FOWL CHOLERA. 229 



somnolent. They suffer from weakness of the legs, and their wings 

 trail. There is freqviently diarrhoea, with slimy greenish evacuations, 

 and death usually ensues after a slight convulsive attack. On 

 making a post-mortem examination the viscera will be found to be 

 congested, and there is intense inflammation of the mucous membrane 

 of the intestine, with haemorrhages. 



The blood from the heart, and the intestinal contents, contain 

 the bacilli which were at one time believed to be pecuHar to 

 this disease. Inoculation subcutaneously, or administration with 

 food, of a small quantity of a broth cultivation will produce death 

 in twenty-four to thirty-six hours. Pigeons, pheasants, sparrows, 



■:■■■■ f" ■ ■■fjSj'C- 







'ii 



kt 



J' 





Fig. 110. — BACTEKinii OJ? Fowl Choleea. Section from liver of Fowl x 700 



(Flugge). 



rabbits, and mice are svisceptible. In guinea-pigs, sheep, and horse.s, 

 an abscess develops at the seat of inoculation. Rabbits are readily 

 infected by sprinkling a broth-cultivatiou on cabbage leaves or any 

 suitable food. It was with this microbe that Pasteur proposed to 

 eradicate the plague of rabbits in Australia. 



Fowl cholera has an additional interest, as it was with this 

 disease that Pasteur first investigated the attenuation of virus. 

 Broth-cultures which were several months old were found, when 

 injected, to produce apparently only a local effect. This weakening 

 of the virus was attributed by Pasteur to exposure to oxygen. 

 After recovery the fowls were protected against the action of 

 virulent cultures, while fowls not immunised died the following day. 

 Kitt, by working with pure-cultures on solid media, showed that the 



