LYMPHATICS OF THE SKIN. 225 



riparous glands, etc., form in its deeper parts a close vascular 

 plexus, from which again oblique branches are given off to the 

 more superficial portion. Near the surface of the corium, and 

 between its pars reticularis and papillaris, is a second vascular 

 plexus, the meshes of which are finer than the former, and 

 indeed correspond in their size to that of the bases of the 

 papillae. Simple capillary loops, proceeding from this plexus, 

 penetrate the papillae, and running near their axes reach almost 

 to their extremities. It is not every papilla, however, that 

 is provided with a vascular loop ; since, speaking generally, 

 those papillae into which medullated nerve fibres enter are 

 destitute of vessels, although there are numerous exceptions to 

 this rule. 



LYMPHATICS OF THE SKIN. 



It is necessary, in the case of the skin, to distinguish between 

 lymphatic vessels and lymphatic spaces. The former constitute 

 closed tubes, bounded by proper walls, whilst the latter are 

 lacunae between the bloodvessels and lymphatics that are 

 filled with lymph. The lymphatics of the subcutaneous con- 

 nective tissue provided with a muscular coat anastomose fre- 

 quently, and run obliquely to the deep surface of the corium, 

 where, like the bloodvessels, they form a double plexus, one 

 lying upon the other (Teichmann, Young). 



The lymphatic plexus of the upper part of the corium 

 lies beneath the vascular plexus, and forms polygonal meshes 

 of small vessels, that, according to Teichmann, have a diameter 

 of O'OIS to 0*054 of a millimeter. The deeper plexus lies again 

 beneath the deeper vascular plexus, and consists of larger ves- 

 sels with coarser meshes than the upper. The anastomoses be- 

 tween the two plexuses are effected by a few relatively large 

 vessels running obliquely from one to the other. In the natural 

 state no lymphatics enter the papillae; but in the hypertro- 

 phied papillae of the sole of the foot a few branches penetrate to 

 about half their length, and terminate caecally (Teichmann). 



The walls of the lymphatics in the upper part of the corium 

 present cell markings that can be brought into view by means 

 of nitrate of silver, subjacent to which, in the deeper-seated 

 lymphatics, is a fine plexus of elastic fibres. 



VOL. II. Q 



