ESSENTIAL METALLIC ELEMENTS 85 



McHargue, J. S., and R. K. Calfee: Effect of manganese, copper and zinc on 



growth and metabolism of Aspergillus flavus and Rhizopus nigricans, Botan. Gaz. 

 91: 183-193, 1931. 

 McHargue, J. S., and R. K. Calfee: Effect of manganese, copper and zinc on the 



growth of yeast, Pkmt Physiol. 6: 559-5G6, 1931a. 

 MacLeod, R. A., and E. E. Snell: Some mineral requirements of the lactic acid 



bacteria. Jour. Biol. Chem. 170: 351-3G5, 1947. 

 Marsh, P. B. : Salts as antidotes to copper in its toxicity to the conidia of Sclerotinia 



fructicola, Phytopathology 35: 54-Gl, 1945. 

 Molliard, M.: Influence d'une dose reduite de potassium sur les characteres 



physiologiques du Sterigmatacystis nigra, Compt. rend. acad. sci. 170: 949-951, 



1920. 

 Mulder, E. G. : On the use of microorganisms in measuring a deficiency of copper, 



magnesium and molybdenum in soils, Antonie van Leeuwenhoek 6: 99-109, 



1939-1940. 

 Mulder, E. G.: Importance of molybdenum in the nitrogen metabolism of micro- 

 organisms and higher plants, Plant and Soil 1: 94-119, 1948. 

 MuNTZ, J. A. : The role of potassium and ammonium ions in alcoholic fermentation, 



Jour. Biol. Chem. 171: 653-665, 1947. 

 Nelson, J. M., and C. R. Dawson: Tyrosinase, Advances in Enzymol. 4: 99-152, 



1944. 

 NiCKERSON, W. J. : Inhibition of fungus respiration : a metabolic bio-assay method, 



Science 103 : 484-486, 1946. 

 Perlman, D. : Some effects of metallic ions on the metabolism of Aerobacter aerogenes, 



Jour. Bad. 49: 167-175, 1945. 

 Perlman, D.: On the nutrition of Sclerotium delphinii, Am. Jour. Botany 35: 360- 



363, 1948. 

 *Perlman, D.: Effects of minor elements on the physiology of fungi, Botan. Rev. 15: 



195-220, 1949. 

 Perlman, D., D. A. Kita, and W. Peterson: Production of citric acid from cane 



molasses. Arch. Biocheni. 11: 123-129, 1946. 

 Rabinovitz-Sereni, D.: Influenza del magnesio suUo sviluppo di alcuni funghi, Dol. 



R. Staz. Veg. 13 : 203-226, 1933. 

 Raulin, J.: Etudes chimiques sur la vegetation, Ann. sci. nat., Ser. V, 11: 93-299, 



1869. 

 Richards, O. W., and M. C. Tkoutman: Spectroscopic analysis of the mineral con- 

 tent of yeast grown on synthetic and natural media. Jour. Bad. 3D : 739-746, 



1940. 

 Rickes, E. L., N. G. Brink, F. R. Koniuszy, T„ R. Wood, and K. Folkers: 



Crystalline vitamin B12, Science 107 : 396-397, 1948. 

 RippEL, A., and G. Behr: Ueber die Verteilung des Magnesiums im Pilzmycel, Arch. 



Mikrohiol. 1 : 271-276, 1930. 

 RippEL, A., and G. Behr: Ueber die Bedeutung des Kaliums im Stoffwechsel von 



Aspergillus niger, Arch. Mikrohiol. 5: 561-577, 1934. 

 RoBBiNS, W. J., and A. Hervey: Response oi Pythiomorpha gonapodyoides to manga- 

 nese. Bull. Torrey Botan. Club 71 : 258-266, 1944. 

 Roberg, M.: Ueber die Wirkung von Eisen-, Zink-, und Kupfersalzen auf Aspergillen, 



Cent. Bakt., Abt. II. 74: 333-371. 1928. 

 RoBERG, M.: Weitere Untersuchungen iiber die Bedeutung des Zinks fur Aspergillus 



niger. Cent. Bakt., Abt. II, 84: 196-230, 1931. 

 Roberts, C. : The effect of iron and other factors on the production of pigment by the 



yeast Torulopsis pulcherrima, Atn. Jour. Botany 33 : 237-244, 1946, 



