A. G. Norman 183 



form a basis for further reading or relate to recent or not well-recognized infor- 

 mation. 



1. Bower, C. A., Soil Sci., 59: 277 (1945). 



2. Clark, F. M., Adv. in Agronomy, I: 241 (1949). 



3. Hoagland, D. R., Chandler, W. H., and Stout, P. R., Proc. Am. 

 Soc. Hort. Sci., 34: 210 (1936). 



4. Katznelson, H., Lochhead, A. G., and Timonin, M. I., Botan. Rev., 



M : 543 (i94 8 )- 



5. Loehwing, W. F., Botan. Rev., 3: 195 (1937)- 



6. Lyon, T. L., and Wilson, J. K., Cornell Agr. Expt. Sta. Mem. 40 

 (1921). 



7. McCalla, T. M., /. Bact., 40: 33 (1940). 



8. , /. Bact., 40: 23 (1940). 



9. Mann, P. J. G., and Quastel, }. H., Nature, 158: 154 (1946). 



10. Norman, A. G., and Bartholemew, W. V., Soil Sci., 56: 143 (1943). 



11. Parberv, N. H., and Swaby, R. J., Agr. Gaz. N.S.W., 53: 357 (1942). 



12. Pierre, W. H., /. Am. Soc. Agron., 40: 1 (1948). 



13. Quastel, J. H., Hewitt, E. J., and Nicholas, D. J. D., /. Agr. Sci., 

 38: 315 (1948). 



14. Shull, C. A., Plant Physiol., 7: 339 (1932). 



15. Virtanen, A. J., v. Hausen, S., and Karstrom, H., Biochem. Z., 258: 

 106 (1933). 



16. West, P. M., and Lochhead, A. G., Soil Sci., 50: 409 (1940). 



