NUTRIENT MEDIA AND METHODS OF CULTIVATION. 



133 



aldehyde. The test-tubes, dishes, or capsules are placed in a cylin- 

 drical irlass vessel containing a pledget of cotton- wool moistened with 



FIG. 68. APPARATUS FOR ANAEROBIC CULTURES. 



(ROSCOE AND LU.NT.) 



formic aldehyde. The vessel is fitted with a ground glass stopper 

 and >-t aside. The growth almost immediately ceases. Any 

 liqueliM gelatine is hardened, so that the exact appearances of 

 cultures are obtained in a permanent form. 



