370 



Part III. — Twentieth Annual Report 



With regard to the growth from the first series to the second, the 

 remarks made on a former page as to the imperfect represen- 

 tation of the early series in the collection must be borne in mind. 

 If the mean sizes then adopted be taken the annual increment from 

 the first series to the second series becomes amended as follows : — 



Septemher, 83-5; 9th-13th October, 82-5; 8th October, 68-4; December, 74-3; 18th 

 October, 67"3 ; 29th November, 67'4 ; the mean being 73'9 mm. 



From the observations it would appear that the average size of the 

 common dab when one year old is about 67 mm,, or 2^ inches ; that it 

 grows in the next year nearly three inches more (73 '9 mm.), attaining a 

 lenffth of abovit 140 mm., or 5| inches; and that in the next year it 

 adds rather over 80 mm. to its length, the dab when three years old 

 measuring about 220 mm., or 8| inches. 



The measurements of the dabs taken in the Firth of Forth in May 

 nearly, but not quite, correspond to these figures, the males of the 

 second series — two yeai-s old — measuring 148 mm., or 5y|^ inches, and 

 the females 151*4 mm., or 5-|-|^ inches, the mean for the group being 

 149'5 mm., or 5^ inches. The best curve in Aberdeen Bay following the 

 spawning season refers to 5th July, when this series (now III.) had a 

 mean size of 178-1 mm., or 7 inches, the females being 178"7 mm., 

 and the males 176"9 mm. 



