COUNCIL - SEPT. 1910 - APPEND. D — 66 — 



age of the group, yet the number of rings was subject to individual varia- 

 tion and did not necessarily give a correct determination of the age of 

 each induvidial fish. 



Prof. Heincke maintained on the other hand that the theory of the 

 determination of the age of the herring or other species from the rings on 

 the scales etc. had been scientifically established. If the first few rings, 

 which were distinct and clear, were admitted to be annual rings, then all 

 later rings must also be regarded as annual rings and if they were not 

 distinct on the scales or otoliths the bones would show them more clearly. 

 The method used by Dr. Hjort might be difficult and not always give 

 certain results but it was quite a correct and scientific method. 



Dr. Hjort stated the reasons of his belief in the reliability of the method, 

 noting especially that herring investigated in all months of the year had shown 

 rings which varied exactly according to the time of year. The great diffic- 

 ulty was really a practical one and great care had to be exercised in the 

 determination of the rings. 



With regard to the selective action of the nets employed, he stated 

 that he intended during next year to extend his observations into the North 

 Sea and to experiment with nets of different sizes of mesh. 



Fourth Sitting: Saturday, 24th September 1910, 2.30 p. m. 



Mr. Archer, Chairman, and in his absence Dr. Hjort. 

 Present: Members of Council and experts. 



Dr. Trtbom gave an account of his report on the investigations with regard to 

 the salmon and salmon fisheries of the Baltic, the marking experiments, growth 

 of salmon and size-limits being discussed. He stated that he would not have 

 any new report on this subject for next year and therefore did not wish 

 to retain his earlier reportership. He proposed that the question of the 

 decrease of salmon in certain rivers of the Baltic might be considered by 

 an international committee, and the mattet' was referred to a subcommittee 

 (see Appendix F). 



Dr. JoHANSEN summarised the contents of his report for the year 1909 — 10. 

 In this report he dealt with the quantitative distribution and frequency of 

 the eggs of the flat-fishes (dab, flounder, plaice and long-rough dab) in the 



