Thirty years ago, many students began their school science projects with a visit to the World Book Encyclopedia, the 22-volume set found in many homes and most school libraries covering topics from A to Z.

Now, the Encyclopedia of Life website provides students with much more information on living beings than those 22 volumes could ever hold.

"Knowledge of all biodiversity is scattered all around the world in databases and drawers and people's heads," Encyclopedia of Life director Bob Corrigan said. "If it flies, crawls, grows, spores, if it is life, we want to have one place to bring it all together."

The Encyclopedia of Life, found at http://www.eol.org, is less than 5 years old but is approaching 1 million species pages that include everything from the names of animals (the Atlantic cod has more than 100 of them in the English language) to information about their habitats (the common wasp's natural habitat is grasslands and woodlands, but it easily adapts to urban habitats) to reproduction habits (the eggs of the longnose sawshark hatch before the young are released from the mother's body).

The site also includes fungi like Armillaria solidipes, the largest living organism in the world, which has been growing for an estimated 2,400 years.

There are around 1.9 million identified living beings in the world, and scientists believe somewhere between 3 million and 10 million are yet to be discovered.

The Web curators take the validity of the information seriously by marking it as "trusted," "untrusted" or "not reviewed."

"There was an article about pika. The first sentence described it as a rodent, and it's not a rodent," Corrigan said. The article was marked as "untrusted" until a new version was posted saying the pika was "rodent-like."

There are about 30 full-time Encyclopedia of Life employees, but hundreds of other scientists volunteer their time and knowledge by adding and confirming the content.

"You can go to Apis mellifera, the European honeybee, and find a wonderful set off descriptions written by scholars and by thoughtful people, not joebanana546," Corrigan said.

When the site came online, its target audience was professional scientists. This past fall, EOL was reworked to appeal to citizen scientists, the general public and students.

Middle school science teacher Jeff Danielian has incorporated the Encyclopedia of Life into his Providence, Rhode Island, classroom. His students choose a plant or animal to research and go to the site for their preliminary information. Then, the students create their own online collections of similar creatures.

"Some of the information is over their heads," he admits, but the students do gain an appreciation for the amount of research that scientists put into each species.

Danielian also uses the site for a classroom discussion of the validity of information on the Internet.

"The fact that we say whether something is 'trusted' or is 'not reviewed' is an incredible teaching opportunity for a teacher," said Marie Studer of Harvard University, who is also the learning and education director of the Encyclopedia of Life.

The site includes videos and pictures of many of the creatures, and includes descriptions in English, Spanish and Arabic.

Dr. Erick Mata, executive director of EOL, says its main accomplishment has been breaking down the barriers that previously made it impossible to find the information in a single place.

"We want to reinvigorate the joy of discovery of the natural world," Studer said.