Evidence is given for the course of reaction outlined below when two radicals, similar or dissimilar, are produced in solution simultaneously and from the same molecule. The evidence is based on two systems: the decomposition of azo-bis-nitriles and tertiary alkyl peroxides. (1) The radicals, produced from the same molecule, may collide and react together or react simultaneously with a third species before either radical has left the site of formation. In this case the radicals are not kinetically free and the products formed are dependent upon the nature of both radicals concerned even though one of the radicals may not appear as an even product in the reaction. (2) If the radicals do not react while caged they may diffuse apart and then react with another molecule by either a kinetically third-order process or individually in bimolecular processes. (3) In the decomposition of the tertiary alkyl peroxides studied, the termolecular processes must be in competition with bimolecular processes.