556 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. 



used with profit, it is in the power of the fish-culturist to eke out the 

 stock of his water to a very considerable degree, which is limited only 

 by the existing- access to fresh, running water, or, more properly, on the 

 renewal of the quantity of oxygen absorbed by the water ; by an ade- 

 cpiate renewal thereof, the number of iish may be increased until the 

 space becomes as closely packed in proportion as a saufjos (sheei)fold) 

 usually is. How far one ought to go in this direction experience will in 

 every place quickly teach. If more fishes are placed in the water than 

 it can sui)port, the leanness of the fish will soon attract attention ; this, 

 however, will not occur, because in case of need they will mutually eat 

 one another. If the supply of oxygen becomes too small in proportion 

 to the need of the abundance of fish, this will quickly and plainly show 

 itself also in this, that the fish will seek at the surface of the water the 

 wanting vital air and that many will die. Probably only a few waters 

 can be found in this country where it will be possible to carry fish-pro- 

 duction to this last extremity, since one observes that the superfluity with 

 regard to the means of nourishment does not exist except in winter and 

 after continued intense cold, which dries up the tributary brooks. The 

 difficulty, and in most cases the imj)ossibility, of furnishing the fishes an 

 extra food-supply during the winter willrestrict stocking far below these 

 extremes, which can be reached only by wholly artificial breeding in 

 smaller especially constructed ponds, where the fish may be supported 

 in the manner which may be most closely compared with the permanent 

 stall-feeding of cattle. But even if one, as will generally be the case, 

 finds it most profitable to restrict the stocking of the waters far below 

 this measure, they may still receive and support a quantity of fish which 

 will considerably exceed what would be considered a great abundance. 



Further, it is important to carry on the collecting in an intelligent man- 

 ner. This will not be done until one constructs his fishing-implements 

 in such a way that he reaps only the mature fruit ; that is to say, that 

 he catches all the fish which have reached the size shown by experience 

 to be the most iirofitable, which, as before remarked, may, however, be 

 very different, according to the species of the fish which one attempts to 

 produce, and the food one may be able to procure for them. To permit 

 a j)ortiou to escape again, in order to reach a greater size, causes, as 

 shown, a greater or less loss in proportion to the shorter or longer time 

 one i^ermits them to live after reaching the most profitable size ; to catch 

 them earlier also causes a loss, though of less importance. 



But it is imj)ortant also to harvest the crop at the time of year when 

 it is most fully mature, most savory, and of the greatest value, not merely 

 on account of its flavor but on account of its greater weight; that is to 

 say, in summer from April until the middle of August at the latest for 

 all the autumn and winter spawning fishes. The difference of quality 

 and weight between the summer and winter is remarkably great ; it may, 

 in the salmon-like fishes, amount to over the half the weight of the fish 

 in its best condition, and so far as the flavor is concerned the proportion 



