THE COCHLEA 



627 



basilaris at its apex, and being, like the basal membrane, continued 

 from the base to the apex of the cochlea, is known as the spiral 

 ligament. Its dense fibrous bands radiate from the attachment of 



FIG. 456. AXIAL SECTION THROUGH A TUBN OF THE COCHLEA OF A GUINEA-PIG. 



a, bone of the outer wall of the cochlea ; J, membrane of Eeissner ; ^, membrana 

 tecloria; DC, cochlear duct or scala media; /, stria vascularis ; ^, organ of Corti; A, 

 spiral ligament; i, cells of Claudius; &, scala tympani; , scala vestibuli; m, vestibular 

 lip of the limbus spirale ; n, spiral sulcus ; 0, nerve fibres of the cochlear nerve, con- 

 tained within one of the radiating canals within the spiral lamina; /?, nerve cells of the 

 spiral ganglion; -, blood vessel, x 90. (After Bohm and von Davidoif.) 



the basal membrane to all portions of the ligament, and are firmly 

 attached to the bony wall of the cochlea, with whose periosteum 

 the deeper fibres of the spiral ligament are blended. 



The surface of the spiral ligament, which forms the outer wall 

 of the scala media, slopes gradually away from the attachment of 

 the basal membrane ; that which impinges upon the scala tympani 



