274 



None was taken in October ajid November. 



Fourth Quarter. — Li December, a male was recaptured 24| miles N.E. -| E. of 

 Cape Wrath and landed at Grimsby ; the distance migrated was about 86 miles 

 in a north-westerly direction. 



Li February 1912, a male was captured 1 6 miles E.N.E. | N. of the Butt of I;ewis, 

 at a distance of 122 miles to the north and westward. This fish was landed at Hull. 



Within the 12 months after liberation, 19 plaice, or 82'6 per cent., were 

 recaptured, but the place of capture of 5 was not ascertained. Of the remaining 

 14, or 60'9 per cent., 5 were taken to the south and west, 3 to the south and east, 

 and the others to the north and west. 



Of the remaining fish from the experiment, 3 were taken in 1912, and 1 in 1913. 



Li April 1912, 2 females were got in the Moray Firth, near Noss Head, 1 at a 

 distance of 12| miles, and the other at 23-| miles to the northward. Tn June, a 

 male was recovered off Wick Bay, 15 miles to the north and west. 



The last fish from this experiment to be recaptured was a female taken in May 

 1913, which obviously had migrated in an imusual direction. It is described as 

 having been found 5 miles S.S.E. fro)n Cruden Bay, or 70 miles distant from the 

 station, to the southwards ; it was landed at Aberdeen. 



Distances travelled — 10 miles and under. — Five of the marked plaice, or 27-8 

 per cent., were recaptured at distances of from 1 to 7h miles, 2 males and 3 females, 

 tlie males an average distance of 4-5 miles, and the females, 3'2 miles. One male 

 and 1 female were found to the south and east, 1 male to the north and west, 1 female 

 to the south and west and 1 to the north and east. 



10 io 20 miles. — Four, or 22-2 per cent., were recaptured at distances of from 

 12-^ to 15 miles, 2 males with a mean of 14 miles, and 2 females with a mean of 

 13| miles. One male and 1 female were found to the north and east, the other 

 male to the north and west, and the other female to the south and east. 



Thus, 9 of the fish, or 50 per cent., were recaptured at distances under 20 miles. 



20 to 50 miles. — Six fish, or 33'3 per cent., were got at distances of from 23| to 

 46 miles, 2 males with an average of 34-7 miles, and 4 females with an average of 

 31"4 miles. One of the males and 3 of the females were found to the south and 

 west, 1 male to the north and west, and 1 female to the north and east. 



50 to 100 miles. — Two fish, or 11-1 per cent., were recaptured, a male at 86^ 

 miles to the north and west, and 1 female 70 miles to the south and east. 



Over 100 miles. — Only 1 fish exceeded 100 miles ; it was taken at 122 miles 

 distant to the north and west, off the Butt of Lewis. 



Maturity. 



Males. — Of the 11 recaptured, the condition of the testes was ascertained in 

 only 2 ; both were " immature." 



Females. — The condition of the ovaries was recorded for 5 of the 12 recaptured. 

 Two were described as "spent," 1 taken in April 1911, 14| miles to the south 

 and east, the other in April 1912, 23| miles to the north and east. All the others 

 were " immature." 



EXPERIMENT II. 



Uth March 19U. 



Tn this experiment, 60 plaice, 27 males and 33 females, were marked and liberated 

 at 58° 10' N.; 2° 55' W., the males measuring from 21 to 36-5 cm., and 21 were 

 under adult size on hberation. The sizes of the females ranged from 22 to 50 cm., 

 and 27 were under adult size on liberation. 



The numbers liberated and recaptured, arranged in 5-cm. groups, are shown 

 in the accompanying table : — 



