The very dark blue at the lower left and right is spongy bone of the periosteal bone collar of the shaft.This will later be remodeled into Haversian systems of compact bone.

• 图片右下方极深兰色的为骨领的松质骨成分，以后，包括骨领都会逐渐被重建改造为由骨单位构成的密质骨。