424 APPENDIX. 



arrangement of its elastic element ; it is, in fact, the dilated 

 termination of the neurilemma of the nerve of the papilla. 



With regard to the mode of termination of the nerves, while 

 not venturing to deny the existence of loops, we doubt it ; on 

 the other hand, repeated instances of the so-called free termi- 

 nation of dark- contoured nerve-tubules on the surface of the 

 corpuscula are described and figured (1. c, p. 3, fig. 4). The 

 termination is not really " free," inasmuch as the tubules 

 become continuous, both here and in the Frog's tongue, with 

 the imperfect, reticulated, elastic fibrils of the papillae. 



As respects the Pacinian bodies, we stated, at that time 

 in opposition to all authorities, that their central portion is 

 solid and not hollow, and that in Birds and in the human 

 hand, the fluid supposed to exist between the concentric laminae 

 was equally hypothetical. In structure, the Pacinian body, in 

 fact, is identical with the corpusculum t actus — being a solid 

 mass of connective tissue, whose apparent lamination depends on 

 the regular disposition of its elastic elements. We stated fur- 

 ther, that the central nerve-tubule gradually terminates, passing 

 into the central solid axis of the Pacinian body. In reality, the 

 Pacinian bodies are also nothing more than thickened processes 

 of the neurilemma of the nerve to which they are attached, and 

 differ from the tactile corpuscles only in the circumstance that 

 in the latter the thickening takes place on one side of the 

 nerve-fibril, while in the Pacinian body it takes place on both 

 sides. 



In the meanwhile, contemporaneous observations on this 

 subject were made by Leydig (' Ueber die Vater-Pacinischen 

 Korperchen der Taube') and by Kolliker ('Einige Bemer- 

 kungen iiber die Pacinischen Korperchen'), and were published 

 in Siebold and Kolliker's < Zeitschrift/ B. V, H. 1. 



Leydig and Kolliker's results are, in the main, in accordance 

 with our own, especially as respects the solidity of the Pacinian 

 body. The "central cavity" is given up by both, but Kolliker 

 still maintains the existence of a fluid between the outer 

 layers, at least in the Cat. Leydig regards the central solid 

 axis of the Pacinian body in the Bird as the expanded ter- 

 mination of the nerve itself. 



Wagner had already drawn attention to the resemblance 

 between the corpuscula tactus and the Pacinian bodies ; Leydig 



