METHODS OF INOCULATION. 



43 



colonies, it is then easy by re-inoculation of gelatine tubes, 

 or other nutritive material, to start pure subcultures of the 

 different species. It must be borne in mind that not all 

 bacteria can be isolated by this method, for some species 

 of pathogenic organisms require for this growth a higher 

 temperature than the one at which the nutrient gelatine 



FIG. 9. PLATE-CULTIVATION. 



1. Glass plate. 



2. Bell-glass. 



3. Wet filter paper. 



4. Glass dish containing the plate-cultivation on a thin layer of nutritive gelatine. 

 This glass dish is covered by a second glass dish. 



remains solid, while others refuse altogether to grow in 

 gelatine, or grow only two slow. In the latter case no success 

 can be looked for, since those bacteria which grow much 

 faster crowd out the others that require a long time to 

 come up. 



In such cases, particularly when one has to deal with 



