SPECIALISATION.—The setting apart of a particular organ for the performance of a particular function.
SPINAL CORD.—The central portion of the nervous system in the Vertebrata, which descends from the brain through the arches of the vertebræ, and gives off nearly all the nerves to the various organs of the body.
STAMENS.—The male organs of flowering plants, standing in a circle within the petals. They usually consist of a filament and an anther, the anther being the essential part in which the pollen, or fecundating dust, is formed.
STERNUM.—The breast-bone.
STIGMA.—The apical portion of the pistil in flowering plants.
STIPULES.—Small leafy organs placed at the base of the footstalks of the leaves in many plants.
STYLE.—The middle portion of the perfect pistil, which rises like a column from the ovary and supports the stigma at its summit.
SUBCUTANEOUS.—Situated beneath the skin.
SUCTORIAL.—Adapted for sucking.
SUTURES (in the skull).—The lines of junction of the bones of which the skull is composed.