rearing trout I shall deal later on.

The size of the ponds, of course, depends upon the number of trout to be
reared. It is better to have several medium sized ponds than one large
one, as then accident or disease occurring in a pond will only affect a
portion of the stock of fish. Mr. J. J. Armistead in _An Angler's
Paradise, and How to Obtain It_, says: "A pond sixty feet long, four
feet wide, and about three feet deep, will hold ten or fifteen thousand
fry at first, and give them plenty of room to grow, but by the end of
July the number should be reduced to five thousand, which may be left
till October, when they should again be thinned out, or, better still,
put into larger pond."

I should advise the amateur who is dealing with only a few thousand fish
to work on a smaller scale in these proportions, and to make these
changes gradually, and yet more gradually as the season advances. That
is to say, work with a third of the number of fry in ponds half the size
and move some fish several times before the end of July. As October
approaches, make changes of smaller numbers of fish more frequently.

Late in the autumn is, in my opinion, the best time to put the young
fish into the water they are to inhabit permanently. It must be a
mistake to rear them artificially longer than is necessary, and by the
end of November they should be fairly capable of looking after
themselves.

Trout, which are artificially reared on chopped meat and other soft
foods, suffer from a lack of development in the stomach walls, and also,
probably, in the rest of their digestive apparatus. The first case I saw
of the stomach of an artificially reared trout was a two-year-old
trout, upon which Dr. C. S. Patterson performed an autopsy. The stomach
walls were as thin as a sheet of tissue paper. At the time I believed,
and, if I remember rightly, he also thought that this was due to
atrophy, but I am inclined to think that this idea was only partially
correct. The stomach walls of the autumn yearling trout, which is
artificially reared on soft food, do not show any marked abnormality in
the way of thinness; but as the trout's age increases, so does the
thickness of the stomach wall decrease in proportion to its size. This
leads me to believe that the development of the stomach wall, at any
rate, and probably also of the glands secreting the gastric juice and
the digestive apparatus generally, gradually ceases when at about the
age of eight or