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The young of the coal fish occur in quantities on the coasts of Scotland and North 

 England, whilst the eggs are spawned on the slope of the North Sea Bank. On the 

 Norwegian coast the young of the coalfish, the haddock and whiting occur much further 

 north than the spawning masses of fish. The adult fishes also show the same pheno- 

 mena. At Finmark and in the Barentz Sea, and even in many years at Spitzbergen, 

 large quantities of adult cod occur, which have without doubt spawned many times on 

 the Norwegian coast far to the south of Finmark. Large quantities of large cod are also 

 found on the north and east coasts of Iceland, which have spawned earlier on the south 

 coast. The Danish investigations through marking experiments on the plaice have shown 

 that the adult fish undertake a spawning migration from the east to the south coast. On 

 the Norwegian side of the Norwegian Sea, further, large specimens of the gadoids were 

 found far distant from the coastal banks on .which they grow up. Marking experiments 

 on the gadoids also permit us to make definite conclusions regarding their migrations, 

 though these experiments have not yet been made so extensively as in the case of the 

 plaice. Nevertheless, as shown earlier in the section on the cod, we possess definite ob- 

 servations based upon marking experiments of the fact, that the cod both undertakes 

 migrations in the North Sea and also migrates in and out of the Norwegian and Ice- 

 landic fjords. 



A third group of results regarding the migrations of the fishes is based upon the 

 statistical data. We may refer here especially to the graphic representations of the 

 fluctuating occurrence of the cod and haddock in the different areas of the North Sea. 

 This method confirms distinctly the observations on the resorts of the fish during the 

 spawning time, which were obtained from the investigations on the plankton eggs. 



We are able to say, therefore, that the earlier, imperfect pictures of the occurrence 

 and migrations of the fishes have assumed more distinct and more definite forms. It has 

 appeared that the question — like most large and extensive problems — resolves itseli 

 into a plurality of questions. The wanderings of each species as also of the separate 

 stages of each species have their characteristics which must be studied separately. As 

 in every science the unknown is here much greater than the known, although our present 

 knowledge considerabl)' exceeds what we knew a few years ago. 



2. There is a second old question, which was always mentioned in connection with 

 the migration question, namely: Is it possible to discover any relation between 

 the migrations or occurrence of the fishes and the physical conditions 

 of the sea? 



The solution of this question offered the same difficulties as the migration question; 

 it required definite knowledge, for example, of the presence or absence of the fishes on 

 any certain ground at a given time. Thus, there were great advantages here also in 

 making the investigations on the newly spawned eggs and the spawning fish the starting 

 point. To this must be added, that everything indicates that the fish just at the spawn- 

 ing time are dependent on definite outer conditions specially characteristic for each 

 species. All investigations are in fact in agreement in showing that the different species, 

 at Iceland, on the Norwegian coasts, as also in the North Sea, everywhere seek the same 



