50 



INATOMK \l. AND PHYSIOLOGICAL STUDIES ON 



1 1! table 18 are given the values for the radial distance between 

 the habenula perforata and the outer corner of the inner pillar 

 at base ii]) to nine days of age. As shown, these values, on the 

 average, increase with age. The increase of this distance means 

 that the base of the inner pillar cell spreads outward more and 

 more. 



When we consider this distance according to the coil of the 

 cochlea, it is at birth about the same through all the turns 

 (table IS; at three days it increases up to turn III, and in turn 



TABLE 18 



Radial distance between the habenula perforata and the outer corner of the inner 



pillar at base — on age 



IV the value is the same at the apex as at the base. At six days 

 the value in turn III is also largest, and next largest in turn IV. 

 At nine days of age the same relations are to be seen. 



In table 19 (chart 8) are given the values for the radial basal 

 breadth of the inner pillar (not pillar cell) on age. At the bottom 

 of the last column are the ratios from 6 to 546, and 20 to 546 

 days. As above noted, the rod can be followed at birth from 

 the upper part to near the base of the cell (fig. 4). At three days 

 (fig. 5), its base reaches the basilar membrane as a thin and slender 

 thread, but we cannot measure its basal breadth accurately. 

 During the next few days it increases in radial breadth rapidly, 

 and at six days has the average value of 29 y. (table 19). After 

 nine days it decreases distinctly till twenty days, after which 

 the value remains nearly constant. These relations are evident 

 in the ratios. While the breadth at six days is about twice 

 that al 546 days, that at twenty days has the same value. 



