Light microscopy of a growing long bone. The dark blue staining band is the epiphyseal growth plate consisting of dividing, maturing and dying chondrocytes. The cartilage made by the plate serves as a temporary substrate on which immature bone will be deposited and formed into mineralized adult bone. Left of the plate is the epiphysis, covered with curved articular cartilage. The metaphysic is the flared region of the bone extending into the diaphysis of the shaft. Many cavities in the bone contain the bone marrow. Magnification x12 when printed at 10 cm.