CULTIVATION OF ANAEROBIC BACTERIA 



73 



being held in ice-water. The colonies develop upon the sides 

 of the tube and can be examined microscopically. 



Gases like Hydrogen to Replace the Oxygen. Several 

 arrangements for passing a stream of hydrogen through the 

 culture: 



Frankel puts in the test-tube a rubber cork containing two 

 glass tubes, one reaching to the bottom and connected with a 

 hydrogen apparatus, the other very short, both bent at right 

 angles. When the hydrogen has passed through ten to thirty 

 minutes, the short tube is annealed and then the one in connec- 

 tion with the hydrogen bottle, and the gelatin rolled out upon 

 the walls of the tube (Fig. 42). 



Fig. 42. Frankel's method of 

 making anaerobic cultures (McFar- 

 land). 



Fig. 43. Buchner's method of 

 making anaerobic cultures (McFar- 

 land). 



Use of Aerobic Bacteria to Remove the Oxygen. Roux 



inoculates an agar tube through a needle-thrust, after which 

 semisolid gelatin is poured in on top. When the gelatin has 



