(j4 



winter rings have a smaller increase than have the drift net herrings 

 of the same age, and are probably still later migrants into the North 

 Sea than those which joined the di'ift net herrings in the beginning 

 of September. 



The 1913 growth increments for the trawled herrings here 

 follow : — 



SAMPLES. 



The numbers of individuals of each yeSbY group in the samples 

 will be found in Table 3. 



Maturity. — Table VI. The state of the gonads was expressed 

 according to Hjort's method, Pub. de Circ, No. 53, p. 35. In the 

 table, stage 7-2, recovering spents, of which there are few, are 

 classified as stage 7, spents. 



In the first samples, those examined in June from North Sunder- 

 land, the greater number of the herrings were virgin fish, and the 

 remainder, except two, at stage 2. As the season advanced the 

 gonads increased in size, and towards the end of August and the 

 beginning of September from 40 to 50 per cent, were at stage 4, 

 and a small number of spa^\'ning fish appeared, samples I to M. 



During the first and second week of September a change 

 appeared in the shoal, and the herrings were at a lower stage of 

 development. This change, which became more marked in the 

 later samples, K to L, alBfords furtner reason for considering that 

 there was an immigration of later North Sea migrants into our local 

 shoals. The change as regards maturity in samples K and L 

 coincides with the change sho\^Ti for the same samples by growth 

 increments for 1913 for herrings havmg three and four winter rings. 

 Sample M which had such a large number of herrings at a low stage 

 of development, and as will be seen from the other tables of young 

 fish of smaller size than the average run, probably points to the 

 maturing herrings leaving our waters and continuing their southerly 

 migration. 



In sample A, taken 19th June, it will be observed that there 

 was present a herring having the body cavity filled with the gonads, 

 that is at stage 5. The question arises, where has this fish come 



