SECT. 234.] VESSELS OF THE COCHLEA. 599 



the lower surface of the commencement of the hahenula denti- 

 culata ; on the third half turn, lastly, they form a nervous border, 

 o - o8'" to 0-09'" in breadth, which also lies on the lower side of 

 the hahenula sulcata. At the last two places however, the nerves 

 are not contained free in the scala tympani, but are covered by 

 the periosteum of the lower surface of the zona ossea. The nerve- 

 tubes attenuated to 0001'", are described by Cortl and others as 

 terminating by becoming suddenly pale, finer, and then ending 

 by free extremities. I have, however, recently found that all the 

 nerve-tubes pass in a pale and attenuated condition through the 

 apertures in the hahenula perforata, and here, as stated above, 

 become connected with the organ of Corti, in a manner which is 

 not yet altogether clear. I was formerly of opinion that the nerve- 

 fibres were united directly and singly with the inner Cortian fibres, 

 but my more recent observations have rendered me very waver- 

 ing in this belief. It is true that I have distinctly noticed the 

 inner Cortian fibres seated upon the nervous tubes, but, on the 

 other hand, I think I have also convinced myself that fibres of 

 the cochlear nerve, after passing through the foramina in the 

 hahenula perforata, make their appearance beneath the teeth of 

 the first series, in their direct course to small spindle-shaped and 

 stellate cells, from the other end of which similar nervous fibrils 

 are then given off. It may be supposed that these fibrils unite 

 themselves with the pedunculated cells of the organ of Corti, but 

 I can at present adduce no direct proof of such a connection. 

 These processes extend so far, that I no longer venture to regard 

 the other parts of the organ of Corti as being decidedly nervous 

 in character; at the same time, I must continue to oppose the 

 views of those who regard this structure as being simply of the 

 nature of the basilar membrane. 



The vessels of the cochlea, though fine, are yet very numerous, 

 and are distributed, firstly, in the periosteum of the walls of the 

 caual of the cochlea, and, secondly, in the lamina spiralis. At 

 the former place, besides the capillary networks occurring every- 

 where, they form a special vascular stripe on the scala vestibuli, 

 immediately over the ligamentura spiralc, the stria vascularis 

 (Corti): although connected with the vessels of the periosteum, 

 the vessels of this stria lie above that membrane, and are imbed- 

 ded, as it were, in the epithelium, along with a little pigment. 

 In the zona spiralis there exists a rich capillary network, both in 

 the osseous part and in the nervous expansion itself; it is con- 

 nected with a vas spirale running on the lower or tympanic surface 



