VI.] 



A. 



THE EAR, 

 FIG. 55. 



159 



13. 



T mr 



TWO VIEWS OF THE MEMBRANOUS LABYRINTH OF COLUMBA 



DOMESTICA (copied from Hasse). 

 A, from the exterior, B, from the interior. 



hor'. horizontal semicircular canal, hor. ampulla of ditto, pag'. pos- 

 terior vertical semicircular canal, pag. ampulla of ditto, 

 //. anterior vertical semicircular canal, fr. ampulla of ditto, 

 u. utriculus, ru. recessus utriculi, v. the connecting tube 

 between the ampulla of the anterior vertical semicircular 

 canal and the utriculus, de. ductus endolymphaticus (recessus 

 vestibuli), s. sacculus hemisphericus, cr. canalis reuniens, lag. 

 lagena, mr. membrane of Reissner, pb. Basilar membrane. 



buli, and (2) the ductus cochlearis, which in birds is a 

 flask-shaped cavity slightly bent on itself, the dilated 

 end of which is called the lagena. The several parts of 

 each of these cavities freely communicate, and the two 

 are joined together by a narrow canal, the canalis re- 

 uniens, cr. 



The osseous labyrinth has a corresponding form, 

 and may be similarly divided into parts : into a bony 

 vestibule, with its bony semicircular canals and recessus 



