of the Fishery Board for Scotland. 



195 



and mature in each division have been calculated, it will be noticed that 

 whilst the proportions between the different divisions are made more 

 equable, yet those within each division are magnified, because in each case 

 a multiplier has to be used to bring each lot to a percentage. Hence, if 

 there is any great disproportion between the numbers of the different 

 divisions this disproportion will be displayed by the multiplier 

 used. For example, if there are 50 in one division and only 5 in another, 

 these two divisions will be brought to the same level in the percentages, 

 and yet the value of the latter group is only yL of the former. In the 

 case of the specimens from the southerly portion of the North Sea this 

 disproportion is not great because the multipliers are small ; in the case of 

 the Aberdeen specimens it is much larger. Theoretically, this error would 

 be done away with if a hundred specimens in each division were examined, 

 and under such ideal conditions the only errors that could enter into the 

 calculation would be errors of observation. 



Table II. 



Showing the Relative Proportions of the Immature and Mature Plaice at 

 Different Sizes, from the Southerly Portion of the North Sea. 



1. Males. 



Region. 



Condition 

 of Repro- 

 ductive 



Size in Millimetres. 





Organs. 



240-260 



260-280 



280-300 



300-320 



320-340 



340-360 



360-380 



H elder 



Immature 



4 



6 



6 



3 



0 



0 



0 





Mature 



4 



7 



10 



4 



1 



3 



5 



Lowestoft 



Immature 



0 



3 



6 



5 



0 



1 



0 





Mature 



2 



5 



16 



10 



14 



15 



10 



Grimsby 



Immature 



3 



1 



2 



2 



0 



1 



0 





Mature 



0 



2 



0 



5 



9 



13 



10 



Total 



Immature 



7 



10 



14 



10 



o 



2 



0 



(188) 



Mature 



6 



14 



26 



19 



24 



31 



25 



Do. inper- 

 centage 



Immature 

 Mature 



54 

 46 



42 

 58 



35 

 65 



35 

 65 



0 



100 



6 

 94 



0 



100 



