43 



also in March 1912, after 469 days, at a distance of 18 miles ; and the sixth, in 

 February 1911, after 74 days, also off Aberdeen, at a distance of 71 miles ; it 

 measured 44-44"3 cm. 



One female was "about three-quarters ripe," in December 1914, when it was 

 caught off Aberdeen, at a distance of 69 miles, after 1476 days ; it measured 42'5- 

 55" 3 cm. 



Two females were " half-rijie," both recaptured to the north and east ; one 

 was taken in February 1911, after 70 days, off Buchanness, 89 miles distant ; it 

 measured 39-39'4 cm. ; the other was caught in August 1911, after 271 days, 

 off Bervie, 47 miles to the north and east ; it measured 4r5-44'2 cm. 



Three were described as " a quarter ripe," and were all recaptured to the north 

 and east ; 1 was taken in December 1910, after only 6 days, 27 miles to the north 

 and east, north of the Bell Rock, and measuring 39-38"8 cm. ; the second, also 

 caught in December 1910, after 35 days, near Aberdeen, at a distance of 64. miles ; 

 it measured 39" 5-39 -7 cm. ; the third, which measured 38- 5-38- 7 cm., was 

 recovered on 3rd January 1911, after 39 days, east of the Pentland Skerries, at a 

 distance of 165 miles. All these three fish showed rapid movement, the respective 

 mean rates, per 10 days, being 45, 18'3, and 42*3 miles. They were obviously 

 females reaching first-maturity, and they would probably spawn in the ensuing 

 season. 



Of the 9 females described as " immature " 1 was caught in January, 1 in May, 

 1 in June, 3 in July, 1 in August, 1 in September, and 1 in November. They 

 were all taken to the north and east, at distances of from 23 to 142 miles, after 

 intervals of from 63 to 668 days. The one caught in January 1911, after 63 days, 

 measured 40-39"9 cm., and was recaptured 39 miles eastwards ; the one taken in 

 May 1911, after 173 days, measured 38"5-4r8 cm., and was caught 38 miles distant. 

 Three had gone long distances ; 1, of 40"5-42"9 cm., was taken in June 1911, after 

 197 days, off Rattray Head, 130 miles to the north-east ; another, of 37*5-42 cm., 

 was caught in August 1911, after 259 days, far offshore, east of Aberdeenshire, at 

 a distance of 124 miles ; the third, measuring 40-46"2 cm., was taken in November 

 1911, after 347 days, off the middle of the entrance to the Moray Firth, at a distance 

 of 142 miles. 



EXPERIMENT IT. 



8th February 1911. 



The number of plaice marked and Uberated in this experiment was 100, viz. 

 35 males, 56 females, and 9 of which the sex was not determined. The sizes of 

 the males ranged from 29 to 39 cm., and of the females from 29-5 to 51*5 cm. ; 

 the sizes of the 9 fish of undistinguished sex varied from 31 to 40'5 cm. The 

 numbers liberated and recaptured are shown in the subjoined table in groups of 

 5 cm. : — 



Seventeen of the males and 39 of the females were under adult size (33 cm. 

 and 38 cm.) when liberated. The plaice for the experiment were trawled by the 

 " Goldseeker " at Station VI. in the Firth of Forth, off Pittenweem, on the 8tli 

 February, and the fish were marked and liberated at the station which is only a 

 few miles from Station VI., in the course of a few hours. 



The number of the marked plaice subsequently recaptured was 55, or 55 per 

 cent., which is a relatively small proportion ; of the total, 24, or 68*6 per cent., 

 were males, 29, or 51-8 per cent., were females, and 2, or 22-2 per cent., were of 

 unknown sex. 



