146 BOTANICAL GAZETTE [February 



26. Perrin, J., Mecanisme de I'electricalisation de contact et solutions 

 colloidales. Jour. Chim. Physique. 3:50-110. 1905. 



27. Philip, J. C, Physical chemistry, its bearing on biology and medicine. 

 New York and London. 1910. 



28. Reed, G. B., The relation of oxidase reactions to changes in hydrogen ion 

 concentration. Jour. Biol. Chem. 27:299-303. 1916. 



29. Reed, H. S., The enzyme activities involved in certain fruit diseases. 

 Va. Agric. Exper. Sta. Rept. 1911-1912. pp. 51-78. 



30. Rose, D. H., Oxidation in healthy and diseased apple bark. Box. Gaz. 

 60:55-65. 1915. 



31. SoRAUER, Paul, Die angebliche Kartoffelepidemie, gennant die BlattroU- 

 krankheit. Internal. Phytopath. Dienst (Beigabe, Zeitschr. Ptlanzen- 

 krank.). 33-59. 1908. 



32. , Die neueren Untersuchungen von Quanjer iiber die Ursache 



der BlattroUkrankheit der Kartoffel und der Sorauer'sche Standpunkt. 

 Zeitschr. Pflanzenkrank. 23:244-253. 1913. 



33. Trillat, O., Sur le role d'oxydases que peuvent jouer las sels manganeux 

 ex presence d'un colloide. Compt. Rend. 138:274-277. 1904. 



34. Wiley, H. W., Oiificial and provisional methods of analysis. Association 

 of Official Agricultural Chemists. As compiled by the committee on the 

 revision of methods. U.S. Dept. Agric. Bur. Chem. Bull. 107 (rev). 1908. 



35. Woods, A. F., Observations on the mosaic disease of tobacco. U.S. Dept. 

 Agric. Bur. PI. Ind., Bull. 18. 17-22. 1902. 



