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Part III. — Twenty -fourth Annual Report 



The smallest one was got on 19th June in St. Cyrus Bay ; it measured 

 \\ inches, or about 3cm., and belonged no doubt to the brood of the year. 

 The next smallest were 4 inches, or about 10cm., and brill of this size 

 were procured on 8th and 12th May, and doubtless represent the fish of 

 the previous year, and would therefore be about one year old. At 4| 

 inches (114mm.) four were taken, two on 4th and 5th May, and two on 

 5th and 6th June. The nsxt size was five inches (127mm.), of which six 

 were taken — four in May, one in June, and one in July (8th). At 6 

 inches (152mm.) there were eleven, six of which were obtained in May, 

 four in June, and one in July. The largest brill secured was 11^ inches, 

 in May. 



Looking down the column for May, the place where the first striking 

 interval occurs is between 8 inches and 8| inches, or about 20cm. to 

 22cm. ; but it is pretty certain that fish of this length, or even of 7f 

 inches (19 - 5cm.) do not belong to the same series, which, as we saw, has 

 individuals measuring as low as 74mm. in May. 



The nature of the net by which the brill were taken must be borne in 

 mind, practically all the very small fish and many of those of the sizes 

 included in the Table no doubt escaping. It seems to me, considering the 

 Table, the rate of growth of other flat-fishes, the much greater increase in 

 weight or volume in the case of the brill than with the plaice, dab, &c, 

 that the one-year-old group is represented in May by those at 4 inches 

 (10*2cm.) and probably at 4| inches (ll"5cm.); that those from 5 to 7 

 inches (12"7cm. to 17"8cm.), or perhaps to 7| inches (19 - 0cm.) are two 

 years of age ; those from 8 to 9| inches (20cm. to 24cm.) — and the group 

 is obviously only partially present — are three years of age ; while the 

 brill at 11| inches (28'5cm.) is probably four years old. 



It seems to me likely that the range of size of the one-year-old brill is 

 from about 70mm. to about 115mm. (2| to 4| inches), or perhaps a little 

 less, with an average size of about 90mm. to 95mm. (3| to 3| inches). 



Attention may now be given to the catches made on board trawlers in 

 the Moray Firth, the particulars in regard to which are given in Table 

 XVIII. These hauls were limited to November, December, and February, 

 and the collection in the latter month was a small one. In none of the 

 cases were the sexes separated, the fish being too valuable to be opened 

 for the purpose, and the collections under the various dates represent a 

 series of hauls, all the brill taken having been measured. Some groups 

 come out with distinctness, and the measurements may be grouped here 

 in centimetres. 



1 Tablk. 



