42 



been caught from January to May. The emigration in autumn is 

 illustrated by recaptures in October and December. One example 

 is interesting, since it migrated northwards from St. Andrews into 

 the Firth of Tay between October and December. It is therefore 

 possible that such a region attracts a number of the winter migrants. 

 The " Goldseeker " experiments evidence the southerly migra- 

 tion of the larger sized plaice. From March four migrated from 

 near the Carr Lightship into St. Andrew's Bay, where they were 

 caught in December and January. Thirteen migrated between 

 June and the following October to March from Carnoustie to St. 

 Andrew's Bay. The subsequent experiments in the region show 

 that such large plaice may migrate as late as October in this direc- 

 tion, so that the winter residents may not necessarily be a remnant 

 of the summer population, but include at least such large plaice 

 which migrate there to replace the winter migrants. An example 

 in the " Garland " experiments serves to indicate that these large 

 plaice may migrate northwards from the inshore regions at the 

 time that the smaller plaice are moving inshore. This one was 

 marked in December and captured in March. 



The Forth plaice must be left out of consideration in the mean- 

 time. Both northerly and southerly migrations were evidenced. 

 As has been said, a large body of plaice winter in the region. At 

 the same time the statistical evidence proves that the area gains 

 and loses like the proximal part of the region to the north. The 

 marking experiments have demonstrated also migrations from the 

 north into the area and from the Forth to the north of that area. 



The marking experiments made in the southern part of the 

 North Sea as reported by Garstang * and by Reichard f for the 

 HeUgoland district show on the other hand that the plaice in that 

 part of the North Sea migrate southwards (or westwards) for the 

 winter, and northwards (eastwards) for the summer. This appears 

 to be clearly established from migration experiments. It cannot 

 yet be definitely stated that the movement produces a corresponding 

 reversed series of maxima and minima, nor can the Umits of the 

 schools be at present indicated. 



It has long been supposed that North Sea plaice consisted of a 

 northern and a southern race ; the opinion, which has been 



* North Sea Fish. Investig. Comm., Reps. 2 and 3. 



t II. Bericht, Arb. d. Deutsch. Wiss. Komm. f. d. Intern. Meeresfor. 



