ACTINOMYCES FABCINICUS. 447 



Actinomyces Israeli. (Kruse.) L. and N. 



Isolated twice from cases of human actinomycosis, 

 grows best anaerobically, exhibits no branching upon 

 ordinary nutrient media, and is readily inoculable into 

 animals. 



Other " atypical or pseudo " causes of actinomycosis 

 have been described (in part, incompletely) by Berestnew 

 (Z. H. xxix, 94, etc.). According to him, organisms re- 

 sembling actinomyces can be very easily obtained if par- 

 ticles of barbs, etc., from grain are stuck into nutrient 

 media which are subsequently kept in an incubator. 



Actinomyces Hofmanni. (M. Gruber.) Gasperini. 



Micromyces Hofmanni M. Gruber (A. H. xvi, 35). 



This organism was obtained on one occasion from air in Vienna. It 

 forms no air hyphae, but the contents of the older threads of the fun- 

 gus break up into cocci-like fragments. Especially beautiful is the 

 formation of clubs exactly like those of the actinomyces and the 

 observation of their final calcification (after several months) in bouil- 

 lon cultures. It grows aerobically, and will only grow anaerobically 

 if sugar is added to the medium. It does not grow below 22°, 37° 

 being the optimum. Does not grow on potato and gelatin, and but 

 poorly on serum and agar, but, on the contrary, it grows well upon 

 most solid and liquid nutrient media with the addition of 0.5% to 

 3% of sugar. Sugar-agar cultures : Superficial colonies are elevated, 

 sharply outlined, wrinkled, lusterless; the deep ones show a radiating 

 structure with a delicate fringe. From sugar it forms acetic acid and 

 some alcohol. 



In animals, especially rabbits, it causes swellings filled with leuko- 

 cytes and coagulated exudate, which then soften and heal by encapsu- 

 lation, and which contain beautiful clusters. 



Actinomyces farcinicus. Gasperini. 



(Plate 66.) 



Synonyms. — Bacille du farcin du Bceuf (Annales de 

 l'lnst. Past., ii, 1888, p. 293). Nocardia farcinica Trevisan 

 et de Toni. 



Microscopic Appearance. — Short, segmented (knotty) 

 threads with true branching. Nocard has photographed 

 true branchings, but has interpreted them as false ones 

 (66, x). 



