John Sawyer was born at Wembley on 19 June 1916, the only child of Arthur Stanley Sawyer,a civil servant, and Emily Florence Sawyer (née Frost). Arthur Sawyer left school at the ageof 16 and joined the Post Office Savings Bank, where he remained until his retirement in 1937.He had a leaning towards science despite his limited education. He bought a Zeiss microscope and built up a collection of botanical slides, most of which he made himself. He also became a keen and skilful photographer, doing his own processing and enlarging until his death in1946. Emily, John's mother, was much involved in singing as a member of the Royal ChoralSociety and lived to be 97 despite prolonged ill-health.