CUTANEOUS NEEVE-TEEMINATIONS IN MAMMALS. 579 



the other. Further, the cells he describes are not terminal, auy 

 more than any point in a circle can be considered terminal ; for 

 the various cells are united to each other in a ganglion by fine 

 nerve-fibres, which, also unite them with the central nerve-centres 

 and to the subepidermic plexus in general ; and it is these fibres 

 which, becoming entangled and broken in the epidermis, constitute 

 the free endings which he describes as having a separate sensorial 

 function from the cells (see figs. 18, 19, and 20, Plate XY .). That 

 the cells themselves should be considered specially tactile is a quite 

 gratuitous assumption ; in fact, hitherto it has been merely an 

 unwarranted physiological assumption to suppose that either 

 touch or temperature, pleasure or pain, or any other special kind 

 of feeling is separately manifested through difi'erent kinds of 

 nerves or nerve-terminations in the skin. If, however, we are 

 to admit that the sense of touch is conveyed through special 

 nerve-endings, and that the physiological tests which can be tried 

 on one's self are the best, then we should say that it is the 

 forked endings on the hair-folHcles that are the true tactile 

 endings, as one may suppose from the sensitiveness of, for ex- 

 ample, the hairs on the back of the hand or on the face to the 

 lightest impression, say of the touch of a feather or of a wet thread. 

 Thus if a feather, even downy in character, be applied to the 

 back of the hand where the hairs are found, the sensation is di- 

 stinctly felt, whereas on the pulp of the fingers it is absolutely 

 imperceptible, although it is there that the tactile cells of Merkel 

 and free endings in the epidermis are most abundant, where the 

 touch-corpuscles 'par excellence (those we have already described 

 as nerves of aborted hair-follicles) are found, which would be sen- 

 sitive to the ruder touch-impressions, and where the Pacinian 

 bodies, the probable organs of jDressure-impressions, also exist. 



If with our present knowledge it be allowable to suggest any 

 function for the so-called tactile cells and free endings in the 

 epidermis, and, indeed, for the whole subepidermic nerve-system, 

 which we hold includes the others, we should say that it conveys 

 impressions of heat, pain, pleasure, and in fact all sympathetic 

 sensations ; for to the sympathetic nerve-system we consider the 

 whole of what we now describe to belong. It equally influences 

 the blood- vascular system ; and under the microscope it is common 

 enough to trace branches upon the smaller vessels, more especially 

 in the papillae of the skin, that are directly connected and even 

 continuous with intraepidermic branches and with the subepider- 



J.3* 



