This study was undertaken in an attempt to evaluate the fate of various types of autogenous cortical grafts in the rabbit by a somewhat different method than those usually employed. The influence of the physical form of the graft is shown, as well as the deterrent effect of fibrous periosteum as a barrier to revascularization. The effect of using a motor-driven saw rather than a osteotome is also shown. Cohen et al.3 have used Ca45 as an indicator of homogenous bone-graft fate. Kiehn et al.7 have used phosphorus for the purpose of comparing the incorporation of autogenous bone grafts into the host. Evaluation of bone grafts from a histological point of view have demonstrated the difficulty inherent in determining the end-point by this means. Each microtome section shows only a small part of the graft and host; the interpretation is often tedious and controversial. The uptake of