Ovule.
Parts.—Nucleus, n, the essential part in which the embryo is formed.
Prīmĭne, p, the exterior coat.
Secundine, s, the interior coat.
Mícropyle, m, the opening of the ovary coats.
Funículus, the stem to which the ovule is attached.
Hilum, h, the point of attachment on the ovule.
Chalāza, c, the place where the coverings and nucleus join
Rhāphe, r, the connection between the hilum and the chalaza.
N. B.—Through the funiculus, the rhaphe, and the chalaza the ovule receives its nourishment from the placenta. Through the micropyle it receives the tubular prolongation of the pollen.
Kinds.—Orthótropous straight; no change in direction of parts (Buckwheat).
Campylótropous, curved; the micropyle brought near the chalaza (Bean).
Anátropous, inverted; the micropyle brought near the hilum, pointing to the placentæ. Rhaphe the whole length of the ovule (Magnolia).
Amphítropous, half inverted; short rhaphe (Mallow).
Direction of Ovary.—Erect,; ascending,; horizontal,; pendulous,; suspended,.