SEA-FISHERIES LABORATORY. 311 



In the original statistics themselves the plaice 

 caught are recorded as "large," ''medium," "small," 

 or " size not distinguished." No attention has, however, 

 been paid to this classification, and the plaice are indeed 

 almost all returned as " large "; only very occasionally 

 are they said to be " medium." It is certain that an 

 ordinary catch of plaice from these grounds cannot 

 properly be described as consisting of " large " fish. 

 The lengths of the fish caught will be seen by referring 

 to the tables of plaice measurements made in this area 

 during the years 1909-1912 by Captain Wignall, of the 

 Lancashire fishery steamer " James Fletcher." These 

 tables are published in previous reports. What is found 

 in this area is a plaice population of a high range of 

 lengths, 10 to 50 centimetres, a range which is only 

 exceeded in the Irish Sea area by that of the plaice 

 caught in Luce Bay, where fish of 62 cms. in length have 

 been taken. The distribution of age and sex is also 

 tabulated in the Reports, but these figures have been 

 obtained only by the examination of monthly samples 

 of about 100 fish each during the various seasons. 

 Unfortunately very few observations at sea have been 

 made, and the figures of the sample catches do not give 

 a reliable estimate of the proportions of sexually mature 

 plaice on the grounds. 



The progress of the fishery is well shown in the 

 tables given in this paper. Table XIII shows the mean 

 daily catch for each week for the period 1907-1912, and 

 Table XII the mean daily catches for each month for each 

 of the years, and the mean daily catch for each 

 month for the whole period. Fig. 3 represents the 

 mean monthly catches for each of the years 1909-1912, 

 and the mean monthly catch for the whole period 1907- 

 1912 as the dotted line superposed upon the curve for 

 the year 1909. The latter curve gives a general picture 



