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



the membrana basilaris between the pillars, which must not be 

 confounded with nerve fibres (Deiters' system of supporting 

 fibres). 



The protoplasmic masses situated near the heads of the 

 pillars have been less known and attended to * They lie at 

 the outer side of both pillars, and therefore in the concavity of 

 the arch of the inner pillar (fig. 327, B e\ close under the most 

 projecting part of the caput, and just beneath the origin of 

 the peduncle of the lamina of the outer pillar. In young 

 animals I have sometimes seen a nucleus at this point, of 

 the same form and size as that at the base. After treatment 

 with a 0*05 per cent, solution of chromic acid, a nucleated 

 structure appears near the caput of almost every pillar (fig. 

 327, B i), whilst the surrounding mass appears finely granu- 

 lar, and is continuous with the just-mentioned protoplasmic 

 mass. 



After the application of hardening reagents, the bodies and bases of 

 both pillars exhibit a fine but very distinct longitudinal striation, and 

 occasionally it may be seen to be split into fine stiff fibres which are 

 prolonged -into the striated lamella of the membrana basilaris. The 

 capitula, on the other hand, always remains homogeneous. I have 

 never seen a cavity either in the bodies or in the bases. The sub- 

 stance of the pillar, as Bottcher first observed, is very resistant ; in 

 solution of potash, however, it rapidly undergoes solution, and shrinks 

 to some extent in solutions of neutral salts and of acids. I have 

 found the pillars well preserved in Man twenty-four hours after death. 

 The principal portion of them appears to belong to the cuticular forma- 

 tions, a view that is supported by their connection with the lamina 

 reticularis, which will be described immediately. 



The two pillars are so connected as to form a kind of arch, 

 the caput of the external pillar lying in the concavity between 

 the capitular lamina and the caput of the inner pillar (fig. 327, 

 B ; figs. 331 and 332). The capitular lamina of the internal 



* Hensen (27, p. 499) mentions that the protoplasm at the bases of the 

 pillars ascends as far as to the heads, but gives no further details. Per- 

 haps the little laminar appendages of the heads of the internal pillars are 

 referrible to these remains of protoplasm which Max Schultze (50) has 

 described, and which project into the cavity of the arch. 



