36 



ments varying from 31 to 63-3 per cent. Tlie percentage of recaptures in the Moray 

 Firth were not so high ; in this firth, as in the Firth of Forth, trawHng is prohibited. 

 In the experiments in the neiglibourhood of Smith Bank, 707 plaice were marked 

 and hberated, and 336, or 47-5 per cent., were recovered, the percentage in different 

 experiments being as low as 28 and as high as 56. In the experiments made in other 

 parts of the Moray Firth, 530 plaice were liberated, and 201, or 37-9 per cent., 

 reca ptured . In the neighbourhood of the Great Fisher Bank, 599 were liberated, and 

 194, or 32-9 per cent., recaptured, many of the fish being landed at foreign ports. 

 In the experiments to the east of the Isle of May, the percentage of recaptures 

 steadily diminished the farther and farther to sea the experiments were made. 

 At 20 miles, as above mentioned, 66-9 per cent, were recaptured ; at 40 miles, 54*4 

 per cent, of the 382 liberated were taken ; at 50 miles, 51-7 per cent, of 207 ; at 

 100 miles, 28-1 per cent, of 192 ; and at 220 miles (to the north of the Great Fisher 

 Bank), of 106 hberated only 17, or 16 per cent., were recaptured. In some cases, 

 the actual numbers were not very large. In the six experiments with the largest 

 number of plaice marked and Hberated, the following results were obtained : — 

 Aberdeen Bank, 10th June 1910 : of 336 hberated, 201, or 59-8 per cent., were re- 

 captured ; at the same place, on 21st October 1910, of 282 liberated, 195, or 69-1 

 per cent., were recaptured ; at Great Fisher Bank, on 16th June 1910, of 287 

 liberated, 116, or 40-4 per cent., were subsequently captured ; at Fair Isle, of 262 

 liberated on 15th September 1910, 131, or 50 per cent., were recaptured and of 246 

 liberated on 4th November 1910, 147, or 59'3 per cent., were recaptured ; at 20 

 miles east of the Isle of May, on 6th December 1912, of 202 liberated, 132, or 65-3 

 per cent., were again caught. 



From the table printed on page 4 it will be seen that 74-5 per cent, of the 

 marked plaice which were recaptured were taken within a year of liberation ; in 

 the second year, the percentage was 22-4 ; in the third year, 4'8 ; and in the fourth 

 year, only 7. 



V. DESCKIPTION OF THE VARIOUS EXPERIMENTS. 



1. Experiments Midway Between Elie and Fidra, Firth of Forth. 



At this station, which lies in the middle of the Firth of Forth, midway between 

 Elie and Fidra (Lat. 56° 8' N. ; Long. 2° 48' W.), with a depth of about 27 fathoms, 

 marked plaice were liberated on ten occasions, from November 1910 to March 

 1913. The total number hberated was 823, viz., 305 males, 469 females, and 

 49 whose sex was not ascertained. The number of the fish recaptured was 489, 

 or 59-4 per cent., namely, 210 males, or 68*9 per cent,, 267 females, or 56*8 per 

 cent., and 12 of undetermined sex, or 25 per cent. The particulars relating to 

 the experiments are as follows : — 



