152 On the Structure and Function of the Rods 



In his later work on the subject he figures these rods very 

 differently, and much more accurately. 



Kolliker, Henle, and others appear to agree with Deiters' later 

 view of the form of the rods, and most of our text-books have 

 copied their drawings. 



Recent writers, such as Drs. A. Bottcher, Waldeyer, Gottstein, 

 and Nuel, give varying drawings, some of which are nearer the true 

 form of the rods than that of Deiters, while others exhibit the rods 

 in all kinds of extraordinary shapes. 



I will proceed at once to detail the results of my own observa- 

 tions. 



In a general view of the rods from above (that is to say, look- 

 ing at the lamina spiralis lying flat) they appear similar to two 

 rows of pianoforte hammers, rather than like the keys of that instru- 

 ment, to which they have been likened, the heads of the rods lying 

 close together. 



In a lateral view, these two rows of rods are seen sloping 

 towards each other like the rafters of a gabled roof, and it is by 

 reason of the difficulty in obtaining these side views (vertical sec- 

 tions) that such very different ideas exist as to the question of 

 shape. 



The rods, as before mentioned, lie between the membrana 

 basilaris and membrana tectoria, and pass directly outwards from 

 the lower lip of the limbus ; they are both firmly attached by their 

 lower extremities to the membrana basilaris, their upper extremities 

 being covered by a peculiar membrane (membrana reticularis), but 

 they are not in any way connected with the membrana tectoria. 

 On every side they are surrounded and supported by cells of a more 

 or less delicate structure. The rods are best described like a long 

 bone, as consisting of a shaft, and two enlarged extremities, but the 

 two rows differ considerably in form. The inner rods (those nearer 

 to the bony lamina) are attached by their lower extremities to the 

 membrana basilaris at its junction with the lower lip of the limbus 

 and just external to the spot where the nerve filaments emerge (the 

 habenula perforata). They are directed outwards and upwards, 

 with a slight undulation to meet the outer rods. 



The lower extremity is enlarged and rounded, gradually taper- 

 ing to the shaft. The shaft is cylindrical, although Deiters, 

 Claudius, and nearly all other observers state that they are 

 flattened ; but by referring to preparations in which the inner rods 

 are cut through their shafts, the cut ends will be seen to be quite 

 circular. 



Curiously enough, although these very investigators say the 

 shaft is flattened from above downwards, they give a thick lateral 

 view of the same. The upper extremity is peculiar in form, and as 

 I differ from all observers on this point, it requires special attention. 



