TUBERCLES. 



521 



in consequence of the attention of observers being 

 diverted by these objects, been allowed to slip out of 

 one's hand again. I am of opinion that a tubercle is a 

 granule, or a knot, and that this knot constitutes a new- 

 formation, and indeed one, which from the time of its 

 earliest development is necessarily of a cellular nature, 

 and generally, just like all other new-formations, has its 

 origin in connective tissue, and which, when it has 

 reached a certain degree of development, constitutes a 

 minute knot within this tissue, that, when it is at the sur- 

 face, projects in the form of a little protuberance, and 

 consists throughout its whole mass of small uni- or multi- 

 nuclear cells. What especially characterizes this forma- 

 tion is the circumstance, that it is extremely rich in nu- 

 clei, so that when it is examined as it lies imbedded in 



Fin. 140. 



the tissue which invests it, at the first glance there seems 

 to be scarcely anything else than nuclei. But upon iso- 

 lating the constituents of the mass, either very small cells 

 provided with one nucleus are obtained and these are 

 often so small that the membrane closely invests the nu- 

 cleus or larger cells with a manifold division of the nu- 



Fig. 140. Development of tubercle from connective tissue in the pleura. The 

 whole succession of transitions is seen from the simple connective-tissue corpuscles, 

 the division of the nuclei and cells up to the. production of the tubercle-granule, the 

 cells of which in the middle are disintegrating into fatty granular debris. 800 

 diameters. 



