32 SHINKISHI HATAI 



d. On the Correlation in Growth Between the Internodal Length 



and Diameter 



It has been stated by the previous investigators that the length 

 of the internode varies with the diameter of the fiber in the sense 

 that the fibers of greater diameter have the longer internodes. 

 According to Birge ('82) during growth the average diameter of 

 the fibers in the frog increases, and the average internodal length 

 also becomes greater. In general, the results just mentioned are 

 in harmony with the findings of Boycott and Takahashi. In 

 this connection however, Boycott has drawn attention to an 

 important point. He stated that 



an examination of the table will show however that the internodal 

 length increases -proportionately more than the diameter, so that in a large 

 frog, the length of the internodes in the fiber of given diameter, is greater 

 than in a small frog (p. 372). 



Later Takahashi advanced this conclusion of Boycott a step 

 further stating that 



in the same frog, the length of the internodes at different levels on fiber 

 of like diameter in the nerves to the leg, increases towards the periphery 

 This increase appears to be associated with the more rapid growth of 

 the distal segments of the leg, but the influence of the segment on the 

 portion of the nerve within it, is less marked as the frogs become larger. 



Thus Boycott's and Takahashi's investigations reveal that 

 the relation between diameter and internodes is far more com- 

 plicated than it was considered to be by the earlier investigators, 

 and varies not only when the different sized frogs are compared, 

 but also at the different levels in the leg of the same frog. 



I shall discuss this problem under two heads : 



1. The correlation of the length and diameter of the internode 

 from a single locality in a given frog. 



2. The relation between the length of the internode and its 

 diameter. 



a. From a single locality in frogs of different sizes. 



6. In the different segments of the leg of the same frog. 



