360 CLINICAL BACTERIOLOGY. 



bodies as spores, on account of their irregular shape and the 

 readiness with which they take stains, but as disintegrated fila- 

 ments and rods. They do not, however, represent dead detritus, 

 for when inoculated upon fresh nutrient media, they again de- 

 velop into rods and filaments. 



Experimental Development of Actinomycosis with 

 Pure Cultures. The various cultures thus present the 

 same structures as the actinomyces-masses in the foci of 

 disease : groups of cocci, rods, and filaments ; the fully de- 

 veloped clubs alone are wanting. Culture shows, further, 

 that the cocci, rods, and filaments represent various phases 

 of development of one and the same organism. Each form 

 is capable of further development in as many generations 

 as may be desired, and in this process the characteristic 

 features always appear. The actinomyces retains its vitality 

 in culture for a long time as long as nine months. 



That the fungus described is the true ray-fungus, in 

 spite of the absence of typical clubs, is demonstrated by 

 the successful inoculation of animals with cultures. Wolff 

 and Israel infected 18 rabbits, 3 guinea-pigs, and I sheep, 

 in part with agar-cultures, in part with egg-cultures, by 

 intraperitoneal injection, or by injection of a suspension 

 of the fungus into the liver. All of the animals, after the 

 lapse of from four to seven weeks, exhibited multiple tumors 

 in the abdomen, which contained typical actinomyces- 

 druses. With these tumors actinomycosis could be again 

 inoculated. Further, from their contents new cultures 

 could readily be obtained, presenting all of the peculiarities 

 of the original culture, including absence of typical club- 

 forms. The chain of evidence in favor of the specific 

 etiologic significance of the actinomyces-fungus cultivated 

 by Wolff and Israel is thus conclusively established. 



The anaerobic actinomyces-fungus described in the fore- 

 going was obtained by Wolff and Israel in two cases of 

 actinomycosis in human beings. According to Kruse, the 

 actinomyces of Wolff and Israel has thus far not been culti- 

 vated by others. On the other hand, it must be pointed out 

 that one of the authors of this work has succeeded in 

 obtaining the same cultures with precisely the same char- 

 acteristics in five cases of actinomycosis in human beings. 



A second species of actinomyces (aerobic actinomy- 

 ces), which is quite distinct from the actinomyces of Wolff 



