5.1 Echinoderm First Cleavage

5.2 Echinoderm Second Cleavage

5.3 Spindles at Fourth (unequal) Cleavage in a Purple Sea Urchin, Strongylocentrotus

5.4 Normal Sea Urchin Development

5.5 Sea Urchin Blastula

5.6 Sea Urchin: Ingression of Primary Mesenchyme Cells

5.7 Sea Urchin: Ingression of GFP-Labeled Primary Mesenchyme Cells

5.8 Sea Urchin Larva Skeleton

5.9 Sea Urchin: Invagination of Archenteron

5.10 Polar Lobe Formation in the Scaphopod Mollusc Pulsellum

5.11 Development of the Ascidian Corella

5.12 Ascidian Embryogenesis

5.13 C. elegans: Normal Development

5.14 First Cell Cycle in C. elegans

5.15 Chromosomes During Fertilization

5.16 P-Granule Migration in C. elegans: First Division

5.17 P-Granule Migration in C. elegans: Third Division