Table I. 



Biology 



features 



Gelatine 

 stab 



+ 



+ 



+ 



Potato 

 tube 



+ 



+ 



Ferment. 

 tube 



*-; 



5 



.a s 



^o 



.g S 



2 

 o 



-W Cj 



:|i 



& s 



o_g 



S 



+ 



Biochemical features 





o 



+ 



4- 



+ 



+ 



Lique- 

 faction 



Gas 



production 



G 



O 



"8 





Milk 



ed 



-fc 



Nutrient 

 agar tubes 



ah 



omogenes 



conditions. The flasks were then placed in jars from which the oxygen 

 had been removed by pyrogallic acid and NaOH. The jars were allowed 

 to stand at room temperature for 6 days, when the flasks were removed 



N 



and their contents titrated against ^ NaOH to determine the acidity. In 



&\) 



every case, fermentation had taken place as was shown by the difference 

 between the acid in the inoculated tube and that of a sterile control 

 which was placed under anaerobic conditions with the inoculated flasks. 

 The amount of acid produced was increased by inoculating a loopful of 

 broth obtained from the lactose broth flask which showed slight amount 

 of fermentation, into another lactose broth flask containing 100 c. c. of 

 broth. These were placed under anaerobic conditions as in the previous 

 case and tested after 6 days. The experiment was carried through five 

 generations and the results are shown in the following table. 



Duplicate flasks grown under aerobic conditions at the same tempe- 

 rature, failed to develop any acid. Fermentation tubes inoculated with 

 these three strains of Proteus and placed under anaerobic conditions 

 showed a growth not only in the open arm, but also in the closed one. 

 This would seem to indicate that Proteus vulgaris can obtain its 

 oxygen from the air much more easily than from lactose, but when it 



