CHAPTER VI. 



ON CUTANEOUS AND SOME OTHER SENSATIONS. 

 SEC. 1. THE NERVE ENDINGS OF THE SKIN. 



869. WE may speak of all the sensations which we derive 

 from the skin as "cutaneous sensations;" we shall later on discuss 

 their various kinds. The afferent nerves of the skin, those 

 which appear to serve as the channels for impulses giving rise 

 to cutaneous sensations, appear to end in two main ways. In the 

 first place nerve fibres given off from a plexus of medullated 

 fibres lying in the dermis immediately below the epidermis pass 

 upward with loss of their medulla into the epidermis, and there, 

 dividing into delicate nerve fibrils, come into connection with, or 

 are lost to view between the epidermic cells. In the second 

 place, nerve fibres still retaining their medulla and for the most 

 part running singly, end in the dermis at a variable distance 

 below the epidermis in special structures made up of modi- 

 fications of the neurilemma, or other wrappings of the nerve 

 fibre, associated more or less distinctly with cellular elements. 

 We will consider the latter kind of ending first. In man the 

 endings of this kind are two : the end-bulbs of limited, and the 

 touch-corpuscles of much more general distribution. To these 

 we must add the Pacinian corpuscles, which however are found 

 not in the dermis proper, but in the subcutaneous connective 

 tissue, and which cannot be considered as distinctly cutaneous 

 organs, since they also occur far away from the surface of the 

 body, in connection with joints and the periosteum of bones 

 and even with internal organs. They can hardly be considered 

 as cutaneous organs, but they cannot be left unnoticed. In 

 various animals we meet with other forms of nerve endings, the 



