286 



THE ESSENTIALS OF HISTOLOGY. 



2. A reticular lamina (fig. 322, /.r.), which is a cuticular structure 

 extending like a wire-net over the outer epithelium-cells of the organ 

 of Corti, and is composed of two or three series of stiff fiddle-shaped 

 rings (phalanges) cemented together in such a manner as to leave 

 square or oblong apertures through which the hair-cells (see below) 

 project. 



FlG. 320. A PAIR OF EODS OP CORTI, FROM THE RABBIT'S COCHLEA, IN SIDE 



VIEW. (Highly magnified. ) 



b, b, basilar membrane ; i.r., inner rod ; e.r., outer rod. The nucleated protoplasmic masses 

 at the feet are also shown. 



3. The outer hair-cells placed external to the rods of Corti. These 

 are epithelium-cells of columnar shape, arranged in three or four series 

 (fig. 321, p, q, r). The free extremity of the cell is surmounted by a 



FIG. 321. SECTION OF THE ORGAN OF CORTI OF THE DOG. (Waldeyer.) ^. 



a, a', end of spiral lamina ; b, c, middle (homogeneous) layer of the basilar membrane ; u, 

 vestibular (striated) layer ; v, tympanal (connective-tissue) layer ; d, blood-vessel ; /, 

 nerves in spiral lamina ; g, epithelium of spiral groove ; h, nerve-fibres passing towards 

 inner hair-cells, i, k ; I, auditory hairlets on inner hair-cells ; I, i', lamina reticularis ; 

 m, heads of the rods of Corti, jointed together ; u, base of inner rods ; o, base of outer 

 rod ; p, q, r, outer hair-cells ; t, lower ends of hair-cells ; w, nerve-fibrils passing across 

 the tunnel of Corti ; z, cells of Deiters. 



bundle of short auditory hairs, and projects through one of the apertures 

 in the reticular lamina ; the fixed extremity is prolonged into a stift 

 cuticular process (fig. 323, pf), which is attached to the basilar membrane. 

 Between them are other supporting cells which are tapered in the same 



