1 86 "Journal of Comparative Neurology and Psychology. 



As Table 10 shows, the average growth of the internodes at S^ 

 is 22.5 per cent, which is greater than that at T, 11.8 per cent, or 

 at T^, 10.4 per cent. Also the percentage increase at the level 

 Si is greater in the larger than in the smaller frogs. These 

 results accord with those previously noted in the examination of 

 the internodal lengths on fibers from the same frogs, in w^hich the 

 length of the internodes in the foot becomes proportionally less 

 as the frog becomes larger (see Table 8). 



To determine the average growth of the internodes on individual 

 fibers, it is necessary to measure the fibers of a given diameter 

 class taken from the same frog, at all three levels, and Table 11, 

 based on the data in Table 10, gives the values found. 



TABLE II. 



Showing the percentage increase in the average length of the internodes on fibers 

 of a given diameter, when all three levels from the same frog are included. The 

 averages used are those given in Table 10. 



It is seen from the foregoing, that the average increase in the 

 length of the internodes in PVog 3, fibers 5.3/( in diameter, is 18.4 

 per cent. Frog 5, fibers ^.^ii in diameter, 1 1.8 per cent, and Frog 5, 

 fibers 6.3// in diameter, 14.5 per cent; the grand average for the 

 three frogs being 14.9 per cent. The nerves to which these fibers 

 belong have lengthened in each case 15.6 per cent, so that the 

 accordance is fair in each instance, except in the case of the 5.3/z 

 group in Frog 5. It should be recalled however that in the 6.3// 

 group in Frog 8, at the level 7", a very low value was obtained 

 (Table 6). Because this value is less than that at S^, it may be 

 considered aberrant, and it is the presence of this value which 

 causes the low percentage, 3.2 per cent, in Frog 5, at the level T. 

 If this observation is excluded, the value for the 5.3/{ group in 



