VALUE OF NORWEGIAN LAKES FOE FISH CULTURE. 5G5 



these some persons would add the bream and lake, which, however, for 

 a reason which I shall mention hereafter, I place out of consideration. 



Trout {Salmo ogla, ferox, fario, punctatus) are the most widely dis- 

 tributed of all our fresh-water fishes. They are found from near the level 

 of the sea up to the snow limit, and at elevations over 1,000 metres 

 above the sea they are the only indigenous fish. Just as the localities 

 differ in which they occur with regard to t<imperature and quantity of 

 water, its mobility, and the nature of the bottom, so the trout, which 

 are considered by naturalists as belonging to the same species, differ in 

 form, size, color of the skin and of the flesh, and in flavor. Although 

 especially well-flavored in places which are suitable for its thriving, in 

 less favorable and turbid livers it may be of very inferior value com- 

 Ijared with other fish, and it suffers at all events from a circumstance 

 produced by its characteristic taste, that one can scarcely find another 

 fish from the sea or the fresh water of which one becomes weary more 

 quickly. In order that the trout may acquire their flavor, clear cold 

 water and a stonj' bottom are necessary. They thrive of course in 

 streams with a muddj' bottom, especially when these have a steady and 

 tolerably strong influx of fresh cold water; but then they seldom have 

 the same flavor if they should become very fat and large. If the influx 

 of water is smaller, and is liable to cease entirely in the summer, so that 

 the water in the lakes is considerably heated, they are not suitable for 

 trout ; and this condition is fulfilled as a rule in all regions of country 

 which are situated lower than 250 to 350 metres above the sea-level ; 

 also in all smaller lakes. It applies even to the largest rivers rising in 

 the mountain-tops — more especially, though, at an elevation less than 100 

 metres above the sea-level. Fresh-water trout should, therefore, scarcely 

 be made an object of culture in small sti-eams lower than 150 metres 

 above the sea-level, or at all events only where the water-course is pretty 

 uniformly supplied with cold water the wliole year round by inflowing 

 brooks or springs. It niay of course live, and through bountiful feeding 

 reach a considerable size, in comparatively^ small streams or artificial 

 basins in a low country near the sea-level, but it acquires there a flavor 

 far inferior to that wliich it has in elevated regions. 



What particularly influences the flavor of the trout naturalists have 

 not with certainty fathomed. It is assumed generally that cold water 

 with more stone than mud bottom, and rich in insect larvae, and espe- 

 cially in the smaller crustaceans, offers the most favorable conditions for 

 this species offish, especially when the supply of this kind of food, as is 

 the case in many places, is so great that the rapacity of the fish is either 

 not at all developed or but little developed, as is plainly- shown to be the 

 case in various waters by the whole form of the fish, and as the vain 

 fishing, with baiting arrangements of the most tempting kind in other 

 waters, appears fully to confirm. But even where the supi)ly of food from 

 the insect world is smaller, and where thus the preying instinct manifests 

 itself, the trout becomes very weU flavored if there is only a, sufficient sup- 



