POLYGAMOUS PLANTS.—Plants in which some flowers are unisexual and others hermaphrodite. The unisexual (male and female) flowers, may be on the same or on different plants.
POLYMORPHIC.—Presenting many forms.
POLYZOARY.—The common structure formed by the cells of the Polyzoa, such as the well-known seamats.
PREHENSILE.—Capable of grasping.
PREPOTENT.—Having a superiority of power.
PRIMARIES.—The feathers forming the tip of the wing of a bird, and inserted upon that part which represents the hand of man.
PROCESSES.—Projecting portions of bones, usually for the attachment of muscles, ligaments, &c.
PROPOLIS.—A resinous material collected by the hivebees from the opening buds of various trees.
PROTEAN.—Exceedingly variable.
PROTOZOA.—The lowest great division of the animal kingdom. These animals are composed of a gelatinous material, and show scarcely any trace of distinct organs. The Infusoria, Foraminifera, and sponges, with some other forms, belong to this division.