222 



THE NERVOUS SYSTEM. 



the skin (Fig. 87). They are associated with the sense of 

 touch, and are most numerous in the hands and feet, where 

 the tactile sense is delicate. The details of their structure are 

 obscure. They are elongated, elliptical bodies, lying in the 

 axis of the papillae, and exhibit transverse or spiral markings. 

 At their lower extremity they are joined by a medullated nerve- 

 fibre (or sometimes more than one), the axis-cylinder of which, 

 losing its coverings, enters the corpuscle, within which it winds 



FIG. 



FIG. 87. 



Tactile corpuscle of Wagner, from 

 human corium (Bohm and 

 Davidoff). 



End-bulb of Krause, from human 

 conjunctiva (Dogiel). 



about and sends off lateral branches. Some authorities regard 

 these corpuscles as aggregations of transverse flat tactile cells, 

 others consider them connective-tissue structures with trans- 

 verse septa. 



End-bulbs or tactile corpuscles of Krause (Fig. 88) : These 

 are small spherical structures in which medullated fibres ter- 

 minate, and pertain to the sense of touch. They occur in the 

 conjunctiva and adjacent portion of the cornea, in the corium 



