^S AVERS. [Vol. VI. 



nerve fibre I have seen in all preparations showing the nerves, 

 but since the nerves are invisible without previous chemical 

 treatment, it by no means follows that the undulations exist 

 during life ; still it is not improbable that this is the case since 

 such a disposition is not uncommon in the smaller nerves in the 

 tissues of other organs. The various authors who have described 

 the system of spiral nerve fibres do not agree among themselves 

 as to what constitute the complete system or where the various 

 bundles are to be found. No one has yet been able to trace 

 the connection between these so-called spiral nerve fibres and the 

 hair cells. Boettcher, whose extensive researches into both the 

 embryonic and adult structure of the cochlea entitle his opinion 

 to great consideration, calls attention to the logical inconsistency 

 of the accounts of the authors describing these courses of fibres, 

 in that they fail to find the origin and end of the spiral nerves 

 and they do not agree as to their position and characters. No 

 one has yet claimed that these tracts of spiral nerves have any 

 representation in any of the other sense organs, nor has their ex- 

 istence been shown in the ear of the Alligator, in which type the 

 mammalian organ exists in a much simpler condition than in any 

 of the mammalia. From what I have already seen of the cellular 

 structure of the Alligator's cochlea I am confident that spiral 

 nerves occur neither in the sauropsid nor in the mammalian 

 organ of this animal's ear. Waldeyer says in his resume of the 

 controversial points of the mammalian cochlea : " In stating my 

 views in regard to the cells and fibres which are the subject of 

 dispute, I will say that the observations which I have made with 

 positiveness in regard to the nerve endings make it probable 

 that neither the granule cells [i.e. the epithelial lining of the 

 sulcus spiralis internus ; these are the cells which Waldeyer 

 had compared with the inner "granule layer" of the retina] 

 nor the spiral fibres have a nervous character ; otherwise we 

 should be obliged to claim a double nerve ending. The differ- 

 ence between the well-established radial nerve fibres and the 

 spiral fibre bands opposes this supposition. Still this point can 

 only be determined by further careful examinations based on 

 embryological researches." 



Boettcher's monograph on the development of the mammalian 

 cochlea appeared after this was written, though the researches 

 were actually carried out some years before, and Boettcher's 



