Listened to Sherrington's introductory talk to the BBC programme 'The Physical Basis of Mind'. Reminiscences of Sherrington's kindness when Huxley was at Oxford. On the issues re: the evolution of mind raised by the talk. On preparing upcoming lectures for the BBC. His realisation that 'evolution by means of natural selection by mutual mutations had come to the end by the end of the Pliocene' - the implications of this re: the role of mind and speech in evolution.