1. 5.1 Echinoderm First Cleavage

2. 5.2 Echinoderm Second Cleavage

3. 5.3 Spindles at Fourth (unequal) Cleavage in a Purple Sea Urchin, Strongylocentrotus

4. 5.4 Normal Sea Urchin Development

5. 5.5 Sea Urchin Blastula

6. 5.6 Sea Urchin: Ingression of Primary Mesenchyme Cells

7. 5.7 Sea Urchin: Ingression of GFP-Labeled Primary Mesenchyme Cells

8. 5.8 Sea Urchin Larva Skeleton

9. 5.9 Sea Urchin: Invagination of Archenteron

10. 5.10 Polar Lobe Formation in the Scaphopod Mollusc Pulsellum

11. 5.11 Development of the Ascidian Corella

12. 5.12 Ascidian Embryogenesis

13. 5.13 C. elegans: Normal Development

14. 5.14 First Cell Cycle in C. elegans

15. 5.15 Chromosomes During Fertilization

16. 5.16 P-Granule Migration in C. elegans: First Division

17. 5.17 P-Granule Migration in C. elegans: Third Division