Kunstformen der Natur (or known in English as Art Forms in Nature) is a book of prints by German biologist, Ernst Haeckel. The geometric shapes and natural forms captured precisely by Haeckel continue to inspire artists and scientists. Via Wikimedia Commons, you may access more than 100 illustrations from the publication.
BILDGEIST is a “visual journal of scientific illustrations, illuminated manuscripts, photographs, prints and artworks from the public domain”. The images are of various themes including astronomy, alchemy, mythology, cartography, anthropology, zoology, botany, and general curiosa. Users can filter the contents by period, categories and keyword tags.
Wikimedia Commons is a “media file repository” of public domain and freely-licensed educational media content, including images, sounds and video clips. Launched on 7 September 2004 by the Wikimedia Foundation, Wikimedia Commons uses the “wiki-technology” that is the same technology used in Wikipedia. Wikmedia Commons also aggregates files from other projects, including Wikipedia, Wikibooks, Wikivoyage, Wikispecies, Wikisource, and Wikinews. As of October 2015, there are more than 28.7 million files in more than 120,000 collections. Users can conduct a keyword search or browse the content by topic, type, author, location, license and source.
Developed by The Open Knowledge Foundation, The Public Domain Review is “an online journal and not-for-profit project dedicated to promoting and celebrating the public domain in all its richness and variety”, as according to the website. Images in their collections are derived from a wide range of online archives, that are on public domain. The images are arranged by topics, where users can search or browse by time, style, genre, type, content and rights.
The Biodiversity Heritage Library (BHL) is “a consortium of natural history and botanical libraries that cooperate to digitize the legacy literature of biodiversity held in their collections and to make that literature available for open access and responsible use as a part of a global ‘biodiversity commons'”. Started in 2011, the staff of BHL began to upload illustrations from books in their collections. These illustrations were created over the past 500 years. To date, more than 98,000 of natural history and botanical illustrations have been uploaded to their Flickr account.
Wellcome Images is one of the visual collections of the Wellcome Library. It contains themes ranging “from medical and social history to contemporary healthcare and science”. To date, there are close to 130,000 images across different themes.