208 



Part III. — Twenty -fourth Annual Report 



but more probably at 42cm. The fish are aggregated between the same 

 limits, 37cm.-40cm., but the greatest number is at 38cm. (15 inches). 



In the December series the lower limit is at 34*5cm.; the greater 

 number of the fishes are at 39cm. and 40cm., most being at 39cm.; but 

 the end of the group is not clear, the line falling gradually from 42cm. to 

 49cm. 



The curve for the measurements of brill taken on 9th— 1 1th Novem- 

 ber shows plainly a group beginning about 35cm., but the greater numbers 

 of fish are at 36cm., after which the line of the curve falls more or less 

 regularly to 41cm., then rising to 43cm., and falling thereafter; there are 

 none between 43cm. and 47cm., but the numbers are not large. 



The fish taken in the Dornoch on 9th-llth November show a group 

 beginning about 35cm., and there is a similar fall at 41cm. to 42cm., and 

 a rise to 43cm. In the hauls on 25th and 26th December this fall at 

 41cm. is also present. The curve of the measurements of the brill taken 

 at Burghead on 21st-27th November show the group beginning at 33-5cm. 

 or 34cm. and ending at 42cm., but there is a depression at 39 '5cm. to 

 40cm.; most of the fish are aggregated between 37'5cm. and 40 5cm. In 

 the brill taken in the early part of February the limits of the great mass 

 are from about 34cm. or 35cm. to 44cm. or 45cm., but there are depres- 

 sions at 39-5cm. and 42cm.; the greater number of the fishes are 

 aggregated between 38cm. and 41cm., mostly at the latter (16 inches). 



Comparison of the upper part of the cone of the curves, that is to say, 

 the " modal " sizes, or the sizes at which the brill are most numerous, in 

 the different periods, is indicated in the following Table: — 





Greatest Number 

 Between. 



Maximum. 



Mean. 



Burghead, November 9, 10 . 



36-39 



36 



37-5 



21-27 . 



37-41 



38 



39 



December 6-12 . 



37-41 



39 



38-5 



February 6-7 . 



38-41 



41 



39-5 



All November 



37-40 



38 



38-5 



All December 



37-41 



39 



39-5 



The next smallest series of brill shown in these collections ends where 

 the last one begins, about 34cm. to 35cm. In all cases the measurements 

 and curves indicate that the smaller fishes in the group are not fully 

 represented. The fish are aggregated in greatest numbers at 31cm. to 

 32cm., which is larger than it ought to be by the limits of the group. 

 The distances from the actual apex in the curves of the two groups, or the 

 sizes of greatest frequency, are as follows, in centimetres: — 





Smaller 



Larger 



Apparent Annual 





Group. 



Group. 



Growth 



November .... 



31-5 



38 



6-5 (2| in.) 



December .... 



32 



39 



7 (2g in.) 



Together .... 



32 



39 



7 (22 in.) 



Burghead, November 9, 10, . 



31 



36 



5 (2 in.) 



The smaller group is well represented in the collection of 21st-27th 

 November, but it is poorly shown in most of the others. It is obvious 

 that the amount of growth in a year, as indicated in this comparison, is 

 small. 



