THE BARENTS SEA (" WHITE SEA ") TO THE NORTH SEA. 



509 



I propose to estimate the increase in weight of the live fish re- 

 ferred to on two bases : — 



A. That the original weight of each fish was equal to that of a 

 normal Dogger plaice. 



B. That the weights thus obtained (A) are on an average 29% too 

 high, as was ascertained for the July fish. 



Estimate A for the original weight being obviously too high, we 

 can be satisfied that any increase shown on this basis is below that 

 actually attained. It is further possible that increments based on 

 Estimate B understate those actually attained. 



The resulting figures are given in Table III below. 



TABLE III. 



Table showing estimated increase in the weight of five plaice 

 transplanted from the White Sea to the North Sea, based on two 

 estimates of their original weight. 



A. That the plaice were equal in weight to Dogger plaice of corre- 

 sponding sizes. 

 B. That estimate A gives an original weight value 29% too high in 

 accordance with observations made on eight fish in July, 



Erom this table it can be seen that, on the lowest possible estimate, 

 the two fish which had been at liberty the longest (and tliis period 

 less than a year and including a winter) had increased by about three- 

 quarters of their original weight (73"3% and 88-8%); the fish which 

 had been at liberty shorter periods also displaying corroborative 

 increments. 



The data are too small to permit of further discussion, but by kind 

 permission of my colleague, Dr. Wallace, I am able to put forward in 

 contrast to the above figures data from his forthcoming report. 



Dr. Wallace finds from otolith investigations that, as regards the 

 plaice of the Dogger and Flamborough region, the weight of six-year- 



