258 



north and west, 3 males and -1 females to the north and east, 1 male and 1 female 

 to the south and west. 



50 to 100 miles. — Ten fish, or 9-1 per cent., were got at distances of from 51 to 

 91 miles, 5 males (11-6 per cent.), with an average of 66-8 miles, and 5 females (7-6 

 per cent.), with an average of 74-8 miles. Two of the males and 1 of the females 

 were caught to the south and east, I of the males to the north and east, 1 male 

 and 2 females to the south and west, and 1 male and J females to the nortn and 

 west. 



Over 100 miles. — Eleven fish, or 10 per cent., were recovered at distances of 

 from 112 to 232 miles, 3 males (6-9 percent.), with an average of 171 miles, and 8 

 females (12-1 per cent.), with a mean of 155-5 miles. One of tne males and 2 of the 

 females went to the south and east, 2 males and 2 females to the north and west, 

 2 females to the south and w^est, 1 to the north and east, and 1 to the south. 



Maturity. 



Males. — As previousl}; stated, most of these fish were taken by English or by 

 foreign trawlers, only the records coming into my possession. Thus, the condition 

 of the testes was ascertained in only 8 of the 46 males recaptured. 



Five were described as " ripe," 1 taken in December 1910, 43 miles to the north 

 and east, 1 in April, 1911, 137 miles to the north and west, 1 in October 1912, 11 

 miles to the south and east, 1 also in October 1912, 69 miles to the south and west 

 and 1 in January 1914, after 1314 days, 156 miles to the north and west. 



A male taken in October 1910, 35 miles to the south and east, was described 

 as " maturing," and 1 captured in May 1911, 36 miles to the north and west, was 

 said to be " spent." 



Females. — The condition of the ovaries was recorded for 13 of the 69 females 

 recovered. 



One was " ripe " ; it was taken on the ground 1| miles to the south and west, 

 in June 1911. 



Among the females under adult size, 1, measuring 33-5-37 cm., caught in May 

 1911, 52 miles to the north and west, was described as " ripe." 



EXPERIMENT VII. 



Uth July 1911. 



In this experiment, w^hich was made north-west of the Bank, at 57° 25' N. ; 

 3° 35' E., 102 plaice were marked and liberated, viz. 50 males, 43 females and 9 

 whose sexes were not determined. The males measured from 29 to 42-5 cm., and 

 23 were under adult size when liberated ; the females varied from 28 to 44 cm., and 

 33 were under adult size on liberation. 



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

 follows : — 



The fish used in this experiment were trawled by the " Goldseeker " in the 

 Firth of Forth, mostly at Station VI., off St. Monans. and in part at Station II., 

 viz. Kirkcaldy Bay. They were caught on the 13th July, between 10 a.m. and 

 4 p.m., and liberated at midnight on the 14th. 



Three marked plaice were captured by the " Goldseeker " at Station VI., and 

 taken to put away again at the Fisher Bank, but they died en route, in addition to 

 other 6 which had been marked, and 36 which were in the tubs unmarked. 



The number recaptured was 43, or 42-1 per cent., viz. 22 males (44 per cent.), 



