Abstract
The authors present simulations of diffusion on an exact fractal and on percolation clusters at criticality for two and three dimensions. The results for the fractal support the Rammal and Toulouse proposition (1983) that dS(N)/dN varies as B(N)/S(N). The results for percolation are in excellent agreement with the Alexander and Orbach conjecture (1982) that the fracton dimensionality d=4/3.