104 



ANATOMICAL AND PHYSIOLOGICAL STUDIES ON 



ference is that the volume in the outer hair cells does not diminish 

 so much after twenty-five days, but holds nearly the same value 

 (table 67, chart 36). In condensed age groups, therefore, we see 

 a large increase in the size of the cells with age. 



To determine the growth of the outer hair cells in each turn 

 of the cochlea, table 67 is used (chart 37). From twenty days on 

 the values increase from the basal to the apical turn. Before 

 twenty days the relations are irregular or reversed. In table 

 76 this relation is clearly brought out. 



Comparing the changes of the volume of the outer hair cells 

 in three age groups (table 67), we find that the average volume 

 increases throughout each turn with age, except in turn I, where 



TABLE 76 Condensed 

 Ratios of the volumes of the outer hair cells according to the turns of the cochlea 



that at eleven days is largest. In the inner hair cells, however, 

 values at eleven days are largest in both turn I and II. 



For the nuclei of the outer hair cells, the diameters are given 

 in table 68). Here the d ! ameters tend to increase from one to 

 nine days. At twelve days they decrease strikingly, and after 

 that very slowly. In table 69 are given the values for the volumes 

 of the nuclei of the outer hair cells. 



In table 68 are given also the measurements for the nuclei 

 of the outer hair cells according to the turn of the cochlea. 

 At nine days and after, the diameters become larger in passing 

 from base to apex, while in the earlier stages this relation is 

 irregular or reversed. The decrease of the measurements in, 

 each turn with age is clearly shown in the three age groups. 



