Excerpt from British Butterflies, Moths and Beetles Insects have six legs in the perfect state, and no more; four (or two) wings, two eyes, composed of a great number of facets, and sometimes one, two, or three eyes of another kind, called simple eyes, or stemmata, on the tip of the head. Their body is composed of thirteen segments, divided into head, thorax, and abdomen. They have neither heart, brain, nor nervous system at all resembling those of the higher animals. The place of the heart is supplied by an organ called the great dorsal vessel, lying along the back and the brain and nervous system of vertebrate animals are represented by a double row of connected ganglia, or knots of nervous matter, lying along the lower surface of the body. They breathe by means of spiracles, or air-holes, opening on each side of the greater number of the segments of the body. The muscular system is highly developed, the muscles being far more numerous than those of vertebrate animals. Insects pass through four stages, called respectively egg, larva (or caterpillar), pupa (or Chrysalis), and imago, though these are more sharply defined in some insects than in others. They also moult their skins more or less frequently in the larva state; and although they sometimes possess more than six legs in this state (and occasionally none at all), yet the larvae of insects are not generally liable to be mistaken for any other animals. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.