n6 



ELEMENTS OF HISTOLOGY. [Chap. xv. 



and which is a single efferent medullated nerve-fibre 

 (Fig. 71), differing from an ordinary medullated nerve- 

 fibre merely in the fact that outside the neurilemma of 



the nerve-fibre there is 

 present a thick laminated 

 connective tissue sheath, 

 which is the sheath of 

 Henle continuous with 

 the perineural sheath of 

 the nerve branch with 

 which the nerve-fibre is in 

 connection. This medul- 

 lated nerve-fibre within its 

 sheath possesses generally 

 a very wavy outline. The 

 corpuscle itself is com- 

 posed of a large number of 

 lamellee, or capsules, more 

 or less concentrically ar- 

 ranged around a central 

 elongated or cylindrical 

 clear space. This space 

 contains in its axis from 

 the proximal end, i.e., the 

 one nearest to the stalk , to 

 near the opposite or distal 



end, a continuation of the nerve-fibre in'the shape of a 

 simple axis cylinder. But this axis cylinder does not 

 fill out the central space, since there is, all round the 

 faintly and longitudinally striated axis cylinder, a good 

 deal of space left filled with a transparent substance, in 

 which, in some instances, rows of spherical nuclei may 

 be perceived along the margin of the axis cylinder. 

 At or near the distal end of the central space the 

 axis cylinder divides in two or more branches, and 

 these terminate in pear-shaped, oblong, spherical, or 

 irregularly-shaped granular-looking enlargements. 



Fig. 71. A Paciniaii Corpuscle, 

 from the Mesentery of the Cat. 



a, The medullated nerve-flbre ; b, the 

 concentric capsules. 



