1612. Insects are distinguished from vertebrated animals (as quadrupeds, birds, fish, and reptiles) by being destitute of a backbone, and furnished with more than two feet; and from worms (Vermes Lin.) by possessing feet. We speak now of insects in their perfect state; before that, many species, while larvï¾µ or grubs, have no feet. The generality of insects are furnished with six feet, but some few have a greater number, as the woodlouse, centipede, crab, &c.