Taking Census (IMAGE) Washington University in St. Louis Caption Students sample the more than 100 species of plants and animals that made a home in the ponds set in a field at Washington University's Tyson Research Center in the second half of a seven-year-long experiment. Credit Jon Chase/WUSTL Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.