MODE OF TERMINATION OF THE CUTANEOUS NERVES. 235 



nerve fibres can be distinguished running sometimes obliquely, 

 sometimes longitudinally, which are accompanied by less 

 deeply tinted small nuclei; such sections, however, furnish 

 no information in regard to their ultimate course or division. 



The corpuscles of Meissner are thus, like those of Pacini, the 

 terminal structure of a medullated nerve ; but we are still un- 

 acquainted with the mode of termination of the axis-cylinder. 



The tactile corpuscles are most constant and most numerous 

 in the terminal phalanges of the fingers. According to Meis- 

 sner,* there are on each of these 108 tactile and 400 vascular 

 papillae. They occur in smaller numbers on the palm of the 

 hand and sole of the foot, and on the dorsum of the hand and 

 foot, whilst they are not constantly present on the nipple 

 (Kolliker, Krause), nor on the lips (Kolliker, Krause, Henle). 



TERMINATION OF THE NON-MEDULLATED NERVE FIBRES. 



The non-medullated fibres form, by the side of the vascular 

 plexus of the pars reticularis corii, a plexus composed of a few 

 thick and many very fine smooth and varicose nerve fibres, by 

 the side of which are numerous nuclei. A few fibres pass off 

 from this plexus towards the mucous layer, beneath which they 

 sometimes run for some distance, and then suddenly bend to 

 enter its substance. Others extend to the papillae, in which 

 they divide, and ascend between the cells of the mucous layer 

 (Langerhans, Biesiadecki). These relations can only be seen 

 in specimens stained with chloride of gold ; but the preparation 

 of the skin by this method is a matter of great difficulty, on 

 account of the thorough imbibition of the corium being generally 

 only incompletely effected, in consequence of the impermeability 

 of the epidermal layers. For this reason Langerhans has re- 

 commended that a few drops of acetic acid should be added to 

 the solution of chloride of gold, in which the thin sections of 

 the cutis are macerated. 



In specimens thus prepared the nerve fibres that enter the 

 mucous layer are rendered visible, and terminate with bulbous 

 extremities at about the level of the third tier of cells. Langer- 



* Beitrage zur Anatomie und Physiologic, der Haut. Leipzig, 1863. 



