Arkive.org (images of life on earth)
Animal Diversity Web U. Mich.
Earth Science World Image Bank American Geological Institute
Forestry Images u.S. Forest Service
Gallery of Images (Smithsonian Institute)
USGS Photographic Library collection of over 400,000 photographs taken during geologic studies of the United States and its territories from 1868 to the present.
Pictures of Science 700 years of Science and Medical Illustration (New York Public Library)
CalPhotos searchable database of plants, animals, fossils, people and landscapes U.C. Berkeley
Electron and Confocal Microscopy Images US Department of Agriculture, Beltsville, MD
JISC Digital Media by discipline
Nature & Science Images (New York Public Library)
Perseptual Science Illusions and Demos Edward Adelson, MIT
Biochemistry Digital Library ACADEMICINFO
Chemistry Art Gallery U. of Liverpool U. K.
Multimedia Chemistry Resources - including Periodic Tables
Centers for Disease Control (CDC) Public Health Image Library photographs, illustrations, and multimedia files
Directory of Medical Images (Duke University Medical Center)
Wellcome Images: "historical and contemporary images on themes ranging from medical and social history to contemporary healthcare and biomedical science"