CHAPTER XVIII. 

 BACILLUS TUBERCULOSIS. 



Introduction. 



1. Types of tubercle bacilli, p. 289. 2. Human tuberculosis, p. 292. 3. Tuber- 

 culosis in the lower animals, p. 294. 4. Associated micro-organisms, p. 297. 

 Section I. Experimental inoculation, p. 297. 

 Section II. Morphology, p. 305. 



1. Microscopical appearance, p. 305. Staining methods, p. 306. The staining of 

 films, p. 307. The staining of sections, p. 310. Appearance of stained bacilli, p. 312. 

 2. Cultural characteristics, p. 314. 

 Section III. Biological properties, p. 322. 



1. Viability and virulence, p. 322. The action of antiseptics, p. 323. 2. Toxins, 

 p. 323. The toxic properties of dead bacilli, p. 323. Koch's old tuberculin, p. 324. 

 Tuberculins T.A., T.O., T.R., p. 328. Maragliano's tuberculin, p. 329. Toxalbumin, 

 p. 329. 3. Vaccination, p. 330. 4. Serum therapy, p. 334. 5. Agglutination, p. 335. 

 6. Immune body, p. 337. 

 Section IV. The detection of the tubercle bacillus, p. 337. 



A. Sputum, p. 339. B. Blood, p. 341. C. Pus, p. 342. D. Exudates, p. 342. 

 E. Granulomata, p. 343. F. Nasal cavities, p. 343. G. Urine, p. 343. H. Ex- 

 creta, p. 344. I. Milk, p. 345. 



The paratubercle or acid-fast bacilli, p. 345. 



The smegma bacillus, p. 346. The bacillus of verruga peruana, p. 346. Pseudo- 

 tuberculoses, p. 347. 



THE tubercle bacillus, discovered by Koch, is the cause of tuberculosis in 

 man and the lower animals. 



In accordance with established practice, the infecting agent in tuberculosis will, 

 in the present chapter and elsewhere in this book, be spoken of as a bacillus although 

 it is now agreed that it should be classed with the genus Discomyces (Streptothrix 

 of Cohn). Metchnikoff has suggested for it the name Sclerothrix kochi. 



1. Types of tubercle bacilli. 



Of the tubercle bacilli recoverable from human tissues and from the tissues 

 of the lower animals four types can be distinguished, differing from one 

 another in various characteristics. It is customary therefore to speak of 

 human, bovine, avian and ichthic tubercle bacilli, meaning thereby the 

 type of bacillus [most commonly] obtained from human, bovine, avian or 

 ichthic sources respectively. 



(a) The human and the bovine types of tubercle bacilli. Most bacterio- 

 logists, Koch's opinion notwithstanding, are agreed in regarding the human 

 and the bovine types of tubercle bacilli as identical, for [in the opinion of these 

 observers ] the facts which can be brought in support of this view are numerous 

 and conclusive. Each bacillus though best adapted to the particular species 



