h from 10 to 15, or even 20 lbs. There is great
reason to believe that all eels found in fresh water are the results of
the first migration; they appear in millions in April and May, and
sometimes continue to rise as late even as July and the beginning of
August. I remember this was the case in Ireland in 1823. It had been a
cold, backward summer; and when I was at Ballyshannon, about the end of
July, the mouth of the river, which had been in flood all this month,
under the fall, was blackened by millions of little eels, about as long
as the finger, which were constantly urging their way up the moist rocks
by the side of the fall. Thousands died, but their bodies remaining moist,
served as the ladder for others to make their way; and I saw some
ascending even perpendicular stones, making their road through wet moss,
or adhering to some eels that had died in the attempt. Such is the energy
of these little animals, that they continue to find their way, in immense
numbers, to Loch Erne. The same thing happens at the fall of the Bann,
and Loch Neagh is thus peopled by them; even the mighty Fall of
Shaffausen does not prevent them from making their way to the Lake of
Constance, where I have seen many very large eels. There are eels in the
Lake of Neufchatel, which communicates by a stream with the Rhine; but
there are none in the Lake of Geneva, because the Rhone makes a
subterraneous fall below Geneva; and though small eels can pass by moss
or mount rocks, they cannot penetrate limestone rocks, or move against a
rapid descending current of water, passing, as it were, through a pipe.
Again: no eels mount the Danube from the Black Sea; and there are none
found in the great extent of lakes, swamps, and rivers communicating with
the Danube--though some of these lakes and morasses are wonderfully
fitted for them, and though they are found abundantly in the same
countries, in lakes and rivers connected with the ocean and the
Mediterranean. Yet, when brought into confined water in the Danube, they
fatten and thrive there. As to the instinct which leads young eels to
seek fresh water, it is difficult to reason; probably they prefer warmth,
and, swimming at the surface in the early summer, find the lighter water
warmer, and likewise containing more insects, and so pursue the courses
of fresh water, as the waters from the land, at this season, become
warmer than those from the sea. Mr. J. Couch, in the Linnaean
Transactions, says the l