No. 3] AUDITORY OR HAIR-CELLS OF THE EAR. 451 



continuous sheet, which stretches downward and inward, at an 

 angle varying with the spiral gradient, until it fuses with the 

 central core of nerve fibres. 



Many of the individual nerve fibres suifer displacement in 

 the vertical plane, both upward and downward, from the plane 

 of the sides of the funnel, the greatest amount of displacement 

 occurring near the ganglion (on either side) and in the region 

 where the fibre is suddenly drawn into the vortex and spun 

 onto the helical core. The fibres may cross the planes of 

 each other's paths several times between the hair-cells and 

 ganglion (PI. I, Fig. i). 



Besides the pictures presented by the three views above 

 described we have still to consider the fibres to be best seen 

 in surface view of the organ (they appear in side view only 

 in transection and consequently as black dots). These fibres 

 are of two sorts {a) those simple radial fibres which, having 

 apparently lost their way when growing toward the modiolus, 

 have pursued a circuitous course before finding their destina- 

 tion, and ip) those fibres which arise as collaterals of the radial 

 fibres and run for greater or less distances in more or less 

 "spiral" direction in the lamina ossea, both within the cochlear 

 ganglion and in the plate of nerve fibres of this lamina (PI. I, 

 Figs. 4 and 7), and finally the third kind {c) composed of the 

 peripheral branches of radial nerves due to the division of the 

 hair-cell without the accompanying partition of its nerve (PI. 

 II, Figs. 8, 9, II and 17; PI. Ill, Figs. 24 and 27). In 

 making a distinction between the kinds b and c, and in calling 

 the former "collateral," I have not attempted to make a dis- 

 tinction based on true morphological grounds, but to direct 

 attention to an apparetit difference which may, in reality, be due 

 to the same process of growth, about which in the present 

 communication nothing more need be said. 



I will add here that the varicosities on the nerve fibres in 

 all parts of the ear appear to be cellular in nature. This does 

 not appear from the Golgi method, nor is it apparent in the 

 case of the finer nerves with any of the ordinary methods, but 

 in Methylen-blue preparations I have yet to find an enlarge- 

 ment of an axis cylinder due to an increase in size of that 



