290 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
tlie subject, killed Ids fry witli tlie yolk of hens’ eggs, the law was laid down, “You 
must not use curd or hens’ eggs for fish food,” and these two really valuable articles 
Avere placed on the blacklist. Unfortunately, Avith all our vaunt of being the most 
advanced of the world’s nations in fish-culture, we are so conservative that it rarely 
happens that an article which once finds itself on the list of prohibited foods receives 
a second trial. As a matter of fact, one of the best experts in the world to-day, one 
who makes the business pay a handsome return ou the money invested. Sir James 
Maitland, of Scotland, as far back as 1878 Avas using fifteen dozens of hens’ eggs 
daily. Again, one of the State fish commissions west of the Mississippi River depends 
largely upon curd as a trout food.* Their work will be shown to compare favorably 
with that of other places where these cheap articles are interdicted. 
Another article iiroscribed by one of tlie books on fish-culture is to-day almost the 
sole food of one of the best-paying private hatcheries in America. These instances 
are stated to show that the rules laid down in the text-books are not in all cases reliable,, 
having been too frequently drawn from a single illy conducted exxierimeut. Scarcely 
any of the writers have anything to say on the really important question, Hoav much 
food is required to produce a giA'en resulf? ISTowhere in the English books are data 
and rules given which would enable one to calculate with any degree of exactness the 
amount of food needed during a given period for a giA^'en number of fish. One impor- 
tant use of such knowledge would be the calcidating of a periodic supply of food for 
some hatchery situated aAvay from the lines of easy and cheap transportation. Should 
the feasibility be demonstrated of the preparation, at the base of cheap supply, of an 
artificial food to be preseiwed and shipped in large quantities by freight to otf-lying 
hatcheries, the question would naturally arise, Hoat much will be needed during the next 
six or twelve months'? The early experimentalists contented themseUes with saying 
that such and such things made safe, cheai), and economical foods (in nearly CAmry 
case having reference to liver, heart, and lungs of animals), and that such and such 
were poisonous to the fish, and quietly ignored the question of definite quantities. 
The fact is that there is scarcely an article in the entire gamut from curd to horse- 
fle.sh that maj'' not be fed to trout with perfect safety. The questions are, or should 
be: What amount per day of a given article will be needed to produce a pound of 
trout within a given time? Is this amount of food beneficial or harmful to the correct 
or normal dcAmlopment of the fish? If harmful, can it be rendered harmless by the 
admixture of other foods? And, finally: Can the -grower for the market find a profit? 
In my Chicago paper it was stated : 
There are among fishes, in common with other animals, several dietaries, some followed from a 
matter of choice, some from necessity, and others from ignorance on the part of the attendant. They 
may, for convenience, he thus classified: First, hare snhsistence diet, merely sustaining life and 
resulting m stunted, deformed fish, or starvation; second, healthy diet, promoting normal growth 
and deA-elopment ; third, fattening diet, fitting for hoarfiest marlretahle weight; and, fourth, ormr- 
fatteniug diet, causing a temporary or permanent suppression of the functions of the reproductive 
organs, a partial or total destruction of the eyes, . and inflammation of the intestines, frequently 
resulting in death. 
A considerable percentage of American fish-culturists are to-day confining their 
stock to the first diet, either in quantity or quality of food, and are yearly producing 
stunted or half-staiwed fry which, by courtesy, are called yearlings. Dismayed by 
their own early experiences and those of the first experimentalists in feeding fishes, 
they have not only stricken article after article from the list of available foods, bnt 
* Practical Trout Culture, Dr. Slack, page 123; “Curd is absolutely poisonous.” 
