[en] Recent measurements of nonsolar isotopic patterns for the elements neon and (perhaps) magnesium in cosmic rays are interpreted within current models of stellar nucleosynthesis. One possible explanation is that the stars currently responsible for cosmic-ray synthesis in the Galaxy are typically super--metal-rich by a factor of 2--3. Other possibilities include the selective acceleration of certain zones or masses of supernovae or the enhancement of ²²Ne in the interstellar medium by mass loss from red giant stars and planetary nebulae. Measurements of critical isotopic ratios are suggested to aid in distinguishing among the various possibilities. Some of these explanations place signficant constraints on the fraction of cosmic-ray nuclei that must be fresh supernova debris and the masses of the supernovae involved