340 THE LYMPHATIC SYSTEM, BY F. V. RECKLINGHAUSEN. 



in those of the mesentery, whilst it is usually altogether absent in 

 the lymphatic glands of the dog, whilst the medullary substance and 

 the efferent vessels, as already mentioned, are much more visible upon 

 the surface. The lymphatic glands of the pig exhibit peculiarities of 

 quite an opposite character ; here the follicular structure preponde- 

 rates in extent over the lymph path, and nodal dilatations appear 

 throughout the entire medullary substance on the follicular cords ; 

 that is to say, true follicles are formed, which make their appearance on 

 section when examined with the naked eye, and the lymph path is so 

 narrow that its injection can only here be effected with the greatest 

 difficulty. According to Franz Schmidt, in other parts of the body of 

 the pig, as in the pharynx, exceedingly strongly developed follicles are 

 found ; but it requires still further investigation to determine whether 

 this is a consequence of the fattening of these animals, as Schmidt 

 thinks, or whether it results from some peculiarity of this genus. 



A more exact investigation is still required in order to determine 

 the relations of the epithelia to the several tissues of the lymphatic 

 glands. I have been unable to discover any epithelial layer on the 

 follicular cords. The mode of connection of the fibrous framework with 

 the epithelium is of special interest. I have frequently distinctly seen 

 that epithelial cells are continued from the surface of the trabeculaa 

 upon the thicker fibrils (see fig. 63, d ) ; these consequently possess 

 an epithelial investment of the same kind as the nerves which traverse 

 the lymph sacs of the frog. It still remains to be ascertained whether 

 this relation is generally present or is only partial, and whether the 

 follicular cords, as has hitherto appeared to me, are destitute of epithe- 

 lial cells, and thus lie naked in the lymph path. 



The CHYLE, or milk-white fluid formed during digestion, 

 and contained in the lymphatics of the intestine, and the LYMPH, 

 which is the colourless, slightly opalescent fluid contained in 

 the remaining portions of the lymphatic system, coagulate like 

 the blood, and then separate into an albuminous serum, and 

 a clot, which last contains the morphological elements the 

 lymph corpuscles or cells. In addition to these there are 

 found, though in very variable proportion, small granules of 

 rather high refractive index, which were formerly termed 

 elementary granules, and are in all probability minute drops of 

 oil. In the chyle there are also extremely small points like- 

 wise consisting of oil, and termed the molecular base of the 

 chyle ; these are present in such enormous numbers as to 



