XII.] THE MEMBRANOUS LABYRINTH. 



391 



Fm. 129. 



TRANSVERSE SECTION OF THE HEAD OF A F(ETAL SHEEP 

 (16 MM. IN LENGTH) IN THE REGION OF THE HIND-BRAIN. 

 (After Bottcher.) 



HE. the hind-brain. The section is somewhat oblique, hence 

 while on the right side the connections of the recessus vestibuli 

 R.L.j and of the commencing vertical semicircular canal F.Z?., 

 and of the ductus cochlearis CO., with the cavity of the primary 

 otic vesicle are seen : on the left side, only the extreme end of the 

 ductus cochlearis (7(7, and of the semicircular canal V.B. are shewn. 



Lying close to the inner side of the otic vesicle is seen the 

 cochlear ganglion GC ; on the left side the auditory nerve G' and 

 its connection N with the hind-brain are also shewn. 



Below the otic vesicle on either side lies the jugular vein. 



