TUBERCULOSIS. 329 



Fowl-tuberculosis {Bacillus tuberculosis avium). — The 

 cases of tuberculosis which occasionally occur sponta- 

 neously in chickens, parrots, ducks, and other birds were 

 originally attributed to the Bacillus tuberculosis hominis, 

 but the recent work of Rivolta, Mafucci, Cadio, Gilbert, 

 Roger, and others have shown that, while very similar in 

 many respects to the Bacillus tuberculosis, the organism 

 found in the avian disease has distinct peculiarities 

 which stamp it a different variety, though not a separate 

 species. Cadio, Gilbert, and Roger succeeded in infect- 

 ing fowls by feeding them upon food containing tubercle 

 bacilli, and keeping them in cages in which dust con- 

 taining tubercle bacilli was placed. The infection was 

 aided by lowering the temperature with antipyrin and 

 lessening vitality by starvation. Morphologically, the 

 organisms are similar, the bacillus of fowl-tuberculosis 

 being a little longer and more slender than that of mam- 

 malian tuberculosis, and showing a more marked tend- 

 ency to assume club and branched forms. The frag- 

 mented or beaded forms occur as in human tubercle 

 bacilli. 



Bovine Tuberculosis {Bacillus tuberculosis bovis). — 

 In his monograph upon tuberculosis Koch called attention 

 to certain differences that exist between the bacilli of 

 human and animal tuberculosis, but very little attention 

 was devoted to the subject. The well-known tubercu- 

 lous diseases of cattle were found to have lesions resem- 

 bling those of human tuberculosis, containing bacilli that 

 in a general way resemble those found in human tuber- 

 culosis and stain similarly. The conclusion that the 

 bacilli and processes were identical was inevitable. 



It is not determined that there is any other difference 

 between the two bacilli than can be "accounted for upon 

 biological grounds, each organism being slightly modified 

 to accommodate itself to its environment. There are, 

 however, a few quite well-marked differences which have 

 been subjected to investigation, and which may have some 

 important bearings upon public sanitation. 



