THE SKIN. 387 



superficial narrow-meshed plexus immediately beneath the papillae. 

 Into the latter empty the lymph-vessels coming from the papillae. 

 After treating the skin by certain methods, a fine precipitate may be 

 noticed here and there in the papillary region of the corium, a 

 proof that lymph clefts are present. These are regarded as the 

 beginnings of the cutaneous lymphatic system. They may also be 

 traced into the epithelium, where they are in direct communication 

 with the interspinal spaces between the epithelial cells (Unna). 

 Cells are also met with in the interspinal spaces of the epidermis ; 

 these are migratory cells, or cells of Langerhans. 



The skin owes its great sensitiveness to the numerous nerves 

 and special nerve-endings present, not only in the epithelium, but 

 also in the corium and subcutis. In certain regions of the skin the 

 nerves have been traced into the epithelium. In the finger-tip, for 

 instance, numerous nerves are seen in the epidermis, where they 

 branch and end in telodendria with or without small terminal swell- 

 ings. There is no direct communication between the terminal 



" Nerve - flber - 



Nerve-fiber. 



M 



\ Nerve-fiber. 



Fig. 310. Meissner's corpuscle from man ; Fig. 311. Meissner's corpuscle from man 

 X 750- X 750. 



nerve filaments and the epithelial cells. (Fig. 309.) In certain 

 peculiarly sensitive regions, as the end of the pig's snout, the nerve- 

 fibers end in distinct saucer-like discs (tactile menisci) which, as a 

 rule, clasp the lower ends of the basal Malpighian cells. 



The special sensory nerve -endings are situated in the corium 

 and subcutis. Of these, we may mention the tactile corpuscles of 

 Meissner, the end-bulbs of Krause, the Pacinian corpuscles, Ruf- 

 fini's nerve-endings, and the Golgi-Mazzoni corpuscles. All these 

 special sensory nerve-endings with the exception of the two last 

 mentioned have been discussed in a former chapter (p. 169). Meiss- 

 ner's tactile corpuscles are situated in the tactile papillae of the 

 true skin. They are especially numerous in the hand and foot. 



