Path'ogenesis 



739 



inoculated into experiment animals, the introduced fungi cither be- 

 coming absorbed or encapsulated by connective tissue and not grow- 

 ing. I n the abdominal cavities of rabbits the peritoneum, mesentery 

 and omcntum 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. 



lomycosis 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. 



