Early models of bone as a composite were all based on considerations of material properties alone. These models proved inadequate for anisotropic tissues systems such as Haversian and plexiform bone. For Haversian bone both the elastic and viscoelastic properties are modelled as hierarchical structural-material composites. On the ultrastructural level, hydroxyapatite is assumed to be infused throughout the collagen in an oriented arrangement. On the microstructural level, osteons are packed in a transversely isotropic arrangement interfaced through the "cement line". The method of Hashin and Rosen has been utilized to obtain sets of the five necessary effective elastic constants based on various combinations of the required input parameters, some of which are known, others of which must be inferred. In the viscoelastic case, the correspondence principle is used to calculate the five necessary relaxation and/or creep functions. Such modelling may provide critical information and insight into the nature and properties of the material comprising the "cement line".