586 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [120] 



Everything wliicli is apt to inflaence the results of the feeding should 

 be considered and carefully noted down. A certain stated weight of 

 food should be given every day, and the quantities of albumen, dry sub- 

 stance, hydrates of carbon, and fat should be accurately ascertained. 

 Observations of the temi^erature of the water should be taken daily at 

 certain stated hours, in the morning, at noon, and in the evening, both 

 near the banks and in the deep places. Similar observations should 

 be taken of the temperature of the atmosphere, so as to get the maxi- 

 mum and minimum temperature. Careful notes should be taken of the 

 rainfall, the wind, and weather, drawing the averages for the entire 

 feeding period, i. e., the whole summer or portions of it. These experi- 

 ments should extend over a period of several years, so that the results 

 of different years may be compared. The main object, viz., to ascertain 

 the effect of different articles of food under the same conditions, will 

 be attained in one year, and tliis will suffice for fixing a standard of 

 feeding, which will stand the test of practice, although in the course of 

 years it may become necessary to modify this standard in some particu- 

 lars. 



All the various articles of fish-food should be used as food, both those 

 containing much nitrogen and those which contain but little ; and the 

 matter of expense should never prevent the use of any article of food, 

 for the question to be answered is this : Are these different aiticles of 

 food cheap or expensive as compared with the results attained ? And 

 this question cannot be answered until the experiments have been com- 

 pleted. It should not be omitted to supply one pond only with such 

 articles of food as nature furnishes for the carp, e. g., beetles, worms, 

 snails, insectsof every kind, &c., which should be gathered from ponds 

 containing a superabuudance of such food. Great care should be taken 

 that the number of fish, their age, and, if possible, their weight, are 

 the same in all the ])onds; and, both iu stocking and fishing the ponds, 

 every individual fish should be weighed. 



As it must be supposed that the effect of food will, as with other ani- 

 mals, vary according to the age of the carp, the fish placed in the ponds 

 for the purpose of experimenting on them should be retained iu these 

 ponds until they have reached a marketable weight, or the number of 

 experiment ponds should be increased, so that during the first year fish 

 of every age can be placed in the ponds, there to be fed on different 

 food. We would suggest a period of four years, even if, as is highly 

 probable, the fish will, during this period, owing to the feeding, exceed 

 the marketable weight. It is to be presumed that in four years suffi- 

 cient data can be collected showing the intiuence of the weather, the 

 food, and the different age on the increase in weight of fish. The num- 

 ber of fish to be placed in each pond should be those given for medium 

 ponds. It is my firm convictioji that if experiments are made in the 

 manner indicated above they will lead to positive results sooner than if 

 they lack this basis. It will also be well to catch a certain number of 



