44 



After 1914 war conditions affected the herring fishing, and 

 comparsion cannot be made. 



The samples of 1914 showed a change in the growth increment 

 made during that year, fish with a small growth for 1914 being 

 found in sample 10. Herrings with thi'ee winter rings in 1914 

 would have six winter rings in 1917, and in order to see if this 

 difference of growth has any connexion with the Firth of Forth 

 herrings the growth made by fish with six winter rings in the 

 Firth of Forth sample during the periods between the formation 

 of the third and fourth and fourth and fifth winter rings has been 

 determined and is shown graphically on the opposite page, together 

 with similar details relating to the growth of herrings with five 

 winter rings. It will be observed that the Firth of Forth sample 

 contains fish which during the years under consideration made 

 varjing growths. 



The connexion shown above between the herrings of the 

 Northumberland coast and the winter fishery of the Forth of Forth 

 naturally brings forward the question of the spa^^iiing which is 

 known to take place off the Xorthumberland coast in August and 

 September. The opinion held at present, but which is open to 

 modification with the obtaining of additional data, is that the 

 3'oung herrings on attaining first maturity ma^^ spawn in the 

 autumn, and that these may be joined b}^ older fish maturing at 

 the same time ; afterwards the herrings which passed their earlier 

 years in summer and autumn shoals off the Northumberland 

 coast tend to become spring spawners in the Firth of Forth. 



It is not intended at present to express any opinion as to 

 spring and autumn spawning heriings in general, or as to what 

 extent other summer shoals of the North Sea may be spring 

 spa^vners, but it is hoped that the investigations now being con- 

 ducted will throw further light upon the subject. 



