endolymph. 



vest i b. 

 pouch 





I at groove 

 vtib.p. 



..coch.. 

 pouch 



6L. 6.6*1 lateral. 



c.sc.post.i 



i- -I at groove 



c.5c.!at. 



cochlea 

 b 9 mm. lateral. 



absorpt.foci 



C. 13 mm lateral 



6 . 2omm iateral. 



f. 3orom. lateral. 



FIG. 366. Six stages in the development of the internal ear. The figures show lateral views of 

 models of the membranous labyrinth a at 6.6 mm.; b, at 9 mm.; c at 13 mm.; d at n mm.; e at 20 

 mm., and/ at 30 mm. (Streeter) (X 25). The colors yellow and red are used to indicate respectively the 

 cochlear and vestibular divisions of the acoustic nerve and its ganglia, absorp. focus, area of wall where 

 absorption is complete; cms, crus commune; c.sc.lat., ductus semicircularis lateralis; c. sc. post., ductus 

 semicircularis posterior; c.sc.sup., ductus semicircularis superior; cochlea, ductus cochlearis; coch. 

 pouch, cochlear anlage; endolymph., appendix endolymphaticus; sacc., sacculus; sac. endol., saccus en- 

 dolymphaticus; sinus litre, lat., sinus utriculi lateralis; utric., utriculus. 



