MS Acc11.034 comprises papers collected by Mason during the writing of a book on Australian oologists, 1835-2009. They consist largely of an alphabetical sequence of files containing information on approximately 250 egg collectors, including personal details, photographs, correspondence, family histories and lists of egg clutches they collected.MS Acc22.028 comprises reference material that Ian J. Mason collated and created for use in: "Passions in Ornithology: A Century of Australian Egg Collectors. And Passions in Ornithology: A Century of Australian Egg Collectors (Supplementary Edition)". It includes: biographical accounts of egg collectors; photographs, negatives and prints relating to birds and egg collecting including an album of bird photographs from Norman Chaffer and J. Ramsay; correspondence, notes, articles and egg data cards and among others.