THE SENSE OF HEARING. 



823 



top, the upper extremity of each being bent at an angle so as to project exter- 

 nally and parallel with the basilar membrane ; these projections are the pha- 

 langar processes of the rods, the phalanges of the inner row overlapping those 

 of the outer row. These phalangar processes of the rods form the points of 

 attachment in fact, the beginning of the reticulate membrane (membrana 

 reticulata), a peculiar cuticular, network-like structure formed of rings and 

 cross-bars, having the appearance of certain vegetable tissues seen under the 

 microscope. The reticulate membrane stretches across the outer rows of hair- 



FIG. 282. Diagram of the constituents of the organ of Corti (from Foster, after Retzius) : A, inner hair- 

 cell; A', the head, seen from above; B, inner, B', outer, rod of Corti; ph, in each, is the phalangar pro- 

 cess ; c, the twin outer hair-cell ; C.c, the cell of Corti ; h, its auditory hairs ; n, its nucleus ; x, Hensen's 

 body ; D.c, cell of Deiters ; n', its nucleus ; ph.p, its phalangar process ; fll, the cuticular filament ; m.b, 

 basilar membrane ; m.r, reticulate membrane ; c', the head of a cell of Corti, seen from above ; D, the 

 organ of Corti, seen from above ; i.hc, the heads of the inner hair-cells ; i.r.h, the head and phalangar pro- 

 cess of the inner rod ; o.r.h, the head of the outer rod, with ph.p, its phalangar process, covered to the left 

 hand by the inner rods, but uncovered to the right ; o.h.c, the heads of the cells of Corti, supported by 

 the rings of the reticulate membrane ; ph, one of the phalangae of the reticulate membrane. 



cells, the body of each of which is enclosed and is held at its top within a ring 

 of the network (Fig. 282, D). 



Each of the cells of Deiters, described above, is continued upward in a 

 process which is attached to a cross-bar or a ring of the reticulate membrane 

 next outside its companion-cell of Corti. The inner or median line of the 

 Deiters cell is also modified into a cuticular thread fused below to the basilar 

 membrane and above to a ring of the reticulate membrane. Thus the audi- 

 tory hair-cells of Corti may be regarded as suspended from the reticulate mem- 

 brane, which in turn is supported by the cuticular processes of the cells of 

 Deiters, which rest upon the basilar membrane, and by the phalangar pro- 



