6 



Mr. Storrow that tliese join spawning shoals as they mature 

 independently of their origin. 



The spring spawners grow more rapidly after maturity. 

 This is probably due to the gonads being developed after the 

 annual growth season. 



In the last re]Jort we submitted evidence as to immigration 

 into the summer feeding shoals of the Northumberland Coast. 

 Further evidence from other shoals points to these immigra- 

 tions taking place generally. Probably the last change which 

 takes place in September or late August is brought about by 

 fish leaving the feeding shoals to join the spawning shoals. 



There is evidence to show that during the early part of 

 1920 the Firth of Forth was visited by more than one shoal of 

 spring spawners, and also herrings were present in these shoals 

 which on account of their stage in development could not 

 become spring spawners this year. From a general considera- 

 tion of the fishing grounds and the currents it is evident that 

 the young are spread over a wide area. These j'Oung fish form 

 the summer feeding shoals, and the feeding shoals give rise 

 to recruits for the spawning shoals. The larvae resulting from 

 the spawning shoals undergo denatation, and may ultimately 

 join other spawning shoals, with the result that there is a 

 relationship between the various schools. 



With regard to the size of the fish, Mrs. Cowan has given, 

 as in former years, an analysis of the age in relation to size. 

 She found that the northern samples consisted of much larger 

 fish than the southern when comj^ared age for age. The autumn 

 spawning shoals were found also to be larger fish than summer 

 feeding shoals when contrasted in this manner. 



AYith respect to the statement made in the above summary, 

 Mrs. Cowan's analysis shows plainly that the first sample which 

 came from the Firth of Forth was smaller in relation to age 

 than the succeeding samples. It appears to be generally true 

 that the herrings are large in the north and gradually become 

 smaller on the successive fishing grounds towards the south 

 when compared age for age. 



