520 REPORT OF COMMISSIONER OF FISH AND FISHERIES. .[54] 



uot to admit the full sni)ply of Avater at ouce. If the circumstances are 

 such as to aUow the water to be admitted aud let out at auy desirable 

 time, and if it is not intended to fill the ponds immediately to their full 

 height, stand-pipes are to be preferred to tap-houses. Taps cannot be 

 drawn until it is desired to drain the pond entirely, because, in ponds of 

 any size, it will be dilBcuIt again to drive them in firmly and make them 

 water-tight. With stand-pipes it is possible to fill a pond to a certain 

 desired height, and to let the superfluous water flow ofl' through the 

 stand-pipe.* A pond which is not entirely filled during the first year 

 should receive a quantity of fish corresponding to the filled portion, aud 

 not to its whole area, and it will be doubtful whether the relative in- 

 crease in the weight of fish will be tlie same as if the pond had received 

 its full stock of fish. More will be said on this subject under the head 

 of stocking the jjonds. 



IV. — Fish- CULTURE. 



As has been said above, pond culture comprises both the raising of 

 fish (fish-culture) and the keeping of fish. Local circumstances, such 

 as the number and size of the ponds, their location, the nature of their 

 soil and water, &c., will determine the manner in which pond culture is 

 to be carried on. In some places, therefore, fish-culture aud the keep- 

 ing of fish will have to be combined, while in others these two branches 

 of pond culture will have to be carried on sei)arately, in order to derive 

 the greatest possible income from a certain given area of water. With- 

 out fish-culture, however, pond culture will always remain incomplete. 

 The keeping offish, without fish-culture, means only to use a pond ac- 

 cording to its locality, nature, and local circumstances. 



A . — Ca rp - c uUure. 



Fish-culture may extend to several kinds of fish, but, as a general 

 rule, pond culture relates exclusively to the culture of the carp. From 

 an economical point of view the carp must be considered as one of the 

 most important food-producers, as it destroys no valuable food-matter, 

 its food principally consisting of products of nature which could not 

 find any other use, aud of the refuse from the human household 5 as it 

 is easily satisfied as regards the nature of the soil and water ; as it is a 

 very hardy fish, which can easily be raised almost anywhere ; and as 

 it grows rapidly, has a fine 'flavor, and everywhere finds a large and 

 ready sale. 



Systematic pond culture requires at least four ponds : 1, a spawning 

 pond; 2, a raising pond; 3, a stock pond; and 4, a winter i)ond. These 

 four kinds of ponds are absolutely necessary for systematic fish- culture. 



The spawning pond is needed because the spawn and young fry, if 

 l)laced in iiouds with larger fish, could not be sufdciently protected 

 against numerous dangers. The young fry should, therefore, be in 



Teichmauu, TJeher Tcichjischei-ei, 1812, p. 40. 



