Planaria Exposed to Pathogenic Bacteria (IMAGE) Stowers Institute for Medical Research Caption This image shows the progression of lesions and tissue resorption in planarians when exposed to pathogenic bacteria. The normal animal is to the left, while the middle animal displays a characteristic head lesion, and the animal on the right has already lost its head to bacterial infection. Credit Chris Arnold, Ph.D. 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.