252 ELEMENTARY PHYSIOLOGY. [XXIV. 



nerve fibrils ; in places the fibrils will be seen 

 to run from the sub-epithelial plexus. 

 The peripheral course of the nerve-fibres in 

 the parts of the skin where there are no 

 special terminal organs, is in the main like 

 that described above for the cornea. 



5. Cut sections of the skin of the tip of a finger 

 which has been placed fresh in osmic acid 1 p.c. 

 and subsequently treated with alcohol. Mount 

 the sections in dilute glycerine. Observe the 

 touch-corpuscles. 



a. They are oval in form, and are found in the 

 axes of the papillce ; many papillae are with- 

 out them, in which case a capillary may 

 generally be seen running up into the papilla. 



b. They appear to consist of a mass of connec- 

 tive tissue in which nuclei are disposed trans- 

 versely. 



c. The nerve-fibre reaches it near the base, and 

 may be traced coiling round it spirally for a 

 variable distance. 



Pacinian bodies (cp. 6) may be seen in the 



subcutaneous tissue. 



The touch-corpuscles are also obvious in sections 



of skin hardened in potassium bichromate 1 p.c. 



but the course of the nerve fibre -is less easily 



traced. 



G. Examine the mesentery in a recently killed cat ; 

 in it will be seen a considerable number of oval 

 transparent bodies the Pacinian bodies. Select 



