STRUCTURE OF THE COCHLEA 



239 



e.r. 



FIG. 279. SEMI-DIAGRAM- 

 MATIC VIEW OF PART OF 

 THE BASILAR MEMBRANE 

 AND TUNNEL OF CoRTI OF 

 THE RABBIT, FROM ABOVE 

 AND THE SIDE. (Much 



magnified.) 



I. limbus ; Cr. extremity or crest 

 of limbus with tootb-like pro- 

 jections ; b.b. basilar membrane; 

 sp.l. spiral lamina with, p, 

 perforations for transmission of 

 nerve-fibres. In part of the 

 spiral lamina here represented 

 the nerve-fibres are left, and are 

 supposed to be seen through the 

 upper layer of that lamina, con 

 verging to three of the perfora- 

 tions ; to the right, in the section 

 of the lamina, they are shown 

 occupying a canal, or cleft, in the 

 osseous substance; i.r. fifteen 

 of the inner rods of Corti ; h.i. 

 their flattened heads seen from 

 above ; e.r. nine outer rods of 

 Corti ; h.e. their heads, with 

 the phalangeal processes ex- 

 tending outward from them and 

 forming, with the two rows of 

 phalanges, the lamina reticu- 

 laris, I.r. On the left of the 

 figure the connective-tissue 

 fibres and nuclei of the under- 

 most layer of the basilar mem- 

 brane are seen through the 

 upper layers. Portions of the 

 basilar processes of the outer 

 hair-cells remain attached here 

 and there to the membrane at 

 this part. 



FIG. 280. AN OUTER HAIR-CELL IN CONNECTION WITH ITS BASILAR 

 PROCESS. From the guinea-pig. (Highly magnified.) 



h, one or two hairlets which have remained attached to the cell ; 6, bulged 

 lower end of cell ; p, basilar process, protoplasmic above, but becoming 

 cuticular below and slightly expanded at the extremity,/, which is broken 

 away from the basilar membrane. 



