Contributors. Foreword. Sea Urchins and Ascidians: G.A. Wray, Introduction to Sea Urchins. R.A. Cameron and J.A. Coffman, Gene Expression and Early Cell Fate Specification in Embryos of the Purple Sea Urchin (Strongylocentrotus purpuratus). A.H. Wikramanayake and W.H. Klein, Otx, b-Catenin and the Specification of Ectodermal Cell Fates in the Sea Urchin Embryo. C.Y. Logan and D.R. McClay, Lineages that Give Rise to the Endoderm and the Mesoderm in the Sea Urchin Embryo. N. Satoh, Cell Fate Determination in the Ascidian Embryo. Nematode: W.B. Wood, Cell Lineages in Caenorhabditis elegans Development. B. Bowerman, The Maternal Control of Polarity and Patterning during Embryogenesis in the Nematode Caenorhabditis elegans. R.E. Ellis, Sex and Death in the Caenorhabditis elegans Germ Line. S.W. Emmons, Cell Fate Determination in Caenorhabditis elegans Ray Development. A. Hajnal, Cell Fate Determination and Signal Transduction During Caenorhabditis elegans Vulval Development. Leech: G.S. Stent, Introduction to the Leech. D.A. Weisblat, F.Z. Huang, and D.E. Isaksen, Cell Fate Specification in Glossiphoniid Leech: Macromeres, Micromeres, and Proteloblasts. S.T. Bissen, Spatial and Temporal Control of Cell Division during Leech Development. M. Shankland, Anteroposterior Pattern Formation in the Leech Embryo. Drosophila: J.A. Campos-Ortega, Studies on Cell Lineage and Cell Fate Determination in Drosophila. R.W. Carthew, R.C. Kauffmann, S. Kladny, S. Li, and J. Zhang, Cell Determination in the Drosophila Eye. E. Siegfried, Role of Drosophila Wingless Signaling in Cell Fate Determination. J. Broadus and E.P. Spana, Asymmetric Cell Division and Fate Specification in the Drosophila Central Nervous System. Frog: I.B. Dawid, Your Origin Is Your Fate-Or Is It? S.A. Sullivan, K.B. Moore, and S.A. Moody, Early Events in Frog Blastomere Fate Determination. D.S. Kessler, Maternal Signaling Pathways and the Regulation of Cell Fate. C.S. Newman and P.A. Krieg, Specification and Differentiation of the Heart in Amphibia. M. Perron and W.A. Harris, Cellular Determination in Amphibian Retina. Zebrafish: W. Driever, Introduction to the Zebrafish. S.E. Fraser, Cell Interactions and Morphogenetic Motions Pattern the Zebrafish Nervous System. R.K. Ho, J.P. Kanki, V.E. Prince, L. Joly, M. Ekker, and A. Fritz, Patterning of the Zebrafish Embryo Along the Anteroposterior Axis. D.W. Raible and J.S. Eisen, Specification of Neural Crest Cell Fate in the Embryonic Zebrafish. Chick: G.C. Schoenwolf, Section Introduction, The Avian Embryo: A Model for Descriptive and Experimental Embryology. A. Streit and C.D. Stern, More to Neural Induction than Inhibition of BMPs. T. Mikawa, Determination of Heart Cell Lineages. R. Adler and T. Belecky-Adams, Cell Fate Determination in the Chick Embryo Retina. Mammals: R.A. Pedersen, Cell Lineage and Cell Fate Determination in Mammals. B.P. Davidson, A. Camus, and P.P.L. Tam, Cell Fate and Lineage Specification in the Gastrulating Mouse Embryo. L. Selwood and D. Hickford, Early Cell Lineages in Marsupial Embryos. M. Zernicka-Goetz, Green Fluorescent Protein: A New Approach to Understanding Spatial Patterning and Cell Fate in Early Mammalian Development. M.L. Ware and C.A. Walsh, Cell Fate and Cell Migration in the Developing Cerebral Cortex. Vertebrate Tissue Specification: S.A. Moody, Tissue Determination: An Introduction. T.D. Sargent and M.I. Morasso, Differentiation of Vertebrate Epidermis. E.C. Liao and L.I. Zon, Conservation of Themes in Vertebrate Blood Development. M. Gannon and C.V.E. Wright, Endodermal Patterning and Organogenesis. M. Buckingham and S. Tajbakhsh, Myogenic Cell Specification During Somitogenesis. Index.