Tuberculosis. 477 



A Qoticeable feature in the tuberculous lungs is the great fre- 

 quency of tubercles of all different ages from the initial trans- 

 parent nodule to the caseated or calcified mass side by side. A 

 tuberculous bronchitis is a familiar accompaniment, with lines of 

 miliary tubercles, ulcers and a flocculent (sometimes gritty) 

 muco-purulent discharge, containing elements of the necrotic 

 tissue and bacilli. Emphysema and interlobular oedema are also 

 met with. 



The pleureB often suffer by continuity of tissue from the 

 diseased lung, but they may be affected primarily through in- 

 fection of the circulating blood. The earliest pleural lesions may 

 be congestion, exudation and the formation of false membranes 

 in fringes, but soon these become the seats of minute nodules or 

 forming tubercles which steadily .encrease to form pale red cauli- 

 flower-like growths — which have been spoken of as grapes, from 

 their supposed resemblance to bunches of that fruit. Extensive 

 areas of the mediastinal, costal or pulmonic pleurae are often 

 completely covered by these productions. Dense, and thick ad- 

 hesions sometimes form, holding in their substance characteristic 

 tubercles. 



The bronchial and mediastinal lymph glands receiving as they 

 do the afferent trunks from the lungs and the greater lymph sac of 

 the pleura, offer in their sluggish currents the most favorable cul- 

 ture vessels, and almost always become affected in consequence. 

 Not infrequently they are found to be tuberculous when the tis- 

 sues which they drain appear to be sound, and we must therefore, 

 conclude that the primary, slight lesions in the latter have re- 

 covered, or that the bacilli have passed through the tissues and 

 lymph channels without establishing any centre of disease. The 

 glandular lesions are primarily congestion and redness, with more 

 or less infiltration and swelling, followed by a nodular induration, 

 with enlargement or exceptionally shrinking. When bisected 

 they may show all stages of the tubercle from the miliary granule 

 to the caseous, dry, yellow, granular or cretaceous necrosis. By 

 aggregation these often grow to a large size, a long diameter 

 of 6 to 12 inches being not uncommon. 



Pericardial and Cardiac Lesions. The pericardium may be 

 iipplicated from the pleurae or independently, and though tuber- 

 culosis of the heart is rare, it may be the seat of primary tuber- 



