fish were not ripe for spawning and had
to be thrown back again, which delayed matters greatly and kept the
party on the water for several days.

Frequently Colin's lips were blue and his fingers numb, while his ears
and cheekbones and chin felt as though they were being sliced off
gradually by the blasts blowing down from icy Canada, but he knew that,
to a certain extent, he was on trial, and he laughed and joked and
managed to keep his spirits up, though his teeth chattered. There was no
great amount of excitement in catching the whitefish and securing the
spawn for development in the hatchery, but it was a test of endurance,
and incidentally the boy learned much about the fishes of the Great
Lakes.

"There's one thing I don't quite see, though," he said one day to the
government fish culturist, with whom he was working; "and that is, why
we need to do this."

"How do you mean, Dare?"

"Well, in the West, they hatch young salmon because the old salmon are
caught going up the river before they spawn, and they die, anyway; but
here they have all the room they want for spawning, and I should think
Nature would look after it."

"You don't want to forget," the fish culturist replied, "that Nature is
very exact. Everything has to balance. The whitefish born are ten times
as many as those that mature, but the number that matures is just
precisely enough to keep the supply going."

"I see that, all right," the boy answered.

"Well, then, if you disturb this balance by extensive fishing, isn't it
easy to see that you've got to make up for it somewhere? We don't have
to worry over keeping up the supply of catfish, for example, because
Nature is being left alone, and she has worked the problem out. But if
suddenly a big catfish market developed--as it easily might, because, in
spite of popular opinion, catfish is good eating--and if thousands of
them were caught, it would be necessary to find some way to help Nature
in keeping up the supply.

"Now, the whitefish," he continued, "isn't like the salmon, which spawns
carefully. The lake fish does that in a sort of hit-or-miss manner, with
the result that only a small percentage of the eggs get a fair start. It
is not difficult for us to put hundreds of millions of young fish into
the lakes every year, and the proportion of these that survive will not
merely keep the supply constant, but will even increase it."

"Then that will disturb the balance in another way?"

"Yes