Book excerpt: The overall scope of this new series will be to evolve an understanding of the genetic basis of (1) how early mesoderm commits to cells of a heart lineage that progressively and irreversibly assemble into a segmented, primary heart tube that can be remodeled into a four-chambered organ, and (2) how blood vessels are derived and assembled both in the heart and in the body. Our central aim is to establish a four-dimensional, spatiotemporal foundation for the heart and blood vessels that can be genetically dissected for function and mechanism. Since Robert DeHaan's seminal chapter "Morphogenesis of the Vertebrate Heart" published in Organogenesis (Holt Rinehart & Winston, NY) in 1965, there have been surprisingly few books devoted to the subject of cardiovascular morpho genesis, despite the enormous growth of interest that occurred nationally and inter nationally. Most writings on the subject have been scholarly compilations of the proceedings of major national or international symposia or multi authored volumes, without a specific theme. What is missing are the unifying concepts that can often make sense out of a burgeoning database of facts. The Editorial Board of this new series believes the time has come for a book series dedicated to cardiovascular mor not only as an important archival and didactic reference phogenesis that will serve source for those who have recently come into the field but also as a guide to the evo lution of a field that is clearly coming of age.