XII.] 



THE MEMBRANOUS LABYRINTH. 



391 



Fia. 129. 



Transverse Section of the Head of a F(etal Sheep 



(16 MM. IN length) in the REGION OF THE HiND-BrAIN. 



(After Bottclier.) 



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

 while on the right side the connections of the reoessus vestibuli 

 R.L., and of the commencing vertical semicircular canal V.B., 

 and of the ductus ooohlearis CC, with the cavity of the primary 

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

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



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

 cochlear ganghon OG ; on the left side the auditory nerve (?' and 

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



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



