253 



Experiments at Great Fisher Bank. 



A number of experiments were made in the region of the Great Fisher Bank, 

 extending from April 1910 to June 1912, but most of them referred to very small 

 numbers. The particulars are given in the following table : — 



EXPERIMENTS I, II, AND III, 



On April 14 and 15 1910, 26 marked plaice, 16 males and 10 females, were 

 liberated to the north-west of the Bank and on the Bank, 4 at one locality, 10 at 

 another, and 12 at the third, which was on the Bank ; only 4 of the fish, or 15-4 

 per cent., were recaptured, 3 males (18-7 per cent.) and 1 feniale. One of the males 

 was taken in July of the same year, 200 miles north-east of Spurn Point (Lat, 

 56° 25' N. ; Long. 3° 10' E.), a distance of 56 miles in the direction S. 33^ W., and 

 had moved at the mean rate of 5-8 miles per 10 days. The female, which measured 

 42-41 cm., was recaptured in June, after 57 days, 47 miles N. 89° W., and had 

 moved at the rate of 8-2 miles per 10 days. One of the other males was captured 

 in May 1911, 55 miles distant, in the direction S. 9° E., and the mean rate was 

 1-4 miles. The remaining male was got in July 1911, 52 miles in the direction of 

 S. 62° W., the average rate of movement being M miles. None of the fish went 

 to the northwards. 



These plaice were all trawled in the neighbourhood of the places where they 

 were liberated. Two were landed at London and 2 at Hull, and nothing was 

 recorded as to the condition of the reproductive organs. 



EXPERIMENT IV. 



16th June 1910. 



In this experiment, 287 plaice, comprising 106 males, 156 females, and 25 

 v.-hose sexes were not determined, were liberated, to the north-west of the Bank 

 in Lat. 57° 25' N. ; Long, 3° 35' E., in 34 fathoms. These fish were not taken 

 locally, but in the northern part of Aberdeen Bay, off Slains Castle and Cruden 

 Scaurs, by the " Goldseeker," in the afternoon of the 15th June, and were liberated 

 between 10 and 11 p.m. on the 16th, having been kept in tubs of rmming water in 

 the interval. The males ranged in size from 31-5 to 41 cm., and 6 were mider 

 adult size (33 cm.) on liberation ; the sizes of the females varied from 30 to 52 cm., 

 and 125 were under adult size (38 cm.) on liberation. 



