486 BACTERIOLOGY. 



certain instances the results of infection are chronic ; 

 the inoculated pectoral muscle atrophies, the pigeon loses 

 in weight and finally dies after one or two weeks. In 

 these cases the organisms are usually absent from the 

 blood and internal organs, and may even be absent from 

 the site of inoculation, or, if present, in only very small 

 number. 



Guinea-pigs usually die in from twenty to twenty- 

 four hours after subcutaneous inoculation. At autopsy 

 an extensive oadema of the subcutaneous tissues about 

 the seat of inoculation is seen, and there is usually 

 a necrotic condition of the tissues in the vicinity of the 

 point of puncture. As the blood and internal organs 

 of both pigeons and guinea-pigs contain the vibrios in 

 large numbers, the infection in these animals takes, 

 therefore, the form of acute, general septicaemia. 



The blood-serum of both pigeons and guinea-pigs 

 that have survived inoculation with this organism i. e., 

 that have acquired immunity from it is bactericidal 

 in vitro for this organism. It also possesses a certain 

 degree of immunity-conferring property, as may be 

 demonstrated by injecting it into normal pigeons and 

 guinea-pigs that are subsequently to be inoculated with 

 virulent cultures. 



Very old cultures of this organism in bouillon be- 

 come distinctly alkaline in reaction. At this stage they 

 contain a toxin that is markedly active for susceptible 

 animals. This toxin is not dissolved in the fluid to any 

 extent, but is apparently in intimate association with the 

 proteid matters composing the bacteria. 



Gastro-enteritis may be produced in both chickens 

 and guinea-pigs by feeding them with food with which 

 cultures of this organism have been mixed. (Gamaleia.) 



