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423 



LESSON I 



Methods of Inoculation Action of Light, Oxygen, and Temperature 

 on the Growth and Metabolism of Bacteria Chromogenic Organ- 

 isms Liquefaction of Gelatine. 



Methods of Inoculation 



SEVERAL coloured organisms are supplied for inoculation 

 on various solid media. Students should come to some 

 arrangement between themselves and divide the work so as 

 to economise the materials. 



Organisms supplied 



1. Bacillus prodigiosus. 



2. Bacillus fluorescens. 



3. Bacillus pyocyaneus. 



4. Aspergillus niger. 



5. Sarcina lutea. 



6. Torula alba. 



7. Staphylococcus cereus flavus. 



8. Staphylococcus pyogenes aureus. 



(1) Make two agar-agar streak cultures of Bacillus pro- 

 digiosus. Place one in the warm incubator at 38 C., and 

 the other in the cool incubator at 20 C. 



Examine after forty-eight hours : the tube kept at 



