The correspondence chiefly concerns arrangements for Denell's visit to the ARC Unit of Animal Genetics to work as a Visiting Fellow on mutation research from 1972 to 1973. Denell was at that time at the Department of Biology, University of California, and his appointment in Edinburgh was funded from Beatty's Ford Foundation grant. The papers also contain correspondence with other parties than Denell as well as a photocopied typescript titled 'The Use of Male-Sterilizing Mutations for Insect Control Programs'.