THE ORGAN OP HEARING. 



445 



bull, and the lower the scala tympani. A mem- 

 brane the membrana basilaris stretches from the 

 free edge of the bony lamina spiralis to the outer 

 wall of the cochlea and completes the scala vestibuli 



j. 307. Section through one of the turns of the osseous and mem- 

 branous cochlear ducts of the cochlea of a guinea-pig: /, Scala vestibuli; 

 m, labium vestibulare of the limbus; n, sulcus spiralis internus; o, nerve 

 fibers lying in the lamina spiralis; p, ganglion cells; q, blood-vessels; a, 

 bone; b, Reissner's membrane; DC, ductus cochlearis; d, Corti's mem- 

 brane; /, prominentia spiralis; g, organ of Corti; h, ligamentum spirale; 

 i, crista basilaris; k, scala tympani (Bohm and Davidoff). 



and the scala tympani, but the two communicate 

 at the apex of the cochlea. The scala tympani 

 begins at the fenestra rotunda, in the inner wall of the 



