Notebooks includes Gray's undergraduate notebooks and subsequent research notebooks. Gray's work on animal locomotion comprises the major portion of the collection, but his early work on cell division and ciliary movement (and his return to this research towards the end of his career) is recorded in notebooks and working papers. B.10 is of interest in describing experiments with bull spermatazoa, which were brought to the attention of Sir Geoffrey Taylor and led to a sequence of papers published by Taylor 1951 -52; see the memoir of Taylor by G.K. Batchelor, Biographical memoirs of Fellows of the Royal Society, 22, 1976 pp.613-614, 630.