Smithsonian research zoologist Anna J. Phillips is helping to sort through the recently acquired National Parasite Collection that had been maintained by the Agriculture Department. (Marvin Joseph/The Washington Post)

Anna J. Phillips picked up the old glass jar filled with alcohol and wads of cotton, and she read the label describing the tangled object inside.

“Oh,” she said, “this is taenia saginata.” A tapeworm, collected from the intestine of an anonymous person in the District on April 4, 1911.

“It’s 21 feet,” she said. “A really great specimen.”

Before her at the Smithsonian Institution’s Museum Support Center were arrayed hundreds of jars and test tubes, some more than a century old, filled with parasites.

Tapeworms, roundworms, flatworms and deer liver flukes. Pinworms, thorny-headed worms, thin-necked bladderworms and one large jar of nematodes, with the unfortunate rat they afflicted.

Everything was dead and pickled. “Nothing’s infectious,” Phillips had said earlier. “I promise.” And all were part of the country’s historic National Parasite Collection.

Yes, there is such a thing.

One of the largest in the world, although now in some disarray, the collection has just been acquired by the Smithsonian from the Agriculture Department, where it resided for more than 80 years in the basement of a small brick building in Beltsville, Md.

Phillips, a research zoologist, and colleague Bill Moser, who coordinated the collection transfer, are sorting through the specimens that the government began collecting in 1892.

There are a total of about 20 million parasites in fluid lots at the support center in suburban Maryland and on dry slides at the National Museum of Natural History in Washington.

“We still are finding out what’s in here,” Phillips said as she stood among the shelves of fluid specimens last month. “It’s so much. We didn’t get a grasp on it when you’re moving massive amounts.”

“It’s all officially here,” she said. “But it’s going to take years to . . . get everything how we want it, to bring it up to Smithsonian standards.”

The collection has long been used by scientists studying livestock and wildlife infections and by other experts studying food-borne pathogens and emerging infectious diseases, she said.

And for years, it has been a collaboration between the Smithsonian and the Agriculture Department, said Steven Shafer, an associate administrator with the department’s Agricultural Research Service.

The collection had been based at the Smithsonian until it was moved to Beltsville in 1936, he said.

Since then, he said, the collection has grown to the point where it was “bursting at the seams.”

“It finally got to the point that we felt that for the safety of the collection . . . it would be best to put it back in the hands of” the Smithsonian, he said.

The move, which cost the department about $100,000, also brings the collection closer to other Smithsonian holdings, and it allows experts to modernize how it is maintained. It remains open and accessible to scientists.

Last month, it looked its age.

Some of the fluid specimens were in dusty Mason jars decades old. Some containers were sealed with deteriorating cork. Many of the jars held numerous test tubes stopped up with cotton.

Shafer said he did not know if any of the specimens had been damaged or had deteriorated over time.

“Whether or not any of the specimens were lost over the years — you’re talking 20 million specimens or more — I can’t believe that some weren’t,” he said.

“But it would be a very small number, because that, to a curator, is a catastrophic failure,” he said.

The collection was moved in stages last year and in 2014. It includes specimens large, small and deadly, such as the plasmodium parasite that causes malaria.

One label on a jar read: “29 lots of parasites of reptiles and amphibians . . . boa constrictor — 1, alligator — 1 . . . frogs — 9.”

Another read: “Parasites of yellow headed blackbird.”

There were also fleas and lice — external or “ectoparasites.”

And internal or “endoparasites, ” like tapeworms.

They are among the biggest. They have no brains, eyes or mouths but they can infect humans, cattle, birds, snakes and fish, Phillips said.

She has a large jar in the natural history museum that contains several tapeworms between 15 and 30 feet long that she removed from the intestine of a dead dolphin in 2014. Sealed with a rubber gasket, it looks like a jar full of pasta.

Tapeworms are acquired when a person or animal eats infected food. A worm latches on to the inside of the intestine with its scolex, which is not a mouth but a gripping tool, and absorbs nutrients through the segments of its body.

But these worms didn’t kill the dolphin. “The tapeworms were not a problem for it,” she said. “There were other things going on.”

Phillips is easy on parasites.

“Most of the time, parasites aren’t causing major harm to their hosts,” she said. “They’re taking a little bit, what they need. . . . They can even be beautiful. . . . They have these really amazing morphological structures that are really pretty.”

Yet magnified under a powerful microscope, they can appear frightening, with their hooks, suckers and spines.

Parasites have plagued human beings for thousands of years, going back to ancient Egypt and China, and they still cause such maladies as river blindness and elephantiasis.

Last year, malaria killed 438,000 people around the world according to the World Health Organization, and the 2015 Nobel Prize in physiology or medicine was awarded to three scientists for their work on parasitic infections, including malaria.

Other strides have been made, too.

“We are on the verge of eradicating Guinea worm,” Phillips said. This is a long, thin water-borne parasite that can be more than two feet long. It produces itchy, burning skin sores from which the worm protrudes and can be gradually extracted.

It is an ancient ailment. Some scholars think that the torment of “fiery serpents” described in the Old Testament’s book of Numbers may have been Guinea worms.

“As recently as the 1980s, it was infecting hundreds of thousands of people a year.” Phillips said. Now, with adequate water filters, there are only a few dozen cases, she said.

The National Parasite Collection is “not the work of any one person,” Phillips said. “There’s been a series of people who have valued this and cared for it.”

“There’s this huge field of parasitology researchers out there that are contributing to this,” she said. “All the work that they’re doing, with all of their papers and their fieldwork, all that’s getting sent here.”

“This is the basis for a lot of the knowledge of parasitology in the world,” she said. “A lot of this tracks back to these specimens.”