68 JOURNAL AND PROCEEDINGS 



definite walls, these again leading to the filters of the system, 

 the lymphatic glands. A large portion of the fluid of the 

 body, concerned with nutrition, passes from the blood vessels 

 to these same lymphatic spaces, there to be taken up by the 

 tissues. The effete matters of the tissues are cast off into the 

 same spaces to l:>e in part taken up by the blood vessels, in 

 part passed on by the small lymphatic tubes to the lymphatic 

 glands where the coarser particles are filtered out. 



KxAMPi.ES : — - 



In the lungs we have precisely the same arrangement of 

 lymph spaces, lymph channels and lymphatic glands, and in 

 them we find that the poison of tuberculosis is carried from 

 the vesicles where it is inhaled to the lymphatic glands at the 

 root of the lung by the lymph channels. 



Just as the tubercle bacillus causes in the air vesicles of 

 the lung irritation of their delicate lining with multiplication 

 of cells and formation of new tissue, so does it exert the same 

 effect on the cells which line the lymph spaces causing, in 

 some instances, softening and caseation, at other times, 

 depending on other factors the formation of fibrous tissue. 



The marked feature of tuberculosis, which has run a 

 chronic course, is the more or less abundant formation of this 

 same fibrous tissue. 



No matter in what part of the lung the bacillus gains a 

 foothold, there is probably at first a temporary harmful effect 

 on the tissue with which it comes in contact, followed later 

 on by degeneration, softening and symptoms of irritation of 

 the surrounding healthy tissues. 



This formation of fibrous tissue furnishes us with direct 

 evidence as to the character of the struggle which the system 

 has been able to put up against the invasion of the tubercle 

 bacillus. In some very chronic cases the quantity to be 

 found will be great indeed. Enormous thickening of the 

 pleura above the lesion and of the septa between the lobules. 

 Numerous areas, which in the early stages of the disease 

 must have been soft and pultaceous, entirely surrounded by a 



