416 AGTINOMYCETES. 



Experimental Observations Regarding Pathogenic 



Effects. — (a) In animals: With T. B. from man it is 

 very easy to infect cattle, swine, horses, and especially 

 monkeys and guinea-pigs; also dogs are easily infected, 

 especially intravenously. Fowls are immune; in hens, 

 at most, there occurs a small, local area from inoculation 

 in the comb. 



Infection follows the introduction of T. B. by all sorts 

 of methods (also inhalation and feeding), but most cer- 

 tainly by the intraperitoneal. At the place of infection 

 a caseous area is formed, and in the neighborhood (omen- 

 tum, peritoneum) an acute miliary tuberculosis. With 

 intravenous infection a general miliary tuberculosis de- 

 velops. Tubercle bacilli, attenuated by iodoform, cause 

 in rabbits, sometimes the picture of chronic phthisis in 

 man, sometimes the typical pearly disease ("Perlsucht") 

 (Troje and Tangl, C. B. xi, 613). 



If rabbits are injected subdurally or into the kidneys, — 

 according to Friedrich, also into the veins, — then areas 

 are often produced which in from fourteen to fifty days 

 correspond throughout to pictures of actinomyces: i. e., 

 a central tangle of genuine branching threads, limited at 

 the periphery by clubs. The central structure is acid 

 proof; the clubs are often only feebly so, and sometimes 

 are stained blue with a counterstain of methylene-blue. 

 Both the threads and clubs stain well by the Gram-Wei- 

 gert method, while in the actinomyces the clubs rarely 

 retain the stain in Gram's method. 



The close relationship between tuberculosis and actino- 

 mycosis is constantly demonstrated by these investigations. 

 Details will be found in the literature cited above. For 

 the latest researches, with beautiful illustrations, consult 

 Schulze and Lubarsch (Z. H. xxxi, 153 and 187). In 

 the same place special staining methods are also described. 



(6) In man: Experimental tests are lacking. Of the 

 clinical experiences, some cases of disease following infec- 



the pus of cavities and pulmonary nodules. The virulence for animals 

 proved to vary very much. If a culture was highly virulent for rabbits, 

 it made no diflerence whether an infection was produced in the eye or 

 subcutaneously or intravenously, and such cultures were also always 

 very virulent for rats. 



