78 ANATOMY OF THE LYMPHATIC SYSTEM. 



branched cells being decidedly more abundant, less branched, their 

 processes uncommonly broad. In some places the cells are so 

 closely situated by each other that they resemble an endothelium ; 

 in this case they are separated from each other by linear inter- 

 cellular substance. In Fig. 14 this change is very distinctly to 

 be seen. 



This figure is taken from a silver- stained preparation of centrum 

 tendineum of a guinea-pig suffering from slight chronic inflamma- 

 tion. At b an important change of the branched lymph-canalicular 

 cells has taken place, the same being arranged like an endothe- 

 lium after having undergone division. To the greatest extent this 

 change is to be found in the tubercular nodules which have their 

 seat in the serosa of the pleural surface. Fig. 22 is a silver prepara- 

 tion of a tuberculous diaphragm of a guinea-pig. The branched 

 lymph-canalicular cells have all undergone the above-mentioned 

 change, being now arranged like an endothelium, with the difference, 

 however, that the cells are for the most part separated by thicker 

 tracts of intercellular material. 



I may mention here that I have frequently succeeded in injecting 

 the lymph-canalicular system of the peritoneal serosa, as well as of 

 the tendons of the centrum tendineum, in some cases also that of the 

 mesentery and the peritoneum parietale, with colouring material ; 

 namely, in guinea-pigs which suffered from artificial tuberculosis, and 

 in rabbits in the peritoneal cavity of which starch and water had been 

 injected several weeks before. In these cases anilin and milk (an 

 alcoholic solution of anilin is mixed with so much water that the 

 anilin is precipitated in form of very fine granules), has been intro- 

 duced into the peritoneal cavity of the affected animals in a quantity 

 of about 4 c.c. ; after twenty-four to forty-eight hours the animals were 

 killed. On microscopical preparation of the centrum tendineum 

 there were many places to be found in which the inflammatory 

 changes of the branched lymph-canalicular cells were very slight, and 

 on which places not only the protoplasm of the branched cells and 

 that of the migratory cells, but also the lymph-canaliculi themselves, 

 contained more or less numerous anilin granules. To a very great 

 extent that was the case in a rabbit which suffered from chronic 



