240 



north cand west, the other in March 1914, on the west coast, south-west of Cape 

 Wrath, 178 miles to the west and south. One was " apparently ripe " ; it was 

 caught in November 1911, off Noss Head, in the Moray Firth, 105 miles to the 

 south and west. Four were "nearly ripe," 1 caught in October 1911, 18 miles 

 to the north and west, and the others to the south and west, at 31, 66, and 77 miles, 

 the last 2 to the east of the Orkneys. Two were "three-quarters ripe," 1 taken 

 in January 1912, off Aberdeen, 164 miles to the south and west, the other in 

 February 1912, off Noup Head, Orkneys, 83 miles to the westward. 



Females. — The condition of the ovaries was recorded for 23 of the 26 females 

 recaptured. One was " spawning " ; it was taken in March 1912, 69 miles to the 

 north and west, at the Shetlands. Another was described as "fully ripe," and 

 was captured in October 1911 — a date which suggests it was not spawning — 

 40 miles to the south and M^est. Six were " nearly ripe " ; 1 was caught in January 

 1912, 23 miles to the south and west, another in September 1912, 58 miles to the 

 solith and west, 1 in November 1911, 28 miles to the south and west, another in 

 November 1911, offshore, to the south and east, at a distance of 90 miles ; the 

 other 2 were recaptured in November 1912, 1 off Noss Head, in the Moray Firth, 

 at 105 miles, and the other at Loch Laxford, on the west coast, at 170 miles. Six 

 were described as " spent," all taken to the south and west, 2 in May 1912, oft' 

 Noss Head, 95 miles and 98 miles distant, 1 in July 1912, at 28 miles, 1 in August 

 1912, east of the Orkneys, at 63 miles, 1 in March 1913, close to Cullen, on the 

 south shore of the Moray Firth, at 139 miles, and the last in May 1913, east of the 

 Orkneys, at 74 miles distant. A female, measuring 39-5-39"7 cm., taken in February 

 1912, near Clyth Ness, in the Moray Firth, was described as "immature." 



EXPERIMENT VII. 



l9thJune 1912. 



In this experiment, 102 marked plaice, 31 males and 71 females, were liberated 

 on 19th June 1912, also at the station 59° 20' N. ; 1° 3' W. The males ranged in 

 size from 28"5 to 41 cm., and 15 were under adult size on liberation ; the females 

 measured 29 to 63 cm., and 36 were under adult size when liberated. 



The fish used in this experiment were taken by the " Goldseeker " in Dornoch 

 Firth, on the 18th June, in the forenoon, and were Hberated at 7 a.m. on the 19th. 



The numbers hberated and recaptured, arranged in 5-cm. groups, are shown 

 in the following table : — 



Forty-six of the marked plaice were recaptured, or 45'1 per cent., namely, 11 

 males (35-5 per cent.) and 35 females (49-3 per cent.). Ten males were of adult size, 

 ranging from 33 '5 to 43-8 cm., and averaging 38 "3 cm., as compared with an average 

 of 34-4 cm., and a range of from 30-5 to 38'5 cm. on Uberation ; they were at liberty 

 for from 123 to 623 days, the mean being 339 clays ; they migrated distances of 

 from 24 to 109 miles, the mean being 68 '8 miles, and the mean rate of movement 

 1-9 miles. Twenty-six of the females were of adult size on recapture, ranging from 

 38-2 to 62-1 cm., and averaging 47-2 cm., as against a range of from 32 to 62 cn«., 

 and an average of 44-1 cm. on hberation ; they were at Uberty for from 110 to 

 881 days, the mean being 333 days ; they migrated from 8 to 215 miles, the ireaii 

 being 55-5 miles, and the mean rate 1*7 miles. Nine of the females were under 

 the adult size on recapture, averaging 35-3 cm., and ranging from 34-3 to 36-7 cm., 

 as compared with an average of 34-5 cm., and a range of from 32 to 38 cm. on 

 liberation ; they were at Uberty for from 75 to 339 days, the mean being 152 days ; 

 they migrated distances of from 28 to 120 miles, the mean being 66-4 miles, and 

 the mean rate 4*3 miles. 



