Cell Library - CRBS, Centre for Research in Biological Systems 10,000 unique datasets and 20 TB of data.
National Science Foundation
New York Public Library: History of Science Imagery
New York Public Library: Zoology 1550-1900
Wellcome Collection.Thousands of digital images from the Wellcome Library's historical, contemporary, biomedical and clinical collections. All are available for free download under a Creative Commons license.
Wildscreen Archive collects, curates, showcases and shares the world’s best wildlife imagery.
Understanding Science Image Library The University of California's Museum of Paleontology
