THE ORGAN OF CORTI. 



239 



articulated together, meeting like the rafters of a roof; they 

 inclose a lymph-space or passage, the "tunnel of Corti," 

 which follows the spiral windings of the cochlea. 



These pillar-cells, inner and outer, have slender shafts of a 

 firm substance, with enlarged extremities, and with nuclei and 

 some ordinary protoplasm at their lower ends. 



External to the pillars of Corti are three or four rows of 

 outer hair-cells, columnar epithelium-cells with hairs projecting 

 from their exposed ends. They extend from the upper sur- 



Fio. 94. 



Organ of Corti, human, in cross-section (Retzius). 



face of the organ of Corti only about half-way to the basilar 

 membrane. 



The outer hair-cells alternate with and are supported by the 

 cells of DeiterSj long columnar sustentacular epithelium-cells, 

 somewhat like the pillar-celis, and with their bases separated 

 by slight intervals, the "spaces of Nuel." 



The upper ends of the pillar-cells and cells of Deiters 



