  Predictions are presented for the oscillation phase in neutrino oscillations
following pion decay at rest and in flight, muon decay and nuclear
$\beta-$decay at rest as well as for muon oscillations following pion decay at
rest and in flight. The neutrino oscillation phases found disagree with the
conventionally used value: $\phi_{12} = \Delta m^2 L/(2P)$. The same
oscillation phase is found for neutrino and muon oscillations following pion
decay at rest. Shortcomings of previous treatments of the quantum mechanics of
neutrino oscillations are commented on.
