THE EAR. 



401 



and behind the lagena. It forms a small, oval, pocket-like protu- 

 berance, with the long axis directed from in front and above, back- 

 wards and outwards, its opening being directed forwards and 



Fig. 250. 





mt 



The membranous labyrinth of Rana ttculenta ; after Retzius. 

 I. Transverse section of the anterior ampulla. Magnified 50 times. 

 II. Piece from under surface of the cupola from the anterior ampulla. Verick'sSyst., Obj.VIII.Oc. 3. 



III. The macula acustica neglecta, seen from below. V6rick's Syst., Obj. IV, Oc. 3. 



IV. Part of wall of the anterior ampulla. 



V. Pan of the cochlea, the pars basilaris cut longitudinally. V&ick's Syst., Obj. I, Oc. 3. 

 VI. Longitudinal section of the pars basilaris. V^rick*s Syst., Obj. I, Oc. 3. 

 VTI. The macula ac. neglecta, seen from below. Ygrick's Syst., Obj. FV, Oc. 3. 

 VIEI. The pars basilarig, seen from behind and the outer side. V6rick's Syst., Obj. I, Oc. 3. 

 IX. Transverse section of the external ampulla. Magnified 175 times. 

 apb Oval opening into sacculo-cochlear space. Nerve-fibres. 

 cr Crista acustica. pb Pars basilaris. 



cu Cupula terminalis. ptf Area of coarsely granular cells. 



dp Ductus perilymphaticus. ppb Papilla acustica basilaris. 



M& Section of thinner wall of pars basi- 

 laris. 



mt Tectorial membrane. 

 mir Thickened membranous wall. 



Epithelium on raphe. 

 rfr Ramulus basilaris. 

 m Ramulus negleotus. 

 / Tegmentum vasculosum. 



outwards. The short ram. la*'t!aris passes in from above to supply 

 it. The walls of this dilatation are thick and stiff, with the exception 



Dd 



