58 



liberation ; the periods of freedom were from 167 to 1682 days, the average being 

 555 days ; the distances migrated were from 5 to 137 miles, the average being 49"7 

 miles, and the mean rate of movement per 10 days "89 mile. Six were immature, 

 the sizes ranging from 25-6 to 37'7 cm., the average being 31-9 cm., compared with 

 24-5 to 37 cm., and a mean of 29*2 cm. on libeiation ; the average period of freedom 

 was 239 days., the distances travelled being from 5 to 29 miles, averaging 13 miles, 

 and the mean rate of travel per 10 days was -56 mile. 



The Extent and Direction of Migration. 



First Quarter. — In September, after 7 days, a male, of 28"5 to 28 cm., was taken 

 near Kirkcaldy, in the Firth of Forth, at a distance of 11-| miles, and in October, 

 after 34 days, 1 of undetermined sex, measuring 29*5 to 28 cm., was caught in the 

 same neighbourhood, off Dysart, at a distance of 9J miles. These were the only 

 fish recovered within the first three months after liberation, and they were found 

 near where they were originally caught. 



Second Quarter. — Two were recaptured in December 1911, a female of 28'5- 

 28*2 cm., ofE Largo, in the Firth of Forth, at a distance of 6^ miles, after 92 days, and 

 a male, measuring 35-36 cm., after 110 days, to the north-east of Tod Head, at a 

 distance of 56 miles ; it is described as " very immature." Two were caught in 

 February 1912, a female of 37-39 cm., and "immature," off Pittenweem, at a dis- 

 tance of 5 miles, after 167 days, and the male, of 35-35*3 cm., and " fully half-ripe," 

 after 158 days, near Buchanness, at a distance, to the northwards, of 78 miles. 



Only 4 fishes were, therefore, recaptured in the second cjuarter, 2 in the Firth of 

 Forth, and 2 at a considerable distance northwards, along the coast. 



Third Quarter.— In March 1912, 2 females were taken, 1, of 37-37-7 cm., and 

 " immature," after 179 days, near Largo, in the Firth of Forth, at a distance of 5| 

 miles, and the other, of 25-5-26 cm., a little farther to the west, off Leven, at a dis- 

 tance of 9 miles, after 191 days. Three males were also got in March, all within the 

 Firth of Forth, 1, of 26-26-5 cm., after 179 days, in Largo Bay, a distance of 5| 

 miles ; another, of 23 cm. on liberation, but of unknown size on recapture, after 

 181 days, on the south shore of the Firth, at a distance of 14 miles ; the third, 

 after 183 days, was taken near Elie, 2| miles distant ; it measured 34-35.3 cm., 

 and was "immature." Another fisli of undetermined sex, measuring 25-28 cm., 

 was recaptured, after 190 days, near Kirkcaldy, at a distance of 11 miles. In April, 

 a female. was found, after 214 days, far up the Firth of Forth, at Bo'ness, a distance 

 of 29 miles ; it measured 24-5-25-6 cm., and was "immature " ; a male, of 32-5- 

 33-6 cm., also "immature," was caught, after 212 days, near Bell Rock, at a 

 distance of 27 miles. In May, a female, of 36-5-39-9 cm., and "immature," was 

 recaptured after 256 days, 43 miles to the north and east. 



In this quarter, 9 fishes, or 24-3 per cent., M^ere found, 7 within the Firth of 

 Forth. 



Fourth Quarter. — Two females were taken in June, 1 after 281 days, off Tod 

 Head, to the north and east, at a distance of 58 miles ; it measured 35-39-8 cm. 

 The other was caught to the south and east, 35 miles N.E. by E. of Scarborough 

 (Lat. 54° 43' N., Long. 0° 15' E.), 137 miles distant, after 295 days ; it measured 

 40-40-7 cm. ; the condition of the ovaries was not ascertained ; the mean rate of 

 movement in this case was 4-6 miles per 10 days. Two males were recovered in 

 August 1912, 1, 24 miles to the south and east, off the Isle of May, after 330 days ; 

 it measured 34*5-39-2 cm., and was " immature." The other, measuring 37-40-5 

 cm., was caught, after 356 days, 4 miles north-east from Noup Head, Orkney 

 Isles, at a distance of 213 miles. 



Within 12 months after hberation, 19 fishes, or 51-3 per cent., were recaptured, 

 of which the unusually high number of 12, or 63-1 per cent, of them, were taken 

 within the Firth of Forth. 



Three fish were found in the remainder of 1912, 2 in September, and 1 in October. 

 A female, of 30-5-37-5 cm., was caught in September, after 370 days, 24 miles to 

 the north and east, and a male in the same locality, after 371 days, at a distance 

 of 21 miles ; it measured 35-39-5 cm. In October, after 393 days, a female, 

 measuring 29-36*5 cm., was got near Grail, in the Firth of Forth, at a distance of 

 8 miles. 



