of the Fishery Board for Scotland. 



145 



An examination of the tables and curves shows that the law in regard 

 to the increase in weight according to the cube of the length, although 

 broadly true, does not accurately apply in the case of the fishes examined. 

 With scarcely an exception, the weight at a given length is greater than 

 the weight calculated from the law, so that if the specie gravity of the 

 fishes remains constant they must increase somewhat more in other 

 dimensions than in length. 



In the case of the haddock, the plaice, and the sprat, I have calculated 

 out the weights at the various sizes on the assumption that the law 

 referred to held true during the growth of the fish, and these are given in 

 the Table on pages 240, 241. It will be seen, by comparing them with 

 the weights actually observed, that the latter exceed the former in all 

 cases as stated. The datum for the calculation in each instance was the 

 smoothed average for the smallest sizes of which the relative numbers 

 were large. The salient features in this comparison may be given here 

 as follows, the weights being in grammes : — 



Cm. 



Plaice. 



Observed Weight. 



1 



3 

 5 

 8 

 10 

 15 

 •20 

 25 

 30 

 35 

 40 

 45 

 50 

 55 

 GO 

 65 

 70 



M7 

 4-78 

 9-62 

 34 



77-10 

 161 

 299-10 

 484-6 

 707-9 

 1,026 

 1,429 

 1,820 

 2,371 

 [3,331] 

 [3,908] 



Calculated Weight. 



•009 

 •252 

 1-167 

 4-78 

 9-34 

 31-51 

 74-70 

 145-90 

 252-10 

 406-45 

 597-50 

 850-84 

 1,167-20 

 1,553-44 

 2,016-79 

 2,564-17 

 3,251-59 



Haddock. 



Observed Weight. Calculated Weight 



7*8 

 28-3 

 66-7 

 140-2 

 243-3 

 381 

 591-6 

 828-2 

 1,117 

 [1,440] 

 [1,915] 

 [3,214] 



•008 

 •213 

 •984 

 4-03 

 7-87 

 26-56 

 62-97 

 122-97 

 212-50 

 337-44 

 503-73 

 717-19 

 983-80 

 1,309-47 

 1,700 

 2,162-14 

 2,699-52 



The figures in brackets represent individual fishes at or very near the dimension stated. 

 The comparison in the case of the sprat was as follows : — 



Centimetre?. 



Observed Weight. 



Calculated Weight. 



1 





•005 



2 





•043 



3 





•149 



4 





•343 



5 



•67 



•670 



6 



1-17 



1-190 



7 



2-02 



1-838 



8 



3-05 



2-744 



9 



4-63 



4-015 



10 



6-71 



5-36 



11 



9-48 



7-13 



12 



12-46 



952 



12 5 



14-34 





13 



[16-4] 



11-78 



14 





14-71 



