584 REPORT OF THE COMMISSIONER OF FISHERIES. 
pelled by some external force. With a dip-net I took these young fish out, and 
found that in every case they were firmly held by a water-bug. The fish were dead, 
and the bugs apparently had been feeding on them. J had no means of determining 
how many of these bugs were in the pond. 
Dimmock gives several references to literature on the same subject, 
and in the report of the United States Fish Commission for 1504 
(1395, page 36) it is stated that carp in the ponds at Washington suf- 
fered from attacks of Motonecta and Nepa. As has been said, how- 
ever, there is little to be feared from natural enemies in the temporary 
ponds and pens as they are conducted in this country, the greater 
dangers arising from impurity of water and other physical conditions. 
ECONOMIC RELATIONS OF THE CARP. 
Under this heading it is proposed to consider the relation of carp to 
aquatic vegetation, and to other fish and their spawn, as well as the 
secondary questions arising from these. The discussion is, for the 
most part, an examination of the numerous charges that have been 
made against the fish as to the damage it does, and in this respect is 
distinct from the succeeding chapter, which discusses the uses to 
which carp are and may be put. In Europe the mass of the literature 
on carp relates to its culture, but in this country it is safe to say that 
more has been written on the present subject than on all the others 
together. It has occupied our newspapers, our periodicals, and our 
scientific proceedings. Although so much has been written and said, 
however, this is nevertheless the subject on which perhaps the least is 
definitely known; the latter fact is probably an explanation of the for- 
mer. Many extravagant statements have been made on the one hand 
as to the value of the carp, while on the other the English language 
has been searched to find words strong enough for its condemnation. 
This state of affairs has, I believe, a very siniple explanation. When 
the fish was introduced, the impression became prevalent that if one 
obtained a few carp, dumped them into any hole containing a little 
water which he chanced to have or could construct on his land, with- 
out further care he would always have a bountiful supply of excellent 
fresh fish. As recently expressed at a meeting of the American Fish- 
eries Society, ‘‘almost every farmer had a carp pond in his front yard, 
back yard, or barnyard, or somewhere.” These expectations were far 
in excess of what was ever claimed for the carp by its introducers, 
and it is little wonder that the people were disappointed. As it was 
seen that the ponds did not yield the phenomenal results expected, and 
as the novelty wore off, they were left neglected and uncared for, so 
that within a short time, through the agency of freshets and the under- 
mining of embankments, the fish had gone to help stock the public 
waters inall parts of the country. Fora time after this, comparatively 
little was heard of them, except that in local lists of fishes they grad- 
