400 REPORT OF THE COUNCIL. 



401 have since been recaptured, making a total of 5,115 liberated 

 and 588 recaptured up to date. 



In the great majority of cases the fishermen have been able to give 

 trustworthy particulars concerning the date and locality of recapture, 

 and the fislies themselves have been forwarded to the laboratory at 

 Lowestoft for examination and measurement. 



These experiments have been eminently successful in throwing light 

 upon the seasonal migrations of this species, and upon differences in the 

 rate of growth on different fishing grounds. 



The experiments in the transplantation of small marked plaice from 

 the inshore grounds to the Dogger Bank, in the spring of 1904, which 

 were briefly referred to in the last annual report, have yielded results of 

 considerable scientific importance, and suggest the possibility of practical 

 applications. The average year's growth of small marked plaice, about 

 20 cm. (8 ins.) in length, on the coastal grounds of the southern and 

 eastern parts of the North Sea, has been found to be not more than 

 5 cm. (2 ins.) ; whereas on the Dogger Bank the average growth of 

 similar fishes has been found to be 15 cm. (6 ins.) in the same time. Tn 

 other words, small 8-inch plaice, weighing about 3 oz., which after a year's 

 growth on the coastal grounds become 10-inch fish, weighing 5^ oz., are 

 transformed in the same time into 14-inch fish weighing 1 lb. each, by 

 transplantation to the Dogger Bank. 



As small plaice do not naturally occur upon the Bank, the problem 

 is raised whether the yield of plaice from the North Sea could not be 

 materially increased by the annual transplantation of large numbers of 

 such fish on a commercial scale from the coastal grounds to the Dogger 

 Bank. 



Experiments in transplantation on a more extensive scale have been 

 carried out during the past few months in various parts of the English 

 area in order to provide additional information bearing upon this 

 subject. 



The marking experiments during the past year have also been ex- 

 tended to a considerable number of other species, including Turbot, 

 Brill, Soles, Lemon Soles, Flounders, Dabs, and Cod. 



Special Experiments. — While the investigations at sea have pro- 

 ceeded, in general, on the same lines as during the previous year, 

 increa.sed attention has been paid to special experiments upon par- 

 ticular problems. Among these may be mentioned : — 



(i) Experiments on the vitality of trawl-caught plaice. 



