of the Cochlea in Man and other Mammals. 155 



Deiters stated that the rods of the outer row were smaller and 

 more numerous than those of the inner, while Claudius positively 

 stated the reverse. Now, Deiters was undoubtedly wrong in both 

 these statements, and Claudius not altogether correct, for although 

 the latter, was right about the inner rods being the more numerous, 

 yet he was incorrect in stating that the inner were the smaller, 

 there being, indeed, no difference in the diameter of the shafts, but 

 only in the width of the upper extremities. 



The rods of Corti appeared to be composed of a homogeneous 

 substance resembling the matrix of delicate cartilage. 



Numerous longitudinal and curved lines are observable, espe- 

 cially at the enlarged extremities, and they may readily be split up 

 into fibres, otherwise they appear quite transparent and contain no 

 nuclei. They evidently possess great elasticity, and are calculated 

 in every way to receive the finest vibrations. 



They are to be stained by all the various colouring fluids, as 

 carmine, and aniline blue, magenta, &c, but they are not so deeply 

 coloured as the nuclei of cells, &c. 



Most authors, with the exception of Deiters, describe nuclei 

 situated in various parts of these rods, principally in the lower ex- 

 tremities, but although at first sight, and especially when seen from 

 above, this does appear to be the case, yet on closer observation 

 these so-called nuclei of the rods are found to be nothing more than 

 the nuclei of cells surrounding the bases of the rods. In my opinion 

 there is no ground whatever for the belief expressed by some modern 

 authors, that they are composed of fine fibres continuous with those 

 of membrana basilaris, and for this reason : the bases of the rods 

 may be easily separated from the membrana basilaris, and in this 

 case are found to be quite rounded, and in no way jagged or uneven. 



The Arrangement of the Nerves in connection with the 

 Rods of Corti. 



The cochlear nerve fibres from the portio mollis pass up the 

 modiolus and turn off at the lamina spiralis. Just at this junction 

 we find in the bone itself a ganglion ; the cells of this are fusiform, 

 bipolar, with distinct nuclei. From this ganglion fibres proceed 

 outwards, these form a close plexus, and give rise to the broad dark 

 band seen in all transverse sections of the lamina spiralis. 



Immediately before the end of the lower lip of the limbus, the 

 nerve filaments pierce its upper surface, by a number of small 

 foramina (habenula perforata), and appear close to the base of the 

 inner row of rods. Concerning the termination of these nerve fila- 

 ments little is really known. I have traced them on to the inner 

 rods themselves, and to the tiny cells lying on their bases, as also to 

 certain delicate cells between the rods, but I have good reason for 

 believing that some of them terminate in the cells of Corti and 



VOL. IX. n 



