The Common Slug is a good example of an individual of this order,
entirely wanting a shell. The Slugs, like the snails, are found in all
countries; they are equally destructive to vegetation, but as yet have
never been used by man for any useful purpose, if we except the fact
of their sometimes becoming the food of ducks and poultry. The _Limax
rufus_, Red, or more properly brown, Slug, for the colour is of a
reddish-brown, varying in intensity to such an extent as to render it
impossible to find two specimens of the same colour, is more commonly
found in fields than in gardens.
[Illustration: _Limax rufus._]
There are many species of the Slug; but they are not well defined, on
account of the variable nature of their colour; the black and the brown
kinds are, however, pretty well known: the black, in particular, is
very destructive in kitchen-gardens, and commits great havoc in fields
of cabbages and turnips.
In one or two species, the buckler, or smooth space near the head,
contains a very small oval shell.
There is a very singular species of Slug found in Teneriffe, under
stones in moist places, it is not more than an inch and a quarter in
length; it is called _Limax noctiluca_, the night-shining Slug. The
buckler, in this species, is very narrow, and covered with pores, which
exude a kind of viscous substance, which has the property of shining
with a phosphorescent light, like that of the glow-worm.
We may have some idea of the rapid increase of Slugs, by a fact
mentioned by Dr. Leech, that two individuals of a small species have
laid as many as seven hundred and sixty-six eggs; and these eggs were
dried in an oven without destroying their vital powers, since, on being
placed in a damp situation, they were afterwards hatched.
The following plan of taking and destroying Slugs was resorted to by
a gentleman near Ipswich. Having heard that turnips were employed to
entice Slugs from wheat, he caused a sufficient quantity to dress eight
acres to be got together, and then, the tops being divided and the
apples sliced, he directed the pieces to be laid separately, dressing
two rows with them, and omitting two, alternately, till the whole field
of eight acres was gone over. On the following morning, he employed two
women to examine the tops and slices, and free them from the Slugs,
which they threw into a measure: and when cleared, they were laid
on those rows that had been omitted the day before. It was observed
invariably, that in the rows dressed with the turnips, no Slugs were
to be found upon the wheat, or crawling upon the land, though they
abounded upon the turnips; while, on the undressed rows, they were to
be seen in great numbers, both 011 the wheat and on the ground. The
quantity of Slugs thus collected was nearly a bushel.