1 MARCH 1975, Page 4

Midnight hags

Sir: Was Brigid Brophy serious in her review of Night's Black Angels, when she said she could find nothing in the book to disclose the source of its title? 'Mr Pearsall and his publishers might have expected most of its readers to be familiar with one of the most evocative passages in Macbeth (Act III, Scene II). T. G. Weiler 372 Jersey Road, Osterley, Middlesex