118 



or 77-7 per cent., were males, 54, or 76-1 per cent., females, and 1 was of unknown 

 sex. Of the males recaptured, 11, or 73-3 per cent., were of the first group mentioned 

 above, of smaller fish, and 10, or 83-3 per cent., of the larger group. Among the 

 females recaptured, 14, or 87-5 per cent., belonged to the smaller group (under 

 36 cm.), 26, or 81-2 per cent., to the next largest group, 11, or 73*3 per cent., to the 

 group from 41 to 45-5 cm. 



All the males were of adult size on recapture, and the particulars in regard to 

 them are as follows : — They had been at Uberty for from 33 to 798 days, the average 

 being 293-6 days ; their average size on liberation was 35-7 cm., and on recapture 

 38*5 cm. ; the distances migrated ranged from 5 to 156 miles, the average being 

 42*75 miles, and the mean rate of movement 1-5 miles per 10 days. 



Of the 54 females, 46 were of adult size on recapture ; they had been at liberty 

 for from 7 to 868 days, the average period being 203-8 days ; their average size 

 on Hberation was 40*1 cm., and on recapture 43-2 cm. ; the distances migrated 

 varied from 3 to 300 miles, the mean distance being 28-8 miles, and the average 

 rate of travel per 10 days was 1-4 miles. 



The other 8 females were under the size of maturity on recapture, the mean 

 size being 35-8 cm. against 33-9 cm. on hberation ; they had been at Uberty for 

 from 12 to 163 days, or an average of 93 days ; the distances travelled were from 

 4 to 8 miles, the average being 5-9 miles, or at the rate of -6 mile per 10 days. 



The Extent and Direction of Migration. 



First Quarter. — In May 1912, the month following their liberation, 13 fish were 

 recaptured, 12 feinales and 1 male. The position of capture was ascertained for 

 all but 1 female ; 4 of the fishes, including the male, had moved to the south and 

 west, in the direction of the coast south of the Firth of Forth, for distances of 

 from 5 to 6 miles ; 5 had gone to the south and east, for distances of from 6 to 

 24 miles ; 2 north and west for 5| and 23 miles, 1 directly east. 



In June, 11 were recaptured, 4 males, 6 females, and 1 of unknown sex. Three 

 had moved to the south-west, for from 5 to 9 miles, 2 to the south and east, each 

 for 5 miles, and 6 to the north and east for from 5 to 20 miles. 



In July, 7 were taken, 6 females and 1 male. Two had moved south and west, 

 each for 5 miles, 2 north and east, for 5 and 8 miles, and 3 to the north and west, 

 in the direction of the coast, for 11, 14, and 15 miles. 



Thus, in the first three months following liberation, viz. May, June, and July, 

 31 fishes were recaptured (or 40-8 per cent, of the total recaptured), particulars 

 being ascertained for 30 of them. Six were males, 22 females, and 1 of under- 

 termined sex, the percentages being 28*6 of the total males recaptured, and 40-7 of 

 the total females recaptured. There was thus a considerable excess of females. 

 None of the fishes had moved to any great distance, the maximum being 24 miles ; 

 and (as the chart shows very well) they were tolerably well dispersed in all direc- 

 tions around the station. In the accompanying table, in which the particulars 

 are summarised, it will be seen that 8 fishes (or 26-7 per cent.) moved to the north 

 and east for a mean distance of 9-4 miles ; 5 (or 16-7 per cent.) moved north and 

 west for a mean distance of 13-7 miles ; 7 (or 23-3 per cent.) moved south and east 

 for a mean distance of 12-5 miles ; 9 fishes (or 30 per cent.) moved south and west 

 for a mean distance of 6 miles ; and 1 had gone directly east for 3 miles. 



Second Quarter. — In the next three months, August, September, and October, 

 13 fishes (or 17-1 per cent, of the total) were recaptured ; 3 were males (or 14-3 per 

 cent, of the total males recaptured) ; and 10 were females (or 18-5 per cent.). In 

 this period the majority of the fishes were caught to the south and west, viz. 8 (or 

 61-5 per cent.), but they had moved only short distances, from 4 to 15 miles, the 

 mean being 6-8 miles. One had gone north and west for 9 miles, and 1 south and 

 east for 34 miles. Other 2 fishes had moved north and east, to off the coast of 

 Aberdeen, 1 for 37 and the other for 50 miles ; and 1 had gone west for 10 miles. 



Third Quarter. — In the 3 months, November and December 1912, and January 

 1913, 10 fishes (or 13-2 per cent, of the total recaptured) were taken, 3 being males 

 (or 14-3 per cent.) and 7 females (or 13 per cent.). In this case also the majority 

 were caught to the south and west, viz. 5 (or 50 per cent.), but the distances were 

 again very small, from 4 to 15 miles, the mean being 7-8 miles. None was got 



