Fig. 2. 



a. Effect of a balanced fertilizer on corn and clover, b, various organisms 

 isolated from a soil particle, c. types of bacteria, Coccus, Bacillus and Spirilla 

 (after P. E. Brown); d. pycnidium (after C. L. Shear), e. conidiophores of 

 Penicillium. 



