This project consists of the development of numerical methods and mathematical software for the solution of ordinary and partial differential equations that describe dynamic physiological processes. Adaptive finite element techniques have been generalized and used for models of nerve conduction, oxygen transport in tissue, uptake of macromolecules into the lymphatic system, and in preliminary studies of subsurface contaminant flow. FORTRAN-coded packages implementing these and other techniques are available for use on the major DCRT computers.