170 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Table XV. Age Groups : Data for Group I, 1908-1916. 



Mean Length. 



Caught 



in 

 6" mesh. 



Caught 



in 

 2" mesh. 



Total. 



Formed by 

 completing 

 last series. 



6-5 



i 



4 



6 



11 



12 



26 



91 



186 



215 



193 



110 



65 



29 



17 



13 



8 



3 



13 



24 

 26 

 55 

 91 

 145 

 178 



151 



136 



89 



68 



40 

 20 



8 



2 



1 



13 

 24 

 26 

 56 

 95 

 151 

 189 



13 



7-5 



24 



8-5 



26 



9-5 



56 



10*5 



95 



11-5 



151 



12-5 



189 







13-5 



163 

 162 

 180 

 254 



258 



14-5 



276 



15-5 



300 



16-5 



272 







17-5 



255 



213 



118 



65 



31 



18 



13 



8 



3 



256 



18-5 



213 



19-5 



118 



20-5 



21-5 



22-5 



65 

 31 

 18 



23-5 



13 



24-5 



8 



25-5 



3 







Totals 



990 



1,047 



2,037 



2,385 







Means 







15-38 



15-28 







Standard Deviations 







3-405 



2142 



to any particular group. Really the odds will be a little 

 different when we apply certain necessary corrections, but we 

 shall only do that when required by the administrators. This, 

 then, indicates the way in which this (and the other) tables 

 ought to be used practically. 



Fig. 7 is a graph of the results of Table 14. It shows the 

 average lengths of plaice of Age-groups to IV, and also the 

 "dispersions," so that some idea of the significance of the 

 overlapping of the various group-lengths may be obtained. 

 The graph is not a straight line, but a logarithmic curve of a 

 kind, and to see how this is we must consider the sizes of 



