An investigation on the tensile properties of osteonic lamellae whose fiber bundles have an almost transversal spiral course has been carried out, using samples obtained from alternately structured osteons by applying a procedure described in detail by
Ascenzi et al. (1973). A very sensitive microwave extensometer based on cavity and pulse technique was employed in order to record the tensile curve from each lamellar sample. The inhomogeneity in thickness within, and between, single lamellae has ruled out any form of comparison between the curves recorded for ultimate tensile strength and modulus of elasticity. This result is in agreement with the morphological finding that there is usually a wide, continuous range of variation in thickness even along the length of single osteonic lamellae.