VALUE OF NORWEGIAN LAKES FOR FISH CULTURE. 573 



cultivated fishes require, will be enabled to increase tlie abundance of 

 lisli in our lakes and rivers to a very considerable degree. All of these 

 waters at one time were ranch richer in fish than they now are, and it 

 is thus a certain thing that, without any care in this direction, they will 

 supply nourishment for a considerable increase of a number of fishes in 

 the futiu^e just as well as they have done in the past. But if one enters 

 into the cultivation of fish, it will be just as unreasonable to stop at 

 the limits which the natural fruitfulness of the water establishes as it 

 would little reward the farmer to neglect to increase the natural fruit- 

 fulness of the soil, esi)ecially as it is just as easy, perhaps much easier, 

 to pi-oduce an increase of the nourishing capacity of the water as to fur- 

 nish to the soil the materials which are necessary to increase the crop. 



Such an increase of the fertility of the water may be brought about 

 in many ways. The simplest, as before remarked, will be, along with the 

 fishes which are the objects of culture, to hatch out, and in the proper 

 degree rear, other fishes, crustaceans and mollusks, as food for them, to 

 the extent which i^revailing circumstances in every place will allow; and 

 these conditions will be found to vary to a considerable extent. Along 

 with these means one may naturally also employ artificial — if one will 

 unnatural — food, and therel^y augment the yield in an extraordinarily 

 high degree ; but the opportunity of procuring this kind of fish-food is 

 in a still higher degree different from increasing living organisms. I will 

 therefore, place it out of consideration. 



As fish-food are adapted, chiefly — 



Orekjyten, Gorkjyte, Gorkim (Phoxinus aphya), which occurs as far 

 up as 900 metres above the sea. It may be that it, like the gwiuiad, will 

 admit of being i)lanted and thrive in still more elevated lakes and brooks 

 than those in which it occurs now. One thousand two hundred to 1,300 

 metres above the sea-level should be regarded as the limit of the occur- 

 rence of the trout, and it is perhaps not impossible to introduce the Orek- 

 jyten to this height ; if not everywhere, at least in certain places, where the 

 proximity of the '■'■ Snchraiernes'''' is not too great. 



It multiplies rapidly, and since it spawns in or after midsummer, its 

 spawn or young will supply the young cultivated fishes of all kinds at a 

 time of the year when other spawn and young do not occur. It is at all 

 times a cherished food for trout. Where this fish will no longer thrive, 

 on account of the elevation above the sea, one has probably no other 

 species of fish to j)lant in its place as food for the larger choicer fishes, 

 except young gwiniad (Sik), as far as these will thrive upwards. The 

 minnow is regarded in many places in the country, as before intimated, 

 as injurious, since it is with reason supposed that it destroys the spawn 

 and young of the choicer fishes in great quantities. Thereby it counter- 

 acts, just as all other fishes without exception, the natural culture of all 

 fishes ; but this circumstance wOl, as repeatedly stated, lose all imj^or- 

 tance when we, as a fundamental condition for fish-culture, begin by con- 

 stantly providing for such a planting of fully-developed young fishes of 



