This chapter discusses various aspects of bone, a tubular structure that encloses a large marrow cavity. Some basic facts about bone structure, periosteum, correlation of bone structure and some of its mechanical properties, formation of bone, and how bones grow are some topics discussed in detail. Bone formation extends from the primary centre towards the ends of shaft. This is accompanied by progressive enlargement of the cartilaginous model. Growth in length of the bone takes place by continuous transformation of the epiphyseal cartilage to bone on the diaphyseal surface of the epiphyseal cartilage. Bone trabeculae and cortical bone are reduced in thickness due to deficiency of vitamin C. Parathyroid hormone and thyro-calcitonin that control calcium levels in blood indirectly affect bone. The epiphyseal plate is supplied on the metaphyseal side by metaphyseal arteries and on the epiphyseal side by epiphyseal arteries. Lymphatic vessels are present in periosteum, but not in bone substance. Nerve fibers accompany blood vessels into the marrow cavity and into haversian canals.