230 INFECTIVE DISEASES. 



weakening was not due to prolonged exposure to oxygen, but that 

 old contaminated broth- cultures after a time completely lost their 

 power, owing to the antagonism of the bacteria accidentally present. 

 Filtered broth- cultures contain the toxic products of the bacillus, 

 and produce slight illness and subsequent immunity. 



FOWL ENTERITIS. 



Fowl enteritis is an acute infectious disease of fowls, the course 

 and symptoms of which are regarded by Klein as distinct from fowl 

 cholera. The fowls suffer from diarrhoea, with liquid greenish 

 evacuations, but are never somnolent, and death occurs in one or 

 two days. After death the mucous membrane of the intestine is 

 found to be congested, and coated with grey or yellowish mucus; 

 the liver is congested, spleen enlarged, and lungs normal. There are 

 a few bacilli in the blood of the heart, very many in the spleen and 

 liver, and they are in the form of a pure-culture in the mucus of 

 the intestine. Klein says that the bacilli are a little longer and 

 thicker than those found in fowl cholera, which they only slightly 

 resemble, and that the course of the disease, the symptoms and 

 pathological appearances, definitely distinguish it from fowl cholera, 

 but that nevertheless it belongs to the same family of bacilli 

 Pigeons are said to be insusceptible, rabbits only slightly susceptible. 

 By feeding and by subcutaneous inoculation the disease can be 

 communicated to healthy fowls, but there is no sign of illness until 

 the fourth day. As regards attenuation, the bacilli behave like 

 those from cases of fowl cholera. 



DUCK CHOLERA. 



Duck cholera is an epidemic disease of ducks which was investi- 

 gated by Cornil. The symptoms are similar to those of fowl cholera. 

 They suffer from diarrhoea and weakness, followed by death in two 

 or three days. 



The bacillus cultivated from the blood of ducks is pathogenic in 

 ducks but not in fowls or pigeons, and large doses are required to 

 kill rabbits. 



GROUSE DISEASE. 



Grouse disease is an acute infectious disease of red grouse. 

 According to Klein the chief pathological feature is severe pneu- 

 monia ; there is also patchy redness of the serous and mucous linings 



