PLATE 1 



EXPLANATION OF FIGURES 



1 Section tangential (and somewhat oblique) to the surface of the organ of 

 Corti, through the second (middle) turn of the cochlea. New-born kitten. 

 Fixation: osmic acid, 1 per cent aqueous solution for about one hour, followed 

 by immersion in Zenker's fluid. Stain: Iron hematoxjdin, Congo red, light 

 green. 



2 Section tangential to the surface of the organ of Corti, through the second 

 turn of the cochlea. Kitten 3 days, 12 hours after birth. Exposure of the cochlea, 

 the bony wall of which had previously been provided, with two small openings, 

 to vapors from a 2 per cent aqueous solution of osmic acid for approximately 

 one hour, and subsequent treatment of the piece by trichloracetic acid 5 per cent 

 in water. Iron hematoxylin, Congo red. 



3 Section tangential to the surface of the organ of Corti, through the basal 

 portion of the second turn of the cochlea. Dog 3 days, 18 hours after birth. 

 Zenker's fluid. Iron hematoxylin, Congo red. 



4 and 5 Sections tangential to the surface of the organ of Corti, through the 

 basal portion of the second turn of the cochlea. Kitten 3 days after birth. 

 Solution of trichloracetic acid 5 per cent in water. Iron hematoxylin, Congo 

 red, light green. 



6 Radial vertical section of the organ of Corti through the third (basal) turn 

 of the cochlea. Kitten 3 days, 12 hours after birth. Exposure of the cochlea 

 to vapors from a 2 per cent aqueous solution of osmic acid and subsequent treat- 

 ment of the piece by trichloracetic acid 5 per cent in water. Iron hematoxylin, 

 Congo red. 



316 



