No. 3] AUDITORY OR HAIR-CELLS OF THE EAR. 455 



E. The Nerve Fibres m the Lamina ossea. 



The course of the fibres of the cochlear nerve in the Lamina 

 ossea I have ah-eady given, but of the characters of the bundles 

 of nerves within this region I can say little. On PI. Ill, Fig. 

 19, are shown several bundles of fibres in this region. The 

 figure illustrates how the fibres group themselves in bundles, 

 leaving elongate interspaces between the bundles quite as well 

 as any of the Golgi preparations show it, but I shall reserve 

 for my paper on the results of the Methylen-blue stain a 

 complete account of the structures occupying the Lamina. 



The same causes seem to operate here that are so effective in 

 the organ of Corti, to turn fibres out of their direct course, and 

 as a result there is an extensive " anastomsosis " of bundles. 



Part of this interchange of fibres is a simple displacement of 

 fibres from a direct path, but apparently another part is of a 

 much more important nature, and consists in the connecting 

 together of different parts of the cochlear apparatus nervously, 

 and in this way, of course, connecting many or few, more or 

 less widely separated peripheral points in the cochlear per- 

 cipient organ with single points in the central nervous system. 

 Collateral fibres are frequent in the region of the Lamina ossea, 

 but whether they occur as abundantly centrad of the ganglion 

 I have not been able to determine. They do occur, but here- 

 tofore they have only been seen in a few instances. 



F. The Auditory Ganglia especially the Ganglion cochlearis. 



The ganglion cells of the cochlear ganglion take a very 

 prominent place in the discussions of ear anatomy at the 

 present time and their origin and nature is a matter of much 

 importance to the proper understanding of the structure and 

 workings of the acoustic appartus. Retzius and van Gehuchten 

 unhesitatingly say that all the cells of the cochlear ganglion 

 are bipolar cells from which the two fine nerve filaments 

 take their rise, one going to the periphery as the hair-cell 

 element the other going to centre as the brain element. At 

 either end the nerve is supposed to end freely and to acquire 

 relations to other nervous structures by mere contact at the 



