MULLENIX: EIGHTH CR-\NIAL NERVE. 229 



body, which contains a central nucleus, with one or two nucleoli. 

 They state that processes always extend from the body of the cell in 

 the form of fibres, which may frequently be followed for a considerable 

 distance toward the free surface of the epithelium, and that they some- 

 times contain a clear supporting fibre. These outward extending 

 processes of the basal cells are represented as meeting the apices of the 

 triangular projections which penetrate inward between the sense cells 

 from the limiting membrane, and blending with them to form a homo- 

 geneous mass; a condition which leads the writers to regard these 

 structures as a kind of intercellular substance produced by the Faden- 

 zellen. 



Inasmuch as the general histology of the ear lies somewhat outside 

 the scope of my problem, I have devoted only such attention to it as 

 has been indispensable to an understanding of the modes of nerve 

 terminations. The methods which I have employed are not well 

 adapted to the study of the non-nervous histological elements, and 

 conseciuently my material does not furnish conclusive evidence con- 

 cerning the matter under discussion. None of my preparations 

 furnish any evidence for the existence of any cells in the auditory 

 epithelium other than the basal cells and the sense cells, though it is 

 not uncommon to find nuclei amongst the axis cylinders in the so-called 

 inter-epithelial plexus. These nuclei, however, I believe to represent 

 basal cells. Neither have I been able to see any processes from the 

 basal cells extending into the spaces between the sense cells. 



I have many preparations which clearly show the cuticula, or limit- 

 ing membrane, separating the ends of the sense cells from the lumen 

 of the ear. In some cases this appears to be entirely distinct from the 

 epithelium, as in Figures 16 (Plate 3), 18, 26 (Plate 4) 28, 33, 36 (Plate 

 5) 41, 43 (Plate 6). In other material it is evident that there are 

 processes extending from this cuticula into the midst of the sense cells 

 (Figs. 38, 40, Plate 5 ; 42, Plate 6), in a manner not unlike that described 

 by Bielschowsky und Briihl. In sections parallel to the surface these 

 processes show well. In no case have I been able to find nuclei in 

 this intercellular material. It often presents the appearance of being 

 continuous with the cuticula, as shown in Figure 39 (Plate 5). In 

 Figure 45 (Plate 6) material is represented in which the cytoplasm 

 of the sense cells was much shrunken, leaving considerable space 

 between it and the cell membranes, which remain in contact with the 

 intercellular substance. Figure 39 (Plate 5) represents a section cut 

 diagonally to the principal axes of the sense cells, and hence the dif- 

 ferent layers of the macula are represented here. 



