GROWTH OF THE INNER EAR OF ALBINO RAT 



59 



their whole length, we can easily measure this distance. After 

 twelve days, however, the breadth consists of the sum of the 

 radial breadth of the outer pillar and the half of the radial 

 distance between the outer corner of the inner pillar and the 

 inner corner of the outer pillar, as previously explained. 



In table 28 are given the values for the radial basal breadth 

 of the outer pillar cell (including the outer pillar) from birth 

 to nine days of age. These values show a rapid increase. Ac- 

 cording to the turn of the cochlea, the breadth at birth diminishes 

 from the base to the apex. At three days it increases already in 

 turn II, but at the later ages it increases gradually from the 

 base to the apex. 



TABLE 30 Condensed 



Ratios of the radial basal breadth of the outer pillars on age according to the 



turns of the cochlea 



In table 29 (chart 11) are given the values for the radial 

 basal breadth of the outer pillar (not pillar cell). As in the case 

 of the inner pillar, here also the outer pillar first appears distinctly 

 at six days of age. After the continuous increase of the values till 

 twelve to fifteen days, they decrease suddenly at twenty days, 

 and then increase again very slowly. This relation is clearly 

 shown by the ratios at the bottom of the last column. That 

 the values tend to increase from the base toward the apex is 

 also shown, though there are some exceptions. Table 30 gives 

 the condensed results. 



From Retzius' work ('84) we have calculated the values for 

 the radial basal breadth of the outer pillar in the rabbit and cat 

 as follows (table 31). 



There are large differences between my results and those 

 of Retzius during the earlier stage, especially in the rabbit. 



