162 



ness, at a distance of 54 miles ; a fourth, of 51-50-9 cm., was taken in August 1913, 

 east of St. Abb's Head, at 23 miles distant to the south and west ; the fifth, of 39- 

 41-8 cm., was recaptured in April 1914, near Buchananess, at a distance of 62 miles ; 

 the sixth, measuring 48-50-7 cm., was caught in June 1914, 14 miles to the north 

 and west ; the seventh, of 40-43-4 cm., was taken in April 1914, offshore, south- 

 east of Buchanness, at 68 miles distant, and the last, measuring 53-52-7 cm., was 

 caught m July 1913, 21 miles to the northwards. 



A female, measuring 40-44-1 cm., was taken in November 1915, offshore, 25 

 miles to the eastwards, and was "about three-quarters ripe " : and 1, of 50-53-7 

 cm., taken in November 1914, near Buchanness, at a distance of 59 miles, was 

 "fully half ripe." 



Among the females whose ovaries were " immature," 1 was recovered in April 

 1914, 11 miles to the north and west ; it measured 45-5-48-6 cm. The others were 

 taken mostly in the summer months. 



Experiments at 50 Miles East of Isle op May. 



At this station, which lies approximately at 56° 24' North Latitude and 1° 6' 

 West Longitude, with a depth of about 36 fathoms, marked plaice were liberated 

 on two occasions, in July and in September 1912. The following table shows the 

 particulars of these experiments : — 



experiment I. 



m Jidy 1912. 



In this experiment, 107 marked plaice were liberated, viz. 47 males, 58 females, 

 and 2 whose sexes were not ascertained. The sizes of the males ranged from 28 to 

 45 on., and 17 were under the adult size. The sizes of the females varied from 

 29 to 61 cm., and 43 were under the adult size. The numbers hberated and 

 recaptured, arranged in 5-cm. groups, are shown in the following tables : — 



F. Lib. 

 F. Recap. 



M. Lib. 



M. Eecap. . 



? Lib. . 

 ? Recap. 



The fish used were recaptured in Kirkcaldy Bay, Firth of Forth, and marked 

 between 2 and 3 p.m. on the 5th July, and were set free at 5.40 a.m. on the 6th ; 

 only one died in the tanks, in the interval. 



The number recaptured was 71, or 66-3 per cent., viz. 32 males, or 68-1 per 

 cent., and 39 females, or 67-2 per cent. 



Twenty-eight of the males, when recaptured, were of adult size, the average 

 being 37*5 cm., and the range from 33-2 to 42 cm., as compared with a mean of 



