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ing endothelium of the lymphatics and an intervening lattice work of 

 connective tissue fibrils. The endothelium, as shown by all the re- 

 cognized methods, forms a complete unbroken membrane, the cells of 

 which are most accurately adapted to one another leaving no per- 

 forations whatever. The intervening lattice work which is possibly 

 continuous with the general basement membrane of the peritoneal 

 epithelium seems to correspond with the fenestrated basement mem- 

 brane described by Bizzozero and Salvtoli as covering the lacunae. 

 Injection of these canals with colored masses tends further to prove 

 the completeness of their walls for they may be widely distended over 

 a large area without any leakage. Increased pressure and long dur- 

 ation of the injection will, it is true, give rise to an oozing of the fluid, 

 but since only a clear fluid comes through when one injects a sus- 

 pension of colored material it seems evident that this is merely a 

 filtration process. 



The granules injected into the peritoneal cavity, nevertheless, enter 

 the lymphatics of the diaphragm in great numbers and soon appear in 

 the mediastinal lymph glands. 



If the injection be made into the living animal it is found after 

 a short time that the peritoneal fluids are swarming with phagocytic 

 leucocytes, each laden with some of the granules and investigation of 

 the roofs of the lacunae in such a case reveals these leucocytes making 

 their way with their load of pigment between the cells through the 

 roof, into the lumen of the lymphatic where they lie in great numbers 

 and are swept on to crowd the lymph sinuses of the mediastinal glands. 

 This process is but slightly affected by the movements of respiration, 

 as can be shown by immobilizing the diaphragm by opening the thorax 

 under artificial respiration. This activity of the phagocytes therefore 

 in transporting granules from the peritoneum into the lymphatics seems 

 to be of the outmost importance. When, however, we eliminate all 

 phagocytic action by killing the dog and allowing it to grow cold one 

 can show, as has been so frequently shown by Ludwig and others, 

 that the granules will still enter the lymphatics of the diaphragm if 

 one eviscerate the dog and hang up the body under artificial respir- 

 ation so that the suspension of granules may be poured on the con- 

 vexity of the diaphragm. The absorption is then mainly if not com- 

 pletely dependent upon the pumping action of the respiratory move- 

 ments. Under these conditions the granules do gain entrance into the 

 lymphatics in considerable quantities, although not so abundantly as 

 when aided by the phagocytic cells. The elimination of every possible 

 vital phenomenon by the killing of all the cells concerned with for- 

 malin, hot-water etc. seemed to prove that the process is a mechanical 



