30 



2. — Periodic Migration of the Schools. 



Reduced to the standard of mean catch per hour's trawHng, 

 the plaice and dabs captured at the Northumberland trawling 

 experiments are indicated in Table I. 



TABLE I 



PLAICE. 



DAB. 



Goswick . . . 

 Skate Roads 

 Aliimouth 

 Druridge ... 

 Cambois . . . 

 Blyth 



7 

 14 



2 

 5 

 33 

 25 

 37 

 16 



It need not be stated that they are incomplete. Moreover, 

 the winter figures refer in most cases to one, in a few cases to two 

 experiments ; those for the summer months are the averages for 

 the experiments made since 1899. They are sufficient to indicate, 

 however, that every year in spring and summer the inshore waters 

 of Northumberland receive an immigration of plaice and dabs, 

 and that the majority retire from the region towards the end of 

 the year. It is also evident that the dabs depart more completely 

 from the shore than the plaice. 



Fortunately far more information has been gathered with refer- 

 ence to the school immediately to the north of the Northumberland 

 one — the Firth of Forth school. From the table on page 17 of the 

 report by Prof. D'Arcy W. Thompson * on the experiments made 



* Fifth Report on Fishery and Hydrog. Investigations, Fisli. Bd. for Scot., 1913. 



