STRUCTURE OF THE CORPUSCLES OF PACINI AND MEISSNER. 233 



assume a red colour with chloride of gold. When seen from 

 the surface, the membranes, both when fresh and after treat- 

 ment with various reagents, exhibit a slightly punctated, 

 homogeneous appearance, with only indistinct indications of 

 striation. 



Solution of silver brings out markings resembling those on 

 the lymphatics.* These consist for the most part of irregu- 

 larly pentagonal areas, bounded by sinuous dark-brown lines, 

 within which the above-mentioned nuclei lie. 



The medullated nerve fibres enter these terminal onion-like 

 structures in a spiral manner, and extend into the cavity of 

 the innermost and smallest capsule. The axis-cylinder runs 

 up the middle to its blind end, and there ceases with one or 

 several finely granular terminal bulbs. 



The nerve medulla, on the other hand, fills this cavity, forming 

 either a finely granular mass (the internal bulb of Kolliker) or 

 an irregularly and coarsely coagulated body, that appears dull 

 in comparison with the nerve medulla, but, like it, assumes 

 an intense violet-black colour when treated with solution of 

 chloride of gold. 



In close proximity to the nerve fibre a large bloodvessel 

 penetrates into the interior of the corpuscle, and forms a close 

 capillary plexus between the outer capsules. 



In Man the corpuscles of Vater measure from 11 to 4*5 

 millimeters in length, and are constantly present on the cutane- 

 ous nerves of the fingers and toes, on those of the palm of the 

 hand and sole of the foot, and on the articular nerves of the 

 extremities (Raeuber). They are comparatively rare on other 

 cutaneous nerves, and are only occasionally found on the great 

 sympathetic plexus near the abdominal aorta, behind the peri- 

 toneum, and near the coccygeal gland. 



THE CORPUSCLES OF MEISSNER OR WAGNER TACTILE 

 CORPUSCLES. 



The medullated nerve fibres that, like "creeping roots," pur- 

 sue a tortuous course beneath the cutaneous papillse, in com- 



* Hoyer. Reiehert und Dubois' Archiv, 1864, 1865. 



