After his retirement, he continued working there, writing, and serving on a number of professional bodies related to his work, including the Linnean Society, of which he became president.
بعد تقاعده ، واصل العمل هناك يكتب ، بالاضافة إلى عمله في عدد من الهيئات المهنية ذات الصلة بعمله ، بما في ذلك جمعية لينيان ، والتي رأسها لاحقا.