1. In seeds treated with X-rays shortly after fertilization numerous paired mosaic areas are found associated with losses of all of the easily identified marker genes such as C, Wx, Pr, Su. In many cases areas showing losses of any of these markers are paired with areas that are either lighter or darker than normal in varying shades of aleurone color. Not all of these can be due to shifts of aleurone color genes and it seems likely therefore that breaks and rearrangements of chromosome fragments may alter the cell metabolism and indirectly affect aleurone color. In the same way other activities of the cell are altered, notably in starch formation, viability, and growth control.

D. F. Jones