249 



25*5 cm. to 405 cm., and 25 were under the adult size on liberation ; the females 

 varied from 25 to 47-5 cm., and 35 were under adult size. The numbers liberated 

 and recaptured, arranged in 5-cm. groups, were as follows :— 



There is doubt as to where the fish used in this experiment were captured, as 

 there is no record on the subject, but, as the " Goldseeker " was working with the 

 herring-trawl on the 12th and 13th to the east of the Isle of May, it is probable 

 that they were caught in that locality. 



Only 25, or 24'7 per cent., of the marked plaice were recaptured, 10 males (23'8 

 per cent.) and 15 females (25"9 per cent.). 



Six of the males recaptured were of adult size, ranging from 33*6 to 40*7 cm., 

 and averaging 37 cm., as compared with a range of 30'5 to 39'5 cm., and an average 

 of 34'8 cm. on liberation ; they were at liberty for from 54 to 943 days, the mean 

 being 394 days ; the distances migrated varied from 50 to 71 miles, the average 

 being 58 miles, and the mean rate of travel 1*5 miles. Four of the males were 

 under adult size on recapture, the average being 30'8 cm., as compared with 27'6 

 cm. on liberation ; they were at liberty for a mean period of 423 days, and migrated 

 distances of from 42-112 miles, the average being 83'2 miles, and the mean rate 19 

 miles. 



Ten of the females were of adult size, ranging from 38-8 to 48-8 cm., and averag- 

 ing 42"6 cm., compared with a range of from 29 to 47 cm., and an average of 39"3 cm. 

 on liberation ; they were at liberty for from 150 to 1065 days, the mean being 402 

 days ; they migrated distances of from 19 to 167 miles, the average being 74'2 

 miles, and the mean rate 1*8 miles. Five of the females were under adult size, 

 the average being 32'7 cm., as compared with 31 "3 cm. on liberation ; they were 

 free for an average period of 248 days, and migrated from 10 to 181 miles, the average 

 being 79'4 miles, and the mean rate 3'2 miles. 



The FiXTENT and Direction of Migkation. 



First Quarter. — Only 1 fish was recovered in this quarter, a male, taken in August, 

 after 54 days, 57 miles to the westwards, south and east of Tod Head. 



Second Quarter. — A male and a female were recaptured in September, the male, 

 after 106 days, at Aberdeen Bank, a distance of 58 miles to the north and west ; 

 the female, after 90 days, off St. Alab's Head, at a distance of 75 miles to the south 

 and west. 



A female was caught in October, after 130 days, 10 miles to the south and west 

 of the station. 



Two females were recaptured in November, 1, 19 miles to the north and east, 

 and the other in the offshore waters, 39 miles to the south and a little west. 



Thus, in this quarter, 5 were recovered, or 20 per cent., 3 to the south and west, 

 and 2 to the north and west. 



Third Quarter. — Only 1 was caught in this period, a female, in December, after 

 181 days, off Aberdeen, at a distance of 61 miles. 



Fourth Quarter. — -Five M^ere taken in April 1914, 2 males and 3 females ; both 

 males had migrated in the same direction, 1 being got south of the Bell Rock, at the 

 entrance to St. Andrew's Bay, at a distance of 94 miles, and the other to the east of 

 the Bell Rock, at a distance of 71 miles ; they measured res^jectively 28*5 to 30'7 

 cm., and 39'5 to 40"7 cm., and were " immature." The 3 females were described 

 as " spent " ; 1, of 43"5-47 cm., taken at Aberdeen Bank, at a distance of 59 miles 



