36 ANATOMY OF THE LYMPHATIC SYSTEM. 



they stand to the actual Ivmphatic vessels. We have already stated 

 that the larger patches are provided with a system of blood-vessels. 

 Disregarding at present the exact details, we shall merely, mention 

 that this system consists of an afferent arteriole, efferent veins, and 

 intermediate capillaries. Regarding, now, the lymphatic system of 

 these patches, it is always to be observed that the efferent vein, more 

 seldom also the afferent artery, is accompanied by at least one capil- 

 lary lymphatic, or is even invaginated in one such. At the point 

 where the vein becomes the capillary that is, where it enters the patch 

 the lymphatic as such terminates, that is to say, its hitherto 

 sharply-defined wall and covering of sinuous endothelium ceases, 

 and only the lymph-canalicular system appears in its place. 



There can be no doubt whatever, if a favourable point is closely 

 observed, that at the point the lumen of the lymphatic vessel on the 

 one hand loses itself in reality in a labyrinth of spaces, which consist 

 of lacunae with uniting canals, representing the lymph-canalicular 

 system, and, on the other hand, the endothelial plates of the lymphatic 

 are continued as branched cell-plates. 



The appearances just now mentioned correspond towhatReckling- 

 hausen first described as to the origin of the lymphatic capillaries in 

 the centrum tendineum of the rabbit, with the addition of the fact 

 that the endothelium continues itself in the lymph-canalicular sys- 

 tem as branched cell-plates. We call, therefore, these patches or 

 nodules peri-lymphangial nodules. When the lymphatic capillary 

 issuing from the nodule is of the invaginating kind, as in Fig. 40, 

 one may see at any time several points at which the lymphatic vessel 

 throws out one or the other of its branches to the lymph-canalicular 

 system of the surrounding tissue. 



We come now to the consideration of the important relation 

 of that kind of nodules which we have described in Chapter II. 

 under c. 



We find, for example, a wide lymphatic vessel invaginating a 

 venous trunk ; the vein collects a small number of capillaries, which 

 come off from a small arterial branch. The lymphatic vessel, however, 

 does not cease to exist as such at the point where the capillaries 

 debouch in the 'vein, as in the former case, but continues on to the 



