the case, I put them into a wire cage, which I sunk in the water,
examining the fish every week, until I found they were in a fit
state for the experiment.

[7] I fancy that if the ova come in contact with the air on
exclusion, they are not so readily impregnated as if they are
always covered with the water, and therefore I have laid some
stress on the desirableness of keeping the air excluded from the
ova as much as possible.

[8] There is, however, one fact which must lead a casual observer
to suppose that the ova are impregnated twelve months before
exclusion. It is this: the male Par (Salmon fry) are at this
season, October, full of milt, almost ready for exclusion; whilst,
in the female, the ova are so small that they require a microscope
to see them individually, and the whole ovary is merely like a
thread, leading to the conclusion that either the milt of the male
is not required for the female Par, or the ova are impregnated
twelve months before exclusion. The fact is, that the milt of the
Par is used to impregnate the ova of the Salmon on the spawning
beds.

[9] When I commenced this paper I had no doubt that hybrids had
been produced between the Sprod (sea Trout) and the common Trout;
since then, having seen the fry said to be so produced, and on
making some further inquiries, I find there is some doubt whether
the female was a _Sprod_, or merely a white Trout, and therefore I
cannot confidently assert (as some time ago I believed I could)
that hybrid fish had already been produced. As some of my readers
may not know what a _Sprod_ is, it may be necessary to explain. In
the Ribble we have a fish ascending from the sea in July and
August, weighing from six to ten ounces, which, in appearance at
least, is a miniature Salmon. I believe the same fish is called a
Whitling in Scotland. Besides this, we have a similar but larger
fish, which begins to come a little earlier, and which weighs from
one to three pounds; this, in the Ribble, is called a Mort (in
Scotland a sea Trout). Both these fish (if they are two species)
afford splendid sport to the angler, who must never consider them
beaten until he has them in the landing-net. They are also
delicate eating.

_Note on cross-breeding of Fish._

Since the above paper was published, the breeding of Hybrids has
been successfully accomplished. I have had fish sent from two
different gentlemen living on the banks of the reservoirs
belonging to the Liverpool Water