88 



(or 15-4 per cent.) had migrated an average distance of 8 miles in the mean direc- 

 tion S. 30° E., at a mean rate of 6-8 miles per 10 days. Four (or 15-4 per cent.) 

 had moved an average distance of 11 miles S. 57° W., at an average rate of 7 miles 

 per 10 days. 



It will thus be seen that the predominant migration was along the coast to 

 the northwards, 3 of the fishes being caught in the Moray Firth, off Banff, and, 

 from the condition of the reproductive organs and the rapidity of movement, 

 it is clear that the migration northwards was a spawning migration. One of the 

 fishes, a female of 43'5 cm., had travelled to the north-east of Aberdeen in 10 

 days, or at the rate of 5'6 miles per day ; a male, of 38*5 cm., had migrated 

 76 miles in 20 days, or at the rate of 3-8 miles per day, and was lecaptured off 

 Peterhead. 



Of the 16 fishes which were got to the noTthward of the station, all were " ripe," 

 "almost ripe," "approaching ripeness," or "spawning," except 4, which were 

 " immature," namely, a male of 35 cm. which was caught oft' Aberdeen, and 3 

 females, 1 measuring 37-5 cm., another 38 cm., got off Aberdeen, and the third, 

 measuring 34.5 cm., taken near the Bell Rock. On the other hand, of 10 fishes 

 got to the south or eastward of the station, and legarding 8 of which the condition 

 of the reproductive organs was determined, all were " immature " except 2, namely, 

 a female, of 44-5 cm., which was caught after 31 days 13 miles south and west, 

 " almost ripe," and a male, of 40"5 cm., got not far fro)n the same position, after 

 19 days., also " aln\ost ripe." There is other evidence that the plaice spawn in 

 this neighbourhood. 



Second Quarter. — In the next 3 months, March, April, and May 1911, 15 fishes 

 were recaptured (or 21 per cent, of the total recaptured), 7 (or 25 per cent.) being 

 males, and 8 (or 18'6 per cent.) being females. The position of recapture of 14 

 of the fishes was ascertained. In this quarter also the majority of the fishes 

 migrated northwards, along the coast, namely, 12 (or 85"7 per cent.), the mean 

 direction being N. 32° E., and the average distance 104 miles, the average rate 

 of movement, per 10 days, being 8"63 miles. Of the 7 captured in March, 5 went 

 northwards, while all those got in April and May took the same directioi>. One 

 (or 7*1 per cent.) went north and west for 12 miles, and another went south and 

 east for 21 miles. Five were recaptured in the Moray Firth, 1 at Fair Isle, and 

 1 at Shetland. 



Of the 5 fishes got in the Moray Firth, the condition of the reproductive organs 

 in 3 was not ascertained ; the other 2, a male and a female, were " ripe " and 

 " spawning." The male caught at Shetland was " spent," and that got near 

 Fair Isle is described as " immature " ; it was taken on 18th March, and measured 

 34-5 cm. Of 2 caught in the neighbohrhood of Buchanness, 1 of 41 cm. was 

 " spent," and the other of 36'5 cm. (and thus under adult size) was " immature." 

 The other 3 fishes, 2 females of 37*5 and 38*5 cm., and a male of 33 cm., which 

 were taken not far from the station, were " immature." The female which had 

 moved north and west to the Bell Rock was under adult size (36 cm.), and was 

 " immature " ; but the female recaptured near St. Abb's Head on 29th March 

 was " spent." 



Third Quarter. — -In the months June, July, and August 6 fishes (or 8*4 per 

 cent, of the total recaptured) were caught, viz. 1 male and 5 females. The positions 

 of recapture were ascertained for 5 of them ; 3 (or 60 per cent.), 1 male and 2 

 females, had gone northwards for 106, 126, and 53 miles (2 into the Moray Firth), 

 the average distance being 95 miles, and the mean direction from the station 

 N. 33° E. Two moved west and south, 1 to the mouth of the Firth of Forth, 

 and the other, well within it, to Aberlady Bay, the average distance being 23 miles. 



The condition of the reproductive organs was ascertained in only 3 cases ; 

 the male, caught on 10th June, off Kinnaird Head, was described as " ripe " ; 

 the 2 females taken in June and August were " immature." 



Fourth Quarter. — No fishes were recaptured in September, but 5 (7 per cent.) 

 were got in October and November, 2 males and 3 females. Three (60 per cent.) 

 were caught to the northwards, 2 females, well off shore at distances of 66 and 

 71 miles, and a male off Stonehaven at a distance of 30 miles. A female had 

 moved almost directly east for 18 miles, and a male for only Sh miles to the south 

 and west. The males, caught respectively on 24th October and 10th November, 



