41 



the average beinp 235-4 miles, wliile the farthest distance reached by a female was 

 189 miles. 



The following table shows the number and percentage of each sex which were 

 found (1) within the Firth of Forth, (2) south of Kinnaird Head, Aberdeenshire, 

 (3) within the Moray Firth, (4) farther to the north or north and west : — 



Only 4, or 6-1 per cent, of the marked plaice, were found within the iirth of 

 Forth, 62, or 93-9 per cent., being recaptiired outside the Forth. It is to be noted, 

 however, that trawhng, by which the vast majority of the recaptured plaice are 

 taken, is prohibited within the Firth of Forth ; of the four fishes recaptured within 

 the Firth, 3 were caught with hooks, and 1 in a crab-net. The majority were 

 recaptured south of Kinnaird Head, but 18, or more than a fourth of the number 

 recaptured (27-2 per cent.) were taken to the north of Kinnaird Head, 9 in the 

 Moray Fivth and 9 outside the limits of the Firth, or farther to the north or north- 

 west. Only a single female (2-6 per cent.) was recaptured in the Moray Firth, 

 where 6 males were taken ; and it is noteworthy that many of the females, both 

 those which had gone farther north than Kinnaird Head, and those which were 

 taken to the south of it, were captured more offshore, towards the east, in deeper 

 water, than the males. 



Maturity. 



The condition of the testes was ascertained in 22 of the 25 males captured. 

 Seven were " spawning " and " partly spent " ; all were recaptured to the north- 

 wards, except 1 which was taken off Pittenweem, in the Firth of Forth, on 

 25th March 1911, after 120 days, at a distance of 5 miles from the station ; it 

 measured 34-5-36-1 cm. Four of the others were also caught in March 1911, 

 2 being remarkable, as being caught at Loch Inchard, on the west coast of 

 Sutherland, after 114 days, at a distance of 256 miles, showing a mean rate per 

 10 days of 22-4 miles ; they measured respectively 36-5-36-3 cm., and 42-41-8 cm., 

 and thus had apparently diminished in length ; they were caught by a Grimsby 

 trawler and landed at that port. One of the others, taken in March, was got in 

 the same direction 8 miles north-east from Whiten Head, on the north coast of 

 Sutherland, at the entrance to Loch Erriboll, at a distance of 225 miles, after 106 

 days, the rate of travel being 21-2 miles per 10 days ; it was caught by an Aberdeen 

 trawler, and landed at Aberdeen, and measured 37-36-9 cm. The other fish 

 caught in March, after 104 days, was taken in the Moray Firth, 17 miles N.N.E. 

 from Lossiemouth, at a distance of 162 miles ; it was captured in a cod-net and 

 measured 37-5-37-6 cm. ; the rate of travel in this case was 15-6 miles per 10 days. 

 Another "spawning" male, measuring 38-37-9 cm., was recaptured in a cod -net 

 on 19th January 1911, after only 55 days of freedom, a mile off Banff, in the Moray 

 Firth, a distance of 136 miles ; the rate of travel in this case was 24-7 miles per 

 10 days, or nearly 2i miles a day. The seventh " spawning " male was caught, 

 also by cod-net, in February 1913, after 820 days, in the Moray Firth, off Berrie- 

 dale Ness, at a distance of 164 miles ; it measured 36-5-42-1 cm., and the mean 

 rate of travel was 2 miles per 10 days. 



Two males are described as "spent"; 1 was caught in March 1911, after 



2* 



