256 



COMPARATIVE ANATOMY 



FIG. 187A. A TACTILE 

 SPOT FROM THE SKIN OF 

 THE FROG. Semi-dia- 

 grammatic. (Modified 

 from Merkel. ) 



a, a, neuro-epithelium ; b, 

 epiderm; A r , nerve, which 

 loses its medullary sheath 

 at X 1 . 



FIG. 187c. A TACTILE CORPUSCLE (END-BULB, 

 OR KRAUSE'S CORPUSCLE) FROM THE MARGIN" 

 OF THE CONJUNCTIVA OF MAN. (After 

 Dogiel.) 



/', nucleated fibrous investment ; n, medullated 

 nerve fibre, the axis-fibre of which passes 

 into a closely coiled terminal skein. 



H 



FIG. 187B. DERMAL PAPILLA 

 KROM THE HUMAN FINGER 

 ENCLOSING A TACTILE COR- 

 ITSCLE (MEISSNBR'S COR- 

 PUSCLE). (After La wdowski.) 



a, fibrous and cellular invest- 

 ment ; b, tactile corpuscle, 

 with its cells ; n, nerve-fibre ; 

 n', the further course of the 

 nerve-fibre, showing its curv- 

 ing branches ; n", terminal 

 twigs of the nerve-fibres with 

 club-shaped endings. 



FK;. 187o. TRANSVERSE SECTION- 

 THROUGH A TACTILE CORFU SIM: 

 (GRANDRYS' CORPUSCLE) FROM 

 THE BEAK OF A DUCK. (After 

 Carriere. ) 



n, nerve, entering the capsule A', 

 its sheath (8) 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 )i\ 



surfaces of the hand and foot respectively and on the conjunctiva 

 and snout, and are especially well-marked on the snout in the Mole : 



