Pronunciation: (ep"i-jen'u-sis), [key]
a. the theory that an embryo develops from the successive differentiation of an originally undifferentiated structure (opposed to preformation).
b. the approximately stepwise process by which genetic information, as modified by environmental influences, is translated into the substance and behavior of an organism.
2. Geol.ore deposition subsequent to the original formation of the enclosing country rock.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.