VALUE OF NOEWEGIAN LAKES FOR FISH CULTURE. 549 



that, just as the farmer by manuring can multiply his crops, so by a suit- 

 able mode of procedure one may also increase the maintaining capacity- of 

 the water by looking after the increase of the nourishment from which the 

 fish, which are made the object of especial care, get their subsistence. The 

 opinion has been much more generally held that this food is injurious to 

 the rearing of the cultivated fishes, as it consists chiefly of living fish 

 of smaller and commoner kinds, which are regarded as enemies of natural 

 culture, as spawn-eating, in competition with all other fishes, small and 

 great, and with a multitude of other living animals, four-footed as well 

 as winged, and insects of a multitude of species, which culture, as 

 remarked, has attributed to it an importance which by no means can 

 or ought to be attached to it if one wishes speedily to reach the goal, a 

 considerable increase of the abundance of fish. 



Since I have chiefly in view to show the value of the lakes and rivers 

 as a field for fish-culture, I shall next take these into consideration by 

 showing what ought to be done, so that the kinds of fishes which should 

 be the objects of cultivation in them may be produced in the greatest 

 possible abundance ; and next, what should be done for the fish which 

 belong to both the sea and the fresh water, although these last have 

 already obtained, and probably by more thorough njiides of proceeding 

 will fui'ther retain, superiority over those in economical respects, and, 

 therefore, ought to stand in the first place. Thus 1 pass on to — 



II. - 



WHAT FURTHER SHOULD BE DONE AND WHEREFORE. 



It is known that in natural fish-culture only a very small fraction of 

 the quantity of eggs deposited are developed ; therefore, the Lord of 

 nature has made their fruitfulness great in proportion to the danger of 

 destruction to which the eggs and the young are exposed. I shall here 

 confine myself solely to the chief representative of the fishes, which will 

 certainly be the especial object of culture — the trout. What percentage 

 of naturally spawned trout eggs reach their fuU development as young 

 it has been found impossible to learn with certainty, just as little as to 

 what age the multitude which come to life as tiny young ones under 

 natural conditions live. Men who have closely studied this matter be- 

 lieve that one out of ten or one out of a hundred eggs develop into young 

 fish. The rest go to ruin, are buried up, destroyed, or eaten up ; per- 

 hai>s the greatest portion disappear in the last mode, for everything 

 that lives in the water, large aiul small, even the fish that lay the eggs, 

 eat them as the greatest delicacy.* Trout or salmon roe is the most irre- 



* Au experienced American fisli-ciilturist tlins describes wliatLaiipens at the siiawn- 

 ing-place : 



"When the spawning time aiiproaches the trout seek a suitable place on a gravelly 

 bottom in shallow flowing water, especially that originating from springs. When 

 they have paired themselves, which takes place only after violent, often deadly bat- 

 tles between the males, both go to the chosen jilace and lie still there if they are not 



