618 . APPENDIX. 



tagious, but infection may result from the ingestion of 

 vegetable products which contain the fungus. The 

 cereal grains, which from their nature are capable of 

 penetrating the tissues, have been repeatedly found in 

 centres of actinomycotic infection. This usually occurs 

 in the vicinity of the mouth, where injuries have been 

 accidentally caused. The micro-organism may also be 

 introduced by means of carious teeth. Cutaneous in- 

 fection has been produced by wood-splinters, and infec- 

 tion of the lungs by aspiration of fragments of teeth 

 containing the fungus. The further distribution of the 

 fungus after it is introduced into the tissues is effected 

 partly by its growth and partly by conveyance by 

 means of the lymphatics and leucocytes. Not infre- 

 quently a mixed infection with the pyogenic cocci 

 occurs in actinomycosis. 



In the earliest stages of its growth the parasite gives 

 rise to a small granulation tumor, not unlike that pro- 

 duced by the tubercle bacillus, which contains, in addi- 

 tion to small round cells, epithelial elements and giant 

 cells. After it reaches a certain size there is great pro- 

 liferation of the surrounding connective tissue, and the 

 growth may, particularly in the jaw, look like, and was 

 long mistaken for, osteosarcoma. Finally, suppuration 

 occurs, which, according to Israel, may be produced 

 directly by the fungus itself. 



The experimental production of actinomycosis in ani- 

 mals has been followed by negative or very unsatisfac- 

 tory results. When artificially introduced into the 

 tissues the organism is either absorbed or encapsulated. 

 If introduced in large quantities multiple nodules are 

 apparently formed in some cases, which may suggest 

 the production of a general infective process; but on 

 closer inspection of these nodules the thread-like por- 



