No. I.] THE VERTEBRATE EAR. 67 



they sustain to the other structure of the organ, are not so well 

 agreed upon. The discussion which is at once opened when 

 the subject of the peripheral endings of sensory nerves is touched 

 upon is one of long standing and exceeding great difficulty when 

 it comes to the presentation of demonstrations and conclusive 

 arguments. 



There are two questions remaining for consideration in this 

 paragraph, — the spiral or longitudinal nerve bands and the 

 peripheral ends of the radial nerves in the hair cells. Dis- 

 covered by F. E. Schultze, described especially well by Deiters, 

 the spiral nerves have been found by the majority of investi- 

 gators since their time (Kolliker, Hensen, Loewenberg, Nuel, 

 Gottstein, Lavdowsky, and Retzius), though some authorities 

 have been unable to satisfy themselves that the spiral fibres 

 are really nervous in nature (Rosenberg, Boettcher, Waldeyer, 

 and Middendorp). With the latter group my own investiga- 

 tions compel me to place myself, for they have led me to the 

 same conclusion arrived at by Waldeyer in 1870. I am fully 

 convinced that there are no bundles of spiral nerve fibres in 

 the cochlea such as Deiters, Hensen, Gottstein, Nuel, Lav- 

 dowsky, and others have described. Cf. Deiters (69), Taf. VII, 

 Fig. 28, and Taf. VIII, Figs. 34 and 36; Nuel (206), PL IV; 

 and Lavdowsky (178), Taf. XXXV, Figs. 5, 12, 13, 20. As to 

 the existence of such structures as are here displayed there can 

 be no question. I have often had the counterpart of Deiters' 

 Fig. 28, PI. VII, but the fibres there shown are not nerves, but 

 connective tissue fibres belonging, as I believe, entirely, and, as 

 I have demonstrated, at least in part, to the basilar membrane. 

 Nuel's figures show mostly fibres of a different nature micro- 

 scopically ; but although I have seen such fibres as he offers in 

 the figure on PI. IV only a few times, they appear to me to be 

 connective-tissue fibres modified by the reagents used and more 

 or less transposed during the preparation. It should be re- 

 called here that the radial nerve fibres after they leave the 

 habenula perforata do not run in straight lines, but suffer two 

 sorts of displacement, one of which is due to the spiral growth 

 of the cochlear canal, by means of which the relations of all the 

 contained structures are considerably distorted in a plane par- 

 allel to the basilar membrane, and the other of which is an easy 

 undulation of the nerve fibre itself. This undulation of the 



