170 BACTERIA AND SOIL FERTILITY 



grown on extracts of non-legumes with the hope of thus increas- 

 ing their virulence. They have been brought in contact with 

 starved non-legumes, and attempts have even been made to in- 

 oculate them into the root hairs of non-legumes, — but so far 

 without success. 



This, however, does not say it is impossible. The legume or- 

 ganisms have slowly evolved to their present condition. From 

 what did this evolution start? Was it, as some have suggested, 

 from the Azotobacter? If so, what were the conditions under 

 which this mutual helpfulness has developed? Will not the 

 future produce the Burbanks in bacteriological breeding? Who 

 will solve this problem? When that day comes, as we all hope it 

 will, the farmer will then inoculate his wheat or his beets, as he 

 now does his legumes, care for them and let the tiny new creation 

 in bacteriology look after the nitrogen supply! 



