Chicken Cholera. Fowl Cholera. Chicken Typhoid, etc. 193 



there is a delicate grayish yellow growth after 48 hours ; if acid, 

 growth ceases. In milk there is no coagulation nor acidification 

 for four weeks ; then it becomes slowly clear and opalescent. 

 With sugars it is not gas producing. With dextrose it forms an 

 acid solution ; with saccharose or lactose an alkaline one. With 

 Canadian germ formed acid in lactose solution, (Higgins). Cul- 

 tures in peptone gave a strong indol reaction (V. A. Moore). 

 I/ignieres found no indol in cultures in pancreatic bouillon. 



The bacterium perishes when heated to 58° C. for fifteen 

 minutes. It dies in carbolic acid solution ( i : 100) in five minutes ; 

 in Sulphuric acid solution (0.25:100) in ten minutes ; in lime water 

 in ten minutes ; and in sulphur fumes in three hours. Easily de- 

 stroyed by disinfectants, it remains potent for months in flasks or 

 buildings that are not subjected to disinfection. It is not killed by 

 drying (T. Smith and V. A. Moore) nor by zero temperature 

 maintained for seventeen hours. 



The cultures, especially those made in agar have a very charac- 

 teristic odor. 



Accessory Causes. Birds sent to poultry shows will often con- 

 tract the disease and introduce it into the home flock on their 

 return. It may also be imported in newly purchased birds, or on 

 eggs obtained for hatching. It is even alleged that it has been 

 propagated by feeding healthy hens on the eggs of diseased ones. 

 When chickens run at large it passes easily from flock to flock in 

 the immediate vicinity. The infected manure is, however, the 

 most common channel of infection. Carried on the feet or bill 

 this contaminates the food and drinking water, and washed into 

 streams and ponds, it finally in any case reaches the alimentary 

 canal of the susceptible bird. Or drying up and raised as dust it 

 is inhaled into the lungs. Or finally from any such source it in- 

 fects any open sore. As granivorous birds, wild and tame, suffer 

 from fowl cholera, it is often introduced by the wild, especially 

 coming from infected poultry yards. Predatory birds, like hawks 

 and buzzards, but the latter especially, are common bearers of in- 

 fection. Rabbits, which contract the affection so readily, transmit 

 it equally with birds, but man or beast, soiled by the manure will 

 convey it. Insects are among the most prolific bearers, hence, as 

 noted by Salmon, the infection may fail to overstep a close fence 

 in winter, but is subject to no such limitation during the fly 

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