204 



(OMTAIIATLVK ANATOMY. 



opposite wall (Figs. 168, Lso, Lso\ and 169, Lo, Xo 1 ). This is 

 continued outwards by two laterals-diverging lamellae (Fig. 160,-ff, 

 7?), mentioned above as the in. -ml) ran a basilaris and mem- 

 bi-'ana Rei^neri; these lie at an angle to one another and 

 correspond to the inner walls of the membranous cochlea. The outer 

 w.-dl of the latter is completed by a portion of the peripheral part 

 ,,f the b.,ny c ichlea the region between L* and the peripheral end 

 of // in Fig. Hi!' . The membranous cochton. which thus appears 



V\>;. 168. Boirz COCHLEA <>K M \s. i After A. Ecker.) 



/, axis : I.*", 1-^, lamina spivalis ossea, the free edge of which, perforated by the 

 tihivs of tli- iimlitory nervo, is visiM" nt < : //". hamuliis. 



JTJ 



-._ 



Kii;. lt;:i.- IMA.. I:\MMATIC TKANSYEIISF, Sr.< i i\ UK THE COCHLEA OF ,v 



.MAMMAL. 



A'.s', bony cochlea ; Lo, Lo 1 , the two layers of tin- lamina spiralis ossea, between which 

 at N the auditory nerve (together with the ganglion, left of L) is seen ; L, 

 linibus lamin;r spiralis ; 11, membrana basilaris, on which tho neuro-epithelium 

 lies; /,', bvissner's membrane : >Y, scala vestibnla ; ,S7, scala tympani; Sm, 

 s -ala media ( membranous cochlea); C, membrane of Corti ; is, ligamentum 

 spirale. 



approximately triangular in transverse section, is called the ductus 

 cochlcaris or scala media. It is apparent that the scala media 

 does not liv any means till up the lumen of the bony cochlea, but 

 that a cavity is left on either side of it, corresponding to those wo 

 have alreadv met with in the auditory organ of Hirds, and known 

 as the scala vestibuli an<i scala tympani (Fig. 1(5!), tfv, M). 



llnth of these are continuous with the cavum perilymphaticum, 

 and following the direction of the scala i lia. <.]ien into one another 



