When we look at biological cells under a microscope, they're usually not very colorful. Normally, to visualize them we have to artificially add color—typically by staining. By doing so, we can see ...

Approximately 145 million: That's the number of specimens—including plants, animals, minerals, and human artifacts—curators estimate are held in the Smithsonian National Museum of Natural History.

For more than 25 years, Arthur Earland and Edward Heron-Allen partnered in studying fossils of Foraminifera, a phylum of marine single-celled organisms often protected by shells of calcium carbonate.