The Induction of Activated, Stable States in the Chromosomes of Tradescantia by Infra-red and X-Rays

Abstract
A temp. shock of 48[degree]C for secs, between exposures of Tradescantia inflorescences to infra-red and X-rays, and to X-rays and infra-red, effectively prevents the infra-red from increasing the frequency of chromosome aberrations. It is suggested that both infra-red and X-rays induce activated, stable states in the chromosomes, and that combined radiation raises these states to the level of primary breaks which may remain open as deletions or recombine with other similarly broken ends to give gross aberrations. These states are removed by high temps. when once induced, and have a transitory and hence undetectable existence if induced at temps. of 23[degree] C and above.