GROWTH OF THE INNER EAR OF ALBINO RAT 



139 



of the cells of the ganglion spirale on the other. The reason for 

 making this comparison was the fact that Levi ('08), Busacca 

 ('16), and Donaldson and Nagasaka ('18) have noted in the cells 

 of the spinal ganglia of several mammals that the postnatal 

 growth in volume was correlated with the increase in the area of 

 the body surface, and recently Nittono ('20) has found in the 

 rat a similar relation between the growth of the cells of the gasserian 

 ganglion and the area of the skin of the head. On examining 

 this problem, it is evident that the correlations thus far reported 



TABLE 107 



Comparison of ratios between the volumes of the cells of the ganglion spirale ami the 



7-atios of the area of the cylindrical surface of the hair 



cells of the organ of Corti — on the maximum value's 



apply to the postnatal growth period, and that we must consider 

 that the functional relations of the skin are well established, 

 even at the earliest age. The data with which we have worked in 

 the case of the cochlea are presented in several tables (107 to 

 110). 



In tables 107 and 108 are given the volumes of the cells of the 

 ganglion spirale and the areas of the cylindrical surface of the 

 hair cells. In table 107 the ratios are computed by dividing the 

 maximum value by the values at each age, and in table 108 by 

 dividing the values at each age by the initial value. 



