276 CLINICAL BACTERIOLOGY. 



Occurrence of the Bacilli. The bacilli are present in 

 the tuberculous lesions of fowl, which consist of dense, 

 tumor-like masses containing calcareous deposits. Giant- 

 cells are present in but small number. Fowl-tuberculosis 

 has been observed in rare cases also in human beings and 

 in mammals. 



Experimental Development of Fowl-tuberculosis. 

 Most birds are highly susceptible, and infection may take 

 place through all portals of entry. According to Baum- 

 garten fowl-tuberculosis occurring spontaneously is con- 

 genital in almost all instances. Rabbits, also, succumb to 

 infection with fowl-tuberculosis. Guinea-pigs and dogs 

 prove rather refractory, without, however, being entirely 

 immune. On the whole, the bacilli of fowl-tuberculosis 

 thrive poorly in mammals, and mammalian tuberculosis, 

 conversely, develops only with difficulty in birds. 



Diagnosis. The examination of tuberculous masses for 

 bacilli is conducted in precisely the same manner as in the 

 case of human tuberculosis. 



PSEUDO-TUBERCULOSIS. 



By pseudo-tuberculosis is understood certain pathologic 

 processes that exhibit the external appearance of tubercles, 

 but are dependent upon other causes than the tubercle- 

 bacillus. The etiology of pseudo-tuberculosis is quite 

 varied. Among the causative factors may be mentioned : 



1. Inanimate foreign bodies. 



2. Animal parasites. 



3. Bacteria. 



4. More highly organized vegetable parasites. 



The tuberculosis due to foreign bodies may be developed 

 experimentally with ease through the agency of all possible 

 substances. It is, however, not transmissible from animal 

 to animal. 



Pseudo-tuberculosis due to animal parasites is observed 

 almost exclusively in animals. Among the varieties that 

 are well known is the tuberculosis of the cat, caused by 

 ollulanus tricuspis ; that of the sheep, due to pseudalius 

 ovis pulmonalis ; that of the calf, due to strongylus ruf- 

 escens ; that of the dog, due to strongylus vasorum. 

 Miura alone has observed a single case in a human being. 



