Abacus of spores (IMAGE) University of California - San Diego Caption Custom artwork illustrates an abacus made from bacterial cells known as spores used to count stimuli. Credit Anne Hashimoto Usage Restrictions Must be used in conjunction with Science paper on bacterial spores exiting dormancy. License Original 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.