274 BACTERIOLOGY. 



After having gained access to the bloodvessels, the 

 results are the same as those following upon intra- 

 vascular injection of the bacilli, namely, general tuber- 

 culosis quickly follows, with the most conspicuous pro- 

 duction of miliary tubercles in the lungs and kidneys, 

 less numerous in the spleen, liver, and bone marrow. 



When inhaled into the lungs, if conditions are favor- 

 able, multiplication of the bacilli quickly follows. With 

 their growth they are mechanically pressed into the tis- 

 sues of the lungs. As multiplication continues some are 

 transported from the primary seat of infection to healthy 

 portions of the lung tissue, there to give rise to a further 

 production of the tubercular process. 



In the same way infection through the alimentary 

 tract is in the main due to mechanical pressure of the 

 bacilli upon the walls of the intestines. Investigation 

 has shown that lesions of the intestinal coats are not 

 necessary for the entrance of tubercle bacilli from the 

 intestines into the body. They may be transported from 

 the intestinal tract into the lymphatics in the same way 

 that the fat droplets of the chyle find entrance into the 

 lymphatic circulation. 



The evidence produced by Cornet, 1 together with gen- 

 eral statistical evidence, points to the lungs as the most 

 common portal of natural infection for the human be- 

 ing. Unlike most pathogenic organisms, the tubercle 

 bacillus is believed to have the property of forming spores 

 within the tissues. These spores, which are highly re- 

 sistant and are not destroyed by drying, are thrown off 

 from the lungs in the sputum of tuberculous patients in 

 large numbers, and unless special precautions be taken 



i Cornet : Zeit. fur Hygiene, 1889, Bd. v., S. 191. 



