118 Extract from Report on the Acts relating to 
But if 50 cod-fish equal 1 fisherman, 2,400,000 will equal 48,000 
fishermen. In other words, the cod and ling caught on the Scotch 
coasts in 1861, if they had been left in the water, would have 
caught as many herring asa number of fishermen equal to all those 
in Scotland, and six thousand more, in the same year; and as the 
cod and ling caught were certainly not one tithe part of those left 
behind, we may fairly estimate the destruction of herring, by these 
voracious fish alone, as at least ten times as great as that effected 
by all the fishermen put together. 
When it is further considered, that the conger and the dog-fish 
probably do as much mischief as the cod and ling, that the gulls 
and the gannets slay their millions, and that the porpoises and 
grampuses destroy additional untold multitudes, it will probably 
be thought no exaggerated under-estimate if we assume that our 
fishery operations, extensive as they are, do not effect 5 per cent. 
of the total destruction of maties and full herring that takes place 
every year. And when it is further considered, that sea-trout and 
innumerable other fish prey upon the herring fry, and that flat 
fish of all kinds resort in immense numbers to the spawning 
grounds of the herring, to prey upon the freshly-deposited ova, it 
would seem, as we have said, that the influence of man, whether 
conservative or destructive, upon herrings must be absolutely in- 
appreciable; and, under these circumstances, it seems almost 
unavoidable that great fluctuations, wholly beyond human control, 
should occur in the abundance of herring in different years. 
If the herrings in any given year multiply with great rapidity, 
owing to favourable circumstances, their enemies also will multi- 
ply in consequence of their better and more abundant supply of 
food ; and if, as must sometimes happen, the ratio of multiplica- 
tion of the enemies is greater than that of the herring, the latter 
will, in that or the succeeding year, be vastly diminished. But 
the very diminution of the herring necessarily tends to starve 
down the fish which destroy them, and to throw them open, in a 
weakened state, to the attacks of their enemies, who, by the same 
law, have necessarily multiplied in consequeuce of their multi- 
plication. By such a concurrence of causes, the herring, relieved 
from their oppressors, will in a year or two appear again in 
immense numbers; and so the alternations of prosperity, over- 
production, and panic in the trade which they originate, will 
occur with as much regularity as if the herring were manufac- 
turers. 
CONCLUSIONS. 
Having in the previous part of the Report given our reasons 
for the conclusions to which we have come, in regard to the sub- 
, 
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