154 THE AUDITORY NERVE AND COCHLEA, BY W. WALDEYER. 



ternal pillars is nearly rectangular. In profile views the foot 

 appears triangular. 



The foot of the external pillar is of considerable size, and is 

 expanded in a fan-like manner on the membrana basilaris. 

 The body is more slender, and the double curvature of the S 

 is much more marked. The caput, in opposition to that of the 

 inner pillar, is bent inwards, and forms, in profile, a segment 

 of a circle somewhat resembling the form presented by a lateral 

 view of the caput astragali. 



The caput astragali is, in fact, the object to which the caput of the 

 external pillar may best be compared, except that in this the two 

 lateral surfaces, corresponding to the malleolar articulations of the 

 Talus, are of equal size, whilst the upper surface is not excavated, but 

 moderately convex. Deiters (13) compares it to a boat (heeled over); 

 Lowenberg (39), to the head of a Bird, the beak of which corresponds 

 to the capitular lamina. If we seek for a comparison for the internal 

 pillar, the upper end of the ulna may be accepted as somewhat 

 resembling it. The coronoid process represents the above-described 

 triangular projection of the caput ; and if we conceive the olecranon to 

 be somewhat prolonged and arched forwards, it would exactly resemble 

 the external capitular lamina, whilst the dorsal tuberositas olecrani 

 corresponds to the hook g (fig. 327, B) ; the lateral groove would also 

 be represented by the sinus lunatus ulnas. 



The capitular lamina of the external pillar arises by means 

 of a long stalk from the middle of the external superior border, 

 and terminates in an oar-like expansion (fig. 327, Ad). It 

 constitutes, as will be subsequently shown, the first phalanx of 

 the lamina reticularis. 



The presence of finely granular cell protoplasm at two 

 points of both sets of pillars, the caput and the foot, is deserv- 

 ing of particular attention (fig. 327, B c and 7 ; fig. 331, n 



head exhibits as a clear circle the indistinctly seen optic transverse 

 section of the bodies of the external pillars ;) I, phalangiform capitu- 

 lar laminse of the external pillars (first phalanges) ; k, first ring with 

 the hairy scales of the first external hair-cells ; m and o, second and 

 third rings and brushes of hair ; n and p, second and third phalanges ; 

 r, supporting cells of Hensen ; q, cuticular meshwork between the 

 epithelial cells (enclosing frames, Schlussrahmen of Deiters). 



