380 



LYMPHATIC SYSTEM. 



It has been a question whether the cell-spaces of the connective tissue are in every case 

 and completely filled by the cells, or whether the spaces may in some cases be either devoid of 

 cells altogether, or but partially occupied by them ; so that room is left for the free passage 

 of fluid. On this point we would remark that in many cases it is impossible to observe a 

 difference between the forms of the cells as shown by the gold method, and those of the xpaces 

 as shown by treatment with nitrate of silver, so that in these instances, at least, no open 

 lymph-passage can be said to exist ; but in other cases the spaces are relatively larger, and 

 here, no doubt, the part unoccupied by the contained cell may be filled by fluid. In 

 cedematous conditions of the tissue, the cell-spaces become somewhat distended with serous 

 fluid, and then in all cases they appear distinctly larger than the cells. Even where the &tft- 

 caniilclirn or lymphatic canaliculi (which correspond with our cell-spaces) are completely filled 



Fig. 438. NITRATE OF SILVER PREPARATION FROM RABBIT*S OMENTUM. (Klein.) MAGNIFIED. 



a, lymphatic vessel ; 6, artery ; c, capillaries ; d, branched cells of the tissue which are seen to be 

 connected both with the capillary walls, and, as at e, with the lymphatic. The cells are, in this 

 instance, stained by the nitrate of silver. 



by protoplasmic cells, lymph can still readily find its way between the cells and the ground- 

 substance by which they are closely surrounded. In other cases where the cells incompletely 

 fill the cavities, a freer passage is left for both fluid and migratory corpuscles. 



A point still more difficult to decide is the existence or not of an open communication 

 between the areolae of the connective tissue and the lymphatic vessels. The result of the 

 inj ection of coloured fluids into the meshes of the areolar tissue in many parts would lead to 

 the conclusion that some such communication may really exist, for the injection most gene- 

 rally finds its way into the lymphatics. But it is very difficult to demonstrate such a con- 

 nection anatomically, and up to the present time it can scarcely be said to be proved. It must 

 be remembered that the ground-substance of the connective tissues is itself by no means 

 impermeable to fluids, nor as we have just stated can it be supposed that the delicate walls of 

 the commencing lymphatics can oppose any material obstacle to the passage of fluid into 

 their cavity. 



