This work contains a large among of information found nowhere else. He reported that it involved 2000 volumes but if so, most have been lost. This work had a profound influence on biology throughout the Middle Ages and practically until the end of the 18th Century. In fact it was the basis for the encyclopedias of Bartholomaeus Anglicus, Konrad of Megenberg and others. He had visited Africa, Greece and Egypt, served in the army in Germany and had traveled to the North Sea.
Several editions are available.
Additional information about Pliny the Elder may be found on the Internet.