dy is accomplished.

Odontoid (Gr. o#x1F40;doys, a tooth, eids, shape). The name of the bony
peg of the second vertebra, around which the first turns.

OEsophagus. Literally, that which carries food. The tube leading from the
throat to the stomach; the gullet.

Olecranon (Gr. olene, the elbow, and kranion, the top of the head). A
curved eminence at the upper and back part of the ulna.

Olfactory (Lat. _olfacio_, to smell). Pertaining to the sense of smell.

Optic (Gr. o#1F40;pteyo, to see). Pertaining to the sense of sight.

Orbit (Lat. _orbis_, a circle). The bony socket or cavity in which the
eyeball is situated.

Organ (Lat. _organum_, an instrument or implement). A portion of the body
having some special function or duty.

Osmosis (Gr. osmos, impulsion). Diffusion of liquids through membranes.

Ossa Innominata, pl. of Os Innominatum (Lat.). "Unnamed bones." The
irregular bones of the pelvis, unnamed on account of their non-resemblance
to any known object.

Otoconia (Gr. oys, an ear, and konia, dust). Minute crystals of lime in
the vestibule of the ear; also known as _otoliths_.

Palate (Lat. _palatum_, the palate). The roof of the mouth, consisting of
the hard and soft palate.

Palpitation (Lat. _palpitatio_, a frequent or throbbing motion). A violent
and irregular beating of the heart.

Papilla. The small elevations found on the skin and mucous membranes.

Paralysis (Gr. paralyo, to loosen; also, to disable). Loss of function,
especially of motion or feeling. Palsy.

Parasite. A plant or animal that grows or lives on another.

Pelvis. Literally, a basin. The bony cavity at the lower part of the
trunk.

Pepsin (Gr. pepto, to digest). The active principle of the gastric juice.

Pericardium (Gr. peri, about, and kardia, heart). The sac enclosing the
heart.

Periosteum (Gr. peri, around, osteon, a bone). A delicate fibrous membrane
which invests the bones.

Peristaltic Movements (Gr. peri, round, and stello, to send). The slow,
wave-like movements of the stomach and intestines.

Peritoneum (Gr. periteino, to stretch around). The investing membrane of
the stomach, intestines, and other abdominal organs.

Perspiration (Lat. _perspiro_, to breathe through). The sweat.

Petrous (Gr. petra, a rock). The name of the hard portion of the temporal
bone, in which are situated the drum of the ear and labyrinth.

Phalanges (Gr. phalagxi, a body of soldiers closely arranged in ranks and
files). The