378 



ELEMENTARY PHYSIOLOGY 



LESS. 



ally adapted for being thrown into vibrations, and is 

 called the basilar membrane. The oryan of Corti 

 itself consists of, in the first place, the so-called rods of 

 Corti, peculiarly shaped long bodies, which are seen in 

 section leaning, as it were, against each other. There is 

 an inner row of these and an outer row all along the 

 spiral, each row consisting of several (four to six) thousands 

 of rods. On tlie inside and on the outside of the rods are 

 very peculiar epithelial cells, also arranged into rows, each 



Fio. 122. — The Membranr of hie Drum of the Ear with the small 

 Bones of thk Ear seen from the Inner Siuk ; and the Walls 

 OF the Tnmpanum, with thk Air-Cbll8 in thk Mastoid Part or 

 THE Temporal Bone. 



The petrous part of the temporal bone containing the labyrinth is svip- 

 posed to be reiiioveti, the foot-plate of the stapes having been detached 

 from the fenestra ovalis. 



M.C, mastoid cells; Mall, malleus; Inc. incuR ; St. stapes; a i, lines 

 drawn through the horizontal axis on which the malleus and incus turn. 



row consisting of several thousand cells. Each of these 

 cells bears short hairs on its free surface, hence they are 

 called hair-cells, inner and outer ; and the auditory nerves 

 passing through the lamina s[jiralis, reach the cochlear 

 tube along the whole length of the spiral and end in 

 filaments which are lost in the organ of Corti, but are 

 probably connected with the hair-cells. 



(viii) The Bony Ijabyrinth. — The essential part of 

 the organ of hearing, the canalis cochlearis, as well as the 



