244 



KENJI NITTONO 



This result differs from that reported by Donaldson and 

 Nagasaka ('18), in which the volume of the spinal ganglion cells 

 increased in the proportion of the increase in the area of the 

 entire body. It is important to note, however, that the differ- 

 ence in this relation is accompanied by a difference in the be- 

 havior of the ganglion cells themselves in the two localities. 



TABLE 8 

 Showing the relative areas of the head and the relative volumes of the ganglion cells — 



on body weight 



TABLE 9 



Data on the relative areas of the head and the relative volumes of the ganglion cells 



in rats younger than sixty-two days 



While in the spinal ganglion the cells continue to increase in 

 volume so long as the body increases in area, the corresponding 

 cells in the gasserian ganglion reach nearly their full volume at 

 puberty, and hence do not follow the postpubertal growth of 

 the entire head. This state of affairs has led me to make a 

 comparison of the area of the head during the time when the 

 largest ganglion cells of the gasserian ganglion were increasing 

 in volume, i.e., prior to puberty. The results are presented in 

 table 9. 



