Royal Australasian Ornithologists Union early 20th century called themselves 'oologists', though the distinction between the notionally scientific discipline of oology and simple egg-collecting was blurred. Identification of any but the most common and distinctive species usually entailed the collection of specimens to be made into study skins. Modern field-guides did not exist and few people could afford the massive multi-volume, lavishly illustrated, handbooks of John Gould and Gregory Mathews. However, both Archibald J. Campbell and Alfred North had produced comprehensive guides to what was known about the nests and eggs of Australian birds, with illustrations of the eggs rather than of the birds themselves,
Nature study students, who were influenced by this philosophy, went on to provide the nature study knowledge in public schools. It was Agassiz who coined the phrase, "Study nature, not books." Nature study can be described as "conceiving of the movement as a loose coalition of communities composed of individuals, societies, and institutions able to find some common ground in the study and appreciation of the natural world". In "Leaflet I: What Is Nature-Study?" from a 1904 collection nature study lessons, Liberty Hyde Bailey presented the following description of nature study: NATURE-STUDY, as a process, is seeing the things that one looks