150 DR. E. KLEIN AND PROFESSOR BURDON SANDERSON. 



learn from many circumstances, arises from the fusion of 

 several subendothelial plasmatic canals, and is covered on one 

 side only with an endothelium. These simple isolated lacunoe 

 communicate with the neighbouring plasmatic canals, or, in 

 other words, the endothelial cells which border the gap are 

 continuous with the surrounding plasmatic canal- cells. 



The endothelium of the surface covering the lacunae is in 

 general flat, only here and there cubical cells with two 

 or three nuclei may be seen arranged round a hole. This 

 hole is an actual breach of continviity in the endothelium 

 leading into the lacuna. It is accordingly a third form of 

 stoma, which also we Avill call a true stoma. 



The subendothelial plasmatic canal-cells are in connection 

 with those of the fascia proper. The latter are also in general 

 flat and more or less branched. At particular spots they are 

 united into groups, and as such form the chief constituents 

 of the nodes, plates, and vascular cords above spoken of, and 

 an enlargement of these structures by multiplication of the 

 plasmatic canal-cells similar to that Avliich takes place in the 

 centrum tendineum may be traced here. In most of them 

 a system of true blood-capillaries may be recognised, which 

 extends itself in proportion as the above-mentioned struc- 

 tures multiply and increase. These vessels are closely con- 

 nected with the plasmatic cells, being completely surrounded 

 by them as by a sheath, and single processes of the cells being 

 directly attached to the capillary wall. The cells are also 

 themselves, as in the centrum tendineum, directly continuous 

 with the endothelial cells of the adjacent lymph- capillaries 

 or lymph-sinuses. 



The formation of new capillary blood-vessels was quite 

 distinctly made out in numerous places to be as foUoAvs : In one 

 of the plasmatic canal-cells which is in connection with the 

 endothelium of the capillary vessels, there arises a cavity or 

 vacuole which extends into a process and ojjens into the 

 cavity of the capillary tube, while the protoplasmic envelope 

 splits up into separate cellular plates. 



Numerous young cells are seen within the plasmatic canals 

 of all these newly formed structures, and are derived from 

 the superficial endothelium. 



Although it is clear from the pathological phenomena and 

 the result of the injections that both the young cells and the 

 foreign bodies introduced into the plasmatic canals are 

 situated KjJon their cells, still it is highly probable that a 

 circulation of these substances also takes place loithin the 

 protoplasma of the cells. 



The adipose tissue which occurs in the omentum in the 



