Max Walters has enjoyed a distinguished career at the University of Cambridge spanning thirty five years, beginning in 1948 when he was appointed Curator of the Herbarium in the Botany School and afterwards Lecturer in Botany, and culminating in 1983 when he retired from the position of Director of the University Botanic Garden, a post which he held for the previous 10 years. He held a Research Fellowship at St. John's, Henslow's own college, and after that an Official Fellowship at King's College. His interest in John Stevens Henslow was awakened during his preparation of his book The Shaping of Cambridge Botany (1981), which considers in part the role played by Henslow in establishing the University Botanic garden on its present site. His research at that time revealed that a new biography of Henslow was possible and desirable, but it was not until some 15 years later, having found a suitable and willing co-author in Anne Stow, that he decided to take up the challenge and begin work on a new biography of this remarkable academic, the first to be published for more than 25 years. Anne Stow, a Southampton graduate and a qualified librarian, is superbly positioned to join Max Walters in producing this biography of an eminent Cambridge scientist, having spent more than 30 years on the staff of the Scientific Periodicals Library (originally the Library of the Cambridge Philosophical Society) in the University of Cambridge, being Librarian for 15 years and gaining particular knowledge of the bibliography of science periodicals, and the science reference sources of the University Library and the Departmental Libraries. During much of this time she also worked closely with the Philosophical Society, one of whose founders was John Stevens Henslow, taking specific responsibility for their archives, book collection and archive index. Patrick Bateson is Provost of King's College, Cambridge and holds a Chair in the SubDepartment of Animal Behaviour, University of Cambridge.