INTRODUCTION. 



DURING the years 1898 1902, 1 carried out a series of investigations 

 relating to the life-history of Salmon and Trout. The results were issued 

 under the title of " 0rret og Unglaks " in 1902, and were afterwards 

 published in English in the " Nyt Magasin for Naturvidenskaberne " 

 B. 42, 1904, under the title of " A Study on Trout and Young Salmon." 



The main result of my numerous investigations and experiments was 

 briefly this : that salmon of sizes between 16 cm. and 45 cm., or in other 

 words salmon between the smolt stage and the grilse stage, were practically 

 not to be found in those waters in which our salmon fisheries were carried 

 on, that is to say in the rivers and fjords and among the outer islands along 

 the coast. What had generally been supposed to be immature salmon were 

 really sea-trout. This I was able to prove by rearing small salmon in salt 

 water until they attained the requisite sizes, when they were found to be 

 different from fish which had previously been considered immature salmon, and 

 further confirmation of this was obtained by catching and examining quantities 

 of sea-trout and showing that there were no small salmon among them. 

 I finally succeeded in ascertaining that immature salmon, in an earlier stage 

 than grilse, are caught in the mackerel nets along our south coast far out at 

 sea, and this discovery I have subsequently been able to confirm by further 

 instances, of which I gave a brief description in 1906 " Nyere oplysninger 

 om Unglaks og dens Opholdssteder," Norsk Fiskeritidende, 12te hefte, 

 1906. 



As a result of these discoveries, when the new law with reference to 

 salmon-fishing was passed in 1905, regulations were made exempting sea- 

 trout fishing from certain restrictions, amongst others the obligation of a 

 minimum mesh in non-stationary appliances (seines and gill nets). These 

 restrictions had previously rendered such sea-trout fishing all but illegal 

 everywhere, and had merely been imposed with the object of protecting the 

 immature salmon that were supposed to constitute a portion of the catches 

 made by this mode of fishing for sea-trout. 



During the discussion on this law it was even proposed to do away 

 with all restrictions as to size of mesh in the case of salmon also. However, 

 it was eventually decided to adhere to the minimum size of mesh previously 



