65 



miles, and another, measuring 37-45-2 cm., in April 1914, after 776 days, at a dis- 

 tance of 58 miles ; the remaining " spent " female was recaptured in the Firth of 

 Forth in February 1913, near St. Monans, at a distance of 4J miles ; it measured 

 4r5-45"6 cm. A female, which was 3I-37"8 cm., and was therefore under the adult 

 size, was taken in March 1914, after 748 days, at Aberdeen Bank, at a distance of 76 

 miles, and was described as " s])ent." 



l\vo females were described as " 1 luce-quarters ripe " ; 1 was caught in Novem- 

 ber 1913, after 618 days, south-east of Buchanness, at a distance of 80 miles, and 

 it measured 39-46-4 cm. ; the otlu^r, of 41-5-54-1 cm., was caught in November 

 1914, after 982 days, not far from the same place, at a distance of 69 miles. 



Among the adult females, 12 were described as " immature." Three were 

 recaptured in tlije spavming season, 1, measuring 35-5-41-3 cm., in January 1913, 

 off 5foss Head, in the Moray Firth, at a distance of 166 miles; another, of 34- 

 399 cm., was taken in February 1913, off Buchanness, at a distance of 89 miles ; 

 and the third, of 39-5-39-8 cm., was got in April 1912, after 28 days, near Pitten- 

 weem, in the Firth of Forth, at a distance of 5 miles. 



Of 9 females, Avhich were under adult size on recapture, and which were " im- 

 mature," 6 were taken in the Firth of Forth. Of the other 3, 1 measuring 37- 

 36-7 cm., was taken in March 1912, after 9 days, 18 miles to the north and east ; 

 another, of 31-32-7 cm., was found in June 1912, after 106 days, near the Bell 

 Rock, 29 miles to the north and east ; and the third was caught in October 1912, 

 23 miles distant, in the same direction. 



EXPERIMENT VIII. 



2m April 1912. 



The number of plaice marked and Uberated in this experiment was 102, viz. 

 44 males, 55 females, and 3 of undetermined sex. The sizes of the males ranged 

 from 27 cm. to 40-5 cm., and of the females, from 30 to 55 cm. ; the sizes of those 

 of undetermined sex were from 33-5 to 42 cm. Of the males, 12 were under the 

 adult size on hberation, and of the females, 35 were under the adult size. 



The numbers liberated and recaptured, arranged in 5-cm. groups, were as 

 follows : — 



All the plaice used were taken by the " Goldseeker " at Station VI., Firth of Forth 

 (Fluke Hole), on the 2.3rd April ; they were marked between 3.10 and 4.5 p.m., 

 and kept in tanks with a good circulation of water until 10 a.m. on the 24th, when 

 they were liberated in good condition. Only 1 of the plaice died while in the 

 tanks. 



The number recaptured was 71, or 69-6 per cent., viz. 33 males, or 75 per 

 cent., 37 females, or 67-3 per cent., and 1 of unknowm sex. 



Of the males, 32 were of adult size on recapture, namely, from 33-4 to 43-2 cm, 

 the average being 38-4 cm., compared with from 27 to 40-5 cm., and an average 

 of 34-6 Ciu. on liberation ; the periods of freedom ranged from 10 to 1074 days, 

 averaging 351 days ; the distances migrated were from 2J- to 192 miles, averaging 

 77-8 miles, and the mean rate of movement was 2-29 miles per 10 days. Of the 

 females, 28 were of adult size, when recaptured, ranging from 38 to 51 cm., and 

 averaging 431 cm., compared with 31-5 to 47 cm., and an average of 38 cm. on 

 liberation ; they were at Uberty for from 35 to 757 days, the average being 366 

 days ; the distances migrated ranged from 2| to 356 miles, the average being 

 73-8 miles, and the mean rate of movement 2 miles per 10 days. Nine of the 

 3 



