ABSTRACT
The group or phylum of animals which mostly have jointed limbs and external skeletons is called the Arthpods. The Arthropods fall into four main divisions; the Trilobites, sea animals of the general appearance of woodlice, and all extinct; the Arachnids, including spiders; the Crustacea, including lobsters, and the Progoneata, including centipedes, millipedes, and insects. The crustaceans include a great many simple creatures like the water fleas; and some of the smaller sea forms are extremely successful, and very important as the main food of some fish which we in turn eat. The most primitive members of the order Hymenoptera lay their eggs in plants, where the larvae live in galls, or else in caterpillars and grubs. This development of parental care and social life from parasitism is one of the most amazing in the whole history of evolution. It may of course be compared with the evolution of human society through slavery and class oppression to communism.
