Polarised light micrograph of a compact bone. The rounded structures with an image of the Maltese cross are osteons, an essential component of compact bone. Osteons are made up of a series of concentric bone lamellae located around a central space corresponding to the Haversian canal. Bony lamellae are also found between the osteons, alternating bright with dark, and together they correspond to the interstitial gaps or lamellae.