GROWTH OF THE INNER EAR OF ALBINO RAT 



107 



to that of the cytoplasm (=cell volume less nucleus volume) 

 are given in the last column. This ratio increases with age, 

 as table 82 shows. While the ratio is 1.5 in the youngest and 

 smallest group, it is 9.9 in the largest. This means that as a 

 group these cells are continually growing in volume. This result 

 may be analysed for the two groups of cells involved. 



TABLE 80 



Average volumes of inner and outer hair cells and of their respective nuclei 



in n 3 according to sex 



The nucleus-plasma ratio of the inner and outer hair cells 

 considered separately. This is shown for the inner hair cells 

 in table 83. The ratios are also progressive, but somewhat 

 larger for the earlier age groups and smaller for the oldest, than 

 in the previous instance. 



The ratios for the outer hair cells are also progressive, and 

 the range is greater than for the inner hair cells as table 84 shows. 

 Here the ratio is 1.2 for the youngest group and 10.6 for the 



