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



free communication with each other. The follicular tissue, 

 as a general rule, forms rounded cord-like masses, connected 

 with one another in a plexiform manner ; these are not usually 

 perfectly cylindrical, but present projections, and are some- 

 times even quite moniliform. Near the surface of the lym- 

 phatic glands the follicular cords give off particularly well- 

 marked dilatations of perfectly globular form, constituting the 

 granules that, both on the surface and also on section, are 

 clearly perceptible to the naked eye, and are commonly de- 

 scribed as follicles. The cortically situated follicles of the 

 lymphatic glands are thus nothing but the club-shaped dilata- 

 tions of the follicular cords of the medullary substance, and 

 may be the more easily identified with the latter, since not 

 unfrequently large globular follicles are to be found deeply 

 situated in the medullary substance. The follicular framework 

 is so intercalated in the meshes of the trabecular system, that 

 the superficies of the follicular tissue never comes into imme- 

 diate contact with the superficies of the trabeculae, and the 

 spaces which intervene between the two are the lymph paths. 

 The form of the latter consequently agrees with the form of the 

 two above-mentioned tissues, so that at the superficies of the 

 alveolar trunks they present an approximation to the form of 

 concave spherical shells (lymph sinuses, His ; investing spaces, 

 Frey) ; whilst in the interior of the gland they simply assume 

 the form of the spaces left by the trabeculse of the follicular 

 network. It is easy to demonstrate, from injected prepara- 

 tions, that the vasa afferentia, which, as is well known, are 

 distributed on the surface of the gland, directly open into these 

 concave areas, or lymph sinuses, and thus suddenly become 

 converted from cylindrical tubes into lacuniform spaces. With 

 injections of solutions of silver it is particularly easy to recog- 

 nise the immediate transition from one to the other, on account 

 of the facility with which the epithelium of the afferent 

 lymphatic vessels can be followed on the outer wall of the 

 lymph sinus. It is, however, unquestionably a matter of 

 greater difficulty to establish the origin of the roots of the 

 vasa efferentia from the internal lymph paths. This is not in 

 any measure due to any difficulty of filling the vasa efferentia 

 with injection in the direction of the current. On the con- 



