IN THE BAYS ON THE SOUTH-EAST COAST OF DEVON. 



497 



regard the average size at first maturity as a comparatively fixed point 

 in the life-history of the plaice, we might therefrom, by comparison 

 with the average size of the adults, obtain a measure of the increase 

 or decrease in the numbers of the species, but the considerations 

 presented above show that we can no more rely upon it than upon 

 any other variable and varying stage. One important consequence is 

 that we cannot accept, without repeated investigation, the results 

 obtained in previous years, as a record of ten years ago may no longer 

 hold true. 



" The plaice on the south-west coast of England have been investigated 

 at various times by Mr. Cunningham, and the results are given in 

 vol. iii. p. 69 €t scq. of this Journal. One hundred and nine specimens 

 were examined during the winter, i.e. during the spawning season, and 

 of these forty-two were males, sixty-seven females. The smallest 

 mature male was 9 inches long, the largest immature 12 inches. 

 The smallest mature female was likewise 9 inches, and the largest 

 immature 14 inches long. 



"During the present investigations a considerable number of plaice 

 were examined from all quarters and at all sizes. The spawning 

 months, from November to March, were deliberately chosen, and all 

 doubtful males have been excluded from the list. The following tables 

 show the numbers at the various sizes mentioned : — 



Table XXX.— 1. Males. 



Length in centimetres 

 Immature 



Percentage 

 ]\Iature 



Percentage 



TotaL 

 54 



237 



2. Females. 



Length in centimetres 1 26, 2 

 Immature 



Percentage 

 Mature 



Percentage 



TotaL 

 91 



178 



" It appears from these tables that the ranges of variation are greater 

 than those detected by Cunningham. The smallest mature males were 

 21 cm. long (8^ inches), and a special search would, I think, discover 

 even smaller mature specimens. The largest immature male was 34 cm. 

 (13| inches), or 13 cm. longer than the smallest mature. The smallest 

 mature female was 26 cm. (10;^ inches), and the largest immature 42 cm. 



