67 



movement of these males were nearly uniform, viz. respectively 5-5, 5-5, and 6-1 

 K miles per 10 daj's. 



^L Thus, in the third quarter, 8 of tlie marked plaice, or 11-3 per cent., were 

 ^Brecaptured, 7, or 87"5 per cent., to the north and cast, and 1 to the south and east ; 

 ^B3 were taken in the Moray Firth. 



^F Fourth Quarter. — In February 1913, no fewer than 13 maiked plaice were 

 ■ recaptured, 7 males and 6 females. Three were caught in the Firth of Forth, all 

 females, 1, of 30-36 cm., and therefore under adult size, off Pittenweera, 5 miles 

 distant, after 303 days, another, of 33-5-38 cm., off Largo, at a distance of 6 miles, 

 after 309 days, the third, of 33-38-1 cm., after 303 days, off Elie, at a distance of 

 2 miles. The ovaries in each case were " immature." One male, of 38-5-41*3 cm., 

 and " ripe," was taken off St. Abb's Head, at a distance of 36 miles, after 283 days ; 

 a female, of 35-5-38-1 cm., " immature," was taken, after 303 days, at a distance 

 of 25 miles, to the east of the Isle of May ; another female, of 32-37-1 cm., and 

 " immature," was got, after 309 days, 26 miles to the north and east. Five fishes, 

 all males, were captured ofi the coast of Aberdeen, 3 on 26th February, after 

 308 days, all near together, 26 to 30 miles S.E. by E. of Aberdeen, at distances of 

 72 and 74 miles : their sizes were as follows : — 37-40-2 cm., 32-37*2 cm., and 

 27-33-5 cm., and they were nil "spawning." The other two were caught, after 

 298 days, in the same locality, at distances of 71 and 72 miles ; they measured 

 34-37 cm., and 40-41-3 cm., and were also " spawning." The remaining two fish, 

 a male and a female, were recaptured in the Moray Firth, the male 10 miles S.S.E. 

 from Helmsdale, at a distance of 166 miles, after 288 days, measuring 38-5-39-7 cm., 

 and " ripe " ; the female, of 32-5-36-2 cm., was taken 1| miles off Whitehills, near 

 Banff, at a distance of 136 miles, after 292 days ; it was "half-iipe." The mean 

 rate of movement of those taken off the coast of Aberdeen was 2-3 miles for 2 of 

 the fishes, and 2-4 miles for 3 of the fishes, per 10 days ; for those taken in the 

 Moray Firth, the average rate was 5-7 for the male, and 4-6 for the female. Two 

 males were recaptured in March 1913, both to the northwards ; 1, 63 miles distant, 

 off the coast of Aberdeen, in the same direction as the male referred to above ; 

 it measured 35-39-5 cm., and was "spawning" ; the other, of 32-33-4 cm., was 

 taken, after 336 days, at the Orkney Islands, at a distance of 192 miles ; it also 

 was "spawning " ; the mean rate of movement of the former was 1*8 miles, and 

 of the latter 5-7 miles per 10 days. In April 1913, 5 were recaptured, 3 males and 

 2 females. Two were taken on the 25th April, after 366 days, to the south and 

 east ; 1, of 38-5-40-9 cm., and " spent," north of St. Abb's Head, at a distance 

 of 24 miles ; the other, of 32-37-5 cm., and "immature," was caught to the east 

 of St. Abb's Head, at a distance of 46 miles. One of the females was caught off 

 Aberdeen, at a distance of 63 miles, after 344 days ; it measured 34-38-8 cm., 

 and was " immature " ; the other, measuring 35-39-3 cm., was taken, after 351 

 days, off Tarbet Ness, in the Moray Firth, at a distance of 172 miles ; the condition 

 of the ovaries was not recorded. The third male was recaptured to the east of the 

 Orlmey Isles, at a distance of 179 miles, after 366 days ; it measured 40-5 cm. 

 when liberated, but the size on recapture and the condition of the testes were not 

 ascertained. 



Thus, in the fourth quarter, 20 fishes, or 28*2 per cent., were recaptured, of 

 which 15, or 75 per cent., were taken to the north and east, with an average migra- 

 tion of 93 miles, and a mean rate of movement of 2*8 miles per 10 days ; 3, or 15 per 

 cent., were taken to the south and east, at an average distance of 35 miles, and 

 a mean rate of 1 mile per 10 days ; 2 were got to the north and west, within the 

 Firth of Forth, the average distance being 4 miles and the mean rate 15 miles. 



Within the 12 months after liberation, therefore, 46 marked plaice, or 64-8 per 

 cent., were recaptured, 31, or 67-4 per cent., to the north-east, 10, or 21-7 per cent., 

 to the south and east, and 5, or 10-9 per cent., to the north and west, within ilie 

 Firth of Forth. 



Of the remaining 25 fish, 14 were taken later in 1913, 4 males and 10 females. 

 In May, 1 male and 3 females were got, all " spent," the male, of 34-38-6 cm., off 

 the Isle of May, at a distance of 15 miles to the soutli and east, after 376 days ; 

 one of the females, measuring 45-51 cm., in the Firth of Forth, off Largo, at u 

 distance of 6 miles, after 386 days ; a female, of 34-5-39-6 cm., was taken, after 

 375 days, offshore, to the east of Aberdeenshire, at a distance of 100 miles ; the 



