360-, 

 330 

 300-1 

 270 

 240 -J 

 ^ 210-1 

 ?| 180- 



1. '20 

 k; 



90-1 

 60- 



150- 



30- 



I 



2 3 



Age 



Figure 18. - Maximum, minimum, and average lengths of each age group 

 of downstream -migrant bluebacks, 1949-53 average. White 

 boxes represent two standard deviations on each side of the 

 mean; black boxes represent 95 -percent confidence limits of 

 the mean . 



27 



