COUNCIL — APRIL 1912 - APPENDIX D — 64 — 



Prof. Heincke pointed out that this had already been drawn attention to in 

 his report. Medium sized plaice were chiefly to be found in a belt which could 

 be designated as situated at a medium distance from land. 



Dr. Hoek made a remark to the same effect. 



Mr. Archer stated that the relation between the size of the plaice and the 

 distance from the coast was demonstrated by Captain Masterman in his first report. 

 He considered that if this fact was accepted it naturally followed that the medium 

 sized fish would be in lesser numbers where the large and small fish are very 

 numerous than where they are found in equal abundance. 



Dr. Hjort congratulated Prof. Heincke on the part of his epoch making 

 work already published. He did not consider it very practical to discuss the 

 report while only the first part of same was available. 



Geheimrat Rose proposed that a committee should be formed later on, to 

 consider and remark upon Prof. Heincke's report, but this need not prevent the 

 present discussion of that part of it which was already published. 



Prof. D'Arct Thompson made mention of Prof. Heincke's survey of the 

 percentage decrease of numbers, as laid down on p. 148 (p. 155 in the German 

 edition). He was however very doubtful as to how far this survey gave a reliable 

 view of the mortality of plaice in the sea. According to the survey there appeared 

 to be a very high mortality among middlesized fish (30 — 40 cm. long) and midd- 

 leaged fish (4—6 years old) in the North Sea, but that both in the case of the 

 somewhat older and the somewhat younger fish the mortality was lower. This 

 was exactly the reverse of the case as applying to human beings, where the 

 mortality was especially high in the first years of life and towards its close, but 

 much lower among persons of middle age. 



Prof. Heincke pointed out that the ages given on p. 148 (English edition) 

 were only approximate. There might be many reasons why the measurements of 

 fish brought to land did not give a correct picture of the stock. Marketable fish 

 of immature age were for instance not so easily caught in winter as those which 

 had reached maturity. 



: Dr. Masterman referred to the great importance to England of a satisfactory 

 solution of the plaice question in the North Sea. As to Prof. Heincke's survey on 

 p. 150 he remarked that the statements as to age of' specimens over 7 years old 

 only referred to a very small number. This was already sufficient reason for 



