METABOLISM OF ACTINOMYCETES 29 



brown pigments on protein media, even if they do not give the 

 tyrosinase reaction, produce an oxidase. 



7. For comparative cultural purposes, a definite incubation 

 period is very important, since two organisms will show a differ- 

 ent relationship in their metabolism (splitting of milk in this 

 case) at different periods of incubation. With the prolongation 

 of the period of incubation the difference in the quantity of the 

 products obtained from the splitting of milk will greatly decrease 

 and may, in some cases, almost disappear. 



REFERENCES 



Beijerinck, M. W. 1900 Uber Chinonbildung durch Streptothrix chromogena 

 und Lebensweise dieses Microben. Centrbl. Bakt., II Abt., 6, 2-12. 



Beijerinck, M. W. 1913 Tyrosinase from two enzymes. Proc. Akad. Weten- 

 scap Amsterdam, 15, 932-937; Ref-J. Chem. Soc, 104, 1, 683. 



Clark, W. M., and Ltjbs, H. A. 1917 The colorimetric determination of hy- 

 drogen-ion concentration and its application in bacteriology. Jour. 

 Bact., 2, 134, 109-136, 191-236. 



Emerson, P. 1917 Are all the soil bacteria and streptothrices that develop on 

 dextrose agar azofiers? Soil Sci., 3, 417-421. 



Fousek, A. 1912 tJber die Rolle der Streptothricheen im Boden. Mitt. 

 Landw. Lehrkanz. K. K. Hochschule f. Bodenkult., Wien, 1, 217-244. 



Griesz, P. 1870 Uber Diamidobenzoensaure. Ann. Chem. u. Pharm., 154. 



Joshi, N. V. 1915 A new nitrite forming organism. Memoirs Dept. Agr. 

 India, Bact. Series, 1, 85-96. 



Klaeser, M. 1914 Die Reduktion von Nitraten zu Nitriten und Ammoniak 

 durch Bakterien. Centrbl. Bakt., II Abt., 41, 365-430. 



Krainsky, A. 1914 Die Aktinomyceten und ihre Bedeutung in der Natur. 

 Centrbl. Bakt., II Abt., 41, 649-688. 



Lutman, B. F., and Cunningham, C. G. 1914 Potato scab. Bull 184, Vt. 

 Agr. Exp. Sta. 



Mace\ E. 1905 De la decomposition des albuminoides par les Cladothrix (Acti- 

 nomyces). Compt. Rend. Acad. Sci. (Paris), 141, 147. 



MiiNTER, F. 1913 Uber Stickstoffumsetzungen einger Aktinomyceten. Cen- 

 trbl. Bakt., II Abt., 39, 561-583. 



Nadson, G. A. 1903 Microorganisms as geological agents (Russian). From 

 the Works of the investigation of the Slavian Mineral Waters. St. 

 Petersburg. 



Rullman, W. 1899 Der Einfluss des Laboratoriumsluft bei der Zuchtung von 

 Nitrobakterien. Centrbl. Bakt., II Abt., 5, 713-716. 



Van Slyke, D. D., and Birchard, F. J. 1914 The nature of the free amino 

 groups in proteins. Jour. Biol. Chem., 16, 539-547. 



Waksman, S. A. 1918 a The importance of mold action in the soil. Soil Sci., 

 6, 137-155. 



