8o 



CUTIS. 



[sect. 39. 



Fig. 3G. 



Vessels 



the cutis. 



of the pajiillte of one entire 

 After Berres. 



and two half ridges of 



which supply the papillae. With certain exceptions, it is only the 



vascular papillae which 

 possess such capillary 

 loops, the simple papillae 

 one loop, the branched 

 several loops, which ex- 

 tend, either in the axis or 

 more towards the surface, 

 near to the apex, and 

 present a gently waving 

 or well-marked tortuous 

 course, or are even twisted 

 round each other in a 

 spiral form. 



The large trunks of the lymphatic vessels can be easily recog- 

 nised in the subcutaneous cellular tissue, and are very numerous. 

 In the corium itself, various anatomists have demonstrated the 

 lymphatic vessels by means of injections of mercury. All agree 

 in this, that they exhibit an uncommonly dense network of fine 

 vessels, measuring, according to Krause, from ^ to ^V °f a line; 

 that in the deeper parts the meshes become wider, the vessels 

 larger, and, finally, communicate bj r single trunks with the vessels 

 of the subcutaneous tissue. Still, it is not yet known whether 

 these plexuses are the real origins of the lymphatics of the skin. 



§ 39. Nerves. — The skin, in the portion next the epidermis, 

 especially in certain places, is one of the structures of the frame 

 most abundantly provided with nerves, while, in the deeper regions, 

 it is remarkable for their scantiness. In the jiwiniculus adiposus 

 and the fascia superficialis no nerves have been hitherto recognised, 

 except those which pass through those parts to the cutis, or pro- 

 ceed to the hairs, glands, smooth muscles, and Pacinian bodies, of 

 which we shall afterwards speak. In the corium itself, the trunks 

 which pass through the areolae of its inner surface ascend gradually, 

 continually giving off branches, but without actually forming ter- 

 minal expansions, towards the papillary layers. Here, anastomosing 

 frequently, they form rich terminal plexuses, in which deeper and 

 more superficial portions can be distinctly distinguished ; the 

 former composed of fine branches, containing several primitive 

 fibres, with wide meshes; the latter of single fibres, or of pairs of 

 fibres, with narrow interstices. In the latter, or the finer terminal 

 plexus, there also occur (whether in all the fibres is not yet 



