Abstract
At a meeting at the BIR, supported by a donation in memory of Mr. R. O. Jenkins, on Saturday December 8, the subject of unorthodox fractionation schedules was discussed. It became quite clear from laboratory work described by Professor Fowler and Dr. Hopewell, and from clinical work of Professor Notter and Dr. Turesson quoted by Professor Fowler and Dr. Kirk, that while the NSD concept applies satisfactorily to early reactions it is not accurate for late effects.