ORIGIN OF NERVE FIBRES IN NERVE CENTRES. 187 



we shall ever be able to observe those anastomoses between ganglion 

 cells which result from the union of the finest outrunners of the 

 branched processes, since the most carefully conducted methods of 

 isolation adopted by Deiters have only led to negative results. Nor 

 have my own numerous researches on the ganglion cells of the electric 

 lobes of the torpedo, which are admirably adapted for this investiga- 

 tion, been more fortunate ; for although Rud. Wagner long ago stated 

 that anastomoses could here be distinctly seen, I, notwithstanding the 

 employment of better modes of isolation, have been unable to discover 

 a single instance of their occurrence. Lastly, an interesting accession 

 to our knowledge of the terminations of the nerves may here be noted, 

 with which I have become acquainted whilst these sheets were 

 passing through the press. Paul Langerhans found, as he has 

 described in Virchow's Archiv, Bandxliv., p. 325, and depicted in the 

 twelfth plate of that volume, that processes of the non-medullated fibres 

 of the cutis in man penetrate between the cells of the rete Malpighii, 

 exactly in the same way as has been described (p. 164) by Hoyer and 

 Cohnheim as the mode of termination of the nerves in the cornea. These 

 nerve fibrils, however, do not terminate by free extremities ; but enter, 

 as is rendered highly probable by Langerhans, in all instances, into 

 small cells lying between the deeper cells of the rete mucosum, which 

 again give off several fine fibrous outrunners into the upper layers ; 

 and these finally terminate with slightly clubbed extremities just 

 beneath the horny layer. These nerve fibres have no connection with 

 the tactile corpuscles. By means of these observations, which supple- 

 ment those of Tomsa and others respecting the mode of termination 

 of the nerves in the corium in several important particulars, the inti- 

 mate connection between the terminations of the nerves and the 

 epithelial layers in the skin of man has been demonstrated, which, 

 since the year 1856, has been gradually shown to occur in all the other 

 organs of sense, although it was in the first instance received with so 

 much mistrust. Thus one more argument in favour of nerve plexuses 

 representing the terminal structure falls to the ground. 



