Embryo (Gr. embryon), the young organism in its earliest stages of development.
Embryogeny (Gr. embryon; genesis, generation), the development of the embryo.
Eugenics (Gr. eugenes, well-born), the science relating to improvement of the human race through good breeding.
Factor, the determiner of a particular hereditary character.
Feeble-Mindedness, deficiency in mental development. For grades, see [p. 244].
Fertilization, union of the sexual cells.
Fetus (L. feuere, to bring forth), the unborn young animal in its later (after the second month in man) stages of development.
Flagellum (L. flagellum, little whip), a vibratile, thread-like organ of locomotion.
Gamete (Gr. gamos, marriage), a mature germ-cell.
Genetics (Gr. genesis, origin), the science which deals with heredity and the origin of individuals in general.