PLATE 2 



EXPLANATION OF FIGURES 



7 Section tangential to the surface of the organ of Corti, through the third 

 turn of the cochlea. Dog 3 days, 18 hours after birth. Solution of trichloracetic 

 acid 5 per cent in water. Iron hematoxylin, Congo red. 



8 Section tangential to the surface of the organ of Corti, through the third 

 turn of the cochlea. Kitten 5 daj'^s, 12 hours after birth. Solution of trichlor- 

 acetic acid 5 per cent in water. Iron hematoxylin, Congo red, light green. 



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

 portion of the first (apical) turn of the cochlea. Kitten 12 days after birth. 

 Osn.ic acid 1 per cent aqueous solution for about one hour, followed by immersion 

 in a 5 per cent aqueous solution of trichloracetic acid. Iron hem.atoxylin, Congo 

 red. 



10 Vertical spiral (parallel with the spiral rows) section of the organ of Corti, 

 through the second turn of the cochlea. Kitten 11 days after birth. Osmie 

 acid 1 per cent aqueous solution for a^bout one hour, followed by immersion in 

 a 5 per cent aqueous solution of trichloracetic acid. Iron hematoxylin, Congo 

 red. 



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

 portion of the second turn of the cochlea. Kitten 12 days after birth. Osmic 

 acid 1 per cent aqueous solution for about half an hour, followed by immersion 

 in a 5 per cent aqueous solution of trichloracetic acid. Iron hematoxylin, Congo 

 red, light green. 



12 Section tangential to the surface of the organ of Corti, through the third 

 turn of the cochlea. Kitten 12 days after birth. Osmic acid 1 per cent aqucd»us 

 solution for about half an hour, followed by immersion in a 5 per cent aqueous 

 solution of trichloracetic acid. Iron hematoxylin, Congo red. 



;ns 



