1020 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [12] 



tion with pond -culture, such as stock-raisiug, distilliug, brewing, &c., 

 which furnish a large quantity of refuse matter suitable for fish-food, 

 which could hardly be put to any other use but feeding carp, it will be 

 understood that this matter will be piincipally used as food, other sub- 

 stances, containing much nitrogen, only being employed to produce a 

 food containing the proper proportion of nutritive substances. As the 

 farmer in feeding his cattle is often obliged to make the best of what 

 food he possesses, and to make lengthy calculations to obtain the proper 

 mixtuie of food without having to buy much, thus, also, the pond-cul- 

 turist will often be obliged to have recourse to the same plan. 



In cases where the refuse matter above referred to cannot be sold, it 

 may be counted at a much smaller i)rice than it could be bought for, 

 and in spite of the great waste of hydrates of carbon, the feeding of 

 sBch matter will yet be profitable, whilst if food containing hydrates of 

 carbon had to be bought, the profits would all be taken away by the 

 high price of the proteine which would be needed. 



Artificial feeding will be particularly advisable in ponds which do not 

 contain much natural food, whilst in highly productive ponds, which at 

 certain times are planted, or which receive the excrements of grazing 

 cattle, &c., and which, as experience shows, if not too thinly stocked, 

 may produce a very large quantity offish, it will not prove profitable; 

 at least 1 have never been able to observe any special eftect of artificial 

 feeding under such circumstances. The cause of it may be found in the 

 circumstance that the stomach of the fish filled with the heavy food 

 furnished by the pond, which requires a longer time for digestion, can- 

 not receive any more food, and that, consequently, the fish does not feel 

 any desire for it. 



It cannot be denied that the regular feeding of fish in ponds has its 

 peculiar difficulties, and requires much labor, especially when the ponds 

 are large. But, if labor can be had, the expense should not be shunned, 

 for the results will certainly pay for the labor and outlay, and the 

 profits, as calculated in examples 2 and 3, will certainly not be dimin- 

 ished. At times it will even be possible to give the carp much food 

 without incuiring any great expense. 



In the neighborhood of many, probably of most, ponds, cattle are 

 grazing, and their excrements will be found in considerable quantity. 

 It will neither be a difficult nor time-consuming labor to gather these 

 excrements, which quickly dry in the sun and become the abode of many 

 beetles, maggots, &c., in a wheelbarrow, and throw them into the ponds. 

 It will be still better to gather these excrements only in summer, and 

 keep them in heaps, sheltered from the rain, using them during the 

 months of August, September, and October, when nature does not pro- 

 duce much suitable fish food. 



The most jirofitable way will be to gather these excrements and throw 

 them into the principal ponds about this time, when their fish are to be 

 sold, and should have the greatest possible weight, and the expense of 



