68 SOIL BACTERIOLOGY 



3. Select a large and firm nodule, cut off, and immerse 

 for three to five minutes in mercuric chlorid solution 

 (i : 500), and finally in alcohol. 



4. Remove alcohol by flaming and place the nodule on a 

 sterile surface (flamed slide). 



** 



Fig. 5. — Bacillus radicicola from a root nodule of alfalfa; X 1200. 



5. Cut open with a sterile knife and take out some of the 

 inner contents. ^^ -i 



6. Inoculate this bacterial mass from the nodule into a 

 few drops of water in a Petri dish. 



7. Make two or more loop transfers from the first Petri 



