1617. The imago, or winged form, is the last stage. An insect arrives at maturity, in regard to corporeal bulk, in the larva state, and never increases in size after it emerges from the chrysalis; but it is only in the imago state that all its organs are fully developed, and that it becomes a perfect being, exhibiting those characters which point out its station in nature. The habits and economy of perfect insects, no less than their external appearance, are, in most cases, totally different from those which belong to the previous stages of their existence. Thus, the caterpillar, furnished with strong jaws for devouring foliage, is changed into a butterfly or moth, without any organs adapted for mastication, and which lives only by sucking the nectar of flowers.