131 



treatment that the iiiiiiilxM's of bacteria in the untreated 

 Arlington soil approach normality. This seems, per- 

 haps, to be slower than would be expected if oxygen 

 were the limiting factor in the mulli])Iication of the 

 bacteria. In the untreated Alabama soil which is a 

 porous sandy loam no decrease in numbers is produced 

 by the mixing and repotting. 



A further investigation of soils in which vanillin has 

 been found to persist, to determine whether bacteria 

 capable of destroying vanillin are present and if they 

 are, to determine why they do not act on the compound 

 is advisable. 



LITERATURE CITED 



1. Brown, P. E. 



1913. Methods for bacteriological investigations of soils. 

 Iowa Agr. Exp. Sta. Researcli Bui. 11, p. 381-407. 



2. Davidson, J. 



1915. A comparative study of the effect of cumarin and 

 vanillin on wheat growth in soil, sand and water cultures. 

 In Jour. Am. Soc. Agr. V. 7, No. 4, p. 145-158; No. 5, i). 

 221-238. 



3. Estes, C. 



1917. A new qualitative lest and colorimetric method for 

 the estimation of vanillin. In Jour. Ind. and Eng. Chem. 

 V. 9, No. 2, p. 142-144. 



4. Fraps, G. S. 



1915. The effect of organic compounds in pot experiments. 

 Tex. Agr. Exp. Sta. Bui. 174, p. 1-13. 



5. Funchess, M. J. 



1916. The effects of certain organic compounds on plant 

 growth. Ala. Agr. Exp. Sta. Bui. 191, p. 103-132, 8 pis. 



6. Bobbins, W. J. 



1917. The cause of the disappearance of cumarin, vanillin, 

 pyridine and quinoline in the soil. Ala. Agr. Exp. Sta. Bui. 

 195, p. 49-64, 2 pis. 



7. Schreiner, 0. and Reed, H. S. assisted by Skinner, .1. J. 

 1907. Certain organic constituents of soil in relation to 

 soil fertility. U. S. Dept. Agr. Bu. Soils Bui. 47, p. 152, 

 5 pis. 



8. Shorey, E. C. 



1914. The presence of some benzene derivatives in soils. 

 In Jour. Agr. Res. V. 1, p. 357-363. 



9. Skinner, J. J. 



1915. Field test with a toxic soil constituent, vanillin. 

 U. S. Dept. Agr. Bui. 164, p. 1-9, 4 pis. 



10. Upson, F. ^Y. and Powell, A. R. 



1915. The effect of certain organic compounds on wheal 

 plants in the soil. Preliminarv paper. In Jour. Ind. and 

 Eng. Chem. V. 7. No. 5, p. 420-422 pi 1. 



