BACILLUS RADICICOLA FROM DIFFERENT LEGUMES 67 



5. Incubate under anaerobic conditions for seven to 

 ten days at 20 C., and make transfers from several well- 

 isolated colonies into tubes of Winogradsky's solution, 

 and incubate as before. If the cultures are not pure, 

 they should be replated. 



Exercise ffif 

 Isolation of Bacillus Radicicola from Different Legumes 



i. Thoroughly wash the roots of several legumes (e. g., 

 red clover, alfalfa, sweet clover, vetch, and soy beans) 

 under the tap. 



Fig. 4. Plate colonies of Bacillus radicicola from clover, after ten days at 



28 C.; X 2. 



2. Compare the number, size, and position of the nodules 

 on the roots of these different legumes. 



