BACILLUS COLT. 459 



swelling of Peyer's patches. The caecum and colon 

 may remain unchanged or present enlarged follicles. 

 There may or may not be an accumulation of fluid in 

 the abdominal cavity ; but peritonitis is rarely present. 

 The small intestine may contain bloody mucus. 



Intravenous inoculation of rabbits may be followed 

 by similar changes, with often the occurrence of diar- 

 rhoea before death, which may, in the acute cases, result 

 in from three to forty hours. In another group of 

 cases acute fatal intoxication does not result, and the 

 animal lives for weeks or months, dying ultimately of 

 what appears to be the effects of a slow or chronic form 

 of infection. For a few hours after inoculation these 

 animals present no marked symptoms ; exceptionally, 

 somnolence and diarrhoea have been observed at this 

 period, indicating acute intoxication from which the 

 animal has recovered. The affection is unattended by 

 fever. The most marked symptom is loss of weight. 

 This is usually progressive from the first or second day 

 after inoculation, with slight fluctuations until death. 



At autopsy the animal is found to be emaciated. 

 The subcutaneous tissues and the muscles appear pale 

 and dry. The serous cavities, particularly the pericar- 

 dial, may contain an excess of serum. The viscera are 

 anaemic. The spleen is small, thin, and pale. Ex- 

 ceptionally ulcers and ecchymoses are observed in the 

 caecum, but generally there are no lesions of the intes- 

 tinal tract. 



The most striking and constant lesions, those most 

 characteristic of the affection, are in the bile and in the 

 liver ; in some cases the quantity of bile may not exceed 

 the normal, but in others the gall-bladder may be ab- 

 normally distended with bile. The bile is nearly color- 



