162 Transactions of the 



of non-medullated nerve fibres there are to be traced fine non- 

 medullated nerve fibres amongst the epithelial ceUs* 



For the mucous membranes it has been shown in the same 

 manner, that beyond the plexus of non-medullated nerve fibres 

 belonging to the proper mucous membrane are to be traced fine 

 non-medullated nerve fibres amongst the epithehum.f 



I must admit that I agree with Beale in not defending a free 

 termination for nerves of common sensation. Because I have been 

 able to convince myself, amongst other points (nerves of the tad- 

 pole's tail, nerves of the serous membranes, nerves of the blood- 

 vessels): 1. That in the substance of the cornea I could trace beyond 

 the known fine non-medullated nerve fibres, still finer fibrils than 

 those which have been supposed to be in connection with the corneal 

 corpuscles, and which finer fibrils still join to form a network. 



2, That the non-medullated nerve fibres which enter the anterior 

 epithelium of the cornea and of the nictitating membrane of the 

 frog, do not terminate in free extremities, but join in a network. 



3. That the observations made upon the epithelial nerves of the 

 mucous membrane of the vagina (Chrschtschonovitsch) and mouth 

 (Elin) made under my direction, do not show free terminations. 



Beale does not admit that there exist fine nerve fibres which 

 spring off from the aheady well-known plexus in the cornea, 

 mucous membrane, skin, &c., and enter the epitheHum — and re- 

 gards the above-mentioned plexuses (which as I have pointed out 

 are not to be called his plexuses) as terminal. For the nerves of 

 the cornea especially, I am able to demonstrate as clearly as possible 

 that his views are entirely erroneous. What Beale calls finest 

 ultimate nucleated nerve fibres are only compound fibres; of the 

 really finest fibres, which have nothing to do with nuclei, Beale 

 has seen absolutely nothing. I must most decidedly call that view 

 erroneous, according to which the presence of a nucleus is in any 

 way decisive anatomically of fine non-medullated nerve fibres, whether 

 in cornea, skin, mucous membrane, or elsewhere. So long as a 

 non-medullated nerve fibre has a sheath, a nucleus can also be found 

 upon it ; but when the fibre has divided into single fibrillae, or into 

 small bundles of these, the sheath (and consequently the nucleus) 

 is no longer to be found. The fibrillae which come off from a non- 

 medullated nerve fibre, either singly or in small bundles, have 

 absolutely nothing to do with any nucleus whatever. Beale 

 apparently no longer adheres to his former viewt that "all fibres 

 which can be followed for a considerable distance, which refract 

 Hke true nerve fibres, and exhibit an appearance more or less 



* Langerhansi, Vii'cliow's ' Archiv,' Bd. 44; Podkopaeff, Max Schultze's ' Arcliiv,' 

 Bd. V. ; Eberth, Max Schultze's ' Archiv,' Bd. VI. 



t Chrschtschonovitsch, ' Sitzunsber. der Akad. der Wissen in Wien,' 63 Bd., 

 Februarhtft, 1871 ; Elin, Max Schultze's ' Archiv,' Bd. VII., 4 Heft. 



X 'Philosoph. Transact.,' 1863, p. 565. 



