Quail Embryo (IMAGE) Optica Caption This is a quail embryo. The bulge on the middle left side of the embryo is its developing heart. Credit Biomedical Optics Express 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.