Embryonic Development (image) American Museum of Natural History Caption This figure shows the progressive developmental stages of modern harvestmen embryos with the expression of a gene that patterns outgrowths, like eye stalks (shown with black staining). In this particular species, adults only have a single pair of median eyes along the middle of the body. White arrowheads indicate domains associated with lateral eye fields, which never actually develop. Black arrowheads indicate the strong expression of the domains that will eventually form the median eyes. Credit ©AMNH/P. Sharma Usage Restrictions Can be used with appropriate credit 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.