BACTERIA IN AGRICULTURE. 343 



morphic and readily undergo marked morphological changes in differ- 

 ent culture media and under varying environmental conditions. 



3. The species or variety of rhizobium living in natural symbiotic 

 or biologic relationship with one given species of leguminous plant may 

 be so modified artificially as to induce it to live in a similar relation- 

 ship with a different species of leguminous plant, indicating great bio- 

 logic adaptability. 



4. It is probable that rhizobia of various leguminous plants may 

 be so modified by special culture methods as to induce them to develop 

 in or upon the roots of non-leguminous plants, continuing their free 

 nitrogen-assimilating function, thus supplying such plants with nitrog- 

 enous compounds which serve as soil fertilizer or food for the plants 

 with which the modified rhizobia will form a temporary intimate rela- 

 tionship. 



5. The bacillus of Caron {Bacillus Ellenhachiensis) also gives 

 promise of great utility in future economic agriculture, especially in 

 the cultivation of gramineous plants. 



