MICEOSPIRA METCHNIKOVI. 485 



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 chol- 

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

 are usually seen sitting quietly with ruffled feathers. 

 They suffer from diarrhoea, but there is no elevation 

 of temperature. Hypersemia of the entire gastro-intes- 

 tinal 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 conspicuous post-mortem lesion is found at the site 

 of inoculation. The muscle is marked by yellow, 

 necrotic stripes ; is more or less cedematous ; 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 in- 

 testines 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 organ- 

 isms 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 



