273 



which is on the Bank at the southern edge. The males measured from 23*5 to 

 42 "5 cm., and 13 were under adult size on liberation ; the sizes of the females 

 ranged from 26 to 61 cm., and 14 were under the adult size when liberated. 



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

 follows : — 



The fish used in this experiment were trawled by the " Goldseeker," on the same 

 day, in Burghead Bay, on the south shore of the Moray Firth. 



The number recaptured was 23, or 54 "8 per cent., namely, 11 males (52 "4 per 

 cent.) and 12 females (571 per cent.). Nine of the males were of adult size on 

 recapture, ranging from 34 to 45 cm., and averaging 37 "8 cm., as compared with a 

 range of from 26 "5 to 42 "5 cm. and an average of 34 "2 cm. on liberation ; they were 

 at liberty for from 40 to 476 days, the mean being 210 days ; they migrated dis- 

 tances of from H to 122 miles, the average being 40*9 miles, and the mean rate of 

 movement 1-8 miles. Two of the males were under adult size, averaging 28 cm., 

 as compared with 27 "7 cm. when liberated ; 1 migrated 23^ and the other 46 miles, 

 the mean rate of travel being 4 "5 miles. Five of the females were of adult size 

 when recaptured, averaging 50"8 cm., as against 47*8 cm. ; they were at Ubcrty 

 for a mean period of 214 days, and migrated distances of from 1 to 23|- miles, the 

 average being 12 '8 miles, and the mean rate of movement '5 mile. Seven were 

 under adult size on recapture, averaging 34 '5 cm., as compared with 311 cm. on 

 liberation ; they were free for from 32 to 832 days, the mean being 196 days ; they 

 moved distances of from 1| to 70 miles, the mean being 311 miles, and the average 

 rate 1 "5 miles. 



The Extent and Direction of Migration. 



First Quarter. — One male and 2 females were taken in March, the male 13 miles 

 to the north and east, off Noss Head, both of the females to the south and west, 

 1 in Burghead Bay (where it was originally captured), at a distance of 32 miles, 

 the other in Dornoch Firth, near Embo, at 35 miles distant. 



In April, 2 males and 5 females were recaptured, 1 of the males 7| miles to the 

 north and west, off Berriedale Ness, the other 46 miles to the south and west, close 

 inshore, near Fort (Teorge. The position of 1 of the females was not ascertained. 

 Of the others, 1 was taken 7 miles to the south and west, 1 on Smith Bank, 1| miles 

 to the north and east, the third, also on Smith Bank, 1 mile to the south and 

 east, and the last to the north of Banff, 14| miles to the south and east. 



A male was recaptured in May, 23^ miles to the north and west, close inshore, 

 north of Tarbet Ness. 



In this quarter, 11, or 47*8 per cent., of the marked plaice were recovered, but 

 the position of 1 was unknown. Of the remaining 10, or 43-5 per cent., 4 were 

 taken to the south and west, and 2 each to the south and east, north and east, 

 and north and west. 



Second Qi.iarter. — In June, a male was got on Smith Bank, \h miles to the south 

 and east. 



Li July, a male and a female were recaptured by foreign trawlers, and landed 

 at Ostend, with the record " caught in the Moray Firth." 



In August, a male was also landed at Ostend, and " caught in the Moray Firth." 

 In these cases, the locality cannot, of course, be determined. 



In the second quarter, therefore, 4 fish, or 17'4 per cent, were recaptured, 

 but, as stated, the positions were ascertained only for 1 of them. 



Third Quarter. — In September, a female was taken 35 miles to the south and 

 west, in the Dornoch Firth, and a male in the " Moray Firth " (precise positiou 

 unknown). 



