346 EFFECT OF CHEMICAL AGENTS [Cn. XI 



JOHNSON, S. W. '68. How Crops grow. 394 pp. New York. 



JORDAN, E. O. and RICHARDS, E. '91. Investigations upon Nitrification 



and the Nitrifying Organism. From Report, Mass. State Board of 



Health, Water Supply, and Sewage. Part II. pp. 865-881. [Dated 



1890.] 

 KEMMERICH, E. '69. Untersuchungen iiber die physiologische Wirkung der 



Fleischbriihe, des Fleischextracts und der Kalisalze des Fleisches. 



Arch. f. d. ges. Physiol. II, 49-93. 

 KOCH, A. and KOSSOWITSCH, P. '93. Ueber die Assimilation von freiem 



Stickstoff durch Algen. Bot. Ztg. LI, 321-325. Nov. 1, 1893. 

 KOSSOWITSCH, P. '94. Untersuchungen iiber die Frage, ob die Algen freien 



Stickstoff fixiren. Bot. Ztg. LII, 97-116. 16 May, 1894. 

 KRUKENBERG, C. F. W. '80. (See Chapter II, Literature.) 



78. Mangan ohne nachweisbare Mengeii von Eisen in der concretionen 



aus dem Bojanus'schen Organe im Pinna squamosa Gm. Unters. 



Physiol. Inst. Univ. Heidelberg. II, 287-289. 

 KUNKEL, A. J. '91. Zur Frage der Eisenresorption. Arch. f. d. ges, 



Physiol. L, 1-24. 25 June, 1891. 

 '95. Blutbildung aus anorganischen Eisen. Arch. f. d. ges. PhysioL 



LXI, 595-606. 25 Sept. 1895. 

 LAURENT, E. '88. Sur la formation d'amidon dans les plantes. Bruxelles, 



1885. 

 LAWES, J. B. and GILBERT, J. H. '53. On the Composition of Foods, 



in Relation to Respiration and the Feeding of Animals. Rept. 22d 



Meet. British Ass. Adv. ScL for 1852, 323-353. 

 LAWES, J. B., GILBERT, J. H. and PUGH, E. '61. On the Sources of the 



Nitrogen of Vegetation, with Special Reference to the Question whether 



Plants assimilate Free or Uncombined Nitrogen. Philos. Trans. Roy. 



Soc. London. CLI, 431-577. 

 LIEBSCHER '93. Beitrag zur Stickstofffrage. Jour. f. Landwirtschaft, 



XLT. [not seen.] 



LOEB, J. '92. (See Chapter X, Literature.) 

 LOEW, O. '91. Die chemische Verhaltnisse des Bakterienlebens. Centralbl. 



f. Bakteriol. IX, 659-663. 

 '91 a . Ueber die physiologischen Functionen der Phosphorsaure. Biol. 



Centralbl. XI, 269-281. 1 June, 1891. 



'96. The Energy of the Living Substance. 116 pp. London. 1896. 

 LOEW, O. and BOKORNY, T. '87. Chemisch-physiologische Studien iiber 



Algen. Jour. f. prakt. Chem. XXXVI, 272-291. 

 LUPKE, R. '89. Ueber die'Bedeutung des Kaliums in der Pflanze. Landw. 



Jahrb. XVII, 887-913. 

 MACALLUM, A. B. '91. On the Demonstration of the Presence of Iron in 



Chromatin by Micro-chemical Methods (Abstract). Proc. Roy. Soc. 



XLIX, 488-489. July 10, 1891. 



'92. Idem. Proc. Roy. Soc. XL, 277-286. Jan. 20, 1892. 

 '94. On the Absorption of Iron in the Animal Body. Jour, of Physiol. 



XVI, 268-297. 17 April, 1894. 



