À STUDY ON TROUT AND YOUNG SALMON. 227 



great areas of water, through a series of years, and by these 

 means endeavouring to pursue the species during their develope- 

 ment through different stages of life, not only by study and 

 observations on single scattered individuals, but by the investiga- 

 tion of large numbers of fish. 



Thanks to the generosity of our storthing, the present 

 author has had the opportunity of planning researches differently 

 to previous investigators. 



As a base of investigation was chosen the Throndhjem 

 fiord with its rivers and the adjacent coast outside the fiord. 

 This district is by far the richest of all our salmon districts, 

 yielding an annual catch of salmon amounting to about the 

 fourth or fifth part of the total yield of the whole country. 



In this district I have, by systematically continued investiga- 

 tions, endeavoured to solve the problems in question and at the 

 same time or later, by more cursory researches in other lo- 

 calities through all parts of the country, effected a control of 

 my results, as to their general value. During the researches in 

 the fiord and the adjacent strech of coast, I have employed a 

 small sailing cutter with a crew of 2—3 skilful fishermen, besides 

 myself. I was thus enabled, at any tmie to move between the 

 different localities, according to the demands of my investigation. 

 In my fishing experiments, which chiefly embraced smaller 

 sizes of fish, than those cought in implements of a mesh in acor- 

 dance with the regulations of law, Danish eelhandseines of 

 large dimensions (30 X ^ fath.) were mainly employed. By 

 floating the headrope more and weighting the groundrope less 

 than usual for fishing with the same gear in Denmark, these 

 seines are made very efficient implements for the catching of 

 smaller salmonids. By numerous direct comparisons, I have 

 found them more efficent, than the ordinary type of seine 

 (without a pocket), as used by our fishmen in „illegal" trout- 

 fishing. Their size of mesh (28 — 32 knots pr. foot — norvegian — ) 

 of course make them a little heavier than the ordinary abovemen- 



