Pathogenesis 



739 



inoculated into experiment animals, the introduced fungi either be- 

 coming absorbed or encapsulated by connective tissue and not grow- 

 ing. In the abdominal cavities of rabbits the peritoneum, mesentery 

 and omentum show typical nodules containing the actinomyces 

 rays in cases of successful inoculation. 



Mode of Infection. — ^The manner by which the organism enters 

 the body is not positively known. In some cases it may be by direct 



Fig. 304. — Section of liver from a case of actinomycosis in man (Crookshank) . 



inoculation with infectious pus, but there is some reason to believe 

 that the organism occurs in nature as a saprophyte, or as an epiphyte 

 upon the hulls of certain grains, especially barley. Woodhead has 

 recorded a case where a primary mediastinal actinomycosis in the 

 human subject was apparently traced to perforation of the posterior 

 pharyngeal wall by a barley spikelet accidentally swallowed by the 

 patient. 



