Six years into the program the total has reached 1,009,000, researchers report. They hope to complete the listing by 2011, reaching an expected total of about 1.75 million species.

Thomas M. Orrell, a biologist at the Smithsonian's National Museum of Natural History, said the finished catalog will include all known living organisms, from plants and animals to fungi and microorganisms such as bacteria, protozoa and viruses.

"Many are surprised that, despite over two centuries of work by biologists and the current worldwide interest in biodiversity, there is presently no comprehensive catalog of all known species of organisms on Earth," Orrell said.

Taxonomy, the formal system of naming living things, was launched by the Swedish scientist Karl von Linne -- known as Linnaeus -- in the 1700s and his name still appears in the database.

The Integrated Taxonomic Information System-Species 2000 Catalog of Life provides access to data maintained by a variety of scientific organizations, each specializing in a certain area.

For example, information on dipteran flies is maintained by the Agriculture Department's Systematic Entomology Laboratory at the Smithsonian's National Museum of Natural History.

Natural history museums in London, the Netherlands and New York maintain clothes moth, dragonfly and spider data. Experts in Canada and Paris keep the data on Ichneumon wasps and longhorn beetles.

"We tidy it up and do a peer review to see which pieces are the best ones to use, like putting together a giant jigsaw puzzle," Bisby said in a recent interview with The Associated Press. "If you want to do international comparisons, you need a master list. It's a little like if you were running a supermarket, you would have to do an inventory."

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