SEA-FISHERIES LABORATORY. 291 



territorial waters than on the offshore grounds, and that 

 there is a greater chance that a fish will be recaptured in 

 the former area. However, it seems most probable that 

 the migrations made by the majority of marketable plaice 

 on this side of the Irish Sea are mainly along shore and 

 in territorial waters. 



Influence of size on migration paths. 



Nevertheless a fair proportion have been recaptured 

 from places well outside the territorial waters, and in 

 some cases at considerable distances from the place of 

 liberation. If the sizes of these fish be compared with 

 those caught in the territorial waters, it will be seen that 

 the sizes of those taken outside are usually greater than 

 those caught inside the district. But the difference is not 

 very striking, and is to be seen only when considering 

 averages. The fish dealt with in these experiments have 

 for the most part ranged from 8 to 12 inches in length, 

 and though the very smallest of these do not migrate to a 

 marked extent, nevertheless it is difficult to draw any 

 distinction between plaice of different sizes within the 

 limits indicated above. Other influences — the season, 

 abundance of food, &c, operate more powerfully than the 

 exact age of the fish. 



General conclusions. 



The experiments here described have so far been 

 made on too small a scale to yield conclusions of a high 

 degree of probability, and it is advisable that they be 

 repeated on a larger scale before any inferences of a 

 practical nature be made from their results. 



The value of these conclusions obviously depends on 

 whether or not a marked plaice behaves normally, that is, 

 like an unmarked healthy plaice. Fishermen express two 



