The Comparison of Ultraviolet and X-Ray Effects on Mutation

The chromosomal derangements induced by ultraviolet treatment of maize pollen are apparently qualitatively different in various ways from those induced by X-ray treatment under the same conditions (Stadler, 1941). This encourages the hope that the mutations also may be qualitatively different. It is now clear that many of the supposed mutations induced by X-ray treatment are due to chromosomal changes, and it is a matter of inference how large a proportion of the remainder may be analogous extra-genic alterations below the level of detectability with present technic. It remains to be seen whether this is true also of the ultraviolet mutations.