Polarized light micrograph of a unstained thick, ground section of adult compact bone. The bone tissue is comprised in part of osteons seen here in cross-section (Haversian systems) each with a central neurovascular channel (circles). These channels, also known as Haversian canals, transport nutrients to the bone via the capillaries that run down the channels. The channels also contain nerve fibres. Osteons are surrounded and supported by interstitial bone matrix or lamellae within which the osteocytes are seen as many small dots. Magnification x 25 when printed at 10cm.