Microscopically small and usually just a single cell, protists are complex, varied organisms that represent more than 30 different phyla (the bulk of eukaryotic diversity on Earth). Some are photosynthetic, some are important pathogens, and their modes of locomotion vary.
These glass models allow the naked eye to see the complex protists. Herman O. Mueller, a Museum preparator whose family had worked as glass blowers in Germany for generations, spent 40 years working on the models. He completed them in 1943.