166 REPORT — 1875. 



grow larger, till each nucleus is able to separate with its own particle of proto- 

 plasm to form an independent, although irregularly shaped fiat cell, the so-called 

 branched or lymphatic cell of the gi-ound substance ; in other words, the connective- 

 tissue cell of a basement membrane. The varieties of form which these cells now 

 assume are unlimited. At one spot in the same preparation the authors can see 

 them pressing together to form the flat and irregularly hexagonal or round cells of 

 the endothelium from (and lying upon) the cells of the basement membrane. At 

 another place they have seen them elongating into fibrous tissues, such as are seen 

 in the skin or in the wall-tissue of an ovarian cyst. When several months ago they 

 discovered that, after rubbing epi- or endothelium off' the surface, and ti-eating the 

 thus exposed surface with silver, there were presented to notice the cells of lym- 

 phatic ground substance, they (having verified this on several structures) supposed 

 they had discovered that basement membranes were really lymphatic membranes. 

 Belbre, however, they had canied their investigation much further, they found that 

 Dr. Debove, of the College of France, had a few months before anived at the same 

 conclusion in regard to the basement membrane of the epithelium of the respiratory 

 and alimentary tracts, and that Dr. Slavianski had done the same in the case of tlie 

 lining of the Graafian follicle. They had, however, discovered that the basement 

 membrane under the human epidermis had the same significance, which Debove 

 had only suggested as probable, but had been unable to demonstrate. While con- 

 tinuing their investigations, they found, after stripping this thin layer or supposed 

 basement membrane from the inside of the wall of an ovarian cyst, an identical 

 structure underneath ; and the same process could be often repeated with always 

 the same result. Thus they were led to see that, these several sheets being identical 

 with each other and with basement membrane, the so-called lymphatic ground 

 substance was formed of the cells of connective tissue, of which basement mem- 

 brane was itself composed. But just as the cells of basement membrane have 

 been called lymphatic cells, so were the cells of these different layers quite as much 

 lymphatic cells ; and found as they are in all tissues, they constitute the radicles of 

 the lymphatic sj'stem. The shape and position assumed by these cells depend on 

 the form of the tissue proper of the organ in which they are found ; separating the 

 tissues proper from each other, while they are largely connected between them- 

 selves, they form nutrient channels, by means of which the tissues proper may 

 supply themselves from the liquid pabulum which passes along the chains of these 

 connective-tissue cells or lymphatic radicles. 



The lymphatic circulation begins in this manner. The branched cells whicli we 

 see depicted in the drawings of all careful observers as lying alongside of the capil- 

 laries and forming the tunica adventitia of small vessels form, the authors believe, 

 the proximal points of the nutrient lymphatic system to the blood- vascular system. 

 From these proximal cells the liquid pabulum is passed on into other similar cells, 

 A\'ith which they have innumerable anastomoses; and the process thus continued 

 through innumerable intricate networks of anastomosing lymphatic radicles or 

 connective-tissue cells, we have, finally, a joining of these cells with lymphatic 

 capillaries or small sinuses, carrj'ing the now effete liquid pabulum (now called 

 Ivmph) into the trunks of the lymphatic system and thence into the blood. 

 " The authors believe that, as the seat of nutrition has been formerly removed from 

 the smaller blood-vessels into the capillaries, so must we now further renio%e it from 

 the capillaries into the network of anastomosing connective-tissue cells or lymphatic 

 radicles. Nor is this hypothesis of nutrition connected with or depending on an 

 hypothetical position or condition of the cells themselves. The authors have 

 traced the cells of the tunica adventitia of a vein until they joined together in 

 opening into a small lymphatic vessel ; but it is from the drawings of others that 

 they prefer to prove this arrangement. Take, for instance, some of Klein's beautiful 

 plates in his monograph on the lymphatics ; we thei-e see, in his drawing No. -34, 

 the branched cells extending by anastomoses amongst themselves, between the 

 smaller vessels of the blood and lymphatic systems. 



Upon the more or less permeable or channelled condition of those cells the 

 autliors did not dilate, although they pointed out that the well-known hollowing 

 out of these branched cells to form new capillaries at the blood-vascular end is pro- 

 bably only the result of a demand for an excessive supply of liquid pabulum from 



