66 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
bers and renders the fisherman’s life a burden by the destruction of his 
bait and the disturbance of the fish. 
Holdsworth (Deep-Sea Fishing) refers to the finding of twelve full- 
sized herring in the stomach of a pollock, and from thirty to thirty-five 
in the stomach of acodfish. 1 have taken forty-seven scup of quite con- 
siderable size from the belly of a bluefish of about 5 pounds weight. 
Instances of this kind could be readily multiptied. 
To what extent fishes are destroyed by invertebrates it is difficult to 
decide, although probably this agency is one of considerable moment. 
Many species are infested with entozoa or intestinal worms, which find 
a lodgment in the brain, in the muscles, or the viscera, and which must 
necessarily involve more or less of mortality. Others have external 
parasites adherent to them, consisting in larger part of crustaceans of 
greatly modified shapes. The free-swimming crustacea, as lobsters, 
crabs, &c., undoubtedly kill great quantities of fish. Their office seems 
to be more particularly that of scavengers to destroy the weakly or dead 
individuals. Certain of the jelly-fishes are known to feed on small 
fishes. It is quite probable that the squids and cuttle-fish live mainly 
upon fish. Enormous numbers of squids are found at certain times 
in certain waters, and represent undoubtedly great destruction among 
fishes. Many illustrations of this relationship could be multiplied, but 
the subject need not be continued, as I merely wish to show the gen- 
eral relationships. 
How far fishes are affected by epidemics or other diseases it is diffi- 
cult to say, although there are many instances on record in which this 
condition is assigned as the cause of their disappearance. It is said 
that the bluefish off the coast of New England were all exterminated 
by some disease shortly after the middle of the last century, their ear- 
casses being found floating in enormous masses over the sea. What- 
ever may have been the cause of their absence it is very certain that the 
bluefish was not known again until about 1820, when they made their 
appearance gradually, of small size, but for many years in nothing like 
their original abundance. It is said that they were often known of 
such magnitude in the last century that fifteen would fill a barrel, rep- 
resenting a weight of 200 pounds when cleaned and dressed. Compar- 
atively few such fish are now taken in Vineyard Sound. 
Of late years there have been seasons, especially in the summer and 
autumn, when fish in the Gulf of Mexico have been found dead in im- 
mense numbers. The cause of this has not been ascertained, some as- 
cribing it to actual disease, others considering it the result of some 
poisonous infusion or exhalations in the water. 
2. THE INFLUENCE OF MAN. 
A very large element in the aggregate of destruction of fishes by the 
agency of other animals is furnished by the fishing and fisheries, man 
deriving, in all parts of the world, especially near the sea-shore, a large 
a 
