368 Part III. — Twentieth Annual Report 



The August results show a further mean increase to 46*5 mm., or 

 1^ inches, and a range from about 18 mm. to 75 mm. (2J-| inches). This 

 would leave about 20 or 21 mm. to be added in the remaining eight 

 months of the year. 



In Aberdeen Bay no hauls were made early in May during the height 

 of the spawning season, and in those at the end of the month only five 

 of this series were taken and they were relatively large individuals. 

 The haul in September 1 900 was imperfect, and the average assigned 

 is probably a little too low. The other averages show in 1 900 a growth 

 of about 6"5 mm. from the early part of October to the third week in 

 December; those of 1901 a growth of 9'0 mm. from 10th September to 

 9th and 29th November, and an additional 1 mm. to 15th January. 



Of the second series of dabs, or those from one to two years old, the 

 earliest collection was that made in the Forth in May above referred to, 

 when they had an average size of 67'5, or as amended 66*5 mm., the 

 largest being about 100 mm., or nearly four inches. 



On July 23rd the range of 498 dabs was from 68 to 127 mm. (2|^ to 

 5 inches), and the average size 101 mm., or four inches, showing a 

 mean increase in the seventy-three days from May of about 33"6 mm., 

 or 1^ inches. The curve in this case is symmetrical. 



On 19th-22nd August the series comprised 110 specimens ranging 

 from 84 to 137 mm. (3^ to b^ inches), with a mean size of 102"5 mm., 

 or A:^-^ inches, showing an apparent increase of only 1-4 mm. The curve, 

 however, shows that a due proportion of the larger dabs were absent. 

 The maximum ordinate is placed at 9 cm., and the median ordinate is at 

 110'5 mm., and this is approximately the mean size of the group at the 

 date, the increase in the twenty-eight days being thus 9'4 mm., or 43 mm. 

 {\W inches) in the 101 days from the early part of May. 



The series in Aberdeen Bay in September 1900 comprised 396 

 females and 307 males, the former ranging from 97 to 173 mm. 

 (3]-|-6^ inches), and having an average size of 127*0 mm., or 5 inches. 

 The males ranged from 91 to 172 mm., and their mean size was almost 

 precisely the same, viz. 127"1 mm. 



On 9th-13th October 205 females ranged from 96 to 197 mm., with a 

 mean size of 131"8 mm., and 186 males, from 101 to 173 mm., had an 

 average size of 133"! mm. The curves in these cases are good. 



These hauls were made with a shrimp-trawl. On 8th October, in a 

 haul with the fine-meshed net (A, fig. 1) over the otter trawl, 123 

 females and 114 males were pi-ocured, the average of the former being 

 120 mm. and the range from 92 to 157 mm., and of the latter 118'3 

 and the range 98 to 152 mm. 



On 13th October 458 females, ranging from 102 to 173 mm. (4 to 6}-f 

 inches), had an average size of 130*6 mm. {^j^ inches), and 574 males 

 a range from 102 to 175 mm., and an average size of 126*1 mm., or 

 4|-|^ inches. The curve in this case is good and symmetrical. 



On 31st October a haul in 8-10 fathoms gave 404 females ranging from 

 100 to 180 mm., with an average size of 137*5 mm., or 5| inches, and 323 

 males from 102 to 173 mm. with a mean size of 134*3 mm., or 5| inches. 

 The curve in this instance is also symmetrical. 



On 17th-21st December this series was not well represented. It 

 comprised 183 females from 96 to 184 mm., and an average size of 

 132*1 mm., or 5| inches, and 173 males from 92 to 180 mm., with a mean 

 size of 127*4 mm., or 5 inches. 



In the hauls in May in Aberdeen Bay the measurements of the dabs 

 obtained in the otter trawl were imperfect and have been discarded, and 

 I am therefore unable to give the size when two years old for this area. 

 On 13th June the series, now over three yeai-s old, was represented in 



