THE centipedes and millipedes (forming a class technically known as Myriapoda) are confined to the earth, there being no aquatic forms. The body is composed of a complete series of rings, and all the rings behind the head carry one or two pairs of legs. The head is quite distinct and bears a pair of antennas. There are two or three pairs of mouth-parts— one pair of mandibles and one or two pairs of maxillse. The centipedes and millipedes form two well-defined groups. The centipedes carry one pair of legs on each body ring; they possess poison fangs, and are compressed. The first four rings of the millipede body do not carry limbs and, as these creatures are vegetarians in contrast to the carnivorous centipedes, they possess no poison fangs, and the limbs are cylindrical. The centipedes are hunters and move quickly; the millipedes have little occasion to move quickly and very rarely do so.
HOW THE CENTIPEDE POISONS ITS VICTIMS THE brown garden centipede which lives amongst the fallen leaves and rubbish of our garden is very active throughout the summer, searching for the insect larva? upon which it feeds; in the winter it hibernates beneath the soil. The prey are seized by the poison fangs and injected with poison which is immediately fatal. The centipede lays its eggs from June to August, and the female quickly conceals the eggs, or else the male eats them. The egg, which is covered with a sticky substance, is rolled about by the female until soil particles have adhered to the whole surface and it is quite indistinguishable from its surroundings. The young centipede has poison fangs but only six pairs of legs—other legs and rings are added later.
The common millipede or wireworm is black in colour, relatively inactive, and feeds on the roots of cultivated plants. It has no poison fangs, but in defence it can secrete a fluid with a nauseating smell. A spherical nest is made beneath the ground by building up a mixture of saliva and soil particles. Through a hole at the top of the nest, the female deposits anything up to one hundred eggs. When this is accomplished she seals the nest, leaving the eggs to hatch and the young to their own devices. The eggs hatch in about a fortnight and
three-legged young emerge—as in the centipedes the rest of the legs are added at a later stage.
The centipedes and millipedes are not very important economically, though centipedes can be beneficial in destroying certain insect larva?, and wireworms harmful on account of the damage they do to the roots of crops.