102 REPORT OF THE COUNCIL. 



The marking experiments made after March, 1909, were intended to 

 cast light on the movements of plaice east of the Dogger Bank, when 

 at a larger size than those marked in the majority of the experiments 

 carried out on the Eastern Grounds. In the month of July 317 plaice 

 were accordingly marked in Clay Deep and the vicinity. 



The following table gives the particulars as to the number of plaice 

 recaptured during the period considered : — 



There have thus been recaptured during the period 1090 plaice. 

 One more of the 23 plaice transplanted from the White Sea on the 

 steam trawler Princess Louise has also reached the Laboratory, making 

 13 of these fish in all. 



Vitality Experiments. — The plaice from 16 hauls of the commercial 

 trawl have been subjected to the tests of vitality which have already 

 been described.* In the majority of these experiments some fish were 

 placed in the tanks immediately after capture, others after exposure on 

 deck of one hour. This furnishes information as to the condition of 

 the fish after a period corresponding roughly to that which small plaice 

 would lie on the decks of a commercial trawler before being returned 

 to the sea. It also enables a comparison to be made between the 

 proportion surviving under these conditions and the proportion which 

 would survive if they were at once returned to the sea. 



Collection of the Eggs and LARViE of Fishes. — A voyage was 

 made in June, 1909, for the systematic collection of fish eggs and larvie 

 in the Southern Bight. The stations were fixed along a series of lines 

 traversing the area several times, an interval of ten miles separating 

 successive stations : at each station a haul of the Hensen net, two hauls 

 of the Petersen small-fish trawl (one near the surface and one near the 

 bottom), and a haul of the Todd trawl were made. The lines of the 

 operation stretched from the Leman Banks to the Haak's Light Vessel, 

 thence to Lowestoft, and so in succession to the Maas, Galloper, North 



* Internal. Invs, Mar. Biol. Assoc. Report, II, Pt. II, Cd. 4G41, p. 1. 



