336 Microorganisms and Soil Fertility 



3. Gilmour, C. M., Allen, O. N., and Truog, E., Soil aggregation as influenced 

 by the growth of mold species, kind of soil, and organic matter, Proc. Soil 

 Sci. Soc. Am., 13:292-296, 1949. 



4. McCalla, T. M., Influence of microorganisms and of some organic substances 

 on soil structure. Soil Set., 59:287-297, 1945. 



5. McCalla, T. M., Influence of some microbial groups on stabilizing soil struc- 

 ture against falhng water drops, Proc. Soil Sci. Soc. Am., 11:260-263, 1946. 



6. Martin, J. P., Microorganisms and soil aggregation. I. Origin and nature of 

 some aggregating substances. Soil Sci., 59:163-174, 1945; II. Influence of 

 bacterial polysaccharides on soil structure. Soil Sci., 61:157-166, 1946. 



7. Myers, H. E., and McCalla, T. M., Changes in soil aggregation in relation 

 to bacterial number, hydrogen-ion concentration, and length of time soil 

 was kept moist. Soil Sci., 51:189-200, 1941. 



8. Swaby, R. J., The relationship between microorganisms and soil aggregation, 

 J. Gen. Microb., 3:236-254, 1949. 



