XX] ANTAGONISM AMONGST BACTERIA 533 



coccus of erysipelas, which had lost their action on rabbits, 

 regained virulence if injected mixed, i.e, simultaneously, 

 with broth culture (four days old) of the proteus vulgaris ; 

 and it made no difference whether the latter culture was or 

 was not previously sterilised. The virulence on the guinea- 

 pig of the bacillus diphtherise is, as I have shown, greatly 

 enhanced by a simultaneous inoculation of the bacillus 

 pyocyaneus. 



