GENTLEMEN,--I am somewhat at a loss to understand the object of
Mr. Horsfall's letter on this subject which appears in the
"Mercury" of to-day. If he means that fish hatched by this process
are as much at the mercy of their natural enemies as they are in
their natural spawning beds I differ from him entirely; but if he
means that there is no good in breeding migratory fish like
Salmon, when the obstacles to their return in the shape of stake
nets, impassable weirs, and poisonous waters are so numerous as
they are at present in many rivers (the Wharfe and the Aire are
examples of both), I entirely agree with him. Let us consider both
suppositions, for the more this subject is ventilated the more
likely is good to arise from the discussion. I think Mr. Horsfall
is entirely wrong in the first supposition, for the following
reasons: By artificial propagation the young fish escape all
damage from floods, and particularly ice floods, which scoop out
all the loose gravel from the spawning beds, which are frequently
entirely carried away by these floods. They escape all danger from
drought, which in some rivers is almost as bad, there being now
several mounds of dry gravel in my length of the Ribble which were
spawning grounds last December. They escape being destroyed as ova
by Trout, Eels, Bullheads, Loaches, the larva of aquatic insects,
ducks (wild and tame), water rats, and water shrews. The last are
said to be destructive to the spawn; but this I do not vouch for,
as these two last-mentioned animals have not come under my own
observation as devourers of spawn.

With regard to the 500 Salmon ova said to have been taken from the
stomach of a Trout, Ramsbottom is the authority for it, only he
says there were nearer 1,000 than 500, and he took them from the
maw of a large lake Trout at Oughterard, when netting the spawning
Salmon for his artificial propagation. When Ramsbottom was fish
breeding for Mr. Peel the year after he first went to Ireland for
that purpose, he went into the brooks at night with a light. He
never found a pair of spawning fish without also finding several
waiters on Providence in the shape of small Trout, which were
picking up the ova that descended the streams towards them.
Several of these he caught, and they were perfectly gorged with
spawn.

With regard to the ducks, Ramsbottom is again my authority. He
found that a flock of tame ducks frequented the spawning beds at
Oughterard; he bought one f