THE BOLL-WEEVIL 17 



roots and supply me with nitrogen and I furnish 

 him with phosphoric acid and potash." 



This was agreed upon, and now the bacteria live 

 in colonies in little nodules on the roots of vetch. 

 Being asked about it later, vetch answered, "It 



FIG. 8. "The little houses may now be found on the roots of vetch, 

 clovers, beans, peas, alfalfa, and other legume plants." 



works fine." The little houses may now be found 

 on the roots of vetch, clovers, beans, peas, alfalfa, 

 and other legume plants. 



"Use vetch or clover for winter and cowpeas for 

 summer and rotate your crops/' said the demonstra- 



