In the discussion of the papers of Section III, Dr L. Gratton stated that in the case of β Lyrae and other close binaries, one may expect that the radii of the components are considerably larger than those of single stars of the same mass. This would cause the central temperatures to be lower and, in turn, the luminosities to be smaller. It might even turn out, according to Gratton, that in close binaries the generation of energy might depend on the p–p reaction rather than on the C–N cycle, notwithstanding the large masses of such stars.