Blood Formation (IMAGE) University of Basel Caption Scanning electron microscopy images confirm the deposition of an extracellular matrix which embeds cells, presumably of both stromal and blood origins. Credit University of Basel Usage Restrictions give adequate attribution to original author 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.