- 1. Sea urchin, blastula, beginning gastrulation Lieder_5210d
- 2. Sea urchin, blastula, progressive gastrulation Lieder_5211d
- 3. Frog, gastrula, sagittal l.s. shows germ layers, dorsal lip, yolk plug Lieder_8303f
- 4. Sea urchin embryology, beginning gastrulation w.m. Lieder_Ec210d
- 5. Sea urchin embryology, progressive gastrulation w.m. Lieder_Ec211d
- 6. Rana embryology: frog, gastrula t.s. Lieder_Am293f
- 7. Sea-urchin embryology. Beginning gastrulation w.m. Lieder_Em420d
- 8. Sea-urchin embryology. Progressive gastrulation w.m. Lieder_Em421d
- 9. Frog, early gastrula, sagittal l.s. shows formation of germ layers and dorsal lip Lieder_Em607f
- 10. Frog, later gastrula (yolk plug stage), sagittal l.s. with germ layers, yolk plug, blastocoel, Lieder_Em608f