DESCRIPTION OF PLATES 



All figures were outlined with a Zeiss camera lucida, at the level of the stage 

 of the microscope, with the aid of a Zeiss ocular no. 3, and 2-mm., homog. im- 

 mersion. Apert. 1.30, except figures 1, 2, 3, 4, 5, and 7, which were outlined with 

 Zeiss ocular no. 1. 



GENERAL ABBREVIATION.? 



aip, apices of embryonic inner pillar 

 cells 



aoh^^, apices or bodies of atrophied 

 hair cells of an outer fourth spiral 

 row 



aop, apices or phalanges of the outer 

 pillar cells 



cy, cytoplasm in process of cytolysis 



c?\ d", d"', apices or bodies of cells of 

 Deiters, respectively, of the first, 

 second, and third rows 



H, apex of the cell of Hensen 



ih, apices or cell bodies of the inner 

 hair cells 



ihd, heads of the inner pillar cells 



ij), inner pillars 



iph, bodies of the inner pillars 



ipl, head-plates of the inner pillars 



ipl^, ipV\ respectively, the superficial 

 homogeneous zone and the deeper 

 fibrillated zone of the head plates of 

 the inner pillars 



t's', is", apices or cell bodies of support- 

 ing cells, respectively, of the first 

 and second inner rows 



A'', Nerve bundle passing through the 

 foramen nervinum 



A'", spiral nerve bundle running be- 

 tween the inner and outer pillar cells 

 or within the tunnel space 



iV"', spiral nerve bundle running be- 

 tween the outer pillars and the cells 

 of Deiters of the first row 



nd, apices of non-differentiated cells of 

 the greater epithelial ridge 



m, nuclei of non-differentiated cells of 

 the greater epithelial ridge 



nih, nuclei of inner hair cells 



niji, nuclei of inner pillar cells 



nis^, nis", nuclei of inner supporting 

 cells, respectively, of the first and 

 second rows 



nop, nucleus of an outer pillar cell, 

 seated near the head (abnormality) 



oh^, oh", oh}", apices or cell bodies of 

 outer hair cells, respectively, of the 

 first, second, and third rows 



ohd, heads of outer pillars 



op, outer pillar cells 



oph, bodies of outer pillars 



oph, phalanx processes of outer pillars 



oph^, opd", opd"^, op<^^, respectively, 

 the subphalanx, intercellular, sub- 

 membraneous segments and the in- 

 tracephalic roots of the phalanx proc- 

 ess of the outer pillar 



pd^, pd", pd"^, phalanx processes or 

 apical filaments of cells of Deiters, 

 respectively, of the first, second, and 

 third rows 



SN, SN\ the first space of Nuel 



t, developing tunnel space 



T, tunnel space 



tb, terminal bars or obturator septa 



VS, vas spirale 



31^ 



