198 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



indicated very clearly by the results of the fish-rnarking 

 experiments. We see that in all cases where plaice have 

 been marked and liberated on the grounds near Nelson 

 Buoy a large proportion of the fishes recaught have been 

 taken from the vicinity of the place of liberation. A 

 certain proportion also migrate in the winter to the chan- 

 nels, and close inshore in the Bays and Estuaries, and 

 another fraction of the fish invariably migrate into Red 

 Wharf Bay and the adjacent grounds towards the end of 

 the year. The mean length of the plaice liberated at 

 Nelson Buoy in 1912-3, and recovered in the Red Wharf 

 Bay area at the end of the same year of liberation was 

 25"5 cms., while the mean length of the other fish 

 recaptured on the Nelson Buoy Grounds during the 

 summer and autumn season -there was 23 cms. Again, 

 the mean length of the fish recaptured from the 

 same experiments, and which had migrated during 

 the winter months into the shallow waters inshore 

 in the Lancashire Estuaries and Bays, was 22 cms. Now, 

 these figures do not go very far — though a close analysis, 

 in this way, of the results of all the experiments would 

 probably make the evidence better — but so far as 

 they go they tend to show that the plaice behave, to some 

 extent, according to their age. The larger ones migrate 

 at the end of the year to the North Wales ground, while 

 the smaller ones return to the Estuaries from which they 

 originally migrated to the Nelson Buoy grounds. 



There can be little doubt as to what becomes of the 

 plaice which inhabit the Beaumaris-Red Wharf grounds 

 during the winter months, and which then disappear at 

 the end or the beginning of the year. Some of these fish 

 — the smaller sizes chiefly — probably migrate back again 

 into the shallow water bays and channels between 

 Anglesey and Morecambe Bay, and remain there during 



