412 SPECIAL HISTOLOGY. 



cochlear nerves in their course. The dark-bordered fibres pro- 

 ceeding from the external side of these cells, are again disposed 

 in anastomosing, and afterwards in simply parallel, flattened 

 bundles, which become less and less close as they approach the 

 hamulus, so that, upon that process, the fibres may be 

 perceived forming a single layer, and even separated 

 by interstices. The end of these nerves, in all the 

 parallel bundles and fibres, is always in the same 

 line, but in the first spiral turn will be found nearer 

 to the outer wall of the cochlea than it is higher up. 

 Besides this, there are terminations, also situated 

 between the two plates of the osseous zone, although 

 exactly at its border ; in the second turn, in an extent 

 of 002 — 0-03'", and even outside it, on the under 

 surface of the commencement of the habenula denti- 

 culata, consequently within the scala tympani ; in 

 the third half turn, lastly, they appear in the form 

 of a nervous border, 008 — 009"' broad, also on the 

 under surface of the habenula sulcata. The actual 

 termination of the nerve-fibres which are reduced to 

 O'OOl'" in diameter, appears to me, as well as to Corti, 

 to take place by their first becoming pale, and 

 still finer, and afterwards ceasing — and I must here express 

 myself as decidedly opposed to the notion of the existence 

 of loops. 



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

 they are distributed, in the first place, to the parietal periosteum 

 of the cochlear canal, and secondly, to the lamina spiralis. In 

 the former situation, besides the capillary plexus, which is found 

 throughout, they constitute a peculiar vascular tract in the scala 

 vestibuli, immediately under the ligamentum spirale, — the stria 

 vascularis of Corti, and which, though continuous with the vessels 

 of the periosteum, still lies above it, imbedded, as it were, in the 

 partially coloured epithelium. In the zona spiralis, we find in 

 the osseous portion, but also in the nervous expansion itself, a 

 rich capillary plexus, continuous with a vas spirale running on 

 the under or vestibular surface of the zona membranacea, through 

 the whole extent of the cochlea. This vessel, which is probably 



Fig. 311. Bipolar ganglion-globules from the zonula ossea of the lamina spiralis 

 of the Pig, x 350 diam. After Corti. 



