458 TUBEBCULOSIS. 



be of a "lymphoid" character, f. i., the granulations of a wound, 



and very likely every disease does originate in a place where it 



does not belong. Besides, Schiippel (I. c.) has demonstrated that 

 the view of a " heteroplastic " origin of the tubercles of the 

 lymph-ganglia is not tenable. 



More recently, efforts have been made to locate the essential 

 sign of the tubercle in its multinuclear elements Rokitansky's 

 mother-cells. In this view, the presence of a central " multinu- 

 clear cell " would be sufficient to stigmatize all the surrounding 

 " lymphoid" new formation as tuberculous. We know that the 

 so-called " giant-cells " occur, not only in normal medullary tissue 

 of bone and in inflamed tissues, such as cornea, cartilage, bone, 

 but also in a number of tumors (sarcomata), so that it is impossi- 

 ble to consider them as definite characteristics of the formation 

 Af tubercle. They are no more specific for this disease than are 

 the "tubercle-cells" of Lebert. 



Neither are we justified in claiming that the minute size of 

 the elements, their transient nature, their "low vitality,"* are 

 characteristic. The so-called " small-cellular" sarcomata and can- 

 cers in disintegration exhibit elements which are certainly still 

 less stable than those of the tubercle. Besides, we find in the 

 tubercle the large, so-called epitheloid, and also the very large 

 multinuclear elements. 



This much is certain, that all previous definitions of tubercle 

 lack clearness. I again return to the question, what are the 

 essential characteristics of tubercle ? 



Beyond doubt (and on this point all observers are agreed) the 

 tubercle is a new formation i. e. f a new product "in a place 

 where it does not belong." It, however, has a peculiarity known 

 to all accurate observers. It contains no blood-vessels. Tubercle, 

 therefore, is an avascular new formation. 



Origin of Tubercle. As early as 1816 Broussais maintained 

 that the tubercle, or rather the "tuberculous matter, 7 ' was a 

 product of inflammation. Much discussion followed this assertion, 

 but all was to no purpose, since nobody then knew what inflam- 

 mation really was. Most later observers have considered the 

 pneumonic form of tuberculosis of the lungs as inflammatory in 

 nature, and even Virchow cannot be suspected, having considered 

 every tuberculosis due to inflammation. 



While Broussais took "irritation" and " inflammation " for 

 one and the same process, Virchow, in a logical manner, sepa- 

 rated them. He says : " Primary tuberculosis of the lymph-glands 



