CHAPTER XX. 



BACTERIACE^E: THE TUBERCLE BACILLUS AND 

 OTHER ACID-PROOF BACTERIA. 



Bacillus (Bacterium) Tuberculosis. Robert Koch in 1882 

 discovered the minute rods in tuberculous tissue, planted the 

 tissue on slanted inspissated blood serum and obtained pure 

 cultures of the tubercle bacillus, inoculated these cultures into 

 animals and produced typical tuberculosis. He succeeded in 

 doing this with natural tuberculosis of man and many other 

 mammals and also with the tuberculosis of birds. Silbey in 

 1889 observed with the microscope morphologically similar 

 bacilli in a snake. Rivolta and Mafucci in 1889 pointed out the 

 differences between the tubercle bacillus of birds and that of 

 mammals and their work, together with subsequent confirmatory 

 investigations, has established a distinct avian type of tubercle 

 bacillus, B. tuberculosis var. gallinaceus. In 1897 Bataillon, 

 Dubard and Terre found acid-proof bacilli in definite histological 

 tubercles in a fish (carp), obtained cultures and recognized it as 

 distinct from the mammalian form, and it was subsequently 

 designated as B. tuberculosis var. piscium. Theobald Smith 

 in 1898 published the results of a careful and extensive com- 

 parative study of tubercle bacilli from human sputum and 

 tubercle bacilli from tuberculous tissue of the bovine pearl 

 disease (tuberculosis), and pointed out distinct differences in 

 morphology, cultural characters and virulence between the 

 organisms derived from the two sources. The mammalian 

 tubercle bacilli were thus divided into two types, and subsequent 

 investigation has fully justified the recognition of B. tuberculosis 



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