118 



THE EAR. 



The membrane of Reissner (fig. 129, 131, E), separates the scala vestibuli 

 from the canal of the cochlea. It is composed of an exceedingly delicate layer of 

 connective tissue continuous with the lining periosteum of the scala vestibuli, and is 

 covered on the surface, which is turned to the cochlear canal with a simple pavement 

 epithelium which is in continuity below with the epithelium of the limbus and 

 above with that lining the outer wall of the canal. The cells have each a circular 

 flattened nucleus, and not unfrequently contain fat-droplets. The vestibular side of 

 the membrane of Reissner is quite smooth, and is covered with an epithelial layer of 

 flattened connective-tissue cells, distinguishable from the epithelial cells on the other 

 side by their greater delicacy of outline,and their larger size. A few blood-capillaries are 

 continued into the adjacent part of the membrane from the neighbouring periosteum. 

 Outer wall of the cochlear canal. The periosteum which lines the scala 

 vestibuli and scala tympani, consists of ordinary connective tissue. There is no COll- 



wall of cochlea 



spiral ligamen t IB 



attachment of 

 Eeissner's membrane 



stria vascularis 



vas prommerts 



; epithelium cells 

 basilar membrane 



Fig. 135. SECTION SHOWING THE STRUCTURE OP THE LTGAMENTUM SPIRALE AND ADJACENT PARTS, 

 FROM THE GUINEA-PIG'S COCHLEA. (Sch \valbe.) A p 



tinuous lining of flattened cells on the free surface, such as covers the surface of 

 serous membranes. On the other hand the periosteum which bounds the canal of 



