64 ANATOMY OF THE LYMPHATIC SYSTEM. 



cells, not only those found free in the fluid, but also those still on the 

 peritoneum, exhibit, in so far, a morphological change, as they appeal- 

 larger, as if swelled up, and their protoplasm is occupied by a greater 

 or smaller number of variously-sized granules. If the fresh membrane 

 is examined microscopically we may recognise that in the circumference 

 of those parts which have become deprived of their endothelium, the 

 individual endothelial cells are distinctly granular, even in the surface 

 view. On silver preparations these spots are distinguished by the 

 endothelial cells becoming more deeply coloured (cseteris paribus), i.e. 

 exhibit a dark granular precipitate. Corresponding to the endothelial 

 cells being more or less loose, we find instead of the well-known 

 sharply-defined silver lines, i.e. instead of the stained intercellular lines, 

 variously-sized, roundish or oblong, dark-coloured, drop-shaped ele- 

 ments. What appear as cell elements are accordingly separated from 

 each other by broad or narrow spaces, in which the above-described 

 bodies lie. I have just said that this substance which appears as black- 

 coloured drops takes the position in which the cementing substance 

 should be found. In fact, nothing is easier than to discover the 

 gradual transition of those broad spaces, filled with the drop-shaped 

 bodies, into the simple dark silver lines. 



The shape, the colouring, the want of every structure, admits of 

 no other interpretation than that just given, namely, that the indivi- 

 dual endothelial cells become loosened, and that there is a more or 

 less fluid substance between them, which has become stained by the 

 nitrate of silver. Whether these drop-like bodies are offsprings of 

 the original cementing substance, or whether they belong to the 

 transudation, would be an idle discussion. From the rapid and 

 abundant transudation from the blood-vessels the loosening of the 

 endothelial cells is quite well conceivable as a simply mechanical 

 result. 



A further important fact is that the nuclei of the endothelial "cells 

 exhibit distinct appearances of division, and this sometimes very ex- 

 tensively. Not only do we find a great number of flat endothelial cells 

 in the fluid, in which the nucleus presents the most various appearances 

 of division, but we especially find, for example, in the centrum 

 tendineum and mesentery, quite extensive places on which we should 



