SKELETON (Gr. _skéllo_, to dry up). The dry, bony frame work of an animal, which sustains the other organs. SPINAL CORD. _Medulla spinalis._ The medullary matter contained within the _spine_, or vertebral column. SPLEEN. A spongy organ situated at the left and behind the stomach. SPLINT-BONE. The fibula or small bone of the leg; so named from its resembling a surgical splint. STERNUM. The breast bone. SUB. A Latin preposition, denoting a position _beneath_ any body. SUB-CLAVIAN. Situated under the clavicle. SUB-CLAVIUS. A muscle arising from the cartilage of the first rib, and inserted into the lower surface of the clavicle. SUB-CUTANEOUS. Beneath the skin. SUB-LINGUAL. Beneath the tongue. SUB-MAXILLARY. Beneath the jaw. SUDOR (L. _sudo_, to sweat). Sweat; the vapor which passes through the skin and condenses on the surface of the body. SUDORIFEROUS CANALS. Minute spiral follicles, distributed over the whole surface of the skin, for the secretion of the sweat. SUTURE (L. _suo_, to sew). A seam; the junction of the bones of the cranium by a serrated line, resembling the stitches of a seam. SYMPATHETIC NERVE. A nerve consisting of a chain of ganglia, extending along the side of the vertebral column from the head to the coccyx, communicating with all the other nerves of the body, and supposed to produce a _sympathy_ between the affections of different parts. T TARSUS. The instep; the space between the bones of the leg and metatarsus. TEARS. A peculiar fluid which lubricates the eye. TEMPORA (L. pl. of _tempus_, time). The temples, or that part of the head on which the hair generally begins to turn gray, thus indicating _the age_; whence _temporal_, pertaining to the temples, as temporal bones. TENACITY (L. _teneo_, to hold). The degree of force with which the particles of bodies cohere or are held together. TENDON (L. _téino_, to stretch). A fibrous cord at the extremity of a muscle, by which the muscle is attached to a bone. TENSOR (L. _tendo_, to stretch). A muscle which _stretches_ any part. TENTACULA. A filliform process or organ on the bodies of various animals. THORAX (Gr. _thórax_). The chest; or that cavity of the body which contains the heart and lungs. THORACIC DUCT. The great trunk formed by the junction of the absorbent vessels. THYROID (Gr. _thureòs_, a shield). The name given to a shield-shaped cartilage of the larynx, and of a gland situated on the trachea. TIBIA. Literally, a flute or pipe. The shin-bone, or the great bone of the leg. TIBIAL. _Tibialis._ Pertaining to the tibia. TISSUE. A web, or web-like structure, constituting the elementary structures of animals and plants. TONSILS (L. _tondeo_, to clip or shear). The round gland situated in the throat between the pillars of the velum palati.