Figure 2.

(a) Typical diffraction patterns obtained from small sections of rhinoceros horn and from the tips of porcupine and echidna quills using a beam centrally located on the sample at the BioCAT facility. (b) Typical diffraction patterns obtained at the BioCAT facility for bundles of parallel fur fibres from Australian marsupials. These samples were found to be poorly diffracting and required thirty or more parallel strands to be irradiated to give reliable results.