SUMMARY AND GENERAL REPORT. 



As in the previous year the work this year has been restricted to 

 investigations made in the Laboratory and at North Shields. 



Resulting, however, from the marking experiments of 1912 

 relating to the crab, an example was returned from Banff which 

 is of pecuHar interset. It was absent about three and a half years, 

 and thus indicates the relationship of ecdysis to growth and the 

 maturation of the ovaries, and through the last the association 

 of aU with migration. 



In spite of the adverse conditions, our fishermen landed 

 herrings at North Shields, and the opportunity was taken to con- 

 tinue our investigations. The samples w^ere examined as before 

 by Mr. Storrow, and are of value since they have yielded addi- 

 tional information with regard to the Northumberland and trawl 

 caught schools. 



A peculiar feature in herring investigation with relation to 

 growth has attracted general attention. It is that when the 

 attempt is made to calculate the growth of the herring from the 

 relative distance of the winter rings from the centre of the scale, 

 the resulting figures form a descending series in the successive 

 year groups. This problem is discussed, and it has been found 

 that when the actual size is contrasted with the calculated it is 

 greater during the period of the formation of the first two winter 

 rings, is about equal at the third, and is greater after the third 

 winter ring. It is evident therefore that since the scale appears 

 only after the herring reaches a size of about 4 cm. it grows more 

 rapidly than the fish. It is not as has been suggested therefore 

 due to selection, but to a want of correlation between the growth 

 of the scale and the fish, a want of correlation which is probably 

 generally true. 



