.STRUCTURE OF THE COCHLEA 



235 



FIG. 273. LONGITUDINAL SECTION OF AN AMPULLA THROUGH THE CRISTA ACUSTICA. 



amp, cavity of the ampulla; sc.c, semicircular canal opening out of it; c, connective tissue 

 attached to the wall of the membranous ampulla and traversing the peril ymph ; e, e, flattened 

 epithelium of ampulla; k, auditory hairs projecting from the columnar cells of the auditory 

 epithelium into the cupula, cup. term. ; r, blood-vessels ; n, nerve-fibres entering the base of 

 the crista and passing into the columnar cells. 



FIG. 274. AUDITORY EPITHELIUM FROM THE MACULA ACUSTICA OF THE SACCULE 

 OF AN ALLIGATOR. (Highly magnified.) 



c,c, columnar hair-cells ;/,/, fibre-cells ; n, nerve-fibre, losing its medullary sheath and passing 

 to terminate in the columnar auditory cells ; h, auditory hair ; h', base of auditory hairs, 

 split up into fibrils. 



