204 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
mated that the writers on fish -culture have been vague in dealing with this subject. 
A few quotations will serve to make this point clear: 
This (juantity varies with the season, the quality, the quantity, and temperature of the Avater, and 
other circumstances, and can not be stated definitely.— (Domesticated Trout, Livingston Stone, p. 236.) 
Under favorable circumstances 5 pounds of meat food may he considered an equiAUiIeut for a 
pound of trout groAvth, with 2 and 3 year olds. For any gdven quantity of 2 or 3 year olds 1 per 
cent of their weight may be regarded a.s an .adequate average daily ration the year round. Two and 
three year olds Avill double their weight aimiially, and can be made to do so in the six mouths from 
May to Se])teiiiber by extra care and feeding. — (Domesticated Trout, p. 265.) 
As to the quantity of food necessary for a given number of trout. This is difficult to give 
exactly, as it Avill vary with the .size of the fish and the season of the year, more being required in 
moderate weather than when it is very liot or cold. For 1,000 three year-olds, about 5 x>ouuds of liver 
or lights per day. — (Trout Culture, Seth Green, p. 51.) * 
When six mouths old a bowlful of curd, diluted with water, Avill answer for 1,000 trout fry. — 
(Trout Culture, Seth Green, p. 38.) 
Since our stock of fishes attained its present size we haA'e n&rev been able to obtain as large a 
supply of food as we would desire ; yet ^xe find that our stock fishes, weighing in the aggregate about 
a ton (2,000 pounds), thriA'e upon 50 pounds of lights a week, fed them in equal proportions on 
alternate days. As an average 50,000 young will require, when 6 mouths old and well supplied Avith 
maggots, about a pound of chopped heart thrice weekly, though the amount Auiries greatly. — (Practical 
Trout Culture, Dr. ,J. II. Slack, jip. 121 and 125.) 
The (juaidity of food required is also large (for 2-year-old trout). Three pailfuls of chopped 
horse are given daily to pond 15, Avhich yields from 20,000 to 22,000 each season. The food is measured, 
not Aveighed, but each pail holds 11 pounds. — (History of HoAvietoun, Sir James Maitland, jip. 73 
and 74.) 
When trout are raised in ponds of the dimensions I have giA'eu it is evident that little or no 
dependeneo is to be placed on natural feed, such as flies and their larvtp. Hence the necessity of 
proAdding curds or liver and lungs of animals, at prices that will not cause too great an expenditure 
for the Amine of the crop. I have found that the curd from the milk of one cow, which gave 14 quarts, 
would feed bountifully 1,000 or 1,200 trout aAmragiug five-eighths or three-iiuarters of a pound, the 
smallest being 7 inches long and the largest from 2 to 3 pounds in Aveight. — (American Fish Culture, 
Thaddeus Norris, p. 74.) 
These quotations, carefully selected as the expressions of the five most generally 
read English writers on fish-culture,* show how little definite and accurate information 
is recorded on the vital question of what shoidd constitute a proper ration for a given 
number of trout. Sometimes the number of fish is stated, sometimes their age, in one 
instance the approximate weight is given, and only one English writer has had the 
courage to approach scientific accuracy. But, alas ! His formula is made to apply 
only to fish 2 and 3 years old. The fry and the fish more than 3 years old are not 
provided for. 
The amount of food necessary for the maintenance in good health of a given lot of 
fish must, as with any other animals, be in direct ratio to their weight, not their age. 
* From writers of other nationalities the following quotations may be acceptable: 
By experiments M. Lugriu has ascertained that a basin * * * may contain 20.000 
young fish from 8 to 12 mouths old, or 3,000 two-year-old trout liaAdng an aA'erage weight of 250 grams 
Gb'i, or a little more than one-half pound). These 20,000 young fish, or 3,0C0 trout, consume about 
22 pounds of small shrimps per day. — (The Piscicultural establishment at Gremaz, France; by C. 
Eaveret-tYattel, Bulletin U. S. Fish Commission, 1887, p. 209 et seq.) 
At HoAvietoun it is on the weight (-one-fiftieth of the living weight) that is determined the food 
to be given, a method Avhich apj)ears'more scientific and at the same time more practical than that of 
feeding them Avithout regard to age or development. — (Notes of M. Desf)res, proprietor of the fish- 
cultural establishment at Nanteuil-eu-Valli-e, France.) [I ha\m not been able to find this formula of 
one-fiftieth of the living weight anywhere in the History of Ho wietoun, and I suppose that M. Despres 
must liaA^e received the information privately. I am fully in accord Avith M. Despres in his criticism 
on the value of this formula,] 
