540 MANUAL OF PHYSIOLOGY. 



of sensation they are devoted. From their comparatively remote 

 relation to the skin, lying some distance beneath it and not in it, 

 as are the other endings mentioned, they are probably connected 

 with the appreciation of pressure sensations rather than those 

 more properly called tactile. 



The sense of touch must be carefully distinguished from ordi- 

 nary sensibility or the capability of feeling pain, which is not a 

 special but a general sensation, and is received and transmitted 

 by different nerve channels. This we know from the facts, that 



FIG. 211. 



Drawing of termination of Nerves on the surface of the Rabbit's Cornea. a, Nerve 

 fibre of subepithelial network; b, fine fibres entering epithelium; c, intraepithelial 

 network. (Klein.) 



the mucous passages in general can receive and transmit painful 

 but not tactile impressions, and that in the spinal cord the sensory 

 and tactile impulses pass along distinct tracts. Further, certain 

 narcotic poisons destroy ordinary sensation without removing the 

 sense of touch. This effect is also brought about by cold, when, 

 for instance, the fingers are benumbed, gentle contact excites 

 tactile impressions, while the ordinary sensations of pain can only 

 be aroused with difficulty even by severe pressure. 



However, most of the nerves we are in the habit of calling 



