in Central Europe.
Careful study of insular faunas, such as that of Madeira by T. V.
Wollaston, and of the Sandwich Islands by D. Sharp, and the comparison
of the species found with those of the nearest continental land, furnish
the student of geographical distribution with many valuable and
suggestive facts.

Notes on habit are given below in the accounts of the various families.
In general it may be stated that beetles live and feed in almost all the
diverse ways possible for insects. There are carnivores, herbivores and
scavengers among them. Various species among those that are predaceous
attack smaller insects, hunt in packs crustaceans larger than
themselves, insert their narrow heads into snail-shells to pick out and
devour the occupants, or pursue slugs and earthworms underground. The
vegetable-feeders attack leaves, herbaceous or woody stems and roots;
frequently different parts of a plant are attacked in the two active
stages of the life-history; the cockchafers, for example, eating leaves,
and their grubs gnawing roots. Some of the scavengers, like the burying
beetles, inter the bodies of small vertebrates to supply food for
themselves and their larvae, or, like the "sacred" beetle of Egypt,
collect for the same purpose stores of dung. Many beetles of different
families have become the "unbidden guests" of civilized man, and may be
found in dwelling-houses, stores and ships' cargoes, eating food-stuffs,
paper, furniture, tobacco and drugs. Hence we find that beetles of some
kind can hold their own anywhere on the earth's surface. Some climb
trees and feed on leaves, while others tunnel between bark and wood.
Some fly through the air, others burrow in the earth, while several
families have become fully adapted to life in fresh water. A large
number of beetles inhabit the deep limestone caves of Europe and North
America, while many genera and some whole families are at home nowhere
but in ants' nests. Most remarkable is the presence of a number of
beetles along the seashore between tide-marks, where, sheltered in some
secure nook, they undergo immersion twice daily, and have their active
life confined to the few hours of the low ebb.

_Stridulating Organs._--Many beetles make a hissing or chirping sound by
rubbing a "scraper," formed by a sharp edge or prominence on some part
of their exoskeleton, over a "file" formed by a number of fine ridges
situate on an adjacent region. These stridulating organs were ment