Abstract
One indication of vitality is growth and repeated transformations. We see it when our children move through predictable somatic and psychological changes as they progress through childhood into adulthood. Nature is replete with metamorphic renovations as juvenile forms give way to more mature forms. The trochophore (free-swimming larva with cilia) and the veliger (second larval stage seen in the diagram above with beginnings of foot, shell, and mantle) bear faint resemblances to their end product, the mature bivalve mollusk that forms the basis of a tasty meal.