The cause of the trouble has not yet been discovered, but there is good
reason for thinking that it lies in some of the circumstances attending
the transfer of the fish from the place of capture, and that the
inclosure itself is perfectly suited to its purpose. This view is
supported by the fact that nearly all the losses occur within a few
weeks after the introduction of the salmon and almost wholly cease by
the end of July. If the cause of disease was located in the inclosure,
we should expect it to be more fatal after a long than a short duration
of the exposure of the fish to its action, and that with the smaller
volume and higher temperature of August it would be more active than in
June and July.

The above description will, I think, give Dr. Bottemanne a sufficiently
correct idea of the character of the inclosures we have tried. There
are, however, several other points to be touched upon to put him in
possession of the practical results of our experience.

The facilities for the recapture of the salmon when the spawning season
approaches must be considered. In the lake at Bucksport village (No. 3)
we hoped at first that their desire to reach a suitable spawning ground
would induce them all to enter the small brook that forms the outlet,
which was within the limits of the inclosure. In this matter our
expectations were but partially realized. Many of the fish refused to
leave the lake through the narrow opening that was afforded them, and
were only obtained by pound-nets, seines, and gill-nets, all of which
involved a considerable expenditure of labor and material.

The drawing of a seine in a large body of fresh water is likely to be
a serious undertaking unless the bottom has been previously cleared of