COUNCIL — APRIL 1912 — APPENDIX D — 66 — 



considering the statements as to average size of older fish for the different years 

 with all reserve. 



Prof. Henking pointed out that it would be of essential importance to 

 ascertain how far the market measurements of plaice from other waters, the 

 Baltic for instance, seemed to indicate a high mortality among medium sized fish. 



In the discussion of the point raised by Prof. D'Arcy Thompson, Prof. Heincke 

 and Prof. D'Arcy Thompson also took part. 



Dr. Johansen congratulated Prof. Heincke on the publication of the first part 

 of his report, and put a question to Prof. Heincke as to the danger stated by him 

 as resulting from the fact that the numbers of older plaice in the North Sea had 

 been considerably reduced by capture. 



Prof. Heincke expressed his opinion that it was to be considered an 

 advantage to have a large number of older plaice in any water, but that when 

 great quantities of these had been removed, the right thing to do was to concen- 

 trate one's efforts on the maintaining of a respectable stock of medium sized fish. 



After further observations had been made by Mr. Archer, Geheimrat Rose, 

 Dr. Hjort and Prof. Heincke it was resolved to postpone the discussion of Prof. 

 Heincke's General Report until a later meeting. 



Second Sitting: Tuesday 23rd April 1912, 3 p. m. 

 Chairman: Dr. Hjort. 



(Agenda b). 



Prof. Ehrenbaum laid before the meeting a provisional report on the mackerel 

 and pointed out inter alia, the desirability of making marking experiments with 

 the mackerel in the various districts. 



Dr. Hjort thanked Prof. Ehrenbaum for his great and valuable work on the 

 mackerel, and suggested whether he might not possibly take up the study of other 

 allied species. It was very possible that experiments could be made in Norway 

 by marking a number of mackerel. 



Prof. Ehrenbaum stated that he had no desire for the present to include in 

 his report any other species of fish than the mackerel. 



Dr. Johansen expressed his appreciation of the excellent work Prof. Ehrenbaum 

 had carried out with regard to the mackerel, and put a question to Prof. Ehrenbaum 

 as to the most practical method of marking the fish. 



