194 



COMPARATIVE ANATOMY 



FIG. 154A. A TACTILE 



SPOT FROM THE SKIN 



OF THE FROG. Semi- 

 diagrammatic. (Modi- 

 fied from Merkel. ) 



N, nerve, which loses its 

 medullary sheath at JV n ; 

 a, a, neuro-epithelium ; 

 ft, epidermis. 



FIG. 154c. A TACTILE CORPUSCLE [(END-BULB) 

 FROM THE MARGIN OF THE.; CONJUNCTIVA OF 

 MAN. (After Dogiel. ) 



n, medullated nerve fibre, the axis-fibre of 

 which passes into a closely coiled terminal 

 skein ; b, nucleated fibrous investment. 



FIG. 154B. DERMAL PAPILLA 

 FROM THE HUMAN FINGER 



ENCLOSING A TACTILE CoR- 



PUSCLE. (After La wdowski.) 



a, fibrous and cellular invest- 

 ment ; />, tactile corpuscle, 

 with its cells ; M, nerve-fibre ; 

 n', the further course of the 

 nerve-fibre, showing its 

 curves and bends ; n", termi- 

 nal twigs of the nerve-fibres 

 with club-shaped endings. 



FIG. 154D. TRANSVERSE SECTION 

 THROUGH A TACTILE CORPUSCLE 

 FROM THE BEAK OF A DUCK. 



(After Carriere.) 



n, nerve, entering the capsule K, 

 its sheath (S) becoming con- 

 tinuous with the latter. The 

 nerve passes between the two 

 covering-cells, DZ, DZ, widen- 

 ing out to form a tactile plate 

 at n\- 



