AUDITORY ORGANS. 



523 



into the scala tympani. The latter ends blindly at the fenestra 

 rotunda. 



The fluid contained in the two scalae, and in the remaining 

 lymphatic cavities of the auditory labyrinth, is known as peri- 

 lymph. 



The cavities just spoken of are formed by an absorption of 



JIB 



C.C 



FIG. 304. SECTION THROUGH THE INTERNAL EAR OF AN EMBRYONIC SHEEP 

 28 MM. IN LENGTH. (After Bottcher.) 



D.M. dura mater; R. V. recessus labyrinth! ; H.V.B. posterior vertical semi- 

 circular canal ; U. utriculus ; H.B. horizontal semicircular canal; b. canalis reuniens ; 

 a. constriction by means of which the sacculus hemisphericus S.R. is formed ; f. 

 narrowed opening between sacculus hemisphericus and utriculus ; C. C. cochlea ; 

 C.C'. lumen of cochlea ; K.K. cartilaginous capsule of cochlea ; K.B. basilar plate ; 

 Ch. notochord. 



