Body lenjTh ( CH) 



tOI 

 921 



I02J 



MU 



IIU 



Figure 2. --Comparison of length 

 frequency. Upper (a): Mean 

 frequency of the schools 1-17 

 shown in Fig. 1. Lower (b): 

 Frequency of the total individ- 

 uals measured during the 

 same period as the samples 

 of the schools 1-17. 



Table 1. --The tests of variance and difference between mean 

 value of body length (5% level) 



GROUP A (50. 1 - 68. cm. ) 



GROUP B (70. 1 - 86. cm. ) 



X : Significant in variance. 



D: Not significant in variance, but significant in difference between mean. 



O: Not significant both in variance and in difference between mean. 



* : The sample numbers correspond to those of the schools of Fig. 1 respectively. 



39 



