76 TH. THJ0TTA 



dysentery bacilli. But if it be so it is a. peculiar thing that it 

 is impossible to find any serological connections between strains 

 of the same kind, such as is the case with all the other patho- 

 genic microbes of the intestinal tract. This point is of great 

 importance. 



Agglutination is of very little value when it comes to con- 

 necting different strains of the colon bacilli. As a rule there is 

 no clear serological connection between colon bacilli from dif- 

 ferent persons, even if strains are tested that are culturally 

 absolutely alike. 



In a very large collection of colon bacilli from calves 

 Christiansen finds that strains of one fermenting type are seldom 

 affected by agglutinating sera produced with other strains from 

 the same fermenting type and that the serological connections 

 are as often found between strains from different fermenting 

 types as within the same cultural type. 



Thus it is the rule of the colon bacilli to behave as we have 

 found the Morgan bacilli do. It is therefore natural to con- 

 clude that the Morgan bacillus is simply a Bacterium coli of a 

 certain fermenting type. Consequently it would be better to 

 give it the Danish name metacolon organism as this name 

 points to the large group of the colon bacilli, while the name of 

 Morgan bacillus gives the idea of a microbe of a certain special 

 type. 



The next question to deal with is this: 



Is the metacolon bacillus pathogenic and does it cause such 

 severe cases of colitis as those related in this paper? Or does 

 it only occur as a simple saprophyte while the real cause is 

 another, undetected microbe. If we consider the metacolon a 

 pathogenic microbe able to produce a dysentery-form colitis it 

 should be expected that the affected organism would produce 

 antibodies against the homologous strain, especially since the 

 rabbits on being treated with parenteral injections of the mi- 

 crobe very easily produce agglutinins and complement absorb- 

 ing antibodies. This has, however, never been found to be the 

 case in this investigation, and we cannot therefore bring forth 

 any certain evidence of the pathogenicity of the microbe. It is 



