108 THE RATE OF GROWTH OF FOOD-FISHES. 



other way. Dr Fulton insisted upon the same interpretation of 

 the terms 'immature' and 'mature,' in 1889 1 > and determined 

 the average size limit of immature individuals in the case of 

 several of the commoner species. 



His work led him to conclude that the following sizes repre- 

 sent the lowest length, without reference to sex, at which 

 maturity is nearly reached in the following species: 



Plaice 12 inches Turbot 18 inches 



Lemon-dab 8 Brill 16 



Dab 6 Sail-fluke 9 



Flounder 7 Haddock 10 



Witch-sole 12 Cod 20 



Long-rough dab 6 Whiting 8 



Little sole 3J Gurnard 8 

 Cat-fish 20 (?) inches. 



The practical application of our knowledge of growth-rates 

 depends largely upon the determination for each species of the 

 average size and age at which sexual maturity is reached. 



A large number of fishes may be caught and measured and 

 their sexual organs examined, and we may thus determine 

 roughly a mean minimum size for the attainment of maturity ; 

 and this has been done in a great number of cases. The results 

 of examination of a number of fishes caught by the ' Garland ' 

 show the following maximum and minimum sizes which were 

 sexually mature 2 . Whilst those below the minima were not 

 sexually mature, it does not follow that individuals above the 

 maxima no longer spawn, in fact, a cod of 46 inches is, on the 

 same Table, recorded as in the ' spent ' condition. 



Male. Female. 



Inches. Inches. 



Cod 23 37 36 (only one example). 



Haddock 1216 1424 



Whiting 915 9 18-J- 



Bib 88 7| 10 



1 T. W. Fulton, 1th Scot. Fish. Board Report, p. 161. 

 - T. W. Fulton, Wth Scot. Fish. Board Report, p. 239 a. 



