Letters, 1892-1942, many from prominent botanists, mainly covering the period J. Lloyd Williams spent studying at the Royal College of Science, South Kensington, 1893-1897, as an assistant lecturer in the Department of Botany and Agricultural Botany at the University College of North Wales, Bangor, 1897-1915, and as Professor of Botany at the University of Wales, Aberystwyth, from 1915 until his retirement in 1925.