Discussion on Papers 2—6

PAPER 3

PROFESSOR J. F. FOWLER, Cancer Research Campaign

Dr Seymour*s finding of some dose-dependent residual damage in Che cells, even after they have demonstrated their ability to survive by growing to confluence, is a remarkable finding with important implications. It goes in the same direction as Sinclair's discovery of microcolonies among survivors after high doses.

Such large corrections make the transmutation curves nearly linear when corrected from their bell shape with dose. They open the question that Elkind and Hill's observation of a reversed dose rate effect with neutrons was a small effect that could easily be wiped out.