214 Journal of Comparative Neurology. 



There is a very eviden-t grouping of the cells in the elec- 

 tric lobes in groups of 2, 3, 4, or larger numbers up to 12 or 

 more. The axis cylinder processes of the members of a 

 group converge towards a common centre, indicating, I think, a 

 common origin from a single cell. 



While most cells of the electric lobe possess a single 

 nucleus, the number having two nuclei is relatively large 

 (500 in each lobe). Cells with three nuclei are occasionally 

 found, 50 in each lobe. 



The centrosome is plainly visible in some of the cells. 



Morphological Laboratory, University of Missouri, Columbia, Mo., March 

 10, 1896. 



THE INNERVATION OF THE AUDITORY EPITHE- 

 LIUM IN MUSTELUS CANIS, DE KAY, 



By A. D. Morrill. 



I wish, at this time, to give a brief preliminary statement 

 of the results obtained by the use of methylen blue in the study 

 of the auditory epithelium of the "smooth dog-fish." 



The fibers of the auditory nerve lose their medullary sheath 

 on entering the sensory epithelium of the ampullae and bra-nch 

 at different levels, although the branches are much more num- 

 erous at the base of the hair cells. From the latter branches, 

 many of which extend horizontally, numerous extremely fine 

 nerve fibers arise which end either in characteristic enlarge- 

 ments in contact with the proximal portions of the hair-cells or 

 pass between them to end free near the surface in similar but 

 smaller enlargements. 



The nerve fiber often branches at the base of the hair-cell, 

 the two portions closely adhering to the cell and ending in en- 

 largements at nearly the same level on opposite sides of the 



