The 20-year-old Manhattan native found the plants- some in the ground and some as high as atop a 20 foot tree - and took them for detailed chemical analyses at the new Cornell Biodiversity Center lab-- right here in the middle of the luxurious Punta Cana beach resort, and in some cases only a few meters from where they were plucked. She meticulously tested some 23 plants and found all but one did, indeed, have some bacteria or fungus killing qualities.

And that was last summer when the lab was makeshift and rough and ready.

If Vargas comes back this summer when the lab will be fully operational, she will be able to run the plants through a modern DNA sequencer in Cornell's $l.5 million laboratory which sits on its own 10 acre (4 hectare) preserve. The preserve itself is in a 1,000 hectare (2,400 acre) ecological park, dedicated by the resort owners, to be forever green - and available for such studies as Vargas' and those by her classmates last summer: how local birds can use plants to protect their young from pests, and how local farmers use other plants to keep cattle clear of insects.

Potential help for skin and pest problems are all in a day's work for what Cornell biologist Francisco Guanchez, calls "the most important laboratory in Latin America."

And it didn't cost Cornell a dime - it was donated by the Punta Cana Group (GPC), largely through the efforts of one of its principal owners, lawyer and mediator Ted Kheel, a Cornell graduate. Kheel convinced his fellow owners, the designer Oscar de la Renta, singer Julio Iglesias, and Dominican business dynamo Frank Rainieri that the laboratory was a good idea for the resort which bills itself as a leader in developing sustainable tourism.

It was an easy sell, according to Ranieri, who runs the day-to-day operation of the beach resort and golf club, even if it did take a few bucks from company profits in the short term.

"We are lucky. These partners aren't looking for a profit," Ranieri said, "They really believe in the work we do here."

Rainieri, who runs the day-to-day operations of Punta Cana, said the Biodiversity Center, and the ecological park, have a threefold mission: "It will be a learning center. It is very important one for the Dominican Republic, a third world country, it to be exposed to the science.

"It will be a role model for other resorts. It is going to be hard from now on for other tourists projects not to get involved in a plan of environmental awareness.

"And it will create diversity awareness. One million tourists come through our airport, and if we can get 100,000 to visit the biodiversity center, we will spread the gospel of sustainability -- we can get people talking about conservation."

Rainieri said Punta Cana will begin add bird watching and medicinal plant tours to the existing walks through the ecological park.

According to Cornell, the laboratory itself has four missions: investigate and catalogue the biodiversity of the region, provide training for US and Dominican students; provide consulting for sustainable development, including tourism, and to look for new pharmaceutical products from the local environment.

To meet these goals Punta Cana and Cornell have installed laboratory equipment that meet all specifications of the Ithaca, New York, home campus of Cornell.

And Guanchez, a friendly-looking teacher with a biology Ph.D., a bushy mustache, and a perennial smile, loves to show it off. "To have a very high tech laboratory from a reputable university - one of the best in the world - on a resort is unknown," said Guanchez, former head of the Caracas botanical gardens.

"Most of the other labs in Latin America specialize. Our aim is going to be very wide, all of biodiversity," he said. "But the real importance is the fact that it will give the philosophy of environmental tourism the information they will need to make it work."

"Also our location is great. When Cornell ran programs in the Amazon everything had to be sent back to Ithaca for analysis. Now we can do it here, and we can be a center for other research in the Caribbean," he said.

A two-way distance learning center with some 16 high-speed computers linked to the Internet will keep the biology students here in touch with their other classes in Ithaca, and connect biology minors in Ithaca with the work here.

The center which will house 16 students and 6 teachers, is aimed at studying marine biology, birds, and ethnobiology -- the study of what has traditionally worked among the local people, and why. Thus Vargas spent many days asking Dominicans what works best for skin problems.

Jake Kheel, a distant relative of owner Ted Kheel, who leads walks through the nature trail for tourists and for Dominican visitors in fluent Spanish, said the local people have a strong tradition of using medicinal plants, and continue to do so.

"I'll point out all the medicinal plants on the tour, " he said, "and afterwards people will come up to me and point out 'you missed this one' or 'there is another one there that my grandmother still uses'. I pass the information on to the scientists."

One of them, lab director Alejandro Herrera is particularly concerned with ethnobiology since he is Dominican and did much of his training in the Dominican Republic, complemented by a degree in ecological economics in Costa Rica.

For him one of the most important factors for the center is the training of Dominican students, at least six of whom will be given scholarships per year.

He also is in charge of a special 5 hectare (12 acre) section of the preserve which is re-planting fruit from all over the Dominican Republic to preserve species and help students studying the island's diversity. He will also direct a replanting of a neighboring national park in which the virgin growth had been destroyed by local charcoal makers. Punta Cana will foot the bill for the future replanting, he said, and he has already begun selecting rain forest species that wold thrive and help return the park to a natural state.

Meanwhile Herrera and Guanchez are concentrating on more immediate studies by last year's students.

Under the powered microscope are oils that birds use to waterproof their feathers -- it turns out they have anti biotic qualities; a fungus attacking local coral, and the plant that some local birds use to cover their nests.

"When they won't use any other plant, any, then there must be a reason," Guanchez says. "We think it has to do with repelling parasites from their young."

The center could make a buck or two if it comes up with something useful -- like Vargas' test on a local plant used to stop mosquito bite's itching.

"I tried it," she said. "It worked."