Nulliplex (L. nullus, not any; plico, fold), the condition in which no determiners of a given character exist in a particular individual.
Oöcyte (Gr. ōon, egg; kytos, cell), the ovarian egg in one stage of development.
Oögenesis (Gr. ōon, egg; genesis, origin), the development of ova from primitive sex-cells.
Oögonium (Gr. ōon, egg; gonos, generation), a primordial egg-cell.
Ovary (L. ovum, egg), the organ in which the egg-cells multiply and are nourished.
Ovum (L. ovum, an egg), the female sex cell.
Parthenogenesis (Gr. parthenos, virgin; genesis, origin), development of an egg which has not united with a male gamete.
Phenotype (Gr. phaino, show; typto, strike), the existing type of individual irrespective of hereditary possibilities which may reside in it undeveloped.
Phototropism (Gr. phos, light; tropē, turning), defined, [p. 198].
Placenta (L. placenta, a flat cake), the organ by which the fetus of the higher mammals is attached to the uterine wall of the mother for purposes of nourishment, respiration and excretion. In it the maternal and fetal blood, although not intermingling, are brought into such close proximity that an interchange of dissolved substances is possible.