The problem of recombination in molecular crystals and liquids is considered from the point of view of continuity of current. The probability for escape of an electron from its parent molecule depends exponentially upon how far it travels before thermalization. When account is taken of the temperature dependence of this distance, good agreement with experiment is obtained. Comparison between β particle and photo excitation suggests that initial back recombination between the emitted electron and the parent molecule may not be important in photoconductivity.