234 BACTERIOLOGY. 



rapidly. In the less acute cases they are somnolent, 

 weak in their legs, and their wings trail. They 

 suffer from diarrhoea, and pass into a state of sopor 

 and die. The micro-organisms are found in large 

 numbers in the blood and organs after death, and 

 in the intestinal discharges. 



A drop of the broth injected into the connective 

 tissue in the region of the pectoral muscles causes 

 the death of the fowl the following day, with charac- 

 teristic pathological changes.* If a culture be kept 

 for some time, and a fowl be then inoculated with 

 it, instead of death only local changes are produced, 

 and the fowl is protected against the action of a 

 virulent culture ; thus affording an example of so- 

 called mitigation of the virus.^ The microbe is 

 aerobic, and its toxic effect has been supposed to be 

 due to the abstraction of oxygen from the blood 

 producing asphyxia. 



Bacterium septicum agrigenum (Bacillus 

 septicus agri genus, Nicolaier). Cells morphologi- 

 cally similar to the microbe of chicken cholera. 

 The colonies on plate-cultivations have a yellowish- 

 brown centre, with a greyish-yellow zone. In test- 

 tube cultivations the appearances are not charac- 

 teristic. They are pathogenic in mice and in 

 rabbits. The organs show no characteristic post- 



* Cornil, " Observ. Hist, sur les Lesions des Muscles determinees 

 par F injection du Microbe du Cholera des Poules " (Archives de 

 Physiologic. 1882); Cornil and Babes, Les Bacteries. 1885. 



t Pasteur, " Sur le Cholera des Poules," Comfit. Rendus. 1880. 



