328 THE LYMPHATIC SYSTEM, BY F. v. RECKLINGHAUSEN. 



that the surface of each follicle is invested by an extraordi- 

 narily close network of lymphatic vessels, the several branches 

 of which are widely separated from those of the neigh- 

 bouring follicles. The results of the investigations of 

 His and Recklinghausen have further shown, and the same 

 thing may be recognised in the illustrations accompanying 

 Teichmann's work, that it is common for the follicles of the 

 intestine to be surrounded by a lymph lacuna, and for the 

 lymphatic plexuses to have become so close that the several 

 tubes coalesce with one another to form a single spheroidal 

 fissure. These lacunae or lymph sinuses (according to His) 

 in some instances surround nearly the whole surface of the 

 follicle, leaving only that extremity or pole uncovered which is 

 directed towards the surface of the mucous membrane ; the 

 follicle therefore hangs freely in the lymph path, or in what 

 we may consider as an enormously dilated portion of it. That 

 we are here dealing with lymphatic lacunse, analogous to the 

 lymph sacs of the Amphibia, and not with simple interstices or 

 spaces between the tissues, is obvious from the action of solu- 

 tions of silver, which bring into view a distinct epithelium 

 immediately continuous with that lining the efferent or larger 

 tubes of the lymphatics. 



The follicles of the digestive tract must therefore undoubt- 

 edly be regarded as belonging to the lymphatic system ; they 

 probably form lymph cells in their interior, which pass into the 

 lymph lacunse, and then constitute ordinary lymph corpuscles. 

 The relations of the epithelium investing the follicle on the sur- 

 face directed towards the lymph lacuna, and the presence or 

 absence of persistent openings for the passage of lymph cor- 

 puscles, are points that still remain to be elucidated. 



Relations to the lymphatic system, of so intimate a nature as 

 this, have, up to the present time, only been demonstrated in 

 the above-mentioned follicles, whilst really nothing is known 

 respecting the lymphatics of the well-known Malpighian cor- 

 puscles of the spleen, though they otherwise agree in structure 

 with the follicles of the intestine ; and we are equally ignorant 

 of the lymphatics of the rest of the splenic tissue. The rela- 

 tions of the Thymus, again, which essentially consists of follicu- 

 lar tissue, to the lymphatic vessels, has also not hitherto been 

 demonstrated. 



