TUBERCLE BACILLUS 



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At first white, it later turns darker. 

 This medium is never liquefied by the 

 culture. On glycerine agar made of 

 veal broth containing 6 percent of 

 glycerine, the organism grows well 

 after isolation from the tissues, often 

 luxuriantly. (Fig. 69.) 



A wrinkled film covers the surface 

 of the agar, from which it is removed 

 with ease. On bouillon, made of 

 veal and glycerinized, it develops 

 rapidly, covering the medium with a 

 dense white wrinkled pellicle, which, 

 though thick, is friable. After a 

 time it falls to the bottom of the flask. 

 It grows well on glycerinized potato 

 also, and milk agar. On egg albu- 

 mins mixed together, sterilized and 

 coagulated, this bacillus also develops 

 well. 



Pathogenesis. The discovery of 

 the tubercle bacillus, its methods of 

 cultivation and differential staining, 

 may be ranked with the greatest of 

 medical discoveries. This organism 

 causes in man and cattle, chiefly, the 

 disease called tuberculosis. It rarely 

 attacks the carnivora, but has been 

 found in such animals when confined. 

 Swine are often infected; cats and 

 dogs sometimes, but sheep, goats, and 

 horses seldom. It is easy to inoculate 

 guinea pigs or rabbits by injection or 

 feeding. The disease is widespread, 



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