Pathogenesis 469 



no fermentation or gas-production results. The organism 

 produces acids and curdling enzymes. 



Pathogenesis. The organism is pathogenic for animals, 

 but not for man. Pfeiffer has shown that chickens and 

 guinea-pigs are highly susceptible, and when inoculated under 

 the skin usually die. The virulent organism is invariably 

 fatal for pigeons. W. Rindfleisch has pointed out that this 

 constant fatality for pigeons is a valuable criterion for the 

 differentiation of this spirillum from that of cholera, as the 

 subcutaneous injection of the most virulent cholera cultures 

 is never fatal to pigeons, the birds only dying when the 

 injections are made into the muscles in such a manner that 

 the muscular tissue is injured and becomes a locus minoris 

 resistenti(B. When guinea-pigs are treated by Koch's 

 method of narcotization and cholera infection, the tem- 

 perature of the animal rises for a short time, then ab- 

 ruptly falls to 33 C. or less. Death follows in from twenty 

 to twenty-four hours. A distinct inflammation of the intes- 

 tine, with exudate and numerous spirilla, may be found. 

 The spirilla can also be found in the heart's blood and in 

 the organs of such guinea-pigs. When the bacilli are intro- 

 duced by subcutaneous inoculation, the autopsy shows a 

 bloody edema and a superficial necrosis of the tissues. 



The organisms can be found in the blood and all the 

 organs of pigeons and young chickens, in such large numbers 

 that Pfeiffer has called the disease Vibrionensepticsemia. In 

 the intestines very few alterations are noticeable, and very 

 few spirilla can be found. 



Immunity. Gamaleia has shown that pigeons and 

 guinea-pigs can be made immune by inoculating them with 

 cultures sterilized for a time at a temperature of 100 C. 

 Mice and rabbits are immune, except to very large doses. 



VIBRIO SCHUYLKILIENSIS (ABBOTT). 



Morphology. This micro-organism, closely resembling 

 the cholera spirillum, was found by Abbott * in sewage- 

 polluted water from the Schuylkill River at Philadelphia. 



Cultivation. Colonies. The colonies developed upon 

 gelatin plates verv closely resemble those of the Spirillum 

 metschnikovi. 



* "Journal of Experimental Medicine," vol. i, No. 3, July, 1896, p. 

 419. 



