Imagine the Book of All Species: a single volume made up of one-page descriptions of every species known to science. On one page is the blue-footed booby. On another, the Douglas fir. Another, the oyster mushroom. If you owned the Book of All Species, you would need quite a bookshelf to hold it. Just to cover the 1.8 million known species, the book would have to be more than 300 feet long. And you’d have to be ready to expand the bookshelf strikingly, because scientists estimate there are 10 times more species waiting to be discovered.

It sounds surreal, and yet scientists are writing the Book of All Species. Or to be more precise, they are building a Web site called the Encyclopedia of Life (www.eol.org). On Thursday its authors, an international team of scientists, will introduce the first 30,000 pages, and within a decade, they predict, they will have the other 1.77 million.

While many of those pages may be sparse at first, the authors hope that the world’s scientific community will pool all of its knowledge on the pages. Unlike a page of paper, a page of the Encyclopedia of Life can hold as much information as scientists can upload. “It’s going to have everything known on it, and everything new is going to be added as we go along,” said Edward O. Wilson, the Harvard biologist who spearheaded the Encyclopedia of Life and now serves as its honorary chairman.

Other experts not involved in the project hail it as tremendously promising. “I certainly think it is a great idea,” said Jody Hey, a biologist at Rutgers University.