114 THE MEMBRANOUS LABYRINTH, BY PROF. RUDINGER. 



into a blunt cone. In Fishes and Frogs they contain a yellow 

 pigment. These columnar cells, which were first accurately 

 described by Leydig in the Eel, by Reich in Petromyzon mari- 

 nus, and by Max Schultze in Sharks and Rays, form everywhere 

 the inner boundary of the epithelium where there is ho special 

 cell-layer. In the Cyprinoids, low clear columnar cells of equal 

 thickness, and a strongly refractile nucleus, are arranged close 

 to one another upon the inner surface, and produce the ap- 

 pearance of a clear pale border at the centric extremity of the 

 auditory hairs. No processes can be recognised in them ; and 

 were they not studied in situ, a single observation might lead 

 to their being mistaken for simple cylinder cells from the 

 marginal region of the planum semilunare. The epithelial 

 forms present in the nerve-epithelium, and which are truncated 

 at both extremities, appear to be only those supporting cells, 

 between which the ends of the fibre cells penetrate. 



These fusiform, thread, or rod-shaped cells (Spindel-Faden- 

 oder Stabchen-zellen) are present in much larger numbers than 

 the columnar cells. They are the flask or thread cells which 

 were originally described in similar terms by Max Schultze, and 

 subsequently by Odenius, Kolliker, Henle, and Hasse. They are 

 fusiform, with a long process running centrally and a rod-like 

 process towards the periphery. The pale aspect they possess 

 when fresh distinguishes them from other cells, and their be- 

 haviour with perosmic acid appears to deserve special notice. 

 For if transverse sections of the ampullae in Cyprinoids be exa- 

 mined under the microscope after the addition of osmic acid, 

 it is soon observable that in proportion as the nerves become 

 dark coloured, the epithelial border, with the auditory hairs 

 also, though somewhat more slowly, assumes a brown tint. 



Lastly, close to the inner boundary of the epithelial layer dark 

 striae occur, which may be followed to the surface. These dark 

 but unequally thick striae are situated at quite definite distances 

 from one another. If the epithelial border be macerated for 

 a somewhat longer time in the acid, the several cells can be 

 isolated, and a black stria becomes apparent in the fusiform 

 fibre cells, which I believe may really be considered to be en- 

 closed within the cells. This appears to be the prolongation of 

 the long fibre-like extremity of the cells, and is in direct con- 



