WHAT DOES A FISH COST? 607 



in the ratio of 1 to 4, according to their feeding. A pike of six years 

 weiglis on an average about 5 pounds ; but if its nniriment is abundant, 

 as was tlie case in the carp pond mentioned, a triple weiglit has been ob- 

 tained. What was the expense for these two pikes ? From former re- 

 sults we know that the same pond had yielded 3,000 pounds of eatable 

 fish when stocked with 2,000 carps (without larger pikes), and taking 1 

 mark as the value of 1 pound, then either of the two pikes costs 100 

 mark per pound ! 



How, during three years, so many enemies to the fry could originate 

 is the question still to be answered, and the answer is quite simple. 

 Just as weeds in the field without direct seeding grow in greatest lux- 

 uriance, so the hosts of unwelcome destroyers originate in the water- 

 basins. If we, for instance, observe ducks swimming among the deposits 

 of eggs (either on plants as with summer-fish or on the bare shore with 

 others), we will see how they carry on their wings the contents of the 

 water when suddenly frightened, the eggs easily adhering to their feet 

 and feathers. Eeaching other, perhaps more quiet, water they dive and 

 get rid of their adhesions, &c. Many kinds of water-fowl, also rats, 

 frogs, and other animals, thus distribute useful seed, as well as that of 

 weeds, if this expression be allowed. 



Whoever, therefore, wants to breed a certain species of fish, must 

 know how to calculate and must thoroughly cultivate the water. The 

 water is like the field ; where there is no cultivation there is no result 

 in either. My experiences serve me as proofs for the statements made 

 in 1863 (in Zoolog. Garten zu Fran1xfiirt-am-Main). The area of my prop- 

 erty, if used for agriculture, would scarcely sux)i)ort a laborer and family, 

 while by i)isciculture it gives employment to fifteen men, three horses, and 

 a steam-engine. The profit to myself is much greater than any farmer or 

 gardener could make of it, for the water is much richer than the field, if 

 pools are cultivated like land. The field is my school, the water my field ! 



CHRISTIAN WAGNER. 



OLDENBURa. 



