396 PATHOGENIC BACTERIA. 



dysentery, the bacillus not only seems to acquire an un- 

 usual degree of virulence, but because of the existing 

 denudation of mucous surfaces, etc., finds it easy to enter 

 the general system, with the result of secondary remote 

 suppurative lesions in which it is the essential factor. 

 When absorbed from the intestine it frequently enters 

 the kidney and is excreted with the urine, causing, inci- 

 dentally, local inflammatory areas in the kidney, and 

 occasionally cystitis. A case of urethritis is reported to 

 have been caused by it. 



In infants cholera infantum may not infrequently be 

 caused by the colon bacillus, though probably in this 

 disease other bacteria play a very important role. 



The bile-ducts are very often invaded by the bacillus, 

 which may cause inflammation, obstruction, suppuration, 

 or calculous formation. 



The bacillus has also been met in puerperal fever, 

 Whickers disease of the new-born, endocarditis, menin- 

 gitis, liver-abscess, bronchopneumonia, pleuritis, chronic 

 tonsillitis, and urethritis. 



For the determination of the colon bacillus the im- 

 portant points are the motility, the indol reaction, the 

 milk-coagulation, and the active gas-production. As, 

 however, all of these features are shared by other bac- 

 teria to a greater or less degree, the only positive differ- 

 ential point upon which very great reliance can be placed 

 is the immunity-reaction of the serum of an immunized 

 animal, which not only protects susceptible animals from 

 the effects of inoculation, but produces with fresh cul- 

 tures of the bacillus exactly the same reaction as that 

 observed in connection with the blood and serum of 

 typhoid patients, and convalescents and immunized ani- 

 mals. This reaction has been considered at length in 

 speaking of typhoid fever. 



For the few who are convinced that the colon and 

 typhoid bacilli are identical, the fact that the typhoid 

 sc ruin is specific for the typhoid bacillus, and the colon 

 serum for the colon bacillus, with rare exceptions / 



