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TH. THJ0TTA AND ODD KINCK EIDE 



bered, that the same volume of the atypical strain cannot con- 

 tain so many bacilli as the typical one, because the mucus pro- 

 duced by the former will take up a space that in the typical 

 strain is filled by bacilli. It is thus obvious that the same 

 amount of culture will contain more bacilli in the typical than in 

 the atypical strain. We cannot therefore expect to find the same 

 titer of virulence in the two strains, unless the virulence of the 

 atypical strain has increased after the transmutation. This is 

 not the case in our strain, the virulence being either the same or 

 slightly diminished. 



It has been pointed out that the new character was quite stable 

 as well under saprophytic as under pathogenic circumstances. 

 We are, therefore, justified in calling the alteration of our strain 

 a true transmutation. Why this had developed is a very inter- 

 esting question which however is, we believe, not solvable. The 

 new character might be looked upon as an effort by the bacillus 

 to obtain a higher resistance against the serumbodies of the 

 probably highly immune patient. In this connection we will 

 point out the fact that increased formation of capsules has been 

 seen in bacteria simultaneously with a strengthened resistance 

 and virulence. Thus Sauerbeck talks about an immunity of the 

 bacilli through a structural adjustment, while Gruber and Futaki 

 have found that weakened anthrax bacilli were not capable of 

 producing such large capsules as the full virulent strains. 



In order to try whether our atypical strain might show any 

 difference in its resistance against serum as compared with the 

 typical strain of our patient we carried out bactericidal tests in 

 active human serum with both strains. The result was the 

 following: 



