| 1 Simple-cell of egg of Frog sec. |
| 2 2-cell of egg of Frog sec. |
| 3 Early cleavage stage of egg of Frog sec. |
| 4 Late cleavage stage of egg of Frog sec. |
| 5 Early blastula stage of egg of Frog sec. |
| 6 Late balstula stage of egg of Frog sec. |
| 7Early gastrula/original intestines stage of egg of Frog sec. |
| 8 Late gastrula stage of Frog frog sec. |
| 9 Neural plate stage of egg of Frog sec. |
| 10 Neural fold stage of egg of Frog sec. |
| 11 Neural tube stage of egg of Frog sec. |
| 12 3mm embryo of Frog W.M. |
| 13 3mm embryo of Frog serial T.S. |
| 14 3mm embryo of Frog serial sagittal section T.S. |
| 15 5mm embryo of Frog Frog W.M. |
| 16 5mm embryo of Frog serial transverse sec. |
| 17 5mm embryo of Frog serial sagittal section |
| 18 7-9mm embryo of Frog serial L.S. |
| 19 7-9mm embryo of Frog serial T.S. |
| 20 7-9mm embryo of Frog serial frontal sec. |
| 21 10-11mm embryo of Frog serial L.S. |
| 22 10-11mm embryo of Frog serial T.S. |
| 23 10-11mm embryo of Frog serial frontal sec. |
| 24 Anterior part of 10mm embryo of Frog L.S. |
| 25 11mm embryo of Frog L.S. |