44 METHODS OF STUDYING MICROORGANISMS 



zation in general are necessary. This term is usually reserved 

 for the killing of bacteria by means of heat, either dry or 



FIG. 15. Erlenmeyer FIG. 16. Petri dish. FIG. 17. Fermenta- 

 flask. tion tube. 



\k 



A B 



FIG. 18. Autoclave, pattern of Wiesnegg: A, external appearance; 

 B, section. 



moist. For the killing of bacteria by other means see 

 Chapter V. 



