

DESCRIPTIONS OF PATHOGENIC BACTERIA. 205 



The various forms of this germ that have been 

 discovered up to the present time are almost 

 the same as those found among tubercle bac- 

 teria. In cultures also the growth-forms often 

 suggest those of the tubercle bacteria ; perhaps 

 these organisms belong to one and the same 

 genus of moulds. The ray-fungus stains by 

 Gram's method like the bacteria of tubercu- 

 losis and leprosy. In the beginning it grows 

 best when the access of air is prevented, but 

 soon adapts itself to aerobic conditions. Infec- 

 tion has succeeded with rabbits and guinea- 

 pigs. 1 Natural infection, it is thought, may 

 take place through introduction of the parasite 

 into the body upon grains of various cereals, 

 but I have not succeeded in demonstrating 

 microscopically or culturally any one of the 

 growth forms in a single case that has pre- 

 sented itself. Actinomycosis may spread from 

 the jaw to the internal organs, lungs, liver, 

 heart and brain ; perhaps the skin also may 

 be primarily affected. Hofmann von Wellen- 

 hof and Gruber found a bacteria-like organism 

 living under saprophytic conditions which 



1 The actinomyces fungus discovered by Duncker in swine is dif- 

 ferent from that occurring in cattle and from that found in human 

 actinomycosis. The microscopic forms of the cattle actinomyces of 

 Germany differ from those shown by an actinomyces from 

 Tasmania and the mainland of Australia, sent me by Archibald Park 

 in 1891. 



