MICROSPIRA METCHNIKOVI . 551 



It is killed in five minutes by a temperature of 50 C. 

 (Sternberg.) 



It is pathogenic for chickens, pigeons, and guinea-pigs. 

 Rabbits and mice are affected only by very large doses. 



Gamaleia states that chickens affected with the choleraic 

 gastro-enteritis of which this organism is the cause, are 

 usually seen sitting quietly with ruffled feathers. They 

 suffer from diarrhea, but there is no elevation of tempera- 

 ture. Hyperemia of the entire gastro-intestinal tract is 

 seen at autopsy. The other internal organs do not, as a 

 rule, present anything abnormal to the naked eye. The 

 intestinal canal contains yellowish fluid with which blood 

 may be mixed. In adult chickens the spirilla are not found 

 in the blood, but in young ones they are usually present in 

 small numbers. 



After the introduction of a very small quantity of a culture 

 of this organism directly into the pectoral muscle pigeons 

 succumb in from eight to twenty hours. The most con- 

 spicuous postmortem lesion is found at the site of inocula- 

 tion. The muscle is marked by yellow, necrotic stripes; 

 is more or less edematous; is swollen, and contains the 

 vibrios in enormous numbers. The intestines are usually 

 filled with fluid contents, which may or may not be blood- 

 stained; the walls of the intestines are often injected with 

 blood, and occasionally markedly so. The conditions of 

 the other internal viscera are inconstant. In fatal cases 

 the vibrios are present in large numbers in the blood and 

 internal organs. In pigeons that survive inoculation the 

 organisms may be found only at the site of inoculation, or 

 very sparingly in the blood also. These animals usually 

 exhibit immunity from subsequent inoculations. In certain 

 instances the results of infection are chronic; the inoculated 



