SKELETON (ante). The chemical composition, structure of hone and cartilage, and their relations, will be found in the articles BONE, CARTILAGE, OSSIFICATION, and SEELE ,TON, ante. The human skeleton is composed of 200 distinct bones, exclusive of the 32 teeth and the three ossicles in each tympanum. See EAR, ante. It is conveniently, and not unnaturally, divided into four regions: 1. the skull, composed of 22 bones; 2. the trunk, composed of 54 bones; 3. the upper extremities, composed of 64 bones; and 4. the lower extremities, composed of 61 bones. Iu some respects it is inure natural to count 62 bones in the lower extremities, including the hip bones, as they are connected with the hip joint in much the same manner as the clavicle and shoulder-blade are with the shoulder joint. These hip bones, however, form a part of a very distinct and func tionally important part of the skeleton, viz., the pelvis, and for this reason it is well to keep this division of pelvis distinct. See PELvis, ante. The skull is described uuder that title. The trunk:may be divided into ribs, 24; vertebrm, 24; and pelvis, 4, the two lower bones of the spinal, column, viz., the sacrum and coccyx, being included in the pelvis. If we include the vertebra: and sacrum and coccyx in one division, the spi nal column, and the two hip bones with the lower extremities, we shall, iu this view, eliminate the pelvic division. A consideration of the fact that the spinal nerves enter the sacrum and pass through 'Orifices having the same anatomical relations as the orifices in the vertebrm, would point to the propriety of placing the vertebrm and the sacrum and coccyx together, bat the physiological connection of these latter bones with the pelvis present sufficient reasons for the division here made. The trunk has also 1 sternum, or breast bone, and 1 hyoid, or tongue bone (see HYOID BONE and ToxGuz), making in all 54 bones. The ribs are described under that title. They are shown in the cut, 12 on each side; 7 true and 5 false or floating ribs. The true ribs are joined to the sternum, which is seen to consist of 3 pieces, viz., the Manubritim, the
gladiolus, and the eusiform cartilage. The manubriuni is the heart-shaped piece to which the internal ends of the clavicles or collar-bones are joined, their external end' being articulated with the shoulder-blade, or scapula, at the shoulder joint, as seen in the cut. See CLAVICLE, ante. and SCAPULA, ante. The gladiolus is the middle piece of the sternum, with which the 7 true ribs articulate. The ensiform cartilage is the small spatula-shaped piece seen pointing downward into the triangular space between the car tilages of the 5 floating or false ribs. The vertebra are described iu the article SPINAL COLUMN, ante. The pelvis (basin) is seen in the middle of the figure supporting the vertebral column, and forming with the thigh bones the hip joints. The upper extremity is divided into bones of the shoulder, 2, clavicle and scapula; of the arm, 1, the hume rus (q.v.); of the fore-arm, 2, the radius and the ulna; of the wrist or carpus, 8; of the metacarpus, 5; and of the phalanges or finger bones, 14 = 32 bones in each upper extrem ity, or 61 in both. For a description of the bones of the upper extremity see HAND, ante. Passing to the lower extremities, we observe the femur (q.v.) Its condyles are seen to be partly covered in front by the knee-pan or patella (q.v.) Below this are seen the bones of the leg. The strong bone on the inner side of each leg is the tibia. Its upper expanded extremity or head forms with the condyles of the femur the knee joint, and.its lower expanded extremity forms with the astragalus, one of the instep bones, the greater part of the ankle joint. See LEG, a4te, and FOOT, ante. There are 7 bones in each instep, or tarsus, 5 in the metatarsus, and 14 in the toes; or phalanges, making in all 26 bones in each foot. These, with the leg; patella, and femur, comprise 30 bones for each lower extremity, or 6d for bothi THE, three rocky islands on the west coast of Ireland, about 8 tn. west of Bolus Head, co. Kerry, in long. 10°32' west. The lights on the Great Skellig are the first visible to ships crossing the