The son of W L Mollison, Master of Clare College, Cambridge, he was born on 20 December 1878 and was educated at Haileybury and King's College, Cambridge, entering the latter as an exhibitioner in natural sciences in 1897. After obtaining a first class in Part I of the Natural Sciences Tripos, he entered the medical school of Guy's in company with E C Hughes in 1901, qualifying with the Conjoint Diploma in 1904 and graduating MB BCh the same year. He was then appointed the last house surgeon to Jacobson and the first to Arbuthnot Lane and was admitted as a Fellow in 1906, the same year taking his MCh. After this he was appointed a clinical assistant in the throat department and in 1910 surgeon in charge of the aural department and, obtaining an Arthur Durham Travelling Fellowship, spent six months in Vienna, Berlin and Freiburg. In 1912, when the combined ear, nose and throat department was inaugurated at Guy's, Mollison and T B Layton became the first heads. For Mollison additional appointments to Bethlem Royal Hospital and the Florence Nightingale Hospital followed. The department at Guy's flourished, Mollison's ability and charm helping to train young consultants many of whom became appointed subsequently to other teaching hospitals. He will always be remembered for his technical skill, his boundless energy and his interest in his students. In 1920 he was appointed a CBE for his voluntary services and from 1938-1950 he was executive chairman of the Children's Aid Association. For several years he was chairman of the medical committee and of the school council, and after his retirement chairman of the governors of the medical school of Guy's, a continuous association with the hospital and medical school for over sixty years. He had the unique distinction at the Royal Society of Medicine of being President of both the Section of Laryngology and also that of Otology. His experience and integrity were of immense value to the London Medical Protection Society of which he was Vice-President and treasurer for over twenty years. Retirement in 1938 found him still active. In 1939 he acted as a consultant to the Ministry of Health on the emergency organisation of hospitals and he volunteered to help in the outpatient department of the London Hospital as they were desperately short of staff during the war. In his time his clinic at Guy's was visited by surgeons from all over the world and he was recognised as the foremost English otologist. The soirées at his house in London after the annual Semon Lecture were a feature of English otolaryngology. Mollison was an extremely modest man, sparing of speech with a lean, furrowed and kindly face and he was one who inspired loyalty and admiration from his juniors. "Molly" was a true friend and guide to many. When he found time to relax, golf was his favourite pastime. In 1908 he married Beatrice Marjory Walker by whom he had three sons and three daughters. One son, Dr P L Mollison MD, FRCP, became a distinguished haematologist. He died on 18 January 1967 in hospital.