The Old World hookworm is an intestinal parasite. The image above was taken by a scanning electron micrograph and was color-enhanced. The worm's actual size ranges from 0.03 inches to 0.3 inches.
David Scharf/Science Source
A farm worker collects cucumbers in a greenhouse in Russia. Mac Callaham, a research ecologist at the USDA Forest Service, says William the Worm likely met its fate in "a greenhouse scenario."
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This is what's called a "specimen lot" — a large mason jar holding smaller vials of parasitic worms gathered by a researcher in 1927. The Smithsonian collection has more than 120,000 specimen lots.