BACTERIUM COLI COMMUNE. 363 



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 some excess of serum. The viscera 

 are ansemic. 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; the quantity of bile may not exceed the normal, 

 but in other cases the gall-bladder may be abnormally 

 distended with bile. The bile is nearly colorless or has 

 a pale yellowish or brownish tint, with little or none of 

 a greenish color. Its consivstence is much less viscid 

 than normal, being often thin and watery. It usually 

 contains small, opaque, yellowish particles or clumps 

 which can be seen floating in it, even through the walls 

 of the gall-bladder. These clumps consist microscop- 

 ically of bile-stained, apparently necrotic, epithelial 

 cells; leucocytes in small numbers; amorphous masses of 

 bile pigment, and bacteria often in zoogloea-like clumps. 

 Similar material is found in the larger bile-ducts. 



