An experiment is described which tests the hypothesis that the cosmic ray meson with a mean life of 2.2 μsec. decays into an electron and a photon. Geiger counter trays are used to select mesons incident on a graphite block, and to detect decay products emerging from the graphite. The electronic circuits record delayed coincidences that correspond to a decay event occurring between 0.6 and 5.3 μsec. after a meson is stopped. The absence of delayed coincidences of a type that could be attributed to the simultaneous emission of an electron and a photon, each of ~ 50 Mev., shows that the above hypothesis of the meson decay process is incorrect. The experiment also demonstrates the absence of a hypothetical unstable neutral meson among the decay products.