Dr Sidnie Manton was one of the outstanding zoologists of the twentieth century. She read Natural Sciences at Girton College, receiving the highest mark in the university in Part II, but missed out on the University Prize because women were not eligible. She was captain of the Cambridge swimming team in 1923 and a hockey blue in 1924. In 1927 she was appointed as university demonstrator in comparative anatomy, the first time that a woman had been appointed to such a post. When that post ceased she took up a fellowship at Girton. Having received her titular PhD in Zoology in 1928, she became the first woman to be awarded a Cambridge Sc.D. in 1934. In 1949 she became reader at King’s College London. Her work focused on the structure, physiology and evolution of the arthropods and led to her election as one of the first female Fellows of the Royal Society. Remarkably, her sister was also made an FRS – the only time sisters have received this distinction.