the
gardener knows too well when he looks {81} at his choice cabbage rows all
gnawed away into skeletons.

In some seasons and places they multiply so inordinately and prodigiously
as to deserve the title of a plague of caterpillars, and several remarkable
instances of this phenomenon are on record.

A note in the _Zoologist_, p. 4547, by the Rev. Arthur Hussey, gives us the
following:--"For the last two summers many of the gardens of this village
have been infested by caterpillars to such an extent that the cabbages have
been utterly destroyed." When the time for changing to the chrysalis state
arrived, the surrounding buildings presented a curious appearance, being
marked with long lines of the creatures travelling up the walls in search
of a suitable place of shelter for undergoing their transformation. A great
number of the caterpillars took refuge in a malt-house, from which they
could not escape as butterflies, the result being that for several weeks
the maltster swept up daily many hundreds of the dead insects.

In 1842, a vast flight of white butterflies came over from the Continent to
the coast about Dover, and spreading inland from thence, did an immense
amount of damage to the cabbage gardens; but so effectually did the
ichneumon flies do their work, that an exceedingly small proportion of the
caterpillars, resulting from this flock of immigrants, went into the
chrysalis state, nearly all perishing just before the period of change.

Those small, silky, oval objects, of yellowish colour, {82} frequently
found in groups on walls and palings, are the _cocoons_ of these useful
little flies, spun round about and over the remains of the dead caterpillar
their victim. "These," as Mr. Westwood observes, "ignorant persons mistake
for the eggs of the caterpillar, and destroy; thus foolishly killing their
benefactors."

Happily these devastating caterpillars have plenty of enemies to prevent
their continued multiplication, and to reduce their number speedily when it
exceeds certain limits. Besides the ichneumons, mentioned above, the
feathered tribes do much towards keeping them down. Mr. Haworth, in his
"_Lepidoptera Britannica_," says, with reference to this: "Small birds
destroy incredible numbers of them as food, and should be encouraged. I
once observed a titmouse (_Parus major_) take five or six large ones to its
nest in a very few minutes. In enclosed gardens sea-gulls, with their wings
cut, are of infinite