LENGTH OF THE INTERNODES 27 



All these changes when compared with group 1 indicate that 

 as a consequence of the growth of the frog, the internodes have 

 grown in length, and therefore the shorter internodes which are 

 so frequent in group 1, have become less frequent in this group. 



With some insignificant modifications, the same statements 

 apply to all the other curves. Finally in group 5 we see a very 

 wide extension of variates from 350 to 2650 micra, and at the 

 same time the ranges found in group 1 can only be found in this 

 case in the lower third of the total range. The position of the 

 mode has now moved from 532 to 1310 micra, indicating that as a 

 whole, the modal value of the internode has increased 146 per 

 cent when compared with group 1. From being nearly sym- 

 metrical, the curve itself has become highly skew. The increase 

 in range of the variates may also be shown from the successive 

 values of the standard deviation which increase gradually in 

 round numbers from 139 micra in group 1 to 351 micra in group 

 5. 



Let us examine now the curves for the diameters. For this 

 character the distributions of the frequencies are very irregular as 

 compared with the curves which illustrate the distributions of 

 frequencies of the internodes. 



Nevertheless in all fundamental features, the two records 

 agree very nicely ; that is the range of variates is smaller in grouD 

 1 than in group 5. The position of the mode moves gradually 

 from a less diameter to a greater diameter; from 7 to 11 micra. 

 The position of the entire curve moves frrom left to right. The 

 only distinct difference which can be found in the curves of the 

 internode and diameter lies in the fact that the total amount of 

 increment during these five successive stages is considerably 

 less in the latter than in the former, and in fact the internodes 

 show almost three times as much increase as the diameters 

 (see p. 28) and consequently the changes in the form of the curves 

 for diameter from group 1 to group 5 is less conspicuous than in 

 the case of the internode. 



