - 42 . 
31. Nikitinsky, J. (1904) : Uber die Beeinflussung der Entwicklung einiger Schimmelpilze durch 
Stoffwechselprodukte. Ibid., pp. 1 - 93 . 
32. Pantanelli, E. (1915) : Uber Ionenaufnahme. Ibid., vol. lvi, pp. 689 - 733 . 
33. Prianischnikow, D. (1911) : Uber den Einfluss von kohlensaurem Kalk auf die Wirkung von 
verschiedenen Phosphaten. Landw. Vers.-Stat., vol. Ixxv, pp. 357 - 76 . 
34. Rautenberg, F., and Kuhn, G. (1864) : Vegetationsversuche im Sommer. Ibid., vol. vi, 
PP- 355-9- 
35. Ruprecht, R. W. (1915) : Toxic Effect of Iron and Aluminum Salts on Clover Seedlings. 
Mass. Agr. Exp. Sta. Bull. 161 , pp 125 - 9 . 
36 . Shive, J. W. ( 1915 ) : A Study of Physiological Balance in Nutrient Media. Physiol. 
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37. Tottingham, W. E. (1914): A Quantitative Chemical and Physiological Study of Nutrient 
Solutions for Plant Cultures. Ibid., pp. 133 - 245 . 
38. -, and Beck, A. J. (1916): Antagonism between Manganese and Iron in 
the Growth of Wheat. Plant World, vol. xix, pp. 359 - 70 . 
39. Trelease, S. F. (1920) : The Growth of Rice as related to Proportions of Fertilizer Salts 
added to Soil Cultures. Philippine Journ. of Sci., vol. xvi, pp. 603 - 27 . 
40. -, and Paulino, P. (1920) : The Effect on the Growth of Rice of the Addition 
of Ammonium and Nitrate Salts to Soil Cultures. Philippine Agriculturist, vol. viii, 
pp. 293 - 313 . 
41. -, and Jurado, M. C. (1920) : The Growth of Rice as related to Concentra¬ 
tions and Proportions of Fertilizer Salts added to Soil Cultures. Ibid., vol. ix, pp. 67 -S 6 . 
42. Van Alstine, E. (1920) ; The Determination of Hydrogen-ion Concentration by the Colori¬ 
metric Method and an Apparatus for Rapid and Accurate Work. Soil Sci., vol. x, 
pp. 467-77- 
43. Wolkoff, M. L. (1918) : Effect of Ammonium Sulphate in Nutrient Solutions on the Growth 
of Soy Beans in Sand Cultures. Ibid., vol. v, pp. 1 23 - 50 . 
