TUBERCULOSIS. 457 



border of the bicuspid valve, nodules the size of a millet- or 

 hemp-seed ; these are sometimes pedunculated, and are papillary 

 vegetations from former endocarditis. Lastly, a number of 

 tumors, fibroma, papilloma, sarcoma, and cancer appear, first as 

 a nodule. Who would think of designating such nodules tuber- 

 cles, although they are in reality " tubercwla" f 



Is it the form of an infiltration ? We have no better grounds 

 for that. The swelled patches and solitary follicles of the mu- 

 cosa of the intestines, the enlarged bronchial and mesenteric 

 lymph-ganglia in typhoid fever, pygemic infarctions of the lungs, 

 etc., furnish examples of circumscribed infiltrations j in croupous 

 pneumonia and in croupous nephritis we have specimens of dif- 

 fuse infiltrations, and such infiltrations, it is 'obvious, have noth- 

 ing in common with tuberculosis. 



We, therefore, look in vain for the shape to distinctly charac- 1 

 terize the disease termed tuberculosis. Not only tuberculosis, but 

 any product of inflammation, may appear at one time as a nodule, 

 at (finer times as an infiltration. Let us search further for a 

 pathological feature peculiar to this disease. 



Is it the cheesy metamorphosis ? We know, on the one hand, 

 that tuberculous nodules dp not always pass on to this meta- 

 morphosis, as is demonstrated by the isolated '"fibrous "tubercles 

 of serous membranes, whose cure is made manifest by the pig- 

 mentary area and by the obsolete nodes of the lungs, which, 

 as mentioned before, sometimes attain the size of a sugar-pea. 

 We know, on the other hand, that the tissues of cancer, of typhoid 

 lymph-ganglia, nay, pus itself, may undergo a cheesy metamor- 

 phosis. Virchow announced that a tissue might, under some con- 

 ditions, become caseous, as it might under other conditions enter 

 calcareous, fatty degeneration or become putrescent. According 

 to his view, there is a hyperplasia which terminates into a cas- 

 eous condition (scrofule of a lymph-ganglion) and a hetero- 

 plasia which also terminates in the same caseous change (tubercle, 

 cancer). This " cheesy" change, therefore, cannot be an essential 

 feature of tubercle. 



Is it the heteroplasia ? In Virchow's classification the miliary 

 tubercles belong to the lymphatic tumors ; they are adenoid 

 i. e., gland-like new formations and heteroplastic productions 

 which means that they originate " in places in which they do not 

 belong." I cannot think that Virchow intended this for a serious 

 definition. We know perfectly well that any inflammatory new 

 formation, without exception, any " accumulation of cells/ 7 may 



