48G ORIGIN OF LYMPHATICS. [BOOK n. 



directly into the lymph-capillaries. When a piece of connective- 

 tissue, such for instance as that lying between the radiating 

 bundles of the tendon of the diaphragm on the pleura! side is 

 treated in a particular way, the result is what is called a "negative 

 staining"; the matrix is stained brown but the corpuscles and 

 ra\ities are left unstained, and appear as irregularly branched 

 clear patches standing out in contrast with the brown matrix. 

 In such a preparation many of these clear spaces are seen to 

 abut upon and apparently to lose themselves in a neighbouring 

 lymph-capillary, which also always stands out in contrast to the 

 matrix, appearing as a clear space marked with the sinuous 

 outlines of its plates. 



Without insisting too much on the argument drawn from this 

 negative staining, and resting rather on the facts previously 

 mentioned and on general considerations, we may probably conclude 

 that all the spaces of connective-tissue, including the cavities of 

 the corpuscles, form a labyrinth of passages Avhich is to be con- 

 sidered as the real beginning of the lymphatics, and that this 

 irregular labyrinth is in some way or other in fairly free communi- 

 cation with the more regular but still labyrinthine lymph-capillaries, 

 lined by a definite epithelioid lining, and that from thence the 

 lymph passes on to the regular and valved lymphatic canals. 



All over the body wherever blood vessels go connective-tissue 

 and lymph-spaces go too. Certain parts of the plasma of the blood 

 passing through the walls of the blood vessels become lymph in 

 these lymph-spaces. As such it soaks through not only the bundles 

 of gelatiniferous fibrillse of the connective-tissue itself, but also 

 the basement membrane and so the epithelium of the mucous 

 membrane and its glands, the unstriated muscular fibre, the sarco- 

 lemma and muscle substance of the striated fibre, the neurilemma 

 and contents of the nerve-fibre of nerves, in fact the elements of all 

 the tissues which are supplied with blood vessels. More than this, 

 lymph goes where blood vessels do not go, and in these situations 

 the value as lymph-passages of the cavities of the corpuscles seems 

 most striking. In the cornea for instance blood vessels and 

 definitely constituted lymphatic vessels cease near the periphery, 

 and the greater part of the nutrition of the cornea (beyond that 

 effected by what we may call mere imbibition, that is by the 

 passage of fluid between the molecules of the actual substance of 

 the tissue) is carried on by the stream of lymph through the cor- 

 puscular cavities. In a similar way in bone lymph finds its way 

 from the blood vessels of the periosteum, marrow and Haversian 

 canals through the very substance of the bone by means of the 

 labyrinth of lacunas and canaliculi. And in cartilage we have 

 reason to think that minute passages in the matrix facilitate the 

 transmission of lymph from the perichondrium through the body 

 of the cartilage from cartilage cell to cartilage cell, far more 

 efficiently than if its progress were left to mere imbibition. The 



