Distribution of Bacilli. 533 



garten, Lubarsch), and according to Rabinowitsch and Schmitz they 

 are also met with in completely calcified lymph glands, although in these 

 latter they have become more or less attenuated. 



When inhaled into the finest ramifications of the bronchial 

 tubes and the alveoli of the lungs, the bacilli produce a catarrhal 

 inflammation resulting in a filling up of the alveoli with fibrin, 

 leucocytes and large epithelioid cells. This cellular exudate 

 soon undergoes cheesy degeneration, the intraalveolar septa 

 break down and thus larger cheesy foci are formed, which are 

 at first surrounded by inflamed catarrhal alveolar tissue and 

 later on by connective 'tissue walls. Fresh tubercles are usually 

 developed in the immediate neighborhood as a result of the 

 migration of bacilli through the lymphatic spaces. Bacilli 

 carried to the lungs with the blood produce typical tubercles 

 in the interalveolar connective tissue or^ in the bronchial walls 

 where they produce fibrinous proliferation. 



After the death of the tubercle bacilli the tuberculous 

 process may come to a standstill in any stage of its develop- 

 ment. Following this phenomenon a reactive inflammation re- 

 sults in the production of a fibrinous envelope around the entire 

 focus (fibrous tubercle). In slightly advanced local affection 

 this process may terminate in complete recovery from the 

 disease. 



Distribution of tubercle bacilli in the body. According to 

 the foregoing explanations in regard to the modes of infection 

 the bacilli pass along the lymph channels to the regional glands, 

 then, to a certain extent at least, to remoter glands and finally 

 into the blood stream. If they are not destroyed by the lymph 

 elements, or otherwise, they produce specific tubercles at points 

 where they happen to lodge. From the tubercle thus formed 

 thev pass through the houph spaces (''the histological highways 

 of the body" Cohnheim), into the neighboring intact tissue 

 where they cause the development of new tubercles. Every 

 new tubercle then becomes the source of other tubercles. As 

 these undergo cheesy degeneration the infected focus becomes 

 larger and larger, cavities are formed in the lungs and ulcers 

 on the mucous membranes. In the periphery of these new 

 tubercles make their appearance. 



In their further course the bacilli follow the lymph spaces 

 into the regional lymph glands and neighboring organs where 

 they produce similar changes. From the affected organs they 

 pass over to their serous membranes, become disseminated 

 through the hmiph plexuses, thus not infrequently giving rise 

 to a diffuse tuberculosis of these membranes. The bacilli may 

 also penetrate the lymph spaces of the diaphragm and the 

 morbid process spread from the peritoneum to the pleura and 

 pericardium. The development of tubercles on the serous mem- 

 branes is not infrequently attended with a sero-fibrinous in- 

 flammation. 



