130 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



smaller plaice, and not to fishing-out. In February only 



2 per cent, of the fish wore under 8 inches in length, in 

 March 6 per cent., in April 17 per cent., and in May 

 as much as 21 per cent. Apparently the conditions at 

 the south end of Cardigan Bay are very different from 

 those off the coast of Lancashire. The natural conditions 

 are no doubt not the same, but much of the difference 

 may be due simply to the fact that the fishery at this 

 part of the coast is very much less intense than in the 

 highly exploited grounds to the North. The distribution 

 of plaice in Cardigan and Carnarvon Bays would be well 

 worth closer attention than we have been able to give to 

 it. 



4. AGE-GROUPS. 



The determination of the modal lengths of the plaice 

 inhabiting the various fishing grounds in the Lancashire 

 district has been the most unsatisfactory part of the whole 

 investigation. The total number of fish examined is a 

 little over 2,500, probably much too small a number. If 

 these fish had all been collected from one fishing ground, 

 and during the same time of year, reliable figures for the 

 lengths of plaice one, two and three years of age might 

 have been obtained. In the Report on this work, 

 published in 1909,* I gave particulars relating to the 

 examination of about 1,000 plaice caught during the year 

 in the northern part of the district ; and it was seen, on 

 considering these figures that the process of " lumping " 

 the fish caught, even on grounds which are not far distant 

 from each other, led to erroneous conclusions. Far more 

 faulty, however, was the method of combining the results 

 of examinations of fish caught at different times in the 

 year ; for while the curve of growth of the fish is a 



* Lancashire Sea Fisheries Report for 1008, p. 33, 1009, 



