xi] BACILLI : SPECIFICALLY PATHOGENIC 209 



2. Fowl cholera. — This disease causes great devastation 

 amongst poultry. The malady, well known by the researches 

 of Perroncito, Toussaint, Pasteur, Kitt, and others, affects 

 fowls, pigeons, and rabbits. In the fowl, after an incubative 

 period varying between sixteen or eighteen hours to twenty- 

 four hours, the disease declares itself by diarrhoea of fluid, 

 greenish evacuations, great drowsiness, and sleepiness of the 

 animal. In about twenty to forty-eight hours the animals 

 are found dead ; the blood in the heart and general circula- 

 tion, and in the vessels of all organs, the intestinal contents, 

 and evacuations teem with short, oval, non-motile bacilli 

 measuring i-i'2 /tin length; in stained preparations they 

 show at each end a stained granule, while the middle part 

 is clear and unstained. On post-mortem examination the 

 viscera are found greatly congested and containing hsemor- 

 rhages ; the mucous membrane of the upper part of the 

 intestine is found congested ; often small haemorrhages occur 

 in its mucous membrane ; the contents are fluid fseces, the 

 spleen is enlarged. Fowls, rabbits, and pigeons inoculated 

 with a droplet of the blood of a fowl dead of the disease, or 

 inoculated with the artificial culture of the bacilli, die of the 

 disease in between thirty-six to forty-eight hours, the blood 

 teeming with the bacilli. Feeding with the intestinal con- 

 tents of fowls, the disease is reproduced in them. From 

 this the conclusion is justified that also under natural con- 

 dition infection is carried out by the healthy fowls picking 

 up the contagium with the food from soil tainted with the 

 evacuations of diseased animals. 



Cultures of the bacilli show the following characters : In 

 plate cultivations the colonies appear before forty-eight 

 hours as minute yellowish-white dots, irregularly outlined 

 or round ; seen under a glass they are discs faintly granular ; 

 the centre is yellow and transparent, then follows a brown 



p 



