139 



recaptured 8 miles to the north nnd east, one 10 miles directly east, and one 4| 

 miles directly west. Of the females, 4 had moved distances of from 5 to 8 miles 

 to the south and west, 2 for 8 and 9 miles respectively south and east, 2 north and 

 east, 1 for 7 and the other for 10 miles, 1 for a distance of 8 miles north and 

 west, one 10 miles directly east, and the last 4 miles directly west. 



10 to 20 miles. — Fifteen of the fish, or 24-2 per cent, of the total, had 

 migrated distances between 10 and 20 miles. Three (12-5 per cent.) were males, 

 which had moved north and west for an average distance of 14-6 miles, and 12 (31-6 

 per cent.) were females, which had migrated an average distance of 14-5 miles ; 5 

 were found to the north and west, at distances of from 11 to 19 miles ; 3 were 

 recaptured at 12 miles distant directly west ; 1 was taken 17 miles to the south 

 and east ; and 3 to the north and east, at distances of from 11 to 20 miles. 



Thus, within 20 miles of the station, 32 plaice were recaptured, or 51-6 per 

 cent, of the whole, viz. 23 females and 9 males. 



20 to 50 miles. — Twelve of the recaptured plaice, or 19-3 per cent., had moved 

 distances of between 20 and 50 miles. Five were males (20-8 per cent.), the 

 average distance migrated being 30-9 miles ; 2 were found to the north and west, 

 1 of them within the Firth of Forth ; the remaining 3 had gone distances of from 

 25 to 48 miles to the north and east. Eight (21 per cent.) were females, which had 

 travelled an average distance of 29-7 miles ; 4 went distances of from 20i to 

 44| miles north and east; 2 for 21 and 28J miles north and west, and 2^ for 

 24 and 33 miles to the south and east. 



50 to 100 miles. — Eight of the fish, or 12-9 per cent., had migrated distances of 

 between 50 and 100 miles, all to the north and east. Three (12-5 per cent.) were 

 males, which had migrated an average distance of 60 miles, and five (13"1 per cent.) 

 were females, and the average distance travelled in their case was 63'6 miles. 



Over 100 miles. — Nine of the fishes, or 14"5 per cent, of the total number re- 

 captured, were taken at distances over 100 miles. Seven of these (29-2 per cent.) 

 ■ were males, which had travelled an average distance of 138 miles, 6 of them to 

 the north and east for distances varying from 106 to 215 miles, and 1 to the 

 south and east, for a journey of 102 miles. Two (5-3 per cent.) were females, which 

 had migrated an average distance of 109 miles, to the Moray Firth. 



Maturity. 



Males. — Of the 22 adult males, which were recaptured, the condition of the 

 testes was ascertained in 19 cases. Four were " ripe," and all had migrated to 

 the north and east, 3 being caught in the Moray Firth and 1 on the North coast 

 of Scotland. One, measuring 36-38-3 cm., was taken in January 1914, after 309 

 days, off Banff, at a distance of 113 miles. A second, of 37-5-41-6 cm., was cap- 

 tured in February 1914, after 324 days, off Whiten Head, at a distance of 215 

 miles. The third fish, of 33'5-38"3 cm., was also taken in February 1914, after 

 330 days, in the Moray Firth, at a distance of 148 miles. And, the fourth "ripe " 

 male, measuring 32-5-34-8 cm., was taken in April 1914, after 386 days, 106 miles 

 distant, ofi Kimiaird Head. The mean rate of movement in these cases was 

 respectively 3-6, 6-6, 4-5, and 2-7 miles per 10 days. 



Two of the males were "nearly ripe." One, of 35'5-43'6 cm., was taken in 

 October 1914, after 562 days, in the Moray Firth, at a distance of 139 miles. The 

 other, of 32-5-42-1 cm., was recaptured in September 1915, after 912 days, 48 

 miles to the north and east, off Aberdeen. The rate of migration in these cases 

 was respectively 2-47 and '5 miles per 10 days. 



Thirteen of the males were " immature." One was caught in April, 4 in June, 

 2 in July, 4 in August, 1 in October, and 1 in December. The fish recaptured in 

 April measured 34-33-5 cm,, and was found in the Firth of Forth, at a distance 

 of 29-5 miles, after 14 days. The fish taken in December measured 34-37 cm., 

 and was got at a distance of 14 miles to the north and west, after 273 days. Two 

 of the " immature " males had migrated for some distance to the north and east, 

 1, of 37-5-38-8 cm., being taken in August 1913, after 147 days, 52 miles distant ; 

 and the other, measuring 35-43-2 cm., in June 1914, after 4.34 days, 55 miles 

 distant, both off the coast of Aberdeen. 



Of the 28 adult females recaptured, the condition of the ovaries was ascertained 



