2. (Biol.) A change in the form or function of a living
organism, by a natural process of growth or development;
as, the metamorphosis of the yolk into the embryo, of a
tadpole into a frog, or of a bud into a blossom.
Especially, that form of sexual reproduction in which an
embryo undergoes a series of marked changes of external
form, as the chrysalis stage, pupa stage, etc., in
insects. In these intermediate stages sexual reproduction
is usually impossible, but they ultimately pass into final
and sexually developed forms, from the union of which
organisms are produced which pass through the same cycle
of changes. See {Transformation}.
3. (Physiol.) The change of material of one kind into another
through the agency of the living organism; metabolism.
{Vegetable metamorphosis} (Bot.), the doctrine that flowers
are homologous with leaf buds, and that the floral organs
are transformed leaves.