518 LECTURE XX. 



(Knotchen), but expresses an equable pervasion of the 

 whole parenchyma, a track was hereby opened, in follow- 

 ing which the old idea of tubercle has more and more 

 been departed from. As soon as the infiltration of tuber- 

 cle had once been created and the form of the neoplasm 

 had thereby been abandoned, the infiltration was gene- 

 rally, as being more extensive and therefore more instruc- 

 tive, taken as the basis of subsequent descriptions, and 

 attempts were made to find out in what respects it really 

 agreed with the other, previously known forms of tuber- 

 cle. It was in this way, that the cheesy stage of tubercle 

 came to be gradually adopted as the common generic 

 characteristic of all tuberculous products, not merely as 

 the principal aid in diagnosis, but as the starting-point 

 for the interpretation of the process in general. It was 

 in this way, in particular, that the idea came to be enter- 

 tained, that tubercles could arise simply by any exuda- 

 tion's losing its water constituents, growing thick, turbid, 

 opaque, cheesy, and remaining in this condition. 



The term, tubercle-corpuscles (corpuscules tubercu- 

 leux), which is, you know, still in very frequent use, has 

 reference to just this cheesy stage, and the accurate de- 

 scription which Lebert has given of them amounts to this 

 that they are formations which correspond with none 

 of the known organic forms, and are neither cells, nor 

 nuclei, nor anything else of an analogous nature, but 

 appear in the form of little, roundish, solid corpuscles, 

 which frequently have particles of fat scattered through 

 them (Fig. 64). But if the development of these corpus- 

 cles be investigated, it is easy to convince oneself that, 

 wherever they occur, they arise out of previous organic 

 morphological elements, and that they are not by any 

 means the first bungling products, unfortunate essays of 

 organization, but that they were once well-grown elements, 

 which by an unhappy chance were early checked in theu 



