ACTINOMYCES GROUP 379 



velops best at 37. It is resistant to desiccation, and maintains 

 its virulence when cultivated. 



Pathogenesis. Experimental Evidence. Guinea-pigs are easily 

 infected by intraperitoneal injections. The organism produces 

 numerous nodules resembling tubercles upon the peritoneum 

 and the abdominal organs, particularly the liver, spleen, and 

 kidneys. Intravenous injection gives rise to a condition resembling 

 generalized miliary tuberculosis. Intraperitoneal injection of the 

 monkey gives rise to similar lesions. Cattle and sheep develop, 

 at the point of a subcutaneous inoculation, an abscess which dis- 



Fig. 164. Actinomyces nocardii, stained mount from culture (Musgrave, 

 Clegg, and Polk, in "Philippine Journal of Science"). 



charges, ulcerates, and may disappear, to reappear after an 

 interval. 



Character of Disease and Lesions. The disease in cattle is 

 characterized by an enlargement of the superficial lymph-nodes, 

 which ulcerate and have much the appearance of farcy in the horse. 

 The internal organs may be affected, with a resultant pseudo- 

 tuberculosis. 



Immunity. Methods of immunization have not been developed. 



Bacteriological Diagnosis. The organism may be recognized 

 in preparations from the lesions, but, for differentiation from other 



