G60 



THE EAR. 



narrow (as in Bg. 474), but when seen from above each cell appears 

 nearly uniform in size throughout (fig. 475). At the lower end the 

 cells seem to end for the most part with a rounded extremity (fig. 475, b) 

 slightly bulged to one side, whilst from the other side a process (;;) is 

 prolonged which continues the oblique direction of the cell parallel to 

 the direction of the outer rod, and is fixed below to the basilar mem- 

 brane. (These processes were broken away in tlie specimen fi'om which 

 fig. 474 was taken.) The nucleus if the cell may be either in the upper 

 end, in the middle, or in the rounded projection at the lower end. 

 It is possil)le that there may occasionally be two nuclei in one cell, 

 one at the upper and the other at the lower extremity, but such is by no 

 means so fi'equently the case as is sometimes described. 



Fig. 474. 



Kg. 474. — Profile view of Inxeu and Outkr Rod in connection with Three 

 Hair-cells, and pakt of Lamina Reticularis (from the Guinea-piq). Bichro- 

 mate OF POTASH preparation. YeRY HIGHLY MAGNIFIED. 



i.r, inner i-od ; e.r, outer rod : Ji^, /;.,, Ji^, hair-cells of first, second, and tliird rows 

 respectively. They ajipear, especially the second and third, nai-row in the middle, the 

 thin edge of the riband being seen, but below have become accidentally twisted so that the 

 flattened side is brought into view. A nucleus is visible in fi^, but none is seen in h„, A., 

 probably owing to its being contained in the part of the cell the edge of which is turned 

 towards the observer. The lower ends of all three, together with their basilar i^rocesses, 

 have become broken off in the preparation of the specimen ; s. one of the succeeding epi- 

 thelial cells ; c, cuticular thread attached to lamina reticularis ; ^5, phalangeal pi'ocess of 

 outer rod ; p.,, p.^, jjlialanges of lamina reticularis seen in section. 



In most animals there are three series of outer hair-cells, and a cor- 

 responding number of rings and phalanges in the lamina reticularis, but 

 in man there are four series (fig. 4G9, h), and the lamina is correspond- 

 ingly larger. Outside the hair-bearing cells the columnar cells are much 

 elongated and obliquely disposed (fig. 474, s), but they become more and 



