504 



EMBRYOLOGY 



kk 



Tig. 283. Fart of a section through the cochlea of an embryo Cat 9 cm. long, after BOETTCHER. 



kk, Cartilaginous capsule, in which the cochlear duct describes ascending spiral turns ; dc, ductus 

 cochlearis ; C, organ of CORTI ; Iv, lamina vestibularis ; x, outer wall of the membranous 

 ductus cochlearis with ligamentum spirale ; Sl r , scala vestibuli ; ST, ST", scala tympani ; 

 (/, gelatinous tissue, which still fills the scala vestibuli (sv'} in its last turns ; g>', remnant of 

 the gelatinous tissue, which is not yet liquefied ; M, firm connective tissue surrounding the 

 cochlear nerve (nc) ; gsp, ganglion spirale ; N, nerve which runs to CoRTi's organ in the 

 future lamina spiralis ossea ; Y, compict connective-tissue layer, which becomes ossified and 

 shares in bounding the bony cochlear duct ; P, perichondrium. 



