ACTINOMYCOSIS. 259 



of the structures, cocci, segmented threads, longer threads 

 and clubs were all found ; threads and clubs alike in most 

 cases being characterized by a branching similar to that met 

 with in the fungus as it grows in the human body. Inocula- 

 tion of this fungus into the peritoneal cavity of rabbits and 

 other animals was usually attended with positive results. 

 Later, by attending to the same details as regards the nature 

 of the seed material, M. Wolff, J. Israel, and Babes have 

 all succeeded in cultivating this organism on agar-agar, 

 blood serum, and especially on the raw white of egg, 

 according to Hueppe's method (see Appendix), and with the 

 cultivations so obtained actinomycosis has been produced 

 experimentally in animals. 



From all these facts it will be gathered that actinomy- 

 cosis is the result of the activity of a living organism 

 introduced into, and existing as a parasite in, the animal 

 tissues ; that the same organism ma}' be found in animals 

 and in the human subject, that the club-shaped organism is 

 really an involution stage, and that the characteristic growth 

 is the mycelial thread-like mass which appears to develop 

 from the cocci. The fact that we are unable to cultivate 

 from the clubs alone, affords ample evidence that, in place 

 of being spore-bearing masses, they are merely encysted, or 

 thick-walled, involution forms. 



As to the mode of infection, it has been pointed out that 

 the actinomyces has been found lodged in the crypts of the 

 tonsils of the pig and of the human subject, and that the 

 parasite evidently leads an epiphytic life on barley and other 

 cereals. It may be introduced from without through 

 wounds, as in cases of scirrhous cord in horses, or through 

 inoculation, by means of accidental scratches of the skin, or 

 of the mouth and pharynx, and it is recorded that a case of 

 primary mediastinal actinomycosis in the human subject 

 was in one case supposed to be traced to perforation of the 

 back of the throat by a barley spikelet swallowed by the 

 patient. In pigs the mammary affection is thought to 

 be due to the entrance of the actinomyces into the teat 

 ducts. 



In Denmark the farmers attach so little importance to 

 infection from animal to animal, that cows in which these acti- 

 nomycotic tumours are well developed are allowed to run 

 with the rest of the herd, at any rate until suppuration 



